CCl 4-induced hepatonephrotoxicity : protective effect of nutraceuticals on inflammatory factors and antioxidative status in rat

Article history: Received on: 24/07/2013 Revised on: 04/01/2014 Accepted on: 23/02/2014 Available online: 27/02/2014 The present study was undertaken to investigate the possible protective effect of two edible parts (leaves and stems) of Rumex dentatus L. on inflammatory factors and oxidant/antioxidative status of rat. Determination of total phenolic content of the two parts and isolation of bioactive secondary metabolites from the promising leaves extract were carried out. The hepatic antioxidant parameters; glutathione, catalase, superoxide dismutase, glutathione peroxidase, nitric oxide and malondialdehyde were measured. Liver marker enzymes and hepatic function enzymes; aspartate and alanine aminotransferases as well as cholestatic markers; alkaline phosphatase, gamma glutamyltransferase, serum total protein content, urea, creatinine were evaluated. In addition, inflammatory markers; interleukin (IL)-2, IL-6, C-reactive protein, and tumor necrosis factor were estimated. Histopathological investigation was also examined. The ethanolic extract of leaves and stems showed antioxidant properties and anti-inflammatory properties. An improvement of liver and kidney functions was also observed. Extract of leaves showed relatively higher biological activity than that of stems, a fact which may be related to their higher total phenolic content. This extract was subjected to chromatographic and spectroscopic analysis. Phytochemical investigation has afforded emodin (1), chrysophanic acid (2), 1,5-dihydroxy-3-methyl-9,10anthraquinone (3), quercetin-3-rhamnoside (4), quercetin-3-rhamnosyl-(1→6)-galactoside (5), Isorhamnetin-3rhamnoside (6), catechin (7) and daucosterol (8). Compounds 3-7 were isolated for the first time from this species. In conclusion, the plant parts extract represents a promising candidate for the treatment of liver fibrosis and renal injury. The isolated bioactive phytochemicals was suggested to be responsible for the pronounced pharmacological activity.


INTRODUCTION
Liver plays a pivotal role in regulating various physiological processes in the body such as metabolism, secretion and storage.It has great capacity to detoxify xenobiotics and synthesize useful principles.Therefore, liver damage inflicted by hepatotoxic agents is of grave consequences (Shanmugasundaram et al., 2006).Evidences developed over the last years have suggested that various forms of liver injuries may be caused by free radical formation and subsequent oxidative stress.Oxidative stress leads to the formation of glycoxidation products, including advanced glycation end products (AGEs) and advanced oxidation protein products (AOPPs).Since advanced oxidation protein products are not only markers of oxidative stress but also act as . .
inflammatory mediators, the knowledge of AOPPs pathophysiology in chronic liver disease could provide valuable information with respect to the relationship between oxidative stress and the inflammatory response related to liver fibrosis (Ali et al., 2011).Carbon tetrachloride (CCl 4 ) is one of the xenobiotics that have been reported to induce acute and chronic tissue injuries and is a well established hepatotoxin (Xu et al., 2010).It has been used extensively to study hepatotoxicity in animal models by initiating lipid peroxidation, thereby causing injuries to kidney, heart, testis and brain, in addition to liver pathogenesis (Khan et al., 2012).Liver is particularly susceptible to oxidative stress due to the direct release of CCl 4 metabolites and cytokines, which propagate inflammatory response.CCl 4 was reported to increase serum hepatotoxicity and nephrotoxicity markers.Free radicals play an important role in CCl 4 -induced liver and renal damage process (Xu et al., 2010).CCl 4 -induced damage is also able to alter the antioxidant status of the tissues, which is manifested by abnormal histopathological changes.Histopathologically, exposure to CCl 4 can result in hepatic steatosis, centrilobular necrosis, and cirrhosis in the liver and acute tubular necrosis in the kidney (Xu et al., 2010;Recknagel et al., 1989).
Alterations in kidney structure and function are frequently encountered in severe liver disease (Lundh, 1964) but the relationship between the hepatic and renal disorders is not clear.The possibilities are that the agent(s) precipitating the liver disease may affect the kidney directly or that the renal lesions develop as a secondary phenomenon to the altered liver function.In absence of reliable liver protective drugs, therefore, attention is focused on natural antioxidants.Plants offer a wide range of natural antioxidants due to the structural diversities of their secondary metabolites; mainly the phenolic compounds (Xu et al., 2004;Kumar et al., 2012).
Rumex dentatus L (Polygonaceae) is one of eight Rumex species native to Egypt (Boulos and El-Hadidi, 1984) and commonly known as toothed dock.Both the leaves and tender stems are traditionally consumed in Egypt and other parts of the world (Tukan et al., 1998).The leaves of a traditional Korean salad plant (R. acetosa) were used as food antioxidant (Chon et al., 2008).Rumex plants have been used traditionally as a green salad, appetite stimulant, astringent, bactericidal, anti-inflammatory and anti-tumor (Xu et al., 2004).Traditionally R. crispus was reported to be used as a botanical hepato-protection during antibiotic therapy (dose of 100-300 mg per day stimulates bile production and release) and a remedy of acute hepatitis, among many traditional folk medicines (Lee et al., 2007).
According to glossary produced by American Diabetics and Association, neutriceutics are substances considered as food or a part of it that offers health or medicinal benefit, including prevention and treatment of diseases (Bloch and Thomson, 1995).Some of the natural products find their use not as pharmaceuticals (real medicine) but as a novel class of dietary supplements or nutraceuticals that fall well into the concept of functional foods.It is commonly known that R. dentatus contains anthraquinones in its roots (Xu et al., 2010).Furthermore, C-glucosyl anthrones, naphthalene glucosides, chromones, phytosterols, flavonoids have been detected (Xu et al., 2010;Zhang et al., 2012).
The present study was designed to investigate the protective effect of the two edible parts of R. dentatus as neuticeutical agents against the hepatotoxicity and nephrotoxicity induced by CCl 4 which has not previously been explored.The evaluation was done through measuring certain antioxidant parameters, hepatic marker enzymes, liver function indices, cholestatic biomarker and histological investigation of both liver and kidney.The work expanded to investigate the phytochemical constituents from the promising leaves extract.

Plant materials
Leaves and stems of Rumex dentatus L (Polygonaceae) were collected from Faculty of Agriculture Farm, in March 2010.They were kindly identified by Dr. S.S. El-Khanagry, Department of Flora and Phytotaxonomy Research, Horticultural Research Institute, Egypt.Voucher Specimens were kept in the Herbarium of National Research Centre, Cairo, Egypt.The plant parts were then air-dried in the shade and reduced to powder.

Preparation of samples for biological assays
The dried plant parts (leaves and stems, 1400 g each), were powdered and macerated with 80% aqueous ethanol (3x5 L) for seven days at room temperature.After evaporation of the solvent under reduced pressure, the respective ethanolic extracts were obtained (122 and 98.4 g for leaves and stems, respectively).

Animals
Male Wistar albino rats (100-120 g) were obtained from the Animal House, National Research Centre, Egypt.All animals were kept in controlled environment of air and temperature with access of water and diet.Anesthetic procedures and handling with animals complied with the ethical guidelines of Medical Ethical Committee of National Research Centre in Egypt.

Doses and route of administration
Administration regimen was twice a week for six consecutive weeks.CCl 4 (0.5 mL/kg) was suspended in olive oil (1:9 v/v) and injected intraperitoneally (Marsillach et al., 2009).Leaves and stems extracts were administrated orally at a dose of 200 mg/kg daily for six weeks (Raghavendra and Reddy, 2011).Silymarin; a reference herbal drug was orally administered at a dose of 100 mg/kg, daily for six weeks (Yuvaraj and Subramoniam, 2009).Normal control group received orally 0.5 mL normal physiological saline and intraperitoneally 0.5 mL olive oil.Control groups were treated orally with each extract and with the same dose.

Experimental groups
Seventy male Wistar strain albino rats were used in this study.Animals were divided into 7 groups (10 rats each).Group1 served as normal healthy control rats.Groups 2 and 3 were normal healthy rats administered leaves and stems of R. dentatus ethanolic extracts.Group 4 injected with CCl 4 .Groups 5 and 6 CCl 4 , coadministered with both stem and leaves extract respectively.Group 7 CCl 4 co-administered with silymarin drug.

Sample preparations
Serum sample: Blood collected from each animal by puncture the sublingual vein in clean and dry test tube, left 10 min to clot and centrifuged at 3000 rpm (4°C) for serum separation.The separated serum was stored at -80°C for further determinations of liver and cholestatic function enzymes, kidney markers, inflammatory parameters and serum total protein.Liver tissue was homogenized in normal physiological saline solution (0.9% NaCl) (1:9 w/v).The homogenate was centrifuged at 4°C for 5 min at 3000 rpm.The supernatant was used for estimation of oxidant/antioxidant parameters as well as liver biomarkers of mitochondria; SDH and cell membrane; LDH.

Antioxidant parameters
Malondialdehyde, as a product of polyunsaturated fatty acids oxidation was determined (Buege and Aust, 1978) and its concentration was calculated using the extinction coefficient value 1.56 × 105M -1 cm -1 and read at 535 nm.Glutathione was assayed (Moron et al., 1979) using dithiobis-2-nitrobenzoic acid (DTNB) in PBS.The reaction color was read at 412 nm.Superoxide dismutase was estimated (Nishikimi et al., 1972) and the increase in nicotinamide adenine dinucleotide (NADH) oxidation was measured at 560 nm using its molar extinction coefficient 6.22 × 103 M -1 cm -1 .Catalase activity detection was undertaken using a slight modification of the method of Cakmak and Marschner (1992).The reaction mixture, in a total volume of 3 mL, contained 1.5 mL of 50 mM sodium phosphate buffer (pH 7.0) and 1 mL of 0.2% H 2 O 2 .The reaction was initiated by adding 0.5 mL of the enzyme extract, and the activity determined by measuring the initial rate of disappearance of H 2 O 2 at 240 nm.Glutathione peroxidase activity based on a previously reported method (Mohandas et al., 1984) was estimated.There action assay was done in a final volume of 2 mL solution constituted by: 1.49 mL phosphate buffer (0.1 M; pH 7.4), 0.1 mL EDTA (1 mM), 0.1 mL sodium azide (1 mM), 0.05 mL glutathione reductase (1 IU/mL), 0.05 mL GSH (1 mM), 0.1 mL NADPH (0.2 mM), 0.01 mL H 2 O 2 (0.25 mM) and 0.1 mL of liver supernatant.The disappearance of NADPH at 340 nm was recorded at 25°C.Enzyme activity was calculated as UM NADPH oxidized/min/mg protein using molar extinction coefficient of 6.22 × 10 3 M -1 cm -1 .NO-scavenging activity of extracts was determined according to the method of Sreejayan and Rao (1997).

Hepatic cell organelles markers
Succinate dehydrogenase (SDH); a marker for mitochondria was estimated (Rice and Shelton, 1957) and the reduction of flavin adenine dinucleotide was coupled with a reduction of tetrazolium salt as 2-p-iodophenyl-3-p-nitrophenyl-5phenyl tetrazolium chloride (INT) and the produced formazan of INT was measured colorimetrically at 490 nm.Lactate dehydrogenase (LDH); a marker for cytoplasm was estimated by the method of Babson and Babson (1973), where the reduction of nucleoside derived amino acids (NAD) was coupled with the reduction of tetrazolium salt and the produced formazan of INT was measured colorimetrically at 503 nm.

Serum biomarkers for liver function tests and total protein level
Aspartate and alanine aminotransferases were measured by the method of Gella et al. (1985), where the transfer of amino group from aspartate or alanine formed oxaloacetate or pyruvate, respectively and the developed color was measured at 520 nm.Total protein was assayed (Bradford, 1976) and Coomassie Brilliant Blue dye reacted with Bradford reagent and gave a blue complex at 595 nm.Alkaline phosphatase catalyzed in alkaline medium the transfer of phosphate group from 4 nitrophosphatase to 2-amino-2-methyl-1-propanol (AMP) and librated 4nitrophenol.The developed colour was measured at 510 nm (Rosalki et al., 1993).Gama glutamyl transferase was estimated (Szasz, 1969), where GGT enzyme reacted with L-g-glutamyl-3carboxy-p-nitroanilide and glycyl-glycine to give L-g-glutamylglycyl-glycine and 5-amino-2-nitrobenzoate.The decrease in absorbance was read at 450 nm at 1 min intervals for 3 minutes.

Histopathological investigation
Liver and kidney slices were fixed in 10% formaldehyde and embedded in paraffin wax blocks.Sections of 5 μm thick were stained with hematoxylin and eosin (H&E), then examined under light microscope for determination of pathological changes (Suzuki and Suzuki, 1998).

Determination of total phenolic content
Total phenolic content (TPC) of leaves and stems of R. dentatus was, separately, determined spectrophotometrically using the Folin-Ciocalteu reagent (Singleton and Rossi, 1965).Values of TPC were estimated by comparing the absorbance of each sample with a standard response curve generated using gallic acid (0, 12.5, 25, 50, 100, and 200 µg/mL).The results were expressed as mg gallic acid equivalents (GAE)/100 g of each plant part.All the measurements were taken in triplicate, and the mean values were calculated.

Extraction and isolation of compounds
The fresh leaves (1.4 kg) sample was homogenized in a mixer with aqueous ethanol 80% (3×5 L) followed by exhaustive extraction by maceration at room temperature (48 hrs × 3 times) with the same solvent.The combined extracts were evaporated in vacuo at 50 °C to dryness to afford 122.2 g (8.73% wet weight basis).An aliquot of the ethanolic extract (90 g) was subjected to Si column chromatography and the column was eluted in the gradient mode from n-hexane gradually to ethyl acetate and then to methanol.Fractions (68, 100 mL each) were collected and monitored by TLC (Si, S 1 -S 5 ).Similar fractions were combined together to obtain 5 groups.These group were further chromatographed on different columns viz., Si column chromatography (eluted successively with a step gradient of nhexane-CH 2 Cl 2 (100:0-0:100 v/v) then gradual increase of polarity with methanol) and Sephadex LH-20 (n-butanol-isopropanolwater, BIW, 4:1:5 (upper phase), methanol or methanol-water mixture (9:1) as different eluents).The homogeneity of the fractions was tested on Comp-TLC (systems S 1 -S 5 ), 2D-PC and Comp-PC using Whatman No. 1 paper (systems S 6 and S 7 ).Eight major compounds were isolated, their purity being checked by Comp-PC using solvent systems S 1 -S 5 for compounds 1-3 and 8, and S 6 and S 7 for compounds 4-7 using spray reagent I or III for compounds 1-3 and 8, and II or III for compounds 4-7.These compounds were subjected to physical, chemical, chromatographic and spectral analyses (UV, MS, 1 H and 13 C NMR) as well as comparison with the available reference standards and available published data.

Statistical analysis and calculations
All data were expressed as mean ± SD of ten rats in each group.Statistical analysis was carried out by one way analysis of variance (ANOVA) and Costat Software Computer Program.Significance difference between groups was at p ≤0.05.% change = (control mean -treated mean)/control mean × 100.% improvement = treated mean -injured mean/control mean × 100.

Extracts safety
Normal healthy rats administrated with leaves and stems ethanol extract recorded insignificant changes in all parameters under investigation revealing extracts safety.

Effect of R. dentatus leaves and stems extract on hepatic antioxidant levels
CCl 4 group recorded significant decrease in GSH (65.59%),GPX (58.14%) and SOD (47.14%) levels, while MDA showed significant increase by 92.20%.Total protein content showed significant decrease in CCl 4 intoxicated rats by percentage decrease reached to 30.34% (Table 1).Treatment with leaves and stems ethanol extract improved MDA level by 10.39, 9.09%, GPX by 42.63, 46.51%, and SOD levels by 30.59 and 23.01%, respectively.GSH levels have been enhanced after treatment with leaves and stems extract by 28.66 and 32.41%, respectively.Also, ethanol extract of R. dentatus leaves and stems improved serum total protein by 38.32 and 34.21%, respectively.Similar results were noticed for treatment with silymarin showed ameliorated percent reached to 40.52, 34.11, 4.51, 3.84, 35.73%,GSH, GPX, MDA, SOD and total protein content respectively.

Effect of R. dentatus leaves and stems extract on hepatic marker enzymes
Fibrotic liver induced by CCl 4 showed significant decrease in SDH, LDH by 12.42, 32.12% respectively (Table 2).Treatment with R. dentatus extracts displayed improvement in marker enzymes.Ethanolic leaves and stems extract showed similar improvement percentages (13.85 and 32.33% for SDH and LDH respectively).However treatment with silymarin improved SDH and LDH by 12.13 and 28.88%, respectively.

Potency of Rumex dentatus in improving liver function enzymes
CCl 4 group, showed significant increase in AST and ALT levels by 148.41 and 66.79%, respectively (Table 3).However, GGT and ALP were significantly increased by 77.79 and 97.40%, respectively in CCl 4 group.The observed changes in liver function enzymes showed that leaves and stems extract recorded the same improvement percentages.AST and ALT were ameliorated by 90.30 and 40.35%, while ALP was improved by 70.34 and 81.28%, for the two extracts, respectively.GGT recoded enhanced level of 77.98 and -60.64%, respectively.On the other hand, silymarin exhibited ameliorating percent of 93.90, 41.98, 68.03 and 71.39%, for AST, ALT, GGT and ALP levels, respectively.

Effect of ethanol extract of Rumex dentatus on kidney-function
As compared to normal healthy rats, CCl 4 group recorded significant increase in urea and creatinine levels by 127.07 and 40.00%, respectively (Table 4).Improvement in urea and creatinine after treatment revealed that leaves and stems extract showed an improvement by high percentages.Treatment with ethanol leaves and stems extract recorded improvment percent in urea reaching 132.92, and 157.07%and for creatinine 47.00 and 44.00 %, respectively.While, urea and creatinine recorded improvement percentages reaching 159.57and 44.00 % post silymarin treatment.
Compound 7 Compound 8 hepatocytes, pyknosis of hepatocytic nuclei and focal hepatic hemorrhage (Figs.2-5) as compared to normal control rats (Fig. 1).CCl 4 treated rats with both leaves and stems of R. dentatus as well as silymarin showed slight Kupffer cells activation, few necrosis of sporadic hepatocytes, slight congestion of central vein, few fatty degeneration of hepatocytes and apparent normal parenchyma cells (Figs. 6-8).
On the other hand, kidney of CCl 4 -intoxicated rat showed congestion of glomerular tufts, vacuolization of epithelial lining renal tubules, atrophy of glomerular tufts and distension of Bowman's space , as compared to normal control (Fig. 9).However, treatment of intoxicated rats with leaves extract of R. dentatus (Fig. 13), showed apparent normal renal parenchyma and no histopathological changes.Treatment of CCl 4intoxicated rats with total ethanol extract of R. dentatus stems (Figs. 14,15) showed slight congestion of glomerular tufts and slight congestion of intertubular blood capillaries.With respect to, treatment of intoxicated rats with reference silymarin drug, slight dilatation of hepatic sinusoids associated with Kupffer cells activation and no other renal histopathological changes were detected (Fig. 16).

DISCUSSION
Hepatoprotective studies showed that plants have active ingredients that are capable of free radical scavenging in living systems (Nikolova et al., 2011;Kumar et al., 2012).Phenolic compounds are promising bioactive secondary metabolites playing an important role in detoxification of free radicals (Tukan et al., 2006;Shanmugasundaram et al., 2006;Chon et al., 2008).The most important phenolic compounds in Rumex plants are flavonoids, anthrones, and anthraquinones (Xu et al., 2004;Zhang et al., 2012).In the present study, a high content of these compounds was detected in the ethanol extract of leaves followed by stems extract suggesting their potential role as antioxidative .agents.Evidence suggests that various enzymatic and non enzymatic systems have been developed by the cell to attenuate ROS.However, when a condition of oxidative stress establishes, the defense capacities against ROS becomes insufficient.Therefore, ROS affects the antioxidant defense mechanisms, reduces the intracellular concentration of GSH, decrease the activity of SOD and enhances lipid peroxidation (Khan et al., 2012).In agreement with these explanations, the observed decrease in SOD was recorded in CCl 4 treated rats that might be due to inactivation of the antioxidative enzymes.This may cause an increased accumulation of superoxide radicals, which could further stimulate lipid peroxidation.In addition, the inhibition in GSH concentration can affect redox equilibrium leading to enhanced lipid peroxidation processes.Treatment with either leaves or stems extract of R. dentatus normalized the antioxidant levels through their high content of flavonoids and anthraquinones as they have the ability to scavenge free radicals.
Silymarin as an antioxidant flavonoid complex derived from the herb milk thistle (Silybum marianum), has the ability to attenuate free radicals elevation, chelates metal ions, inhibits lipid peroxidation and prevents liver glutathione depletion (El-Hawary et al., 2011).
ALT and AST have been reported to be sensitive indicators of liver injury (Motawi et al., 2011).Significant elevation of ALT and AST in CCl 4 group is in agreement with

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those reported studies (Lee et al., 2007;Motawi et al., 2011).In addition, CCl 4 induced changes in the process of protein synthesis.Hence, significant decrease in total protein content can be deemed as a useful index of the severity of cellular dysfunction in liver diseases as clearly shown in our studies.Stimulation of protein synthesis has been advanced as a contributory self healing mechanism, which accelerates liver regeneration process.The significant increase in AST, ALT, GGT and ALP as well as total urea and creatinine in CCl 4 group in the present study is in agreement with Reyes-Gordillo et al. (2007) who recorded significant increase in liver enzymes and kidney function post CCl 4 intoxication of rats.The authors added that, the GGT is an indicator of bile duct lesions and its determination alone is considered as a poor indicator of cytotoxicity and the combination of other markers like AST and ALT has been suggested for accurate detection and early diagnosis (Ali et al., 2013).Serum enzymes elevation may be explained by the basis of increase in hepatic cell membrane fluidity and permeability that led to enzyme release into circulation (El-Hawary et al., 2011).
Treatment with leaves or stems extract of R. dentatus attenuated the increased level of serum enzymes and caused a subsequent recovery towards normalization.This gives an additional support that R. dentatus extracts are able to restore hepatocytes, accelerate regeneration of parenchyma cells, and protects against membrane fragility and decrease leakage of the enzymes into circulation.Therefore, plant extracts acted by the same mode of action of silymarin (El-Hawary et al., 2011).The observed decrease in SDH after CCl 4 intoxication was in parallel with the finding of Rusu et al. (2005).This decrease in enzyme activity was attributed to the increase in free radicals that affected the inner mitochondrial membrane and intracellular calcium stores leading to structural and functional disorganization, overall loss in energy production, irreversible damage, and loss of enzymatic activity.The decrease in hepatic LDH after CCl 4 intoxication was confirmed (Rusu et al., 2005).Enzyme inhibition was mainly due to increase membrane fluidity as a result of ROS involvement leads to enzyme leakage into circulation.The repair mechanisms after treatment may be explained on the basis of enhancement in phospholipids content of cell membrane that coupled with thymidylate synthetase and thymidine kinase enhancing activities confirming liver regeneration (Motawi et al., 2011).
Injury of hepatocytes results in the recruitment and stimulation of inflammatory cells, as well as resident ones, including Kupffer cells.Factors released by these inflammatory cells lead to activation of HSCs and their transformation into a myofibroblast-like phenotype.Chronically activated HSCs produce large amounts of extracellular matrix proteins (ECM) and enhance fibrosis by secreting a broad spectrum of cytokines such as TGF-β 1 .This exerts pro-fibrotic actions in other cells and in an autocrine manner perpetuates their own activation (Xu et al., 2004).This is accompanied by a decrease in anti-inflammatory cytokines such as IL-10 and increase in IL-2 and IL-6 (Moron et al., 1979).Oxidative stress, including the decrease of antioxidant capacity, plays an important role in the pathogenesis of liver fibrosis via different pathways (Ali et al., 2013).Increased ROS, reactive nitrogen species (RNS), and MDA, are commonly detected in most types of experimental liver fibrosis (Nishikimi et al., 1972).Oxidative stress induces activation of HSCs through the direct effects of ROS, reactive aldehyde products of lipid peroxidation and finally via the reaction of NO with ROS, yielding peroxynitrite (ONOŌ).The latter is a very reactive, toxic and strongly oxidizing compound, able to induce DNA damage and lipid peroxidation.This process leads to membrane damage and correlates positively with fibrosis through inducing fibrogenic cytokines and increasing collagen synthesis in fibroblasts and hepatic stellate cells (HSCs) (Reyes-Gordillo et al., 2007).
Hepatic fibrosis is usually initiated by hepatocyte damage, leading to the recruitment of inflammatory cells and platelets with the subsequent release of cytokines, chemokines, and growth factors (Khan et al., 2012).These factors probably affect the inflammatory and repairing phase of liver fibrosis by activating HSCs (Khan et al., 2012).This is accompanied by down-regulation of anti-inflammatory cytokines, which has an important role in attenuating the progression of fibrosis (Moron et al., 1979).In parallel with the above information, the present study revealed that, the hepatotoxic agent, CCl 4 , leads to pronounced increment in serum pro-inflammatory fibrogenic cytokine, TGFβ 1 , IL-2, IL-6 and CRP .These results are confirmed by previous studies indicating the alterations in these cytokines in response to liver fibrosis (Lee et al., 2007).
Regulatory effect of R. dentatus extracts on hepatic marker enzymes was documented in our study as free radicals scavengers that could in turn normalize microsomes, lysosomes, mitochondria and plasma membranes permeability and integrity which help to restore the hepatic enzymes to their normal levels.The current study evaluates the in vivo role of R. dentatus in protecting the liver against injury and fibrogenesis caused by CCl 4 in rats and further explores the underlying mechanisms.We hypothesize that R. dentatus might protect the liver from CCl 4 caused injury and fibrogenesis by attenuating oxidative stress and suppressing inflammation.This report demonstrates that R. dentatus significantly protects the liver and kidney from injury by reducing the activities of serum AST, ALT, GGT ,total urea and creatinine ,as well as by improving the hepato-renal histological architectures of intoxicated rats.In addition, R. dentatus attenuates oxidative stress by increasing content of hepatic GSH, antioxidant enzymes; SOD, catalase and GPX leading to the reduction in the level of both lipid hydroperoxide and R. dentatus dramatically suppresses inflammation by regulation of inflammatory cytokines, including TNF-α, IL-2, IL-6 and CRP.
The leaves contained higher percentage of total phenolic than the stems.Phytochemical investigation of leaves resulted in the identification of three anthraquinones, four flavonoids in addition to one glucosyl sterol.
Chromatographic properties of compounds 1-3 and the fact that they turned red with sodium hydroxide indicated their anthraquinonoid nature.The UV spectra revealed the absorption bands characteristic of -hydroxyanthraquinone.Compound (1) EI-MS showed peak at m/z 270. 1 H NMR spectrum showed two singlets each of one H at 12.30 and 12.12 pointing to two perihydroxy protons present in C-8 and C-1, respectively, around the quinone system.The spectrum displayed also two aromatic systems bearing individually two meta-coupled protons and one of them bears an aromatic bounded methyl group at 2.46.The compound was identified as emodin, which was further recognised during a comparison of the data with literature (Abd El-Fattah et al., 1994) as well as authentic sample.
Compound (2) EI-MS showed peak at m/z 254.The 1 H NMR spectra displayed two aromatic systems, one containing an O-and m-coupled protons of 1,2,3-trisubstituted aromatic system, and two meta coupled protons of another aromatic system along with an aromatic bounded methyl signal ( 2.43).The 13 C NMR confirmed the carbonyl of C-9 ( 189.4) is flanked between two peri-hydroxy groups (OH-1,8).Additionally, five methine carbon signals were in the region of  136.9  112.3 and four other quaternary carbon signals between 145.5  116.2.In the aliphatic region one methyl carbon signals was at  23.5.This confirms the compound as 1,8-dihydroxy-3-methylanthraquinone; chrysophanic acid which was supported by comparison with literature (Abd El-Fattah et al., 1994).
Compound (3) EI-MS showed a peak at m/z 254 corresponding to [M] + . 1 H NMR spectrum of compound 3 exhibited five aromatic signals each of 1H corresponding to one 1,2,3-trisubstituted aromatic ring and two meta-coupled protons.In aromatic bounded methyl group was shown as singlet  2.48, in contrast to the included singlet of 2H at 12.97 of peri-hydroxy proton in compound 2, they were shown as two singlets each of 1H at  12.13 and 12.02 pointing mostly to two peri-hydroxy protons present in two opposite directions (C-1 and C-5) around the quinone system.In 13 C NMR of compound 3 displayed similarly 15 carbon signals as in compound 2; two of them were shown at 192.4 and 192.3 characteristic for quinone system with two equivalent peri-hydroxy groups.Thus the compound 3 was confirmed to be as 1,5-dihydroxy-3-methylanthraquinone which was further confirmed by comparonis the data with literatures (Lu et al., 1992) and it was reported in R. pulcher (Harborne and Mokhtari, 1997).
The physicochemical properties of compounds ( 4)-( 6) (color under UV light, change with ammonia vapor and responses towards spray reagents, II and III) can suggest their flavonoid glycosides character.On the basis of physicochemical properties and UV spectral data, compounds (4) and ( 5) were expected to be quercetin-3-glycoside and compound (6) as isorhamnetin aglycone.Acid hydrolysis of the three compounds afforded quercetin as an aglycone and L-rhamnose for compound (4) and ( 6), L-rhamnose and D-galactose for (5) (Markham, 1982;Harborne and Mabry, 1982).
UV spectrum of compound (6) showed the presence of free 7-hydroxyl group in ring A which is manifested by an intensive bathochromic shift or band II in addition of NaOAc as shift reagent.The bathochromic shift of band I on NaOMe spectrum confirmed the presence of a free OH at C-4'.Complete acid hydrolysis afforded isorhamnetin and rhamnose (by Co-PC). 1 H NMR spectrum showed the downfield shift of H-2' to  7.32 indicated that the methoxyl group is located at position 3' to confirm the identity of the aglycone as isorhamnetin.Also, singlet proton of the methoxy group at  3.99 was found.The signal of the anomeric proton of the rhamnose moiety appeared as a doublet at  5.21 (J=1.2Hz) and methyl rhamnosyl protons at  0.90 as a doublet (J=6 Hz).The configuration was confirmed by the coupling constant 1.2 Hz as -L-rhamnose.The compound (6) was identified as isorhamnetin 3-O--L-rhamnoside.In 13 C NMR spectrum it was observed that the C-3 is shifted downfield at  134.1 ppm indicating that the linkage between the sugar unit and the aglycone is at C-3.Also, it was observed that the C-3' is shifted downfield at  147.2 ppm indicating that C-3' is substituted.The spectrum showed methoxy group at  56.0 ppm and one anomeric carbon at  101.8 ppm and a methoxy group at  17.4 ppm corresponding to --L-rhamnose (Iwashina and Ootani, 1990).
UV spectra of compound (7) can suggest the presence of the isolated benzenoid chromophores.In the aromatic region of its 1 H NMR, the characteristic five hydrogen resonances of the positions 6, 8, 2', 5' and 6' of a flavonoid skeleton were observed.A doublet (J=2.4Hz) at  5.89 assigned to H-8 showed metacoupling with doublet (J=2.1 Hz) at  5.70 assigned to H-6.On the other hand, the doublet (J=2.1 Hz) at  6.74 assigned to H-2' showed meta-coupling with doublet of doublet (J=1.8,6.5 Hz) at  6.60 assigned to H-6' and the later exhibited an ortho-coupling with doublet (J=8.1 Hz) at  6.69 assigned to H-5'.The spectrum indicated that compound ( 7) is a catechin-type flavanol with transconfiguration at C-2 and C-3 (coupling constant between H-2 and H-3 was 7 Hz).The compound was identified as catechin (Nonaka et al., 1983).
Compound (8) m.p. and gave positive Liebermann-Burchard for sterol.The mass spectrum and NMR spectroscopic measurements 1D 1 H-and APT and 2D 1 H-1 H COSY, HMQC and HMBC and by the aid of the published data the compound was identified as 3-O-glucopyranosyl-β-sitosterol (daucosterol) (Anton et al., 1993;Faizi et al., 2001).Inspection of the APT spectrum of showed the existence of 35 signals, the sugar moiety gives rise to one methylene group and five methine groups, whereas the aglycone part exhibits twenty-nine carbon signals, arising from six methyl groups, eleven methylene groups, nine methine groups and three quaternary carbon atoms.The aglycone moiety was identified as β-sitosterol from its 1 H and APT spectra.The sugar moiety was connected to C-3 atom as shown from its HMBC spectrum cross peaks H-1`/C-3.The sugar moiety was identified as glucopyranose from its 1 H-NMR, APT, 1 H-1 H COSY and HMQC spectra.Acid hydrolysis confirmed the presence of glucose in aqueous layer and the organic layer contained β-sitosterol as compared with authentic reference sample.The data were compared with the literature and the compound was identified as β-sitosterol-3-O-glucopyranoside, which was previously isolated from R. dentatus roots growing in China (Zhu et al., 2006).
Quinones constitute a structurally diverse class of phenolic compounds with a wide range of pharmacologial properties, which are the basis for different applications in the broad field of pharmacy and medicine.In traditional medicine all over the world, genus of Rumex which is rich in quinones is used for the treatment of a variety of diseases (Xu et al., 2004;El-Hawary et al., 2011).Some anthraquinones were reported to have hepatoprotective and antiproliferative effect (Kumar et al., 2007;Zargar et al., 2011).
In the current study, one of the bioactive secondary metabolites is the anthraquinones (Fig. 17).The most abundant compound of R. dentatus, emodin was previously reported to possess immunostimulant, anti-inflammatory activity, and protective effects on hepatocytes and cholangiocytes against αnaphthyl isothiocyanate-induced cholestatic liver injury in rats (Zhao et al., 2009).
Three flavonoid glycosides were isolated from R. dentatus in the present study.Compounds (4) and ( 5) were identified as quercetin derivatives.Flavonoids were reported as classes of bioactive constituents showing hepatoprotective activity (Kumar et al., 2012;Shalaby et al., 2012).Certain quercetin glycoside isolated from R. aquaticus Herba was reported as a protective agent against ethanol-induced cell damage.The cytoprotective effect of this flavonoid may involve inhibition of ROS generation and downstream activation of the ERK 1/2 in feline esophageal epithelial cells (Cho et al., 2011).Another study reported that quercetin glycoside, hyperoside (quercetin-3galctoside) has protective effect against CCl 4 -induced liver damage in mice and this protection is likely due to enhancement of the antioxidative defense system and suppression of the inflammatory response (Choi et al., 2011).Rutin was previously isolated from R. dentatus.The hepatoprotective effect of rutin against CCl 4 -induced oxidative stress and its role in alleviation of lipid peroxidation and restoration of p53 and CYP2E1 activity were reported (Khan et al., 2012).In the current study, daucosterol was isolated from R. dentatus leaves.This steroidal glycoside was previously isolated together with different steroids as main constituents from the hepatoprotective plant; Imperata cylindrical (Mohamed et al., 2009).β-Sitosterol, β-sitosterol glucoside, chryasophanic acid, quercetin, aloe emodin glucoside, rutin have been isolated from Ficus ingens as the main bioactive compounds.The hepatoprotective effect of this plant was suggested to be attributed to its phytochemical constituents (mainly polyphenolic compounds) with their antioxidant and membrane stabilizing properties (Donia et al., 2013).Also, catechin was also identified in the current study.Hepatoprotective potential of R. vesicarius extract against hepatotoxicity induced by CCl 4 was reported (El-Hawary et al., 2011).In which, catechin was investigated as one of bioactive compounds in plant extract.Hepatoprotective effect of semen of R. crispus (Lee et al., 2007) was reported.Protective effect of R. patientia (English Spinach) roots on ferric nitrilotriacetate (Fe-NTA) induced hepatic oxidative stress was explored (Lone et al., 2007).Its liver protection activity was expected to be due to the presence of anthraquinones and other phenolic compounds.
This study demonstrates that Rumex protects the rat liver from CCl 4 -caused injury and fibrogenesis by suppressing hepatic inflammation and attenuating hepatic oxidative stress.Our results suggest that R. dentatus might be a therapeutic antifibrotic agent for the treatment of hepatic fibrosis.

CONCLUSION
Rumex dentatus L has the ability to down regulate free radicals elevation, improve liver and cholestatic biomarkers, ameliorate hepatic marker enzymes, reduce fibrosis severity and normalize the hepatic cells architecture.The ethanol extract of leaves recorded potent effect in improving the selected parameters.The hepatoprotective effect of R. dentatus L demonstrated in this study may explore its nutraceutical role in human diet.The isolated bioactive phytochemicals was suggested to be responsible for the pronounced pharmacological activity.Therefore, further studies are needed for its clinical application.

Fig. 2 :
Fig. 2: Liver of CCl4 intoxicated rat showing congestion of central vein, Kupffer cells activation and necrosis of sporadic hepatocytes (H & E X 400).

Fig. 6 :Fig. 7 :
Fig. 6: Liver of CCl4 intoxicated rat treated with leaf total extract of Rumex dentatus showing few fatty degeneration of hepatocytes and Kupffer cells activation ( H & E X 400).

Fig. 13 :
Fig. 13: Kidney of rat CCl4 intoxicated rat treated with leaf total extract of Rumex dentatus showing no histopathological changes (H & E X 400).

Fig. 14 :Fig. 15 :
Fig. 14: Kidney of CCl4 intoxicated rat treated with stem total extract of Rumex dentatus showing slight congestion of glomerular tufts and slight congestion of intertubular blood capillaries.(H & E X 400).

Table 1 .
Effect of R. dentatus leaves and stems extract on hepatic oxidant/antioxidant (GSH, MDA, NO, GPX, CAT and SOD) levels and total hepatic protein content in CCl4 intoxicated rats.

Table 2 .
Effect of R. dentatus leaves and stems extract on liver function markers SDH and LDH following CCl4 intoxication in rats.

Table 3 .
Effect of R. dentatus leaves and stems extract on liver function enzymes; AST, ALT, ALP and GGT in CCl4 treated rats.

Table 4 .
Effect of R. dentatus leaves and stems extract on kidney-function tests in CCl4 intoxicated rats

Table 5 .
Effect of R. dentatus leaves and stems extract on inflammatory markers in CCl4 intoxicated rats.