A brief review on medicinal plant Tagetes erecta Linn

Article history: Received on: 19/06/2015 Revised on: 10/07/2015 Accepted on: 17/08/2015 Available online: 15/11/2015 Medicinal plants, its derivatives and characterized secondary metabolites are widely used for medicinal purposes, are becoming popular all over the world as a natural alternative to synthetically produced chemicals both in Traditional and Allopathic system of medicine. The beneficial effect of herbal medicine typically result from the combination of secondary metabolites produced in the herbs such as glycosides, alkaloids, flavonoids, tannins, gums etc. There is a need for the documentation of research work carried out on these herbs, hence forth timely review on the herb Tagetes erecta Linn. Methodology used in the review is based on the published original research articles through exhaustive search through scientific databases; Saudi Digital Library, Pubmed, and Science Direct etc. Reviewed parameters are ethonomedicinal uses chemical constituents and pharmacological and non Pharmacological studies on medicinal plant Tagetes erecta Linn.


INTRODUCTION
Medicinal plants, its derivatives and characterized secondary metabolites are widely used for medicinal purposes, are becoming popular all over the world as a natural alternative to synthetically produced chemicals both in traditional and allopathic system of medicine.The beneficial effect of herbal medicine typically result from the combination of secondary metabolites produced in the herbs such as glycosides, alkaloids, flavonoids, tannins, gums etc (Nadakarni 1954;Ben and Michael, 2009;Ahito 2015).
There is a need for the documentation of research work carried out on these medicinal plants, hence on time review on Tagetes erecta Linn.Tagetes is a genus of annual or perennial, mostly herbaceous plants in the sunflower family (Asteraceae).It was described as a genus by Linnaeus in 1753.The name Tagetes is originated from the name of the Etruscan Tages.The most commonly cultivated varieties of Tagetes are known variously as African marigold, taxonomically known as Tagetes erecta L.

METHODOLOGY
Methodology used in the review is based on the published original research articles through exhaustive search through scientific databases; Saudi Digital Library, Pubmed, and Science Direct etc using different key words.Reviewed parameters are ethonomedicinal uses chemical constituents and pharmacological and non Pharmacological studies on medicinal plant Tagetes erecta Linn.

Plant types
There are two basic types of marigold; T. erecta Linn and T. patula Linn.T. erecta is also known as American marigold contains larger flowers, T. patula also known as French marigold contains smaller flowers.Yellow, orange, golden or bicolored flowers are held either well above the fine textured dark green foliage or tucked in with the foliage.The plant grows to the height of 1 -3 feet and spreads to 0.5 feet.Leaves are arranged in opposite/subopposite pattern and leaf types are of odd pinnately compound.The margin is dentate and shape is oblong.The leaf blade length is less than 2 inches and colour of leaf is green.Colour of the flower is orange; yellow; golden; bicolored.Characteristic of flower is showy (Edward and Teresa, 1999).

Pharmacognostic, phytochemical and physicochemical parameters
Pharmacognostic, phytochemical and physicochemical parameters of Flowers of T. erecta as follows,

Macroscopic Characteristics
T. erecta flower has bright colour, an aromatic odour and distinctly bitter taste.It has the length of 2 -3 cm and of thickness 3 -5.5 mm.Corolla is bright orange and calyx of dark green ovate type (Kadam et al., 2013).

Transverse Section of Flower
The transverse section of calyx contains cortical portions and fibro vascular bundles.In the cortical portion the cells are rectangular and compactly arranged.The transverse section of the corolla contains epidermis, veins and vein reaches through the semen portion (Kadam et al., 2013).

ETHNOMEDICINAL USES
Flowers of Tagetes erecta Linn used traditionally from ancient times.Different parts of this plant including flower are used in folk medicine to cure various types of diseases.Leaves are used as an antiseptic agent and also used in kidney troubles, muscular pain, piles, and applied to boils.The flower are used to cure fever, epileptic fits according to Ayurveda, astringent, carminative and stomachic, scabies and liver complaints and is also employed in diseases of the eyes.They are said to purify blood and flower juice is given as a remedy for bleeding piles and is also used in colds, rheumatism and bronchitis (Nadakarni 1954; Kadam et al., 2013).The Cherokee used it as skin wash and for yellow dye (Nadakarni 1954;Kadam et al., 2013;Ahito, 2015).In India juices of flowers occasionally used as blood purifier and remedy for piles.In Brazil flower and leaf infusion used as vermifuge.Mexicans used decoctions of flowers and leaves as diuretics and carminative.Aztecs used marigold for eye infections.In Brazil and Mexico, marigold used for joint pain and for muscular spasm.Other folklore uses of Tagetes include its use in anaemia, irregular menstruation, abdominal pain, muscular and bone pain.Internally Tagetes used for indigestion, colic, cough and dysentery.Externally used for ulcers, eczema, sore eyes and rheumatism (Shetty et al., 2009;Manisha et al., 2013;Ahito, 2015).

TOXICOLOGICAL DATA
Both aqueous and ethanolic fractions of flowers of T. erecta found to be safe during acute toxicity study.The study was in accordance to OECD Guidelines 425, Up and down procedure using albino Wistar rats (Shetty, 2008;Shetty et al., 2009;Manisha et al., 2013).The LD 50 value for chloroform fraction was found to be 8964.8mg/kg body weight on Long Evan rats (Farjana et al., 2009).The study carried out according to the Lork D Method of acute toxicity study (Lorke, 1983).Chloroform fraction of the drug did not alter biochemical and hematological parameters, no changes detected in histopathological studies during sub acute toxicity study (Farjana et al., 2009).Seed and leaf extract of T. erecta shown LD 50 value 357.43µg/insect against the strain Tribolium castaneum (Islam and Talukder, 2005).

PHRMACOLOGICAL DATA
Ethanolic extract of T. erecta reported to possess central nervous stimulant and antidepressant property through serotonergic pathway may decrease the seizure threshold if used in epileptic patients.The extract may precipitate seizure, hence use in epileptic patients is contraindicated (Shetty, 2008;Shetty et al., 2009).Extract has significant antipyretic property, revealed that flowers of T. erecta may have used to treat febrile epilepsy in Ayurveda practice as reported by Nadakarni (Nadakarni, 1954;Shetty et al., 2009).Fractions of chloroform, methanol, hydro alcoholic and ether fraction of T. erecta reported to possess analgesic and anti-inflammatory property.All the fractions were significant in acetic acid induced writhing in mice, hot plate method in mice, tail immersion method in mice and in carragenanan induced paw edema method in rats (Ghose et al., 2004;Natarajan et al., 2006;Chatterjee et al., 2009;Charaborthy et al., 2009;Shinde et al., 2009).Hydro alcoholic fractions of leaves were evaluated on adult albino rats.Results shown significant wound healing activity, comparable to the nitrofurazone control.The study supports the wound healing properties of the leaves as claimed in folkloric literature (Ghose et al., 2004).The wound healing activity may due to free radical scavenging action and the phytoconstituents (flavonoids) present in it which either due to their individual or additive effect on the process of wound healing (Ibrahim, 2011).An ethanolic extract of flowers and volatile oil of plant were studied for antioxidant activity.Results shown antioxidant activity in all in vitro assays -DPPH, reducing power, and superoxide radical scavenging activity, with better reducing power than standard ascorbic acid (Rosa et al., 2006;Basavraj, 2011).Ethyl acetate fraction of T. erecta shown significant hepatoprotective activity in carbon tetra chloride induced hepatopathy model (Giri et al., 2011).Different fractions of flowers shown significant antibacterial, antimicrobial activity; volatile oil of the plant reported to possess fungitoxic activity (Majia et al., 1997;Patrick et al., 2011;Rhama and Madhavan, 2011).Hydro alcoholic extract of the flower possess antidiabetic and hypolipidemic activity (Rodda, 2011;Raghuveer et al., 2011).

NON-PHARMACOLOGICAL DATA
Studies showed that T. erecta plant exhibited insecticidal (Sarin, 2004;Nikkon et al., 2009), larvidical (Marcia et al., 2011), mosquitocidal (Nikkon et al., 2011) and nematicidal activity (Patrick et al., 2011).Flower extract was found to contain biologically useful lutein compounds and studied for use as nutritional supplement and as poultry food colorant (Leigh, 1999).The petals yield a natural dye, the colorants consisting mainly of carotenoid-lutein and flavonoid-patuletin, with crude extracts used for dyeing textiles.The study describes an innovative dyeing process with net enhancement of dye uptake due to metal mordanting.Results suggest a potential for industrial application (Padma et al., 2009).

CONCLUSION
The literature survey revealed that the plant T. erecta is an important source of many pharmacologically and medicinally important phytoconstituents.There is huge scope for research; the plant could be further exploited in future as a source of useful phytochemical compound for the pharma industry.There are many other traditional uses of T. erecta species in different traditional systems, which serves as basis for further studies.This review will definitely help the researchers to explore its different properties and interactions of T. erecta plant.