Survey and documentation of anthelmintic plants used in traditional medicine system of tribal communities of Udalguri district of Assam, India

Study area and its description

The present study was carried out in different villages under Udalguri district of Assam. Geographically, it covers an area of 1,852.16 sq. km. According to the 2011 Census report of India, Udalguri district has 802 villages (791 human inhabited and 11 uninhabited) and population size of 832,769, more than 95% living in the rural areas.

Data collection and identification of plant samples

The survey was done during the months of May to November, 2018 and information regarding the anthelmintic plants traditionally used by tribal communities of Udalguri district was collected. The information was collected from different community development block (CDB) with the help of informants (village traditional healer or Kaviraja in local language and elderly village people) having ethnomedicinal knowledge. Within every CDB, approximately 20 adjacent villages were taken as a single cluster and one sample (informant) was collected from a cluster. The information was collected in a face-to-face interview manner with the help of readymade questionnaires. Based on the number of villages per CDB, sample size varied from one CDB to another. Out of 11 CDBs, we did not collect any data from two CDBs, namely, Pachim-Mangaldai and Dalgaon-Sialmari because of less numbers of village(s). The information collected from informants mainly included—informer’s bio-data, plant(s) part(s) used, local name of plant(s), traditional formulations, and mode of administration. The plants were collected as per the information given by the informer. A total of 42 informants were interviewed from 39 different villages. One informant was interviewed from each of the 36 villages, while two informants were collected from Pakribari, Barnagaon, and No. 2 Kadabil. The various information collection sites under different CDB were represented in Figure 1. Based on the information provided by the informants, sample plants were collected and processed for identification. Herbarium sheet were prepared and submitted to the Department of Botany, Bodoland University for identification.

Data analysis

Following quantitative analysis was carried out to assess the importance of medicinal plants following Hussain et al. (2018).

Frequency of Citation (FC): It is the number of informants who mentioned a certain species.

Relative frequency of citation (RFC): It is obtained by dividing FC by total number of informants (N). The value of RFC indicates the citing percentage of each species of medicinal plants. RFC was calculated by using the following formula (Tardio et al., 2008):

RFC = FC / N

The value of RFC varies from zero (when nobody cites to a plant as important) to one (when all the informants consider a certain species important).

Family importance value (FIV): FIV indicates the local importance of the families of plant species and is calculated by counting the percentage of informants mentioning a specific family (Vitalini et al., 2013).

FIV = [FC (family) / N] × 100

Statistical analysis

All the statistical calculations, graphs, etc. were carried out in Microsoft excel and Origin software.

Demography of informants and collection sites

Traditional knowledge system of herbal medicines based on the plant product is a healthy practice among the tribal communities of India. Living in the rural areas and far away from towns and cities, economically downtrodden tribal communities depends on plant-based medicines for common diseases. In our present study, we selected 39 sample villages from 9 CDBs and 42 numbers of traditional informants have been interviewed. The names of CDBs, villages, its geographical location, and demography of the selected informants were presented in Tables 1 and 2, respectively. Out of 9 CDBs, a highest of 12 villages was visited from Udalguri CDB and 14 numbers of informants were interviewed. However, only one informant was collected each from Borchola and Pub-Mangaldai CDBs.

Figure 1. Map of Udalguri district of Assam and sample collection sites. Red dots represent the villages where data has been collected. [Numbers represents the serial no. of villages of Table 1 ]. [Click here to view]

A total of 39 villages were surveyed with the help of local people via the administration of semi-structured interviews and ready-made questionnaire (Table 1). A total of 42 informants were interviewed out of which 64% constitute the male informants (Table 2). Among the informants, 83% is traditional healer who possess the ethnomedicinal knowledge and practice regularly and earn little amount of money. Seventeen percent of the informants are the elderly people who do not practice but possess ethnomedicinal knowledge gathered from their forefathers. It is also seen that most of the traditional knowledge bearers are above 40-year old. Very few (about 12%) were found to be below 40 years of age. In terms of literacy rate, about 79% informants were having formal education, while 21% were illiterates. Among the literates, 19% were having college level education, while 60% have school level education. However, compared to females, the males were found to be more educated. Out of 27 numbers of male informants, 85% are found to be educated. Meanwhile, the female literacy was found to be about 60% of the 15 female informants. Among 42 informants, very few (18%) have government salaried job. In terms of plant citations, however, the literates and illiterates cited more or less similar number of plants, an average of 4.4 citations/informants and 4.2 citations/informants, respectively. The names of the plant species, its local name, habit, habitat, parts used, and traditional formulation of the herbal medicine is shown in the Table 3.

Use of medicinal plants for the treatment of diseases is a common practice to the rural, economically, and educationally backward tribal communities of India (Fayaz et al., 2019; Singh et al., 2017). Most of the times traditional medicine (TM) Systems do not have any form of written documents and are transferred orally from generation to generation. Like many other parts of the worlds, in Indian subcontinent also, TMs are practiced mainly by uneducated, poor, old, and aged people. It is also reported in many survey reports that male folks act as the major information bearer than females. Our study also revealed similar kind of traditional knowledge bearers where most of the informants are aged and male individualsx (Ritter et al., 2012; Teklehaymanot, 2017). However, unlike many other countries, such as Kenya, and Pakistan, where TMs are reported to be practiced mostly by illiterates, we found dissimilar result with most of the informants (79%) having formal education (Ahmad et al., 2015; Maphosa and Masika, 2010). Fayaz et al. (2019) also found that 71% of the informants from Jakholi Block of district Rudraprayag, Uttarakhand state were having formal education. It has also been seen that out of 42 informants 18% were having government salaried jobs, and none of them practice professional herbal treatment and they gathered their ethnomedicinal knowledge from their forefathers. Most of the traditional healers make some business out of their ethnomedicinal knowledge by making small packets and mixtures, which they sell to other villagers. During our survey, we have also come across many people who visited the traditional healer in their homes to purchase the herbal preparation.

Table 1. Name of the CDB, villages and geographical locations of survey sites. [Click here to view]

Anthelmintic medicinal plants used by tribal communities

A total of 160 plant citations were recorded from 42 informants (Table 3). Out of total plant citations, 32 plants were found to be reported more than once by the local traditional healers. However, 27% (43 citations) of the plants do not have any repetitions among the informants. A total of 75 plants species, belonging to 67 genera and 44 families were recorded from Udalguri district that are consumed as deworming medicines. The plants belonging to 16 families are found to be more common and have more than one citation. Andrographis paniculata was found to be the most popular plant species (FC = 12, RFC = 0.286) followed by Ananas comosus (FC = 9, RFC = 0.214), Hydrocotyle sibthorpioides (FC = 8, RFC = 0.190), Centella asiatica (FC = 8, RFC = 0.190), and Psidium guajava (FC = 8, RFC = 0.190). Similarly, out of 45 plant families, Acanthaceae was seen to be the most popular family with FIV value 32% followed by Bromeliaceae, Myrtaceae, Apiaceae, Araliaceae, and Lamiaceae with more than 15% FIV value (Fig. 2). Thirteen plant families do not seem to have any popularity among the traditional healers in terms of FIV value. However, in terms of plants species used under a single family, Rubiaceae was seen to be important with eight number of plant species, followed by Lamiaceae (six species), Zingiberaceae (four speciess), Cucurbitaceae and Apocynaceae (three species each), and Verbenaceae, Piperaceae, Oxalidaceae, Myrtaceae, Leguminosae, Lauraceae, Euphorbiaceae, Acanthaceae, Amaranthaceae, Anacardiaceae, and Asteraceae (two species each). However, from 29 families only one plant citation was reported. It has been found that most of the plants (53%) cited are wild in habitat, while others are domesticated. Our study also revealed that majority of the plants belongs to trees (39%). In our study, we also found that 37% of the plant species are herbs, 20% are shrubs, and 4% are climbers. Figure 3 shows the citation of the plants by different informants.

Table 2. Demography of informants from different villages of Udalguri district of Assam. [Click here to view]

Table 3. List of medicinal plants used in the traditional medicine system against helmintic infection by tribal communities of Udalguri district of Assam with their identification numbers. [Click here to view]

Figure 2. Graph showing the popularity of different Families of plants in Udalguri district of Assam having anthelmintic property. [Click here to view]

Figure 3. List of plants citations by different informants of Udalguri district of Assam. [Click here to view]

Our survey reported a total of 75 species of plants used in TM system as deworming medicines. Ananas comosus, A. paniculata, C. asiatica, H. sibthorpioides, and Psidium guajava were found to be the most popular plants used as an anthelmintic agent among the tribal communities of Udalguri district. The traditional popularity has also been confirmed experimentally by many investigators (Molla and Bandyopadhyay, 2014; Pina-Vázquez et al., 2017). Similarly, plants having two or more citations, such as Aegle marmelos (Singh et al., 2012), Alstonia scholaris (Panda et al., 2017), and Clerodendrum infortunatum (Swargiary et al., 2016) also possess experimental evidence about anthelmintic activity. Out of 75 plant species reported by informants, 65% are having scientific and experimental evidence of anthelmintic property. The presence of such experimental evidence about the medicinal plants traditionally practiced by traditional healers suggests the efficiency and popularity of ethnomedicine. In a similar kind of research, several species of plants were reported from Cachar district of Assam having anthelmintic property (Das et al., 2008). Similarly, Sharma and Sharma (2010) reported many anthelmintic plants from Sonapur area of Kamrup district of Assam. Many plants from northeast India were investigated by Lyndem et al. (2008) showing effective anthelmintic agents. It can therefore be believed that although traditional healers do not perform any laboratory experiment, they have some kind of customary procedure by which they formulate their herbal doses.

Different plant parts are generally used in the preparation of herbal remedies. Among the plant parts used, leaves were found to be the most commonly used for the preparation of deworming herbal medicines (Fig. 4a). Unlike others, for three plants, namely, Musa balbisiana, Cocos nucifera, and Clerodendrum indicum, the corm, endosperm, and flower were found to be used for herbal formulations. Our survey also found that Rauvolfia tetraphylla is the most common plant in terms of parts used where all the leaves, barks, and roots were found to be used. Our survey also found that four plants, viz., Cen. minima, Cissus quadrangularis, H. sibthorpioides, and C. asiatica, the whole plant parts was used for the herbal formulations. Regarding the herbal formulations, it has been seen that tribal communities of Udalguri district follows three methods of herbal formulations—decoction, infusion, and raw. Most of the time, traditional healers use raw plants for the preparation of herbal medicines (Fig. 4b). Trees are the most commonly used plants used by the herbal healers to cure helminthiasis followed by herbs, shrubs, and climbers. Because of its easy accessibility and availability, leaves tend to be the most commonly used plant parts. Many such studies have reported similar use of traditionally used medicinal plants (Choudhury et al., 2015; Raj et al., 2018). Although there are variations in the nature of herbal formulations among the traditional healers, three main traditional formulations are practiced by tribal communities of Udalguri district—raw, infusion, and decoction. Similar to our findings, decoction, extract, infusion, powder, and juice were found to be the main traditional formulations practiced by Neelum Valley, Pakistan (Ahmad et al., 2017).

Figure 4. (a) Plant parts used in the traditional herbal formulation and (b) types of traditional formulations practiced. WP- whole plant. [Click here to view]