Ethnomedicinal plants used by the Nag clan of the Rai Ghatual tribe of Moulvibazar district, Bangladesh.

CONTEXT: Medicinal practices of the tribes of Bangladesh remain largely un-documented. AIMS: The aim of the present study was to conduct an ethnomedicinal survey and documentation among the Nag clan of the Rai Ghatual tribe of Bangladesh. SETTINGS AND
DESIGN: The survey was carried out among the Nag clan of the Rai Ghatual tribal community of Moulvibazar district. The clan, according to them, is the only Nag clan of the Rai Ghatual tribe in Bangladesh. The clan has three tribal healers, still continuing their traditional medicinal practices.
MATERIALS AND METHODS: Interviews of the healers were carried out with the help of a semi-structured questionnaire and the guided field-walk method.
RESULTS: The Nag clan healers were observed to use 28 different plant species distributed into 22 families for treatment of ailments such as fever, loss of appetite, male infertility, dysentery, lower abdominal pain during menstruation, jaundice, stomachache, burning sensations during urination, bodily pain and weak health.
CONCLUSIONS: This is the first reported study of the traditional medicinal practices of Nag clan healers. Several of the plants can be validated in their uses on the basis of existing scientific literature. The medicinal plants used by the Nag healers warrant further scientific studies, for the plants are readily available and can form alternative medicinal sources instead of costlier biomedical drugs.

INTRODUCTION

Documentation of indigenous medicinal practices is important not only from the point of view of anthropology, but more so because many important modern drugs have come out following close observations of the traditional medicinal practices of indigenous communities.[1] Bangladesh has a number of indigenous communities (otherwise referred to as tribes), many of these communities are composed of clans and sub-clans. With the exception of about a dozen tribes, socio-cultural data on the other tribes are scant or absent because many such tribes have dwindled into such small numbers that they are no longer accounted for in population censuses and considered as members of the mainstream Bengali-speaking population. Quite a number of these small tribes can be found as “pocket” communities working in the various tea estates of Moulvibazar district, which falls in the Sylhet division of Bangladesh. A few reports on the indigenous medicinal practices of the tribes of Bangladesh have only recently been published.[2345678910] However, more studies are needed to get an overall picture of the medicinal practices of all the tribes of Bangladesh.

MATERIALS AND METHODS

The Nag clan of the Rai Ghatual tribe was located in a tea estate at Tanki Tila village in Moulvibazar district of Bangladesh. The tribal population numbers around 700 (according to their own estimate) and all adult members (around 150) worked in the tea estate. They claimed themselves to be “Sonaton” Hindus, with their main festivals being Bish Hari puja and “Holi” festival. Though small, the tribe had three practicing tribal healers, their names being Joy Roy, Laxmicharan Roy and Sunil Roy.

Informed consent was obtained from the tribal healers. Repeated visits were made to the healers during the whole of 2012, the purposes of the visits explained to them and consent obtained to disseminate any information collected. Interviews were conducted in Bengali with the help of a semi-structured questionnaire and the guided field-walk method of Martin[11] and Maundu.[12] In this method, the healers took the interviewers on guided field-walks through areas from where they collected their medicinal plants, pointed out the plants and described their uses. Plant specimens were collected and photographed on the spot, dried and later brought back to Dhaka for proper identification at the Bangladesh National Herbarium. Voucher specimens were deposited in the Medicinal Plant Collection Wing of the University.

RESULTS

The healers were observed to use a total of 28 plants distributed into 22 families for treatment of various ailments. The various ailments treated included fever, loss of appetite, male infertility, gastrointestinal disorders (such as diarrhea and dysentery), lower abdominal pain during menstruation, jaundice, stomach ache, burning sensations during urination, bodily pain and weak health. One formulation was used to treat what the healers mentioned as “evil eye” [Table 1].

Table 1

Medicinal plants and formulations of the Nag clan of the Rai Ghatual tribe of Bangladesh

“Evil eye,” according to the healers is said to be “cast” when somebody “eyed” another person with jealousy or covetousness. The various symptoms of “evil eye” included swelling of stomach, vomiting, watery stool and loss of cognitive functions, i.e. the patient became unable to recognize anybody. Although these symptoms can be seen in patients with severe gastrointestinal disorders, where frequent passage of watery stools can lead to dehydration and ionic imbalances with consequential impairment of cognitive faculties because of weakness, the healers distinguished “evil eye” from diarrhea or dysentery because according to them, loss of cognitive functions did not occur during diarrhea or dysentery.

Both complex and simple formulations were observed to be used by the healers. For instance, a complex formulation for treatment of fever and loss of appetite consisted of leaves of Andrographis paniculata (Burm. f.) Wall. ex Nees, Ocimum tenuiiflorum L. and Justicia adhatoda L. along with seeds of Myristica fragrans Houtt. and Nigella sativa L., to which were added cloves of Allium sativum L. The various plant parts were mixed and juice obtained from the crushed mixture or pills made from the crushed mixture were administered orally. The healers apparently understood adverse effects of improper diet while undergoing treatment. The patients were advised not to eat any sour substance while taking this formulation.

A paste of leaves of Centella asiatica (L.) Urban was orally administered for loss of appetite and diarrhea. In another formulation used by the healers for treatment of lower abdominal pain during menstruation in women, the patients were advised not only not to take any sour substance, but also hilsa fish, grass pea, duck meat and duck eggs [S. No. 7, Table 1]. In a third formulation for treatment of jaundice [S. No. 9, Table 1], patients were forbidden to take any eggs, turmeric and any fish, with the exception of three fish species. Furthermore in this case, patients were advised to take salt only sparingly.

In addition to the medicinal plant formulations shown in Table 1, the Nag healers also used two incantations in their remedies. The first incantation was recited in front of every patient prior to giving the patient any medication.

The second incantation was uttered in front of a snake-bitten person followed by blowing on the person.

DISCUSSION

The results suggest that the Nag healers possessed quite extensive knowledge of the medicinal properties of plants that they used for treatment of various ailments. This is also borne out from existing scientific literature on ethnomedicinal uses of plants and pharmacological properties of the various plants used by the healers. For instance, the healers used a combination of six plants, namely A. paniculata, O. tenuiiflorum, J. adhatoda, M. fragrans, A. sativum and N. sativa for treatment of fever. A. paniculata has been in use in China for treatment of fever for centuries and a component of the plant, dihydroandrographolide, has been reported to possess anti-pyretic properties.[13] Tender leaves of O. tenuiiflorum boiled with tea reportedly acted as preventive medication against malaria and dengue fever.[14] Various phytochemicals such as vascinine and vascinone in J. adhatoda can act against fever and other respiratory problems;[15] M. fragrans is reportedly used by the Arabs and Jews of Israel for treatment of fever;[16] aqueous extract of A. sativum reportedly showed inhibitory effect against clinical isolates of Salmonella typhi, the causative organism for typhoid fever;[17] and in Indian traditional medicine, N. sativa is used against intermittent fever.[18]

Achyranthes aspera L. was used by the Nag healers for treatment of impotence; such use has been reported for traditional medicine in various countries;[19] inhibitory activity of C. asiatica has been observed against enteric pathogens,[20] the plant being used by the Nag healers for treatment of diarrhea. A combination of a number of plants, namely Calotropis gigantean (L.) R. Br., Piper nigrum L., M. fragrans and Trigonella foenum graecum L. was used by the Nag healers for treatment of lower abdominal pain during menstruation; analgesic effect of C. gigantea has been reported.[21] Piperine isolated from P. nigrum also reportedly has analgesic properties;[22] the analgesic effects of ethanolic extract of M. fragrans has been described;[23] the analgesic and anti-inflammatory activities of T. foenum graecum seed extract has also been reported in mice.[24] Thus, the combination of plants used by the Nag healers for treatment of lower abdominal pain can have synergistic actions and so exert a powerful analgesic effect.

Cajanus cajan (L.) Millsp. reportedly is used by various ethnic groups in Africa for treatment of jaundice;[25] a similar use was made of the plant by the Nag healers. Litsea monopetala (Roxb.) Persoon, used by the Nag healers for treatment of dysentery has similar ethnomedicinal uses in other parts of Bangladesh.[26] Moringa pterygosperma Gaertn. was used by the Nag healers for treatment of pain. Analgesic effect of ethanolic extract of the plant has been demonstrated in pain-induced mice model.[27] Four other plant parts were used by the Nag healers in combination with M. pterygosperma for treatment of pain, namely A. sativum, P. nigrum, Amomum subulatum Roxb. and Cinnamomum verum Presl. The analgesic property of piperine isolated from P. nigrum has been discussed previously. Analgesic and anti-nociceptive properties of A. sativum has been shown in experimental animal studies.[28] Analgesic activity of A. subulatum,[29] and hydroalcoholic extract of C. verum has also been reported.[30] Thus, once again, as has been demonstrated for a previous formulation, the various plant parts used by the Nag healers have been demonstrated to possess individual analgesic activities and hence, they can together exert a synergistic effect for alleviation of pain.

Peperomia pellucida (L.) Kunth was used by the Nag healers for treatment of fever. Anti-pyretic activity of leaves of the plant has been reported.[31] It is interesting that the Nag healers did not administer the leaves of the plant orally; rather they used a paste of leaves of the plant topically. However, it is very much possible that possible anti-pyretic components of the plant may be absorbed through the skin and so exert the desired effect of reducing fever. Cumulatively speaking, it can be said that quite a number of the plants used by the Nag healers have been validated in their uses through scientific research, which once again goes on to show the remarkable knowledge of medicinal properties of plants possessed by these healers. It is expected that more scientific studies on the plants can lead to identification of bio-active compounds, which can prove to be effective drugs. Simultaneously, recognition of medicinal efficacy of these plants can spur conservation efforts of these plant species.