Herbal medicine & healthcare practices among Nicobarese of Nancowry group of Islands - an indigenous tribe of Andaman & Nicobar Islands

Traditional medicinal practices and use of herbal medicine date back to pre-historic era1. Precious ancient knowledge of traditional medical methods is now restricted to some of the closed communities particularly the remote tribal populations. It is a part of their cultural practices and provides the means for maintaining health and preventing diseases among them23. In India, about 1.5 million practitioners of herbal medicine use around 25,000 plant based formulations, of which only 10 per cent are used in drug and pharmaceutical industries45. Studies have been initiated to gain knowledge about the traditional health care systems of indigenous communities in various parts of India. Ethnobotany of the medicinal plants used by the tribes of Andaman and Nicobar Islands is not well studied67.

The Nicobarese are the inhabitants of the Nicobar group of Islands of the Andaman and Nicobar Archipelago. The Nicobar group is divided into three zones, viz., the Northern zone, consisting of Car Nicobar Island; the Central zone (also known as Nancowry group of Islands) and the southern zone consisting of Great and Little Nicobar Islands. The Nancowry group is comprised of nine Islands viz., Chowra, Teressa, Nancowry, Kamorta, Katchal, Bompooka, Trinket, Isle of Man and Tillangchong, of which only the first five are inhabited. The Nicobarese belong to the mongoloid race. They are coast-dwellers and enjoy the vicinity of exuberant and verdant tropical forests8.

Nicobarese of Nancowry group of Islands, particularly those inhabiting Chowra and Teressa Islands, still maintain their traditional way of life though the lifestyle of those living in Nancowry, Kamorta and Katchal Islands are in a state of rapid transition due to frequent exposure to modern amenities9. The tribal inhabitants of these Islands continue to lead a life closely linked to the nature and are mostly isolated from modern influences. Documentation of ethnomedical practices of the tribes of these islands is scarse and the wealth of the their traditional knowledge remains unexplored710. We carried out an extensive ethnobotanical survey with the aim of documenting the use of medicinal plants and the allied traditional knowledge of the Nicobarese tribe living in the presently inhabited Islands of Nancowry group.

Material & Methods

Study area: Nancowry group of Islands include the islands of Chowra (8 km²), Teressa (101 km²), Katchal (174 km²), Kamorta (188 km²) and Nancowry (67 km²) that are inhabited and other Islands such as Bompooka (10 km²), Trinket (86 km²), Isle of Man and Tillangchong (17 km²). Kamorta is the Administrative Headquarter and centre of activity of the Nancowry group of Islands. Of the total population (9140, 2011 census) of the Nicobarese, 3557 live in Kamorta Island, 1298 in Chowra, 1934 in Teressa, 1016 in Nancowry and 1335 in Katchal. There are 42 villages inhabited by Nicobarese in Nancowry group of Islands and people of these Islands speak Nicobarese language which is written in Roman script.

Study participants and interviews: This study was planned and conducted by the Regional Medical Research Centre, Port Blair, Andaman and Nicobar Islands. Field visits were conducted in 2012-2013 to all the 42 villages spread across the five inhabited islands. Prior permission to conduct the survey in these islands was obtained from the local authorities. Meetings were conducted with the local Tribal Councils of Nancowry group of Islands. Tribal Councils comprise the Chairman, the Vice-chairman, the Secretary and the Captains of all villages. The survey was conducted in all the villages and the traditional knowledge practitioners (TKPs) of each village were identified.

Each TKP was interviewed individually using a structured questionnare to obtain the data on diseases he/she has been treating, medicinal plants used, mode of preparation of medicines, methods of administration of the preparations and the dosages. Teachers and young literates in the community, who were well versed in Hindi language, voluntarily functioned as translators/interpreters during the survey as many of the TKPs spoke in the Nicobarese tounge. The interviews were repeated on different days to ascertain the consistency of the information given by the TKPs.

Plant specimens collection and identification: The plants were collected in and around the villages with the help of TKPs and photographs of specimens, and global positioning system (GPS) locations of the respective plants were recorded. Taxonomic identification of the specimens was done by Botanical Survey of India, Andaman & Nicobar Circle, Port Blair. Voucher specimens were deposited at the Regional Medical Research Centre (ICMR), Port Blair. Information related to details of TKPs, ailments treated, formulations, dosage and duration of treatment was collated in the form of Community Biodiversity Registers.

Results

A total of seventy seven TKPs (46 male and 31 female) who were currently practicing traditional medicine among the people of the five inhabited Islands of Nancowry group of Islands (Table I) were identified during the survey. These TKPs together were using a total of 132 species of plants belonging to 113 genera of 62 families. Seventy one medicinal plant species were newly identified and were not part of the previous studies71011. Community Biodiversity Register, a collection of information sourced from each TKP, contained the list of ailments treated by each TKP in vernacular language (Nicobarese), botanical name and family of the plants used and route of administration ordered alphabetically by the name of the ailment (Table II). The largest number of medicinal plant species were from Euphorbiaceae (12) family followed by Verbenaceae (7); Fabaceae (7); Malvaceae (6); and Asteraceae (6).

Table I Traditional knowledge practitioners (TKPs) interviewed in different Islands

Table II Remedies used by Nicobarese traditional knowledge practitioners (TKPs)

This study recorded seven endemic and three rare plants species used as medicine (Table III). The use of three rare plant species was unique to Nicobar group of Islands12.

Table III Showing details of rare and endemic plants used as medicines by traditional knowledge practitioners (TKPs)

The 132 plant species used by the TKPs in Nancowry were employed in the treatment of 43 ailments, either individually or in combinations. Most of practitioners used a combination of plants to treat diseases. Of the 270 remedies documented, the largest number was to cure fever (37), followed by abdomenal pain (19), headache (16) while remedies for other ailments were few (Table II).

Among the 132 plant species used by the TKPs, 38 species grew as trees, 35 shrubs, 30 as herbs, 15 as small trees and 14 as climbers. The most commonly used plant parts were the leaves (122 species). Whole plant, root, stem, bark, fruit, nut, seed and flower were also used occasionally. Herbal medicines were commonly prepared using water (111) and coconut oil (79) as the excipients, but occasionally remedies were prepared with other excipients including coconut milk, toddy, honey, rain water, sea water, pig blood and pig fat. Some of remedies were used directly.

The medicinal plant preparations were administered to the patients through different routes including oral, topical and others. Topical (148 preparations) was the most commonly used route of administration, followed by oral (94 preparations) and other routes of administration including ear and eye drops (28 preparations).

Discussion

The Nicobarese tribes is the predominant indigenous tribe of Andaman and Nicobar Islands. Traditional medicine is used extensively by the tribal people of Nicobar group of Islands despite an increase in the use of modern medicine. The Nicobarese tribe is a repository of vast knowledge of the flora of their surrounding environment. As in the case of most of the traditional practices in India and all over the world among the Nicobarese including those living in Nancowry group of islands, traditional healing knowledge is passed on from the older generation to the younger in the family through oral narrations and informal training imparted while working as helpers to the folk healers131415161718. No written texts are maintained.

It was also interesting to note that a proportion of plants that were reported in earlier survey did not feature during our interactions with TKPs7891011. A study conducted in 1989 reported the use of 23 plant products in folk medicine practices among Nicobarese in Bompoka Island in the Nancowry group of islands. However, the documentation was partial and incomplete11.

In the present study, fever appeared to be the most common ailment among the Nicobarese of these Islands. Other common ailments included body ache, headache, snake bite, abdomen pain, ear ache, diarrhoea, vomiting and nausea, cough for short duration, paralysis, giddiness, prolonged labour, malaria, tuberculosis, skin injuries and fracture of bones.

The way a TKP used a plant to cure a particular ailment often differed from that followed by other TKPs, even of the same village. Often, the same medicinal plant was used by one TKP to cure one ailment and another to cure a different ailment. For example, Claoxylon indicum (Reinw. ex Blume) Hassk was used to cure 17 ailments. It has been observed that some plants are known by different names among the tribal groups of different Islands. For example, Ipomoea pes-caprae (L.) R.Br. is commonly called as Kőheok fang in Chowra Island, Hunguőh kap in Kamorta and Nancowry, Kamong heyő in Teressa and Lanan kāp in Katchal. Similar observations have also been made in other ethnobotanical studies19. Most of the medicines were prepared and prescribed with multiple medicinal plants as ingredients. This has been reported for the Kani community of India20. Most of the tribal remedies were prepared from leaves and excipients were commonly used for extraction. Water and coconut oil were common, readily available excipients used by Nicobarese. Similar observations have been recorded among the Kalanguya tribe21.

The present survey identified a large number of medicinally useful floras in the Nancowry group of Islands. There is a paucity of published comprehensive literature on this topic. No sincere efforts have been taken for systematic documentation of first hand information from TKPs involved in the practice of ethno-medicine. The present survey filled this gap to a large extent and generated comprehensive Community Biodiversity Registers of the Nicobarese of Nancowry Islands.