Anti-Malarial Plants of Jonai, India: an Ethnobotanical Approach

North-East India represents a unique ecosystem with treasured medicinal plant wealth closely related with Folk medicines. A large number of plants having medicinal properties and their folk uses have remained confined to the natives of this region. The tribal community of Jonai, Assam was explored to expose the indigenous herbal remedy for malaria. Sixteen antimalarial plants belonging to 13 families were reported. The analysis revealed highest fidelity level (FL) value for Ajuga integrifolia (100%) followed by Ricinus communis (94%), Alstonia scholaris (88%), Oroxylum indicum (86%) and Achyranthes aspera (82%). The percentage of respondent’s knowledge (PRK) about anti-malarial plants showed Alstonia scholaris as the most commonly known antimalarial species (53%) within this region. Preference ranking (PR) unveiled eight species to be very effective against malarial parasite, which includes Allium sativum, Artemisia indica, Azadirachta indica, Carica papaya, Clerodendrum glandulosum, Ocimum tenuiflorum, Oroxylum indicum, Piper longum and Piper nigrum . All medicine preparations are made using water as the medium and are orally administered in the form of crude extract, powder, juice and decoction. Overall analysis suggested Ajuga integrifolia, Achyranthes aspera, Alstonia scholaris, Artemisia indica, Oroxylum indicum and Ricinus communis to be used for the development of novel, economical, effective and ecofriendly herbal formulations for healthcare management.


Introduction
Malaria is the most prevalent disease that kills more than one million people every year, with as many as 300-500 million people being infected. It is a parasitic disease caused by Plasmodium falciparum and Plasmodium vivax (Paul et al., 2013). According to the world malaria report, approximately 219 million malaria cases are reported each year (WHO, 2012). In spite of several control measures, there has been very scarce improvement in the control of the disease, which leads to both economic and human fatalities (Shankar et al., 2012). It is one of the major devastating problems in North-East India and this region was also labeled as 'malaria zone' by the Center of Excellence in Disaster Management and Humanitarian Assistance (COEDMHA) and Pacific Disaster Management Information Network (PDMIN) survey team within their report during 2005. Moreover, World Health Organization (WHO) classifies this region as a highly endemic area for malaria (Korenromp, 2004).
Since immemorial times, the use and knowledge of herbal medicines was a treasured possession and prominent culture in rural India. This treasured medico-lore is then passed down over many generations chiefly by oral transmission (Katuura et al., 2007). Many tribal communities worldwide use herbs to monitor different ailments, many of which are reported to be exceptionally effective and very promising (Shankar et al., 2012). North East India represents an extremely unique ecosystem treasured with medicinal plant wealth and rich tribal assortment related with folk knowledge, including traditional medicinal practices.
A huge number of plant species has been reported to be used in ethno-phytotherapy treatment of malaria worldwide. The North Eastern region of India alone uses at least 68 plants, belonging to 33 families, to treat malaria (Shankar et al., 2012). The success of the quinine as an antimalarial drug, and the synthesis of artemisinin, the most potent antimalarial drug from plant sources, has encouraged the study of plants as antimalarial agents (Saxena et al., 2003). Although several ethno-medicinal survey of North Eastern India has been done by different researchers, the utility of thoroughgoing traditional phytotherapy by ethnic communities is still unexplored (Chakraborty et al., 2012).
The present study was conducted to accumulate the knowledge on traditional uses of therapeutic plants for the treatment of malaria as fulfilled by the ethnic communities inhabiting Jonai, sub-division of Assam in North East India.

Study area
The extensive field survey was carried out in Jonai, an Eastern subdivision of Dhemaji district, Assam, located at 27º83'N Latitude to 95º22'E Longitude (Fig. 1). The subdivision covers a total geographical area of 1,112 km 2 ; it is surrounded by Sipiya River and Sadiya subdivision of Tinsukia district at the East, Simen River to the West, the state of Arunachal Pradesh to the North and the mighty Brahmaputra River to the South. Jonai is inhabited mostly by the Mishing community along with Nepalese and Assamese.

Ethnobotanical data collection
Field studies were conducted following Martin (1995) ethnobotanical techniques of data and voucher specimen collection. Ethno-medicinal data has been collected through Participatory Rural Appraisal (PRA), based on personal interaction with the indigenous population and practical observation in the field survey (Chambers, 1994). A total of 80 informants, mostly traditional herbalist and village elders, were approached based on their knowledge, skills and practices in folk medicinal plant application. Semi-structured questionnaires were designed for obtaining objective information, mainly focusing on information regarding the uses of plants to treat malaria and other ailments of human beings, local names of the plants, growth forms, parts used, modes of preparation and administration of the herbal remedies.
The specimens were identified according to "The Plant List" and voucher specimens were deposited in the unit of Plant Systematic and Ethnobotany Laboratory, Rajiv Gandhi University, Rono Hills, Arunachal Pradesh.

Data analysis
The following quantitative and qualitative ethnobotanical methods were used for data analysis. Fidelity level (FL) was calculated to know the percentage of informants claiming the use of a plant species for the same major purpose. It was calculated for reporting ailments as: The Np is the total number of informants that are claiming to use a plant species to treat malaria and N is the number of informants that use the plants as a medicine to treat any disease (Alexiades, 1996).
The percentage of respondents having knowledge (PRK) regarding the use of a species (frequency of citation) in the treatment of malaria was estimated using the formula: The Np is the total number of informants that are claiming to use a plant species to treat malaria and Nt is the total number of individuals interviewed (Yaniv et al., 1987).
Preference ranking (PR) method was used to rank plants according to their effectiveness within malaria treatment (Martin, 1995). The rank is given an integer (1, 2 or 3), with the most effective plants assigned a value of 3.

Documentation of indigenous ethno-medicinal knowledge
The study revealed 16 plant species belonging to 13 taxonomic families which were commonly used by most of the tribal communities and traditional healers against malaria. The most prominent families were Lamiaceae and Piperaceae with 2 species each, while the other families, with single species, were Amarnanthaceae, Amiaceae, Amaryllidaceae, Apocynaceae, Acanthaceae, Asteraceae, Meliaceae, Caricaceae, Bignoniaceae, Euphorbiaceae, Poaceae and Combretaceae. Most of the plants used for malaria treatment are collected directly from wild, while few of them were also reported to be cultivated.
The documented antimalarial plant species can be categorized into five different groups, based on their conservation status: cultivated and abundant (CA), cultivated and frequent (CF), wild and abundant (WA), wild and frequent (WF), wild and rare (WR) (Fig. 2). It can be concluded in this regard that out of the 16 species, 15 are either abundantly or frequently, found near forests or even cultivated in home gardens, while Piper longum was recorded as wild and rare in terms of its accessibility.
On behalf of each plant species, the authors have provided the herbarium voucher number, botanical name, family, vernacular name, life form, plant part used, method of preparation and mode of administration in Table 1.

Method of preparation, mode of administration and prescription of dosage
Herbal formulation of antimalarial plants varies from plant to plant (Table 1). The preparation and utilization of plant parts were grouped into four categories. Most commonly used method of preparation was decoction (52.94%) followed by juice (23.53%), powder (17.65%) and raw (5.88%) (Fig. 5). The decoction was obtained by boiling the plant parts (evenly chopped or grounded parts) in water until the volume of the water reduced to the required amount. The paste was prepared by grinding the fresh or dried plant parts with water as solvent. The powder was generally prepared by the grinding of shade dried plant or raw plant parts.
Some of the herbal preparations were recorded to be supplemented with honey and sugar. According to the local 29 Flower and bark (approx. 10 g) are dissolved in 100 ml of water and decoction is consumed thrice a day. informants, the prime purpose of these supplements was to counteract the bitterness and make the overall preparation more palatable as well as for improving the acceptability. All the preparations were orally administered and prescribed for once a day, twice a day or thrice a day, depending on the proficiency of the prepared dosage (Table 1). These plants were used in most of the household owing to the availability and easy collection from wild. Herbal self-medication practices were always the first choice of treatment among the locality, unless the patients grab hold of severe fever. The native healers opined that those herbal drugs prescribed were devoid of any side effects. There was a serious lack of any information regarding treatment standardization or the procedure. Thus, the quality could vary greatly among the prescriptions.

Investigation of qualitative and quantitative ethnopharmacological parameters
Following quantitative and qualitative ethnobotanical methods to determine culturally and ethnomedically important species of this region, fidelity level (FL) of plants has been analyzed based on the number of informants (Table 2). FL value of Clerodendrum glandulosum was reported to be the least, with only 9 informants out of total 80 using it for malaria treatment (11.25%). Even so, the value was more than 10%, therefore all the species were considered for the final comparison. The analysis revealed highest FL value for Ajuga integrifolia (100%) followed by Ricinus communis (94%), Alstonia scholaris (88%), Oroxylum indicum (86%) and Achyranthes aspera (82%). The maximum fidelity level indicated 100% for Ajuga integrifolia, thus the species 30   represents a common choice among all interviewed informants for treating malaria and this could be a clue of the healing potential of the species (Ayyanar and Ignacimuthu, 2011). The percentage of respondents who have knowledge (PRK) about anti-malarial plants unveiled A. scholaris (53%) as the most commonly known antimalarial plant within the study region, while some other commonly known plants were Achyranthes aspera (40%), Azadirachta indiaca (39%), Ricinus communis (38%) and Allium sativum (36%) ( Table 2).

Discussion
Dependency on these plants was primarily due to their safety, effectiveness, cultural preferences, affordability and their abundance. It is imperatively vital that the entire ethnoflora of this region to be documented, as this information could assist in identifying of conservation strategies for target species, followed by supporting the health and economy of the entire community (Asase et al., 2005). The therapeutic activity of medicinal plants has made an outstanding contribution, but then the traditional knowledge on medicinal plants and their utilization are prone to disappear because of insufficient written records and rapid modernization. However, commencement of ethnobotanical surveys and compilation of information regarding medicinal plants within a systemic manner can pave new thresholds in research and developmental areas.
It was observed that the contribution of herbaceous species in the context of antimalarial effect was at maximum, while roots were the most frequently used plant parts for the preparation of herbal drug against malaria. Similar findings were also reported by Paul et al. (2013) among Bodo people of Manas Biosphere reserve, Assam; Ibrahima et al. (2012) while studying Nigerian Medicinal Plants; Katuura et al. (2007) while studying traditional antimalarial plants of Mbarara District, Western Uganda; Madureira et al. (2002) in S. Tomé and Principe islands; Asase et al. (2005) among some Ghanaian anti-malarial plants and Bora et al. (2007) in North East India. On the other hand, many researchers observed leaves as the prime ethnomedicinal ingredient against many ailments (Mahishi et al., 2005;Srithi et al., 2009;Giday et al., 2010;Ayyanar and Ignacimuthu, 2011). The reason for their extensive utilization is that leaves can be easily collected compared with the underground parts, flowers or fruits etc. (Giday et al., 2009). Similar state of plant uses was also reported by Asase et al. (2005) in Upper West Region of Ghana. Yet, insufficient data or written records on the clinical utility of the traditional drugs in this region are some of the major hurdles.
Owing to the crucial role played by plant derived compounds within drug discovery, isolation of new bioactive compounds, based on the knowledge of the traditional use of medicinal plants, would be a very promising approach in the near future (Tushar et al., 2010). However, a suitable approach is needed to use these agents as templates for scheming new derivatives with enhanced properties (Saxena et al., 2003). There is a high possibility that therapeutically active antimalarial compounds can be isolated from these species, which can play a crucial role in the advancement of improved antimalarial drugs. Nonetheless, further profound analysis and controlled clinical trials are essential before these traditional remedies can be recommended on a large scale.

Conclusions
The current work was a preliminary effort to quantify the information on antimalarial plants among the Mishing indigenous tribal communities of Jonai, which revealed the competency of traditional medicines in treatment of malaria. The study also provides better option for the selection of widely used medicinal plants, for searching bioactive compounds. An accurate knowledge on the plants' medicinal properties is held by few individuals, including traditional healers. Thus, there is an urgent need for detailed investigation of the knowledge held by tribal communities before they cease to exist. The efficacy and safety of all the reported ethnomedicinal plants needs to be evaluated further, using phytochemical and pharmacological methods. Plants with high fidelity level and use report should be given priority to carry out bioassay and toxicity studies. From the current study, it might be suggested that Ajuga integrifolia, Achyranthes aspera, Alstonia scholaris, Artemisia indica, Oroxylum indicum and Ricinus communis are promising species that should be taken into account for further pharmacological studies. The results indicated that this species may be used for the development of novel, economical, effective and ecofriendly herbal formulations for healthcare management.