Keywords

1 Introduction

The knowledge of ethnomedicine is very ancient. It shares vast information regarding the traditional uses of plants by the people. The use of plants and plant products in human life is immense and their uses as medicines have been in practice since time immemorial and can be traced from the beginning of human civilization. The people of India are using medicinal plants since the prehistoric period [1]. Medicinal plants have a long-standing history among indigenous communities and are an integral part of treating various diseases, particularly to cure day-to-day ailments and this practice of traditional medicine is based on hundreds of years of belief and observations [2]. The earliest record of medicinal plant use in the Himalayas is found in Rigveda. This work was written between 4500 BC and 1600 BC, is supposed to be the oldest repository of human knowledge and describes 67 plants. After the Rigveda, Ayurveda (the foundation of the science of life and the art of healing of Hindu culture) describes the medicinal importance of 1200 plants. This wealthy inheritance of knowledge and the age-old wisdom of India might well be among the earliest in the world. About 70% of the Indian population dwell in rural areas and many of them reside in the neighbourhood of forest and use various plant parts as food, medicines, and for many other purposes for their daily livelihood [3, 4]. Some of the notable contributions in the state of Assam are medical plants used by the Karbi Anglong of Mikir Hills [5, 6]; medicinal plants from the Tezpur district [7] and plants used to cure jaundice in the Golaghat district documented by Pandey et al. [8]. The herbal remedy of the Nepalese of Assam was also reported by Borthakur et al. [6]. Medicinal plants used by Garo tribes are also studied by Rao [9]. The present study also aims at highlighting the ethnomedicinal uses of plant resources. Like other deadly diseases, respiratory diseases are also a major cause of mortality worldwide. In most of the developing countries like India, it causes a nationwide burden. Pneumonia, asthma, lung cancer, tuberculosis, etc., are some common respiratory diseases that have been causing concern since ancient times. In the present-day scenario, due to so many reasons like air quality, smoking tobacco, etc., the rate of these kinds of patients is on the rise. Children are the most susceptible targets of respiratory illnesses. Pneumonia is reported as the leading killer of young children all over the world, while asthma affects about 14% of children globally each year and is the most common chronic disease among children and adults. Although modern medicines have advanced the quality and lifestyle of humankind in many countries in recent decades yet the cost of health care for respiratory diseases is an increasing burden of all the leading and underdeveloped countries. For example, in the United States, asthma alone costs about $18 billion annually [10]. So, there is an urgent need for information about alternate complementary medicines like traditional ways of curing these diseases using surrounding plants. There are many efficient medicines for these respiratory diseases in the present allopathic medical system. But, in areas where the modern medical system is not easily available, people happily use traditional systems to treat these diseases even today. The knowledge of their ethnomedicine is very ancient, transferred orally for generations and generated mainly through the trial-and-error method. It shares just a part of the vast information regarding traditional uses of common plants by the people. So, the survey of medicinal plants becomes extremely important for researchers because it gives information about a particular plant in a particular area. The northeastern part of India is the huge storehouse of traditional knowledge as the life of numerous tribal communities in this area is almost fully forest dependent. They collect almost everything to survive from the floristic vegetation of their areas. Assam is one of the eight states of Northeast India covered mostly by forest with innumerable forest villages that are yet to avail the benefits of modern developmental facilities [11, 12]. With its boundless forests and hills, Assam is a home of abundant medicinal plants with different individual tribal communities [5, 6]. Lakhimpur and Dhemaji districts of upper Assam are also mostly inhabited by many tribal communities who practise traditional plant-based medicines. However, a few such preliminary works have been done in the area that is quite insufficient against the potentiality of the region [13,14,15,16,17].

2 Methodology

2.1 Study Area

The survey was carried out in Lakhimpur (26°48′ N to 27°53′ N latitudes and 93°42′ E to 94°20′ E longitudes) and Dhemaji (27°05′27″ N to 27°57′16″ latitudes and 94°12′ to 95°41′ longitude) districts of Assam (Fig. 1) during 2018–2020.

Fig. 1
3 maps. On the left, it displays a political map of India. A square box on the map encloses the northeast region along with Bhutan. Top right, a political map of Assam. On the bottom right, a map presents the Lakhimpur and Dhemaji districts.

Map of study sites, Lakhimpur and Dhemaji districts of Assam, India

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The area is located on the northern bank of the river Brahmaputra and the northeastern corner of the Indian state of Assam, with an area of 2227 sq km for Lakhimpur and 3237 sq km for Dhemaji districts. Both districts encounter hot and humid summer, cold and dry winter with high precipitation during monsoon [18, 19]. Inhabitants of the area belong to different tribes and communities including Mishing, Tiwa, Boro, Sonowal-Kachari, Deuri and Adibasi are living in both the districts. While they are having their respective languages, the main communicating language is Assamese. Earlier the entire area was covered under forest and people were living mainly in the forest. Even today, apart from small township areas, most of the people live in such villages and survive well in their traditional ways.

2.2 Data Collection

A random and regular household survey was carried out from August 2018 to March 2020 in different villages of the area selected randomly. A semi-structured questionnaire was prepared for the survey following Jain and Mudgal [20]. Traditional healers, elderly villagers of both sexes, were interviewed for their knowledge about traditional medicinal plants used in treating Pneumonia and asthma.

2.3 Collection and Identification of Plants

Plants are initially identified in their local language (Assamese) and voucher specimens were collected for scientific identification. The specimens were then processed into mounted herbarium sheets [21, 22]. Plants were identified referring to literatures [23,24,25] and compared with the Herbarium of Arunachal University (HAU-Herbarium). Updated names of plants were obtained from websites of the world online organization on plant taxonomy [26, 27]. Specimens were deposited in the HAU-Herbarium for future reference.

Quantitative Evaluation:

For a better understanding of the collected information, (i) relative frequency of citations (RFC) and (ii) fidelity level (FL) were calculated following Umair et al. [28].

  1. (i)

    Relative frequency of citations (RFC): It describes the local significance of each species from a study area. RFC is calculated by the formula

    RFC = FC/N (0 < RFC > 1), where FC is the number of informants citing for a particular species and N is the total number of informants.

  2. (ii)

    Fidelity level (FL): It is the percentage of informants mentioning a plant species for a single disease. FL is calculated as

    FL (%) = (Np/N) × 100, where Np is the number of informants that suggested the use of a plant in a particular disease and N is the number of informants. A high FL value indicates the high use of a particular plant species in treating a particular disease by the healers of that area.

3 Result and Discussion

In the present study, a total of 61 plant species belonging to 35 families were recorded that are used traditionally by local healers and elderly people in treating pneumonia and asthma by interviewing 80 informants. The most dominating families are Lamiaceae and Zingiberaceae with four species each. Young shoots are the most used parts during crude medicine preparation with 22.95% followed by leaves (14.75%), bark (13.11%), fruit, root and whole plant with 9.84% each. Table 1 enumerates all the recorded plants with field number, family, local names, habits, status of all plants, diseases treated, RFC and FL% among 80 informants of the study area, whereas Tables 2 and 3 show the name of the medicinal plants, parts used, mode of preparations (traditional formulations) and nature of administration in managing the diseases.

Table 1 Plants recorded from Lakhimpur and Dhemaji districts of Assam for the treatment of respiratory diseases such as pneumonia and asthma
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Table 2 Traditional remedies for pneumonia
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Table 3 Traditional remedies for asthma
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During the preparation of medicine/formulation, healers mainly used freshly collected plants from the wild or their surroundings. Usually, they do not store prepared medicine, for the next batch preparation, they used to collect all required plants freshly from the wild. Crude preparations are in the form of fresh juice, decoction, paste and tablets. The mode of administration is mainly oral but some practitioners also use the external mode of administration. Healers often recommend a strict diet to the patients during the period of treatment like restrictions to meat, fish, eggs, certain vegetables, etc.

Among the recorded plants, 48 species were found to be used in treating pneumonia (Table 2), while 18 species were used in asthma treatment (Table 3) with some species such as P. nigrum, G. bonduc, C. limon, D. cordata, C. verum, E. cardamomum, M. fragrans and S. aromaticum being used as common additives for both the diseases during the preparation of crude medicines by various healers. A similar ethnomedicinal survey related to respiratory disease was carried out in other parts of India and reported similar plants such as O. tenuiflorum, L. aspera, Z. officinale, A. conyzoides, H. sibthorpioides, C. asiatica, O. diffusa, O. indicum, G. bonduc and P. Guajava [29,30,31,32,33] and for asthma L. aspera, P. nigrum [34] and A. calamus [35]. However, in the present study, the use of Tamarix dioica and Potentilla indica against asthma treatment and the use of Hygrophila phlomoides and Stephania rotunda against pneumonia recorded from the region are new ethnobotanical records.

4 Conclusion

The wild plants in Assam are in use in disease management in households and are still popular. Often new ethnobotanical records also surface through similar field studies, viz. Tamarix dioica and Potentilla indica (anti-asthma); Hygrophila phlomoides and Stephania rotunda (anti-pneumonia). Contrary to the anti-bacterial properties reported for Thunbergia coccinea [36] none of the informants cited the species for pneumonia treatment from the region. Therefore, for understanding the actual efficacy and for the scientific exploitation for the benefit of mankind phytochemical analysis and biological validation is recommended for each of these plants. Therefore, the present study will open up possibilities for further pharmacological research.