Ethnobotanical information about plants are usually collected from traditional healers, community leaders, and native people of rural and urban areas.  Nigeria is one of the countries in the world with wide range of snake species found in terrestrial, arboreal and aquatic habitats. This is so because of the presence of sparsely populated areas like food storage facilities, unkempt bushes, holes, crevices, and areas where prey is readily or likely to be available for them (Altimari, 1998; McDiarmid et al., 1999; Schmidt et al., 1957).  This makes snake envenomation a health problem worldwide, especially in many tropical countries like Nigeria and was consequently declared as a neglected tropical disease by the World Health Organization in the year 2009. It has been estimated that global mortality from snake envenomation is up to 100, 000 people per year (Venkata et al., 2015). Snake such as Naija nigricollis, Echis carinatus and Bitis arietans are common in Nigeria and responsible for about 95% snake bite cases (Adzu et al., 2005; Abubakar et al., 2010; Adeiza and Minka, 2013). Poor accessibility and exhorbitant cost of antivenoms have disrupted steady supply to snakebite locations where therapy are seriously needed (Bhavya et al., 2014). Another major challenge is the unavailability of a general antidote for either cure and or prevention of snakebites (Yogendra and Sharada, 2014). Medicinal plants, therefore, still remain the mainstay of treatment for snake bites in most developing countries (David, 2010). Medicinal plants have been used as folk medicine for treatment of snakebites for centuries, and the reliance on medicinal plants is primarily due to their effectiveness, cultural preferences, inexpensive nature, non-toxic nature and dependence on neighboring forests (Andrews et al., 2004; Du and Clemetson, 2002; Gupta and Peshin, 2012). Globally, traditional healers are using herbal medicine to cure and prevent snake envenomation (Gupta and Peshin, 2012; Yogendra and Sharada, 2014). Nigeria has many medicinal plants that are yet to be exploited and some are known traditionally to be used in the prevention and treatment of snake bite (Sule, 1999). However, there is paucity of data and no documentation on these plants. Thus, the need to establish an informational database of these medicinal plants used against snake venoms is long overdue. This will serve as a readily available source of information for pharmacological investigation of potential antivenoms and development of phytomedicines and or lead compounds in drug development process. This study therefore attempted to provide information on medicinal plants used in the management of snakebite by traditional practitioners in three northwestern Nigerian States.

Section 3: Plants and recipes used in the management of snakebites were inquired with questions like types of herbal preparation, arrangement of plant part(s) ingredient, traditional solvent of choice, traditional extraction methods or method of preparation and method of administration were all considered.

Demography/personal information on respondents

A total of fourteen respondents made up of one herb seller (7%) and traditional medical practitioners 13 (93%) were obtained. Majority of the respondents were male, as observed from demographic information of respondents (Table 1).

Professional experience of the respondents

The survey showed that only herbs are used for the cure of disease by the respondents and also inherited the knowledge of herbs from their ancestors (Table 2).

Medicinal plants commonly used in management of snake bite in North Western Nigeria

The survey also showed that a total of 25 medicinal plants   species  were  in  use  by  different  categories  of practitioners. Botanical names, local names, family, plant part(s) and number of citations obtained were presented in Table 3.

Plant forms and parts used in the treatment of snake bite in the survey

Majority of the plant life forms and parts used are trees and root/bark respectively. Other plant forms and their frequencies were reported (Table 4).

Snakebite poisoning is one of the unheeded disease in most of the developing countries. African countries are global diversity center for snakes that could be deadly from different families like Vipers, Krait and Cobras (Swaroop and Grab, 1954). Additionally, people living in tropical countries are at high risk of snakebite because of their engagement in agricultural, pastoral and hunting as means of survival. Most medical treatment for the snakebite is the use of antisera, which is costly and inaccessible by the rural patients (Cannon et al., 2008). Thus, medicinal plants are used as essential sources of medicines for humans especially in developing countries (Pankhurst, 1995; Dery and Otsyina, 2000). In this study, an ethnobotanical survey to provide information on the medicinal plants used in the management of snake bite was conducted. Most of the herbal medicines came from trees,  many  of  which  also  have  other  uses   such   as providing timber and protection of the environment. They have taxonomic classes which enable their classification with respect to their role in economic development (Ekanem and Udoh, 2009). In the study areas, the use of traditional medicine is widely acceptable and on the increase daily especially for snakebite. This was evidenced from the number of plant reported to be used in management of snakebite. So also, some of the plant species reported used were identified as medicinal plants in some other states across Nigeria (Aiyeloja and Bello, 2006; Kayode, 2008). The species variations recorded in this study were comparable to some of those recorded in a study of medicinal plants used in Katsina State in Northwestern Nigeria (Danjuma and Darda’u, 2013) and those of Biu Local Government area of Borno State, Nigeria (Ampitan, 2013). The local people reported these medicinal plants to be  very  useful  in  their  communities and preferred them over orthodox medicines in management of snakebite. Trees were the plants life forms commonly used in the form of leaves, root and bark. This is similar to other studies which reported the use of trees more in traditional medicines, with leaves widely used in most African countries like Nigeria, Uganda, Ethiopia and Mali (Ugbogu and Akinyemi, 2004; Tagola, 2005; Muniappan and Savarimuthu, 2011; Shehu et al., 2017). Some of the medicinal plants were reported to be cited in treating different ailments such as asthma, stomach-ache, headache, diarrhea, whitlow, dysentery, gonorrhea and cough, among others. Ethnobotanical surveys of medicinal plants used in certain localities support tropical conservations of bioresources (Shehu et al., 2017). It has been known to help in passing down information on traditional medicine from generation to generation    through   documentation   of   facts   that   is made available to researchers worldwide (Peter et al., 2018). Documentation also helps reports on herbal information from being lost gradually with every person that dies (Ogbole et al., 2010), which led to slow pace of development of traditional medicine in Nigeria and Africa in general. The rate of depletion of medicinal plant resources is generally high, yet little is known about most of Nigeria’s plant species especially tropical floras (Igoli et al., 2005).  Survey of this nature assists in providing an informational source for the therapeutic potential of medicinal plants, stimulating the urgent need to retard the current trend of decimantion of useful medicinal plants and promote bioconservation.

The traditional practitioners in this study  stated  that  in most cases, snakebites were first treated locally with traditional medicine at home and transferred to the hospital only when there is no improvement or critical condition. It was reported earlier that initial local treatment of diseases is quite common among the African people (Brown, 1973; Isa et al., 2015). This could be part of the reason why there is diverse modes of preparations and routes of administration of these medicinal plants in the area and in most parts of Africa were traditional medicine is fast gaining grounds.  An evidence for use of medicinal plants was reported in this study in which 25 plants were reported useful in snakebites in North-western Nigeria.

The  study  identified  Securinega  virosa  as  the   most popular anti-snake bite followed closely by Senna singuena. S. virosa has been reported to possess several medicinal advantages that were reported pharmacologically. Psychopharmacological potential (Magaji et al., 2014), anti-diabetic properties (Yusuf et al., 2010) and in vitro inhibition of glioblastoma multiforme cell survival (Magaji et al., 2015) of S. virosa were scientifically validated. The use of S. singuena was reported as an alternative or adjuvant therapy for malaria (Hiben et al., 2015). Out of the 25 medicinal plants documented in this survey, only one, Xerompis nilotica has been scientifically validated to possess anti-snake bite (Ushanandini et al., 2009). Some of the common recipes, methods of preparation and administration procedure were also documented.

This study has provided information on the usefulness of medicinal plants in management of snake bite in Zamfara, Kebbi and Sokoto State, Nigeria. An informational data for accessing and documenting traditional knowledge of medicinal plants used in management of snake bite was established. Further work is currently ongoing in the laboratory to validate the folkloric claims of these plants.

The authors have not declared any conflict of interests.

The support of Mr Kabiru Abdullahi of the Department of Pharmacognosy and Drug Development is highly appreciated.