Ethnobotanical survey of medicinal plants used as antiulcer in Gwandu Emirate, Kebbi State, Nigeria

—Background: Peptic ulcer is a common disease of the gastrointestinal tract often self-treated in Nigeria, particularly among the rural population with various forms of herbal remedies. Aim: The ethno-botanical survey conducted was aimed at collecting and identifying medicinal plants used and sold for the treatment of peptic ulcer in Gwandu emirate, Kebbi State, Nigeria. Methods: Administration of structured questionnaire/interview was employed. Herb sellers around some major towns in Gwandu emirate (Birnin Kebbi, Aliero, Kalgo, Bunza and Jega Local Government Areas) were the respondents. Plant species were photographed and identified from December families of antiulcer plant as well as the mode of preparation and administration of these plants were also documented. Results: A total of 27 respondents mentioned 16 medicinal plants used, plant parts, mode of preparation and administration. Medicinal plants with high frequently index include Mangifera indica (37.04%), Moringa oliefera (37.04%), Acacia nilotica (33.30%), and Azadirachta indica (29.63%). The plant parts mostly used in antiulcer herbal preparations are the roots, leaves and seeds and are usually administered orally. Conclusion: This documentation showcases the indigenous knowledge and inventory of traditional antiulcer medicinal plants used locally for ulcer treatment in Gwandu emirate, Kebbi State, Nigeria.


I. INTRODUCTION
The scientific study of relationship that exists between people and plants is known as ethnobotany [1]. It is a preliminary method of research, suitable for gathering information on the use of plants [2]. The study of ethnobotany is very ancient and of great importance as it gives a proper understanding of the interrelations of all several traits and of the whole material and intellectual culture of a people in its entirety. In recent time, it has become an important and crucial area of research and development in resource management, sustainable utilization and conservation of biodiversity, and socioeconomic development. At a global scale, available evidence points toward a direction of increasing relevance of traditional ethnobotanical knowledge as an invaluable, underutilized and under documented knowledge pool [3]. The documentation of medicinal uses of African plants and traditional systems is becoming a pressing need because of the rapid loss of the natural habitats of some of these plants due to anthropogenic activities and also due to an erosion of valuable traditional knowledge [4].
Ulcer is a common gastrointestinal disorder which is seen among many people. It is basically an inflamed break in the skin or the mucus membrane lining the alimentary tract [5]. equilibrium caused by either enhanced aggression or diminisshed mucosal resistance [6]. Ulcer may be caused by Helicobacter pylori infection, long term use of non-steroidal anti-inflammatory agent such as aspirin, ibuprofen etc., stomach cancers or lifestyles such as excess fasting, stress, too much spicy foods and alcohol. There are many types of ulcers; such as mouth ulcer, esophagus ulcer, peptic ulcer, and genital ulcer [5]. Peptic ulcer is the most common and it includes ulcers of digestive tract; in the stomach or the duodenum. The commonly available synthetic antiulcer drugs are associated with many adverse effects including relapse of the disease and are often expensive for the poor populations [7]. Therefore, the search for safe antiulcer from nature is an area of intense research.
Nigeria is blessed with large number medicinal plants and it is patronized by both local masses as well as elite. In Nigeria, many people strongly rely on traditional healing practices therapy particularly the use of medicinal plants for their daily healthcare needs despite the advancement in modern medicine. This is due to the notion or believes that herbal remedies are of natural origin and as such have no toxic effect, are readily available, affordable and less complicated compared to conventional drug treatment. Indigenous knowledge of using medicinal plants for healing human ailments is, however, in danger of gradually becoming extinct, because this knowledge is passed on orally from generation to generation without the aid of a writing system and because many traditional

Study Site
The ethnobotanical study was carried out in major towns of Gwandu emirate. Gwandu emirate is one of the four (4) emirates that make up Kebbi State in north-western Nigeria. It is comprised of ten (10) Local Government Areas (Aliero, Jega, Bunza, Kalgo, Koko, Maiyama, Suru, Gwandu, Birnin-Kebbi and Bagudo). The emirate is a sub group of Hausa speaking people and Islam is the predominant religion. The occupations of the people is majorly farming and trading. It has 1,400 mm per annum rainfall.

Collection of Ethnobotanical Information
Data were collected from December, 2017 to February, 2018. Herb sellers in market places, motor parks and popular bus stops of the major towns of Gwandu emirate were individually interviewed. Use of structured questionnaire and oral interview were adopted to gather the ethno-medicinal data. Questionnaire was administered directly to those who could read and write, while others were filled after being interview orally using an interpreter. Information collected included knowledge on the use of the medicinal plant species, the local names of the plant species, parts of plant used, dosage, methods of herbal preparation, mode of administration, duration of treatment and other traditional uses. A total of 27 herb sellers were interviewed while field surveys were done on farm lands and forest reserves to identify the plants.

Plant Identification
On field, plant identification was carried out using some texts useful for plant identification. Samples and Photographs of the surveyed plants were further identified at the Herbarium of Kebbi State University of Science and Technology, Aliero, Kebbi State, Nigeria by Professor Dhramendra Singh.

III. DATA ANALYSIS
Information gathered from the structured questionnaires was tabulated and analyzed using descriptive statistics with the aid of Microsoft excel computer software package. The frequency index for each plant was calculated using the following formula; Frequency index = n/N x 100 Where 'n' is total number of respondent who listed a particular plant species and 'N' is total number of respondents [9].

Plant information and taxonomic diversity
The information gathered from all respondents showed that about 16 plant species are used in Gwandu emirate for the treatment of peptic ulcer. These plants are from 15 different families. Botanical names, local names, common names, number of citation and frequency index are presented in Table  1. Frequently index of commonly mentioned plants are Mangifera indica (37.04%), Moringa oliefera (37.04%), Acacia nilotica (33.30%), and Azadirachta indica (29.63%). The result also showed that most (92.6%) of the medicinal plants mentioned by the respondents have been duly validated scientifically from literature search. This implies that despite the encroaching of the desert, Gwandu emirate is endowed with these afore mentioned plants.

Respondent details
The herb sellers reported that they majorly collect plant samples from the wilds around their respective Local Government Area. Medicinal plant parts when collected, may be used fresh but preferably used when dried. All respondents affirmed that the medicinal plants were efficacious and had no side effect.

Herbal preparation and administration
The methods of preparation as well as administration of the medicinal plants used in Gwandu emirate for the treatments of peptic ulcer is presented in Table 2. It was observed that methods of preparation were either by decoction or maceration and is taken daily until one feels relieved of ulcer symptoms. The plant parts mostly used in antiulcer herbal preparations are the roots, leaves, seeds and stem bark. (Figure 1).
The etiology of peptic ulcer is unknown in most of the cases, yet it is generally accepted that it results from an imbalance between aggressive factors and the maintenance of mucosal integrity through the endogenous defense mechanisms [34]. To regain the balance, different therapeutic agents are used to inhibit the gastric acid secretion or to boost the mucosal defense mechanisms by increasing mucosal production, stabilizing the surface epithelial cells or interfering with the prostaglandin synthesis. The causes of gastric ulcer are believed to be due to stress induced increase in gastric hydrochloric acid secretion and/or stasis of acid and the volume of secretion is also an important factor in the formation of ulcer due to exposure of the unprotected lumen of the stomach to the accumulating acid [35].
The goals of treating peptic ulcer disease are to relieve pain, heal the ulcer and prevent ulcer recurrence. Currently there is no cost-effective treatment that meets all these goals. Hence, efforts are on to find a suitable treatment from natural product sources. In recent years, there has been growing interest in alternative therapies especially from plant sources due to their perceived lower side effects, ease of accessibility and affordability [36]. For instance, Onyeka et al. [37] reported that methanolic extract of E. hirta combined with honey protect the gastric mucosa against damage by HCl and also has ulcer healing effect. Similarly, hydromethanolic crude extract and solvent fractions of R. nepalensis root and Ficus thonningii stem bark showed promising anti-ulcer activity [38,39]. In another study, plants belonging to the Leguminosae family were reported to inhibit ulcer [40]. Gastroprotective effects of β-sitosterol and β-sitosterol-3-o-β-glucopyranoside from bridelia ferruginea stem bark has also been reported [41]. Previous studies in our Laboratory demonstrated the antiulcer of Piliostigma thonningii Leaf and Citrullus Lanatus seed while the studies is in progress for the antiulcer activity of Ficus plathyphylla leaf [42,43]. Eremomastax speciosa leaf protected rats against chemical-induced gastric ulcer through anti-cholinergic and antihistaminic mechanisms [44]. Abubakar et al. reported the gastroprotective effects of Hannoa klaineana methanol leaves extract in ethanol and indomethacin-induced ulcers [45]. On the other hand, Sida acuta Leaf Extracts   [46]. Also, research has shown the ameliorative roles of Spondias mombin and Ficus exasperata leaves in indomethacin-induced gastric ulceration in rats [47].
Plants are some of the most attractive sources of new drugs, and some have been shown to have promise for the treatment of gastro-duodenal ulcer with minimum side effects [49]. Plants with ethnomedicinal uses in peptic ulcer management thus need to be identified for potential sources of antiulcer lead compounds. Various plants have been used as folk medicine by the people of rural areas,which show significant effect against peptic ulcer. Hence, this article documents some of the plants reported to possess antiulcer and ulcer healing properties within Gwandu Emirate of Kebbi State, Nigeria. Preliminary phytochemical screening of some of these medicinal plants flavonoids and tannins which are the active principles of antiulcer activity [50].
The limitation of the present search for herbal alternative ulcer treatment in this study, was the non-disclosure of the source, ingredients that make up the herbal remedy and mode of preparation by the herb sellers. Most herbal sellers are hesitant when contacted because they feel that divulging these information (family secrets passed from one generation to another) would affect their daily source of income and there are no economic benefits gained when cooperating with researchers. As evident from the number of respondents, just a few amongst many herb sellers contacted were willing and responded.