ETHNOMEDICINAL PLANTS AND TRADITIONAL KNOWLEDGE AMONG LOCAL PEOPLE OF SHERPUR SADAR AND SREEBARDI UPAZILAS OF SHERPUR DISTRICT, BANGLADESH

An ethnomedicinal investigation was carried out in Sherpur Sadar and Sreebardi upazilas of Sherpur district to record, and document the traditional knowledge alongside with determining the consensus factor, citation frequency and fidelity level among the folklore medicinal practitioners. A total 51 plant species belonging to 49 genera and 38 families were cited with their mode of application for treating different ailments. The most frequently used plant species were represented by herbs (35.94%) followed by trees (33.33%), shrubs (19.61) and climbers (11.76). Leaves were found to be the most utilized part (50%) followed by root (14%), fruit (10%), flower (10%), stem (10%), bark (4%) and seed (2%). The reported ailments were categorized into 14 diseases and the maximum species were employed to treat digestive and gastrointestinal disorders. Leaves of Eclipta alba (L.) Hassk. are used in treatment of cataract without applying in eyes at the initial stage which is the first report for Bangladesh, and this species could be further screened for bioactive compound which can lead to discovery of new and potential drugs. Many species reported in the current study were found to be very rare which need to be conserved to maximize the sustainable uses of these vital resources in the study area.


Introduction
Ethnomedicine refers to traditional medicine practiced by various ethnic communities, and the origin over 50% of all pharmaceutical drugs could be traced back to ethnomedicine (Van Wyk et al., 1997). Many studies have shown that 80% of people in developing countries depend on traditional medicine for their basic primary health care (Faruque and Uddin, 2014;Getu et al., 2015;Hanako and Tsurho, 2016;Rajamurugan et al., 2016). According to WHO, about 80% of the world's population, mostly the rural people of developing countries still primarily rely on traditional medicines (WHO, 2001). The global herbal medicine market size was estimated to be US$ 83 billion in 2019 and is expected to reach US$ 550 billion by 2030 (https://www. insightslice.com/herbal-medicine-market). Currently, this market for medicinal plants and plant products has been rising day by day because of easy availability, effectiveness in chronic diseases, less side effects, and cost effective. The Conference of Parties (COP) gathered in Rio de Janeiro, Brazil in 1992 with the Agenda 21 in order to formulate biodiversity conservation policy that gave emphasis on the documentation and sustainable utilization of traditional knowledge of medicinal plants.
Bangladesh is richly endowed with floral diversity and it has been estimated that more than 5,000 angiosperm species exist in the country (Rahman, 2020). The traditional medicinal practices have long been in use in Bangladesh like Ayurveda, Unani, folk medicine and home remedies, all of which utilize plants to a major extent for treatment (Ghani, 2003). Several studies on ethnobotanical and ethnomedicinal plants were carried out to document the traditional knowledge in different parts and among different ethnic communities in Bangladesh Khan, 1986, 1996;Mia and Huq, 1988;Alam et al., 1996;Uddin M.Z. et al., 2006Uddin M.Z. et al., , 2008Uddin M.Z. et al., , 2012Uddin M.Z. et al., , 2015Uddin M.Z. et al., , 2017Yusuf et al., 2002Yusuf et al., , 2006Uddin S.N. et al., 2004;Uddin S.B. et al., 2011;Sajib and Uddin, 2013;Rahman, 2013;Ferdoushi et al., 2016;Kona and Rahman, 2016;Hossain and Rahman, 2018;Khatun and Rahman, 2018), However, no any ethnobotanical study was carried out in Sherpur Sadar and Sreebardi upazilas under Sherpur district. Therefore, the present study aims at recording, integrating and documenting the traditional knowledge of ethnomedicinal species as well as to determine the informant consensus factor, fidelity level and citation frequency of the plants in Sherpur Sadar and Sreebardi upazilas of Sherpur district.

Study area:
Sherpur Sadar upazila is located at 24°55' to 25°06' N latitudes and 89°53' to 90°07' E longitudes with an area of 356.12 sq. km. and consists of 14 unions. It is bounded by Sreebardi, Jhenaigati and Nalitabari upazilas on the north, Jamalpur Sadar upazila on the south, Nakla upazila on the east, Islampur and Melandaha upazilas on the west. Sreebardi upazila is situated in 25°03' to 25°18' N latitudes and 89°53' to 90°03' E longitudes with an area of 270.34 sq. km. and comprises 10 unions (Fig. 1). The annual average temperature of Sherpur district ranges from 12℃ to 33.3℃, while the annual rainfall is 2174 mm (BBS, 2011). Garo Hill tract also known as Shalbon is present in this district where mainly Garo tribal people live along with local people. Luxuriant growth of seasonal herbs, aquatics and climbers were observed in this area during growing season. Some native tree species were also found in Sherpur Sadar and Sreebardi upazilas. A good number of people possess traditional botanical knowledge and they use such plant species in their primary health care management. The tribal people are mainly dependent on plants for their ailments.

Plant samples and data collection:
Plant specimens were collected from the study areas during field survey from July 2019 to December 2020. The specimens were critically studied and identified by experts and using standard literature and online databases (Ahmed et al., 2008(Ahmed et al., -2009The Plant List 2013;TROPICOS, 2018). The voucher specimens of the medicinal plants were prepared following standard herbarium protocol (Alexiades, 1996) and were deposited at Dhaka University Salar Khan Herbarium (DUSH). Data were collated through semi-structured questionnaires (Alexiades, 1996). Authentic informants were interviewed independently from 54 informants, of which 29 were women and 25 men of 23 to 95 years of ages. The respondents provided plant names, parts used, mode of application and the disease to be treated.

Data analyses: Factor of informant consensus (Fic):
In order to estimate the use diversity of the medicinal plants, Factor of informant consensus (Fic) was calculated using the following formula: Fic = Where, N ur denotes the number of use reports in each category and N taxa refers the number of species in each category (Heinrich et al., 1998). Where, n is the number of people interviewed citing species and N denotes total number of people interviewed (Friedman et al., 1986).

Fidelity level (Fl%):
The fidelity level value is useful for identifying the informants' most preferred species in use for treating certain ailments. Fl value was computed using the following formula: Where Ip is number of informants who indicate use of a species for the same major ailment, Iu is the total number of informants who mentioned the same plant for any other use (Friedman et al., 1986). Medicinal plants that are widely used by the local people for a particular ailment have higher Fl values than those which are less popular.

Results and Discussion
The present study has revealed a total of 51 medicinal plant species belonging to 47 genera and 38 families with 60 formularies for treating different ailments indicating that there is rich diversity of ethnomedicinal plants with different uses in the study areas. For each species, updated nomenclature with authority, family names, local name, parts used, diseases to be treated, mode of treatment and voucher numbers have been provided (Table 1). The study depicts that local people and folk medicinal practitioners of the study areas have a rich traditional knowledge about medicinal plants that has been inherited from generation to generation. Moreover, the present investigation has displayed that people of Sherpur Sadar and Sreebardi upazilas emphasize on using medicinal plants with a discovery of application method. However, the traditional medical practitioners from study area were not much aware in conserving medicinal plants and local people are not also aware to conserve the plants used for sustainable uses.

Factor of informant consensus:
The Factor of informant consensus (Fic) model was used to determine the use diversity of medicinal plants and to identify the ethnopharmacologically important plant species (Heinrich et al., 1998). The Fic values among the investigated species varied from 0.840 to 1 ( Table 2). The highest Fic value 1 was found in the cases of anthelmintic, jaundice, bone fracture and kidney stone, and the cited species for treating the species are Ananas comosus Saccharum officinarum, Cissus quadrangularis and Kalanchoe pinnata, respectively. In case of the second highest Fic value category disease i.e. respiratory diseases, the most cited species is Justicia adhatoda.
The use of Ananas comosus as anthelmintic as revealed from the study was found in the same line with that of Kadir et al. (2012), Saccharum officinarum applied for treating jaundice was found to be consistent with Rahim et al. (2012), Cissus quadrangularis in bone fracture was found similar to Ramachandran et al. (2021), and administration of Kalanchoe pinnata against Kidney stone was found consistent with Islam and Uddin (2022).

Fidelity level:
The current investigation displayed 100% fidelity level (Fl) in Litsea glutinosa, Azadirachta indica, Justicia adhatoda, Zingiber officinale, Terminalia arjuna, Aloe vera, Aegle marmelos, Allium sativum, Tinospora crispa and Clerodendrum viscosum against dysentery, body pain, phlegm-catarrh, gastrointestinal problems, cardiovascular disease, hypertension and fever, respectively (Table 3). The higher FL value of a species indicates the prevalence of a specific disease in an area and the utilization of plant species by the inhabitants to treat that disease (Srithi et al., 2009;Bibi et al., 2014).

Citation frequency (Cf):
Citation frequency of some selected plant species are shown in the Table 4. Litsea glutinosa showed the highest Cf value (94.11) which indicated that this species is very commonly used in the study areas to treat dysentery followed by Azadirachta indica, Zingiber officinale and Justicia adhatoda. In contrast, the lowest citation frequency was found in Allium sativum.
In the current study, the most commonly cited mode of administration is in the form of juice followed by paste, crushed, decoction, powdered and chewed. Our results were found to be concordant with that of previous study (Uddin et al. 2017). The maximum informants preferred oral consumption of medicines instead of external application. This finding was also supported by several other Faruque et al., 2018;Islam and Uddin, 2022).   The present study has revealed novel information regarding the uses of some species which are not found in previous studies carried out in different parts of Bangladesh (Uddin et al., 2006(Uddin et al., , 2017Sajib and Uddin, 2015;Nahar et al., 2016;Sohel et al., 2016;Yasmin and Rahman, 2017;Khatun and Rahman, 2018). A few of the noteworthy and novel findings include: Eclipta alba is reported for the first time to treat cataract, Moringa oleifera to treat cancer, Ficus hispida to reduce water from foot swelling of pregnant women, Coccinea cordifolia to treat extreme dandruff and Coix lacryma-jobi to treat stomach problems. From the present survey, some threats to the medicinal plant species have come in light including habitat destruction and fragmentation, deforestation, over-exploitation, lack of awareness for conserving the species diversity among local people and plantation of exotic species. According to local people, these species might possess threats to native ecosystem as no birds sit in these trees and no fish can survive in nearby ponds. To protect valuable medicinal plant species in the present study area, a number of protective measures should be undertaken i.e. nurseries should be developed for propagating important and threatened medicinal plants, distribution map with specific longitude and latitude for the important species to be generated, and ex-situ conservation strategies should be applied for conserving the medicinal plants in the study area for their sustainable uses and development. The species with the highest Fic value, fidelity level and citation frequency might be phytochemically screened for searching novel bioactive compounds. The study might unveil a new window for drug discovery in future that will have a significant impact on socio-economic development and health sector of Bangladesh.