Ethnobotanical database development and screening of medicinal plants in villages under the Jongilanga Traditional Council, Mpumalanga

Abstract

Ethnopharmacological relevance: Medicinal plants still play an integral part in the livelihood of people in the rural areas. The aim of this study was to document information about the medicinal plants used by Shangaan people in villages under Jongilanga Tribal Council, Ehlanzeni district, Mpumalanga. This is the first documentation of medicinal plant uses in the study area, and it provides significant pharmaceutical information. Methods: An ethnobotanical survey of medicinal plants was conducted using a semi-structured questionnaire with 15 traditional healers as informants; one of them also served as a field guide during data collection. The results were analysed by using various quantitative indices such as information consensus factor, user report and conservation status. Biological assays (antimicrobial assay for Prevotella intermedia and Candida albicans, antioxidant assay was tested using 1.1-dipheny-2-picrylhydrazyl free radical scavenging assay and cytotoxicity assay was determined using the XTT method) of the medicinal plants were analysed. Results: The study reported 207 medicinal plant species belonging to 54 families. The Fabaceae family was the most represented family of all the medicinal plants recorded in the study. Roots were the most frequently used plant part, accounting for 56 % of the parts reported, while decoction is the most common method of preparation to treat various ailments. The most treated ailment category is skelto-muscular pain and swelling and urenogenital disorders, which account for 20% and 19% of plants collected, respectively. The medicinal plant use value ranged from 0.06 to 0.27. From the 207 collected medicinal plant species, ethanol extracts of 90 plants were prepared and tested for their antimicrobial properties. Eighteen plant extracts showed good activity compared to the positive control Chlorhexidine. The most significant antimicrobial activity was shown by Combretum collinum and Terminalia sericea with MIC and MMC values ranging between 0.39mg/ml and 3.13mg/ml. All 18 extracts that showed antimicrobial activity were also tested for antioxidant and cytotoxicity activities. The best antioxidant activity was shown by Combretum collinum, Sphedamnocarpus pruriens, Rhoicissus tridentata and Kalanchoe thyrsiflora respectively, with IC50 values ranging from 1.653μg/ml to 1.81μg/ml, compared to the positive control vitamin C, which is 1.62μg/ml. Six plant extracts (Catunaregam sp A, Peltophorum africanum, Phyllanthus reticulatus, Sphedamnocarpus pruriens, Terminalia sericea and Xerophyta retinervis) showed little toxicity or were not toxic at all against human cell line U937. Conclusion: This study revealed that medicinal plants are still widely used in rural areas and this documentation can serve as an ethnopharmacological basis for selecting plants with potential pharmaceutical properties. Future work will focus on identifying and elucidating the active constituents of the active plant extracts.