Diversity, Phytochemical Screening and Ethnobotany of Macrophytes Within Freshwater Streams in the Coastal City of Limbe (Cameroon)

The emergence and spread of diseases continue to be a major public health concern. Despite the successful management of common tropical diseases by conventional medicine, the high cost of drugs and the lack of health facilities in rural areas of most developing countries limit its use and promote over reliance on alternative medicine for the treatment of diseases. Freshwater streams are good sites harboring some of these medicinal plants. There is very little information on the floristic composition of these streams. The main objective of this study was to assess the floristic composition, ethno-botanical uses and to conduct a phytochemical screening of some aquatic macrophytes in Limbe 1 Municipality. Following the floristic survey on three prominent streams, 300 semi-structured questionnaires were purposively administered to inhabitants of Limbe 1 Municipality. A show-and-tell method was used to identify aquatic plants with medicinal value. Qualitative phytochemical analysis of nine selected plants was done using standard procedures. A total of 46 macrophytes from 23 families and 41 genera were identified across these streams; Forty were emergent. Submerged plants were Ceraptoteris thalictroides, Hydrocharis dubia, Anubias bateri, and Persicaria amphibia while Lemna minor and Nymphaea lotus were floating. A high Shannon diversity (2.70, 2.68 and 2.66) was recorded in Moliwe, Bosumbu and Laverie Espoir, respectively. Only 24 aquatic plants identified had medicinal value, with Commelina benghalensis, Costus lucanucianus, Eremomastax speciosa, Acmella caulirhiza and Ageratum conyzoides having the highest use value and had varying quantities of flavonoids, alkaloids, glycosides, saponins, steroids, tannins, cardiac glycosides and terpenes in their methanol extracts. Most cited disease categories treated using these aquatic plants were gynecological, respiratory and dermatological, etc. Further empirical investigations to characterize these bioactive phytochemicals and their biosafety should be carried out. These valuable ecosystems should be protected for their valuable ecosystem services.