Ethnomedicinal plants used for malaria treatment in Rukungiri District, Western Uganda

Abstract Background Malaria remains a major global health challenge and a serious cause of morbidity and mortality in sub-Saharan Africa. In Uganda, limited access to medical facilities has perpetuated the reliance of indigenous communities on herbal medicine for the prevention and management of malaria. This study was undertaken to document ethnobotanical knowledge on medicinal plants prescribed for managing malaria in Rukungiri District, a meso-endemic malaria region of Western Uganda. Methods An ethnobotanical survey was carried out between May 2022 and December 2022 in Bwambara Sub-County, Rukungiri District, Western Uganda using semi-structured questionnaire. A total of 125 respondents (81 females and 44 males) were randomly selected and seven (7) key informants were engaged in open interviews. In all cases, awareness of herbalists on malaria, treatment-seeking behaviour and herbal treatment practices were obtained. The ethnobotanical data were analyzed using descriptive statistics, informant consensus factor and preference ranking. Results The study identified 48 medicinal plants belonging to 47 genera and 23 families used in the treatment of malaria and its symptoms in the study area. The most frequently cited species were Vernonia amygdalina, Aloe vera and Azadirachta indica. Leaves (74%) was the most used plant organ, mostly for preparation of decoctions (41.8%) and infusions (23.6%) which are administered orally (89.6%) or used for bathing (10.4%). Conclusions Indigenous knowledge of medicinal plants used as prophylaxis and for treatment of malaria still exist among the local communities of Bwambara Sub-County. However, there is a need to investigate the antimalarial efficacy, phytochemical composition and safety of species (such as Digitaria abyssinica and Berkheya barbata) with high percentage use values to validate their use

Anthocyanin Profile and Antioxidant Activity of Edible Leaves of Dissotis brazzae Cogn (Melastomataceae)

Anthocyanins are colored bioactive phytochemicals in the class of flavonoids with high potential as dietary antioxidants. Demand for anthocyanins in functional food and nutraceutical industries has continued to increase over the past decades. However, sources of anthocyanins for commercial exploitation are currently limited. Tropical Africa and Uganda in particular, harbors many plant species with potential to serve as new sources of anthocyanins. In this study, the anthocyanin profile and antioxidant activity of edible leaves of Dissotis brazzae, a plant of tropical African origin, were investigated. Two known anthocyanins, (1) cyanidin 3-O-β-glucopyranoside (1.28±0.44 mg/g fr. wt.) and (2) cyanidin 3-O-α-rhamnopyranoside (1.89±0.42 mg/g fr. wt.), were isolated from D. brazzae purple leaves by a combination of chromatographic techniques. Their structures were elucidated mainly by homo- and heteronuclear NMR spectroscopy and online HPLC/UV-Vis spectroscopy. The isolated anthocyanins showed appreciable level of antioxidant activity against DPPH, with 1 (IC50=9.2±0.2 μg/ml) showing slightly higher antioxidant potency than 2 (IC50=14.0±0.6 μg/ml). However, quercetin (IC50=4.5±0.4 μg/ml) used as a reference showed a higher antioxidant activity than 1 and 2. The total anthocyanin content of D. brazzae leaves (317 mg/100g) was within the range (80 – 680 mg/100g) of anthocyanins content in most dietary sources. This is the first report of fully characterised anthocyanins from the genus Dissotis, which may be of taxonomic importance. A new dietary source of the rare cyanidin 3-O-α-rhamnopyranoside has been identified