Evaluation of 43 species of Congolese medicinal plants used traditionally for the treatment of schistosomiasis leading to the isolation of an anti-schistosomal phaeophytin from Pseudolachnostylis maprouneifolia Pax.

ETHNOPHARMACOLOGICAL RELEVANCE: Schistosomiasis (bilharzia) is an important, prevalent and neglected tropical disease for which new treatments are urgently required. In the DR Congo and other sub- and tropical countries, traditional medicines are widely used for the control of schistosomiasis. AIM OF STUDY: To evaluate 43 Congolese plant species used traditionally for the treatment of urogenital schistosomiasis against Schistosoma mansoni. MATERIALS AND METHODS: Methanolic extracts were screened against S. mansoni newly transformed schistosomula (NTS). Three of the most active extracts were evaluated for acute oral toxicity in guinea pigs and activity guided fractionation of the least toxic was carried out using S. mansoni NTS and adult stages. An isolated compound was identified by means of spectroscopic techniques. RESULTS: Thirty-nine of 62 extracts killed S. mansoni NTS at 100 µg/mL and 7 extracts were active at ≥ 90% at 25 µg/mL; 3 extracts were selected for acute oral toxicity evaluation; the least toxic of these, Pseudolachnostylis maprouneifolia leaf was then subjected to activity-guided fractionation. 173-ethoxyphaeophorbide a (1) was isolated as an active compound with 56% activity against NTS at 50 µg/mL and 22.5% activity against adult S. mansoni at 100 µg/mL but these activities are significantly less than those of the parent fractions suggesting that other active compounds are also present and/or that synergistic interactions are taking place. CONCLUSION: This study has identified 39 plant extracts with activity against S. mansoni NTS lending support to their traditional use in the treatment of schistosomiasis for which new treatments are urgently needed. P. maprouneifolia leaf extract was found to have potent anti-schistosomal activity and low in vivo oral toxicity in guinea pigs; activity-guided fractionation resulted in the isolation of an active compound, 173-ethoxyphaeophorbide a. Phaeophorbides may merit exploration as potential anti-schistosomal agents and further work on plant species shown to have potent activity against S. mansoni NTS in this study would be worthwhile.

Ethnobotanical survey of herbs used in the management of diabetes mellitus in Southern Katanga Area/DR Congo.

INTRODUCTION: Diabetes is becoming a public health burden for sub-Saharan countries due to its prevalence which is growing rapidly. Traditional medicine is more and more used to treat diabetes in RD Congo as well as in other African countries. This study was undertaken in order to list plants used in the management of diabetes by traditional healers in four agglomerations of southern area of Katanga in the Democratic Republic of Congo. METHODS: Forty-nine traditional healers were randomly met and interviewed about diabetes treatment in traditional medicine. The survey concerned the plant identification, their part used, method of preparation and the route of administration. The inquest concerned also traditional medicine users. RESULTS: Ninety-five plants from 47 families were indicated as antidiabetic. Fabaceae (24.2%), Euphorbiaceae (7.4%), Apocynaceae and Strychnaceae (4.2 each) are the more representative families. This inventory showed that the root is the most used part of the cited plants, the decoction with water as the main preparation method and the oral administration as the principal way to give antidiabetic traditional formulations. CONCLUSION: In Lubumbashi region, many plant species are used to treat diabetes either through traditional praticians or by anyone from well-known ancestral knowledge.

Hypoglycemic and Antihyperglycemic Activities of Nine Medicinal Herbs Used as Antidiabetic in the Region of Lubumbashi (DR Congo).

The aim of this study was to assess the hypoglycemic and antihyperglycemic activities of nine plants used as antidiabetic treatments in Lubumbashi and its surroundings. Those are Albizia adianthifolia, Azanza garckeana, Cassia occidentalis, Cassia sieberiana, Erythrina abyssinica, Gladiolus klattianus, Rauvolfia caffra, Strychnos spinosa, and Vitex madiensis. Aqueous extracts, obtained by decoction and maceration, were administered (500 mg/kg) per os to guinea pigs (Cavia porcellus), both in glucose baseline conditions and in oral glucose tolerance test (OGTT) conditions (glucose, 2 g/kg; follow-up over 210 min). For OGTT experiments, area under the curve of blood glucose levels, maximum glucose concentration (Cmax), and time to reach Cmax (Tmax) were used to compare test groups with the control conditions (glucose group). In hypoglycemic tests, only three species induced significant (p < 0.001) lowering of normal glycemia: A. adianthifolia (33% reduction), C. occidentalis (32%), and V. madiensis (43%); in the same conditions, the positive control glibenclamide (6 mg/kg) induced a blood glucose lowering of 55%. In OGTT conditions, all tested herbs were active, with the highest inhibition of glycemia increases for V. madiensis (62%) and A. adianthifolia (57%), compared with the hyperglycemic inhibition rate of glibenclamide (50%). Oral glucose tolerance test conditions appear as essential to detect the extracts most interesting for clinical use. These data support the use of studied plants for diabetes treatment in traditional Congolese medicine and indicate a good knowledge of tradipraticians in the field. Copyright © 2017 John Wiley & Sons, Ltd.