An ethnopharmacology survey concerning the medicinal plants used in Bandjoun village (La'Djo) to cure infectious diseases was carried out in three districts of this village. The survey led to the identification of 79 medicinal plants species listed in 41 families. These plants were cited to be use to treat about 25 infectious diseases among which malaria, diarrhea and intestinal-worms were the most cited. Chromolaena odorata, Voacanga africana, Moringa oleifera, Mammea africana, Euphorbia hirta, Psidium guajava, Allium cepa, Enantia chlorantha, Alstonia boonei and Picralima nitida, were the ten most cited plants. Extractions of parts of these last plants were performed in hydro-ethanol (3:7) solvent and then tested in-vitro against an Escherichia coli isolate. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were assessed by microdilution assay and the time-kill assessment was carried out by measure of log reduction in viable cell count, on a period of 48 hours. MIC and MBC determined were ranged between 1.00 and 32.0 mg/mL. Eighty percent (80%) of plant extracts tested have been bactericidal (MBC/MIC = 1 or 2) after 24 hours of incubation. A significant dose-dependent decreasing (P<0.05) in test organisms population was observed in the time with log reduction in viable cell count was ranged between 0.13 log10cfu/mL and 100% of inhibition. This antimicrobial activity has been attributed to metabolites groups in plant extracts namely, Phenols, flavonoids, tannins, coumarins, terpenoids, anthraquinones, cardiac glycosides, anthocyanides and alkaloids. These results obtained against Escherichia coli give a scientific validation to the traditional medical knowledge of Bandjoun-village populations and confirm some of the plants identified like a source of potentially active compounds against infectious diseases.

Immunomodulatory therapy is now being recognized as an alternative to conventional chemotherapy for a variety of disease conditions, involving the impaired immune response of the host. The goal of this study is to valorize Gouania longipetala (Hemsl.) like potential source of drugs against immune system dysfunction. This medicinal plant is commonly used in the Cameroonian pharmacopeia to cure a lot of diseases including inflammatory diseases. In this work, we evaluated the immunomodulation properties of infused stems extract (GLE) and triterpenes from G. longipetala (Hemsl.), with respect to the phagocytosis. GLE was obtained by infusion of dry bark powder in water and the triterpenes were isolated after fractionation of GLE in solvent systems following by column chromatography. The structure elucidation of isolated compounds was based on analysis of spectroscopic data including 1Dand 2D-NMR. The immunomodulation activity was evaluated by two methods. Firstly, the capacity of GLE and triterpenes to modulate phagocytic activity of polymorphonuclear (PMNs) cells was assessed in vitro against Candida albicans. Secondly, the ability of GLE to modulate reticuloendothelial system was investigated in vivo on wistar rats by carbon clearance test. Two triterpenes were isolated, alphitolic and epigouanic acids. The stimulation percentage of PMNs by plant extracts was ranged between 4.25 and 42.55% with GLE and between 14.89 and 46.80% with alphitolic acid. Epigouanic acid show biphasic activity profile, with stimulation of phagocytic activity of PMNs cells at lower concentrations and suppression effects at higher concentrations. In vivo test showed that GLE liberates the glutathione particles from animal's liver and enhance the phagocytic activity by stimulating the reticuloendothelial system. The phagocytic index obtained was ranged between 0.020 ± 0.004 and 0.074 ± 0.006. The results obtained from this study show that extract from G. longipetala (Hemsl.) modulate phagocytic activity and would be therefore the potential sources of drugs against immunological disorders.

An ethnopharmacological survey concerning medicinal properties of Baillonella toxisperma (Pierre) was carried out by interview with the indigenous population of Dimako village situated in the East region of Cameroon. The result showed that the plant is implicated in the treatment of many infections among which is fungal infections. To confirm the antifungal property of B. toxisperma (Pierre), the barks and leaves of the plant were collected and serial extractions in water, hydro-ethanol mixture (3:7), ethanol, methanol and ethyl acetate were performed in vitro. One part of the hydro-ethanol (3:7) extract was degreased by mixing in water-hexane mixture (1:1). The extracts were then tested in vitro against Candida albicans, Candida parasilopsis, Candida sp. responsible for superficial, deep or systemic mycosis and against Cryptococcus neoformans responsible for sub-acute meningitis in immunodeficient individuals. The susceptibility of yeasts to plant extracts was evaluated using the wells diffusion method and yeasts growth inhibition parameters were evaluated according to the proposed National Committee for Clinical Laboratory Standards (NCCLS) M27-A2 standard guidelines (2002). The minimal inhibitory concentrations (MIC) and minimal fungicidal concentrations (MFC) determined were between 0.93 and 30.0 mg/ml. The extracts were fungicidal on clinical yeasts tested with MFC/MIC ratio of 1 or 2. The hexane phase HT2 from the hydro-ethanol crude extract of the barks gave the best antifungal activity on C. neoformans, with a MIC of 0.93 mg/ml and a MFC of 1.87 mg/ml. This activity was similar to the one obtained with fluconazole. Phytochemical screening revealed the presence of polyphenols, phenols, tannins, flavonoids, steroids, alkaloids, saponins, phlobatannins, triterpenes, anthocyanins, cardiac glycosides, leucoanthocyanins and fats, which are bioactive substances. The results could explain scientific validation to the traditional medical uses of B. toxisperma (Pierre) to treat fungal infections.

The purpose of this study was to evaluate anti-trichophytic effects of Baillonella toxisperma (Pierre) extracts against Trichophyton rubrum and Trichophyton soudanense. The tests were performed by the agar dilution method and the results have showed the effective inhibition of the mycelia growth of theses strains by B. toxisperma (Pierre) extracts. After 7 days of incubation at 28°C, the percentages of mycelia growth inhibition PI (%) by plant extracts and fluconazole were range between 20.81 and 100% on T. soudanense, and between 19.92 and 100% on T. rubrum. Some B. toxisperma (Pierre) extracts were exhibited similar anti-trichophyton activities compared to those obtained with fluconazole which was used like reference antifungal drug (p < 0.05). The best anti-trichophyton activities of B. toxisperma (Pierre) extracts were obtained at 5 mg/ml on T. Rubrum with almond oil and hexane phase of water-hexane partition of hydro-ethanol crude extract of barks bromobentseeni (HBb), and at 10 mg/ml on T. soudanense with (HBb). This anti-trichophyton activity of B. toxisperma (Pierre) extracts was attributed to secondary metabolites. The phytochemical analysis has showed that the plant contain bioactive metabolites groups such as phenols, flavonoids, saponins, coumarin, tanins, anthocyanins, lipids and triterpenes. The metabolic groups have been mentioned in several studies for their antifungal activities. The results from this study provide a scientific validation for the ethnomedicinal uses of B. toxisperma (Pierre) in the treatment of fungal infections.