Antiviral and antibacterial effects of 16 plants used in Ivorian traditional medicine

Over 160 million people are chronic carriers of Hepatitis C Virus (HCV), which is a major cause of chronic liver diseases¹. A few efficient antiviral drugs against HCV are currently available, but they are expensive and not easily accessible to people in developing countries². In addition, resistance to these new drugs are already emerging. Therefore new HCV inhibitors are needed. A major symptom of HCV infection is icterus and could correspond to the “yellow malaria” known in African traditional medicines. An ethnobotanical survey and a bibliographic search allowed us to select 16 Ivorian plants, based on their traditional use against “yellow malaria” and other infectious diseases.

For each plant, 20 g of leaf, root or bark powder were macerated in 100 mL of methanol (3 × 24h). The resulting extracts were then screened against 36 strains of bacteria using an agar dilution method with a Steers multipoint inoculator, and against HCV using an immunofluorescence method with Huh-7 cells (extracts at 10 or 25 µg/mL).

Ten extracts were active on at least one strain of bacteria at 0.6 mg/mL or less, with one extract (Anogeissus leocarpus) (Combretaceae) being active on 19 strains. The Momordica charantia (Cucurbitaceae) extract was particularly active on 3 Streptococcus strain, with some MIC as low as 40 µg/mL. Carapa procera (Meliaceae) and Pericopsis laxiflora (Fabaceae) showed very interesting activities against HCV. For these 2 plants, leaf powder (20 g) was successively macerated in 100 mL of dichloromethane, methanol and ethanol-water (50:50) respectively (3 × 24h extraction per solvent). The resulting 6 dried extracts were then dissolved in methanol and screened against HCV. Amongst them, the dichloromethane were not active, the hydro-alcoholic extracts were mildly active (> 50% infected cells), but the methanolic extracts (10 µl/mL) prevented over 80% of Huh-7 cells from being infected. Bio-guided fractionations of several plant extracts are in progress.

Keywords: Ivorian pharmacopeia, ethnobotanical survey, bio-guided fractionation, antibacterial, antiviral, HCV.

References:

[1] Dhingra A., Kapoor S, Alqahtani SA. Recent advances in the treatment of hepatitis C. Discov Med 2014; 18: 203 – 208

[2] Calland N, Dubuisson J, Rouillé Y, Séron K. Hepatitis C virus and natural compounds: a new antiviral approach? Viruses 2012; 10: 2197 – 2217