In vitro antimalarial, antitrypanosomal and HIV-1 integrase inhibitory activities of two Cameroonian medicinal plants: Antrocaryon klaineanum (Anacardiaceae) and Diospyros conocarpa (Ebenaceae)

Abstract

Antiplasmodial, antitrypanosomal and anti-HIV-1 activities of crude extracts, fractions and some isolated compounds from two Cameroonian medicinal plants : Antrocaryon klaineanum Pierre (Anacardiaceae) and Diospyros conocarpa Gürke ex K. Schum. (Ebenaceae) were assessed. The phytochemical studies led to the isolation of eight compounds ( 1 – 8 ) from Diospyros conocarpa and six compounds ( 6, 9 – 13 ) from Antrocaryon klaineanum . These compounds were identified as mangiferolic acid ( 1 ), 3β, 22(S)-dihydroxycycloart-24E-en-26-oic acid ( 2 ), lupeol ( 3 ), aridanin ( 4 ), betulin ( 5 ), betulinic acid ( 6 ), bergenin ( 7 ), D-quercitol( 8 ), entilin C( 9 ), entilin A( 10 ), antrocarine A( 11 ), 7R,20(S)-dihydroxy-4,24(28)-ergostadien-3-one( 12 ) and stigmasterol glucoside ( 13 ). The criteria for activity were set as follows: an IC 50 value < 10 μg/mL for crude extracts and < 1 μg/mL for pure compounds. The hexane/ethyl acetate (1:1) fraction of A.klaineanum root bark (AKERF1) and the hexane/ethyl acetate (1:1) fraction of A.klaineanum trunk bark (AKETF1) presented the strongest antiplasmodial activities with IC 50 values of 0.4 and 4.4 μg/mL, respectively. Aridanin ( 4 ) and antrocarine A( 11 ), as well as the crude extract of D.conocarpa roots (EDCR), AKERF1 and AKETF1 showed moderate trypanocidal effects. The crude extract of A.klaineanum root bark (AKER) and AKETF1 exhibited attractive activities on HIV-1 integrase with IC 50 values of 1.96 and 24.04 μg/mL, respectively. The results provide baseline information on the use of A.klaineanum and D.conocarpa extracts , as well as certain components, as sources of new antiplasmodial, antitrypanosomal and anti-HIV drugs.