In vitro antiplasmodial evaluation of medicinal plants from Zimbabwe

Abstract

In this study the in vitro antiplasmodial activities of extracts from Cussonia spicata (Araliaceae), Artemisia afra, Vernonia colorata, V. natalensis (Asteraceae), Parinari curatellifolia (Chrysobalanaceae), Clutia hirsuta, Flueggea virosa, (Euphorbiaceae), Adenia gummifera (Passifloraceae) and Hymenodictyon floribundum, (Rubiaceae) were evaluated. The lipophilic extracts from the aerial parts of Artemisia afra and Vernonia colorata proved to be the most active against the chloroquine-sensitive strain PoW and against the chloroquine-resistant clone Dd2 of Plasmodium falciparum. Bioassay-guided fractionation of the extract of A. afra yielded seven flavonoids, from which acacetin, genkwanin and 7-methoxyacacetin showed in vitro activity; the IC(50) values ranged from 4.3 microgram/mL to 12.6 microgram/mL. In addition, several sesquiterpene lactones could be obtained from the most active fractions. Whereas eudesmaafraglaucolide proved to be inactive, the guaianolides 1-desoxy-1alpha-peroxy-rupicolin A-8-O-acetate, 1alpha,4alpha-dihydroxybishopsolicepolide and rupicolin A-8-O-acetate revealed in vitro antiplasmodial activity. Evaluation of V. colorata gained four sesquiterpenes 11beta,13-dihydrovernodalin, vernodalol, 11beta,13-dihydrovernolide and 11beta,13,17,18-tetrahydrovernolide, from which the first two constituents exhibited the strongest antiplasmodial activity (IC(50) values: 1.1-4.8 microgram/mL).

In vitro antiplasmodial activity of medicinal plants native to or naturalised in South Africa

“…ex Willd. (Asteraceae) (Kraft et al, 2003) agree with previous reports on their antiplasmodial activity. The activity of Aloe marlothii A. Berger (Asphodelaceae) has been reported on before (IC 50 > 50 g/ml), although it was considerably lower than that observed in this study (Van Zyl and Viljoen, 2002).…”

“…(Gu et al, 1988) and Hypericum calcyinum L. (Decosterd et al, 1991) have shown in vivo and in vitro activity Kirkia wilmsii 3.7 No previous reports of antiplasmodial activity Lippia javanica 3.8 Reported to be a mosquito repellent (Govere et al, 2000), but no previous reports of antiplasmodial activity Ocimum americanum a 4.2 Used as a mosquito repellent (Seyoum et al, 2002) (Alves et al, 1997;Oketch-Rabah et al, 1998;Abosi and Raseroka, 2003;Kraft et al, 2003) …”

“…3.0 Several Vernonia species have shown activity in vitro and in vivo (Alves et al, 1997;Oketch-Rabah et al, 1998;Abosi and Raseroka, 2003;Kraft et al, 2003) Vernonia oligocephala 3.5 Several Vernonia species have shown activity in vitro and in vivo (Alves et al, 1997;Oketch-Rabah et al, 1998;Abosi and Raseroka, 2003;Kraft et al, 2003) a Naturalised in South Africa.…”

“…Croton (Euphorbiaceae) (Prozesky et al, 2001), Acacia (Fabaceae) (El Tahir et al, 1999b), Hypericum (Clusiaceae) (Decosterd et al, 1991;Gu et al, 1988), Triumfetta (Tiliaceae) (Muñoz et al, 2000) and Vernonia (Asteraceae) (Abosi and Raseroka, 2003;Kraft et al, 2003;Oketch-Rabah et al, 1998;Alves et al, 1997)) have previously been shown to have antiplasmodial activity. In addition to identifying further species within these genera that display activity, our findings are substantiated by earlier reported antiplasmodial activity elsewhere in the genera.…”

Acacetin inhibits the proliferation of Hep G2 by blocking cell cycle progression and inducing apoptosis

“…They are strong antioxidants that occur naturally in foods and can inhibit carcinogenesis in rodents [5,6]. Acacetin (5,7-dihydroxy-4 0 -methoxyflavone), a flavonoid compound, has been reported to possess antiperoxidative, anti-inflammatory, and antiplasmodial effects [7][8][9], and to enhance differentiation-inducing activity in HL-60 cells [10]. In addition, acacetin can also inhibit glutathione reductase, cytochrome P450, and topoisomerase I-catalyzed DNA religation [11][12][13].…”