Tohoku J. Exp. Med., 2009, 217(2)

Peltophorum Africanum, a Traditional South African Medicinal Plant, Contains an Anti HIV-1 Constituent, Betulinic Acid

ANDROS THEO,¹ TRACY MASEBE,² YASUHIRO SUZUKI,¹ HARUHISA KIKUCHI,³ SHOKO WADA,³ CHIKWELU LARRY OBI,⁴ PASCAL OBONG BESSONG,² MOTOKI USUZAWA,^1,5 YOSHITERU OSHIMA³ and TOSHIO HATTORI¹

¹Laboratory of Emerging Infectious Diseases, Internal Medicine, Graduate School of Medicine, Tohoku University, Sendai, Japan
²Department of Microbiology, University of Venda, Thohoyandou, Limpopo Province, South Africa
³Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
⁴Academic and Research Directorate, Walter Sisulu University, Nelson Mandela Drive, Mthatha, Eastern Cape, South Africa
⁵Japan Foundation for AIDS Prevention, Tokyo, Japan

The biodiversity of medicinal plants in South Africa makes them rich sources of leading compounds for the development of novel drugs. Peltophorum africanum (Fabaceae) is a deciduous tree widespread in South Africa. The stem bark has been traditionally employed to treat diarrhoea, dysentery, sore throat, wounds, human immunodeficiency virus/ acquired immune deficiency syndrome (HIV/AIDS), venereal diseases and infertility. To evaluate these ethnobotanical clues and isolate lead compounds, butanol and ethyl acetate extracts of the stem bark were screened for their inhibitory activities against HIV-1 using MAGI CCR5+ cells, which are derived from HeLa cervical cancer cells and express HIV receptor CD4, a chemokine receptor CCR5 and HIV-LTR-β- galactosidase. Bioassay-guided fractionation using silica gel chromatography was also conducted. The ethyl acetate and butanol extracts of the stem bark of Peltophorum africanum showed inhibitory activity against HIV-1, CXCR4 (X4) and CCR5 (R5) tropic viruses. The ethyl acetate and butanol extracts yielded previously reported anti-HIV compounds, (+)-catechin, a flavonoid, and bergenin, a C-galloylglycoside, respectively. Furthermore, we identified betulinic acid from the ethyl acetate fraction for the first time. The fractions, which contained betulinic acid, showed the highest selective index. We therefore describe the presence of betulinic acid, a not well-known anti-HIV compound, in an African medicinal herb, which has been used for therapy, and claim that betulinic acid is the predominant anti-HIV-1 constituent of Peltophorum africanum. These data suggest that betulinic acid and its analogues could be used as potential therapeutics for HIV-1 infection.

keywords —— South Africa; Medicinal plants; HIV-1; Extracts; MAGI CCR5+ cells.

© 2009 Tohoku University Medical Press

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Tohoku J. Exp. Med., 2009, 217, 93-99

Correspondence: Toshio Hattori, M.D., Division of Emerging Infectious Disease, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan.

e-mail: hattori.t@rid.med.tohoku.ac.jp