title: In vitro anti-HIV and antioxidant activity of Hoodia gordonii (Apocynaceae), a commercial plant product.
abstract: BACKGROUND
  Hoodia gordonii products are widely commercialized for anti-obesity purposes; however, minimal research is available on the other health properties demonstrated by this popular herbal plant.
  
  
  METHODS
  H. gordonii crude extracts (ethanol and ethyl acetate) were assayed for in vitro anti-HIV-1 protease (PR), reverse transcriptase (RT) and integrase activity. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) and reducing power assays were used for the antioxidant analysis. In addition, qualitative and quantitative phytochemical analyses of the extracts were determined using standard methods.
  
  
  RESULTS
  H. gordonii extract demonstrated good inhibition against HIV RT with IC50values of 73.55 ± 0.04 and 69.81 ± 9.45 μg/mL for ethanol and ethyl acetate extracts, respectively. Both extracts also demonstrated inhibitory activity against HIV PR with IC50values of 97.29 ± 0.01 and 63.76 ± 9.01 μg/mL for ethanol and ethyl acetate extracts. In addition, H. gordonii also showed good antioxidant activity with IC50values of 124.6 ± 11.3 and 126.2 ± 3.15 μg/mL obtained for ethanol and ethyl acetate extracts, respectively. The reducing power of H. gordonii extracts increased as the concentration increased which confirmed the presence of antioxidants (reductants) in the extracts. Phytochemical screening of H. gordonii revealed the presence of phenolics, alkaloids, terpenes, steroids, cardiac glycosides and tannins in the ethanolic extract, while the ethyl acetate extract only showed the presence of phenolics, cardiac glycosides and steroids. The total phenolic content was 420 ± 0.17 and 319.9 ± 0.2 mg GAE/g for the ethanol and ethyl acetate extracts, respectively. The ethanol extract, which revealed the presence of tannins, had a tannin content of 330 ± 0.2 mg TAE/g extract.
  
  
  CONCLUSIONS
  This data suggests that H. gordonii has good in vitro inhibition against selected HIV-1 enzymes as well as antioxidant properties, suggesting new potential uses for this commercial plant.
authors: Department of Chemistry and Biochemistry, Faculty of Science, University of Namibia, P/Bag 13301, Windhoek, Namibia. pkapewangolo@unam.na.
authors: Petrina
authors: P
authors: Kapewangolo
authors: School of Pharmacy, University of Namibia, P/Bag 13301, Windhoek, Namibia.
authors: Michael
authors: M
authors: Knott
authors: Department of Chemistry and Biochemistry, Faculty of Science, University of Namibia, P/Bag 13301, Windhoek, Namibia.
authors: Regina E K
authors: RE
authors: Shithigona
authors: Department of Chemistry and Biochemistry, Faculty of Science, University of Namibia, P/Bag 13301, Windhoek, Namibia.
authors: Sylvia L
authors: SL
authors: Uusiku
authors: Department of Chemistry and Biochemistry, Faculty of Science, University of Namibia, P/Bag 13301, Windhoek, Namibia.
authors: Martha
authors: M
authors: Kandawa-Schulz
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D001713:Biphenyl Compounds; D016333:HIV Protease / Q000187:drug effects; D054303:HIV Reverse Transcriptase / Q000187:drug effects; D000068798:Hoodia / Q000737:chemistry*; D010636:Phenols; D010851:Picrates; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018894:Reverse Transcriptase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D013634:Tannins
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D010636:Phenols; D010851:Picrates; D010936:Plant Extracts; D018894:Reverse Transcriptase Inhibitors; D013634:Tannins; C004931:1,1-diphenyl-2-picrylhydrazyl; D054303:HIV Reverse Transcriptase; D016333:HIV Protease
keywords: Antioxidant activity; HIV PR inhibitor; HIV RT inhibitor; Hoodia gordonii; Phytochemicals