In vitro anti-HIV and antioxidant activity of Hoodia gordonii (Apocynaceae), a commercial plant product

Petrina Kapewangolo; Michael Knott; Regina E K Shithigona; Sylvia L Uusiku; Martha Kandawa-Schulz

doi:10.1186/s12906-016-1403-7

In vitro anti-HIV and antioxidant activity of Hoodia gordonii (Apocynaceae), a commercial plant product

BMC Complement Altern Med. 2016 Oct 24;16(1):411. doi: 10.1186/s12906-016-1403-7.

Authors

Petrina Kapewangolo¹, Michael Knott², Regina E K Shithigona³, Sylvia L Uusiku³, Martha Kandawa-Schulz³

Affiliations

¹ Department of Chemistry and Biochemistry, Faculty of Science, University of Namibia, P/Bag 13301, Windhoek, Namibia. pkapewangolo@unam.na.
² School of Pharmacy, University of Namibia, P/Bag 13301, Windhoek, Namibia.
³ Department of Chemistry and Biochemistry, Faculty of Science, University of Namibia, P/Bag 13301, Windhoek, Namibia.

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 IC₅₀ values 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 IC₅₀ values 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 IC₅₀ values 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.

Conclusion: 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.

Keywords: Antioxidant activity; HIV PR inhibitor; HIV RT inhibitor; Hoodia gordonii; Phytochemicals.

MeSH terms

Antioxidants / chemistry
Antioxidants / pharmacology*
Biphenyl Compounds
HIV Protease / drug effects
HIV Reverse Transcriptase / drug effects
Hoodia / chemistry*
Phenols
Picrates
Plant Extracts / chemistry
Plant Extracts / pharmacology*
Reverse Transcriptase Inhibitors / chemistry
Reverse Transcriptase Inhibitors / pharmacology*
Tannins

Substances

Antioxidants
Biphenyl Compounds
Phenols
Picrates
Plant Extracts
Reverse Transcriptase Inhibitors
Tannins
1,1-diphenyl-2-picrylhydrazyl
HIV Reverse Transcriptase
HIV Protease