Inhibition of HIV-1 Protease by Carpobrotus edulis (L.).

Beauty E Omoruyi,Anthony J Afolayan,Graeme Bradley,David I Ighodaro

doi:10.1155/2020/9648056

Abstract

Carpobrotus edulis (L.) is a plant commonly found in the Eastern Cape Province of South Africa and is used for the general treatment of infections relating to the human immunodeficiency virus (HIV). HIV-1 protease plays an important role during HIV replication and maturation to its infectious form, and therefore inhibition of the enzyme is one of the main focus areas in drug development. The inhibitory effect of a water extract of C. edulis leaves against HIV-1 protease activity was determined using the SensoLyte® 520 HIV-1 protease assay fluorimetric kit and employing a HiLyte Fluor™488/QXL™520 fluorescence resonance energy transfer (FRET) peptide. Cytotoxicity of the extract towards HeLa Chang cell lines was determined using an in vitro MTT assay, and the phytochemical profile of the extract was determined with FT-IR and LC-MS. HIV-1 protease activity was inhibited 83.06% (IC50 1.6 mg/ml) (p < 0.0001) by the pepstatin A inhibitor control. Treatment with all C. edulis extract concentrations (16, 1.6, 0.16, and 0.016 mg/ml) inhibited HIV-1 protease activity significantly (p < 0.0001) in a typical dose response manner. With regards to cytotoxicity, the negative controls containing untreated HeLa Chang cells exhibited high formazan formation rates in contrast with the positive controls, containing curcumin, which reduced formazan formation significantly (p < 0.001), exhibiting cytotoxicity towards the cells. There was no significant (p > 0.05) difference in the formazan formation rates between the negative controls and 1, 0.5, 0.125, 0.065, 0.031, and 0.015 mg/ml plant extract, confirming no toxicity of C. edulis extracts towards HeLa Chang cells. Major functional phytochemical compounds identified included alcohols, phenols, alkanes, amines, carboxylic acids, and esters. LC-ESI-TOF/MS analysis revealed the putative identities of main compounds present in the aqueous leaves extract, including some that contribute to its anti-HIV-1 protease action.

Highlights

Carpobrotus edulis (L.) is a plant commonly found in the Eastern Cape Province of South Africa and is used for the general treatment of infections relating to the human immunodeficiency virus (HIV)
Without HIV-1 protease, the polyproteins would not be able to cleave into functional products and would not produce viruses from a host cell nor cause any infection. erefore, due to the fundamental importance of HIV-1 protease for the realization of HIV, it has become the main target in the development of anti-HIV drug therapy [7]
AS-71147, AnaSpec, Fremont, California, USA) provides a convenient assay for high throughput screening of HIV-1 protease inhibitors and continuous quantification of HIV-1 protease activity using a fluorescence resonance energy transfer (FRET) peptide as substrate. e general sequence of the FRET peptide is derived from the native p17/p24 cleavage site on protease gag for HIV-1 protease

Summary

Introduction

Carpobrotus edulis (L.) is a plant commonly found in the Eastern Cape Province of South Africa and is used for the general treatment of infections relating to the human immunodeficiency virus (HIV). E inhibitory effect of a water extract of C. edulis leaves against HIV-1 protease activity was determined using the HIV-1 protease activity was inhibited 83.06% (IC50 1.6 mg/ml) (p < 0.0001) by the pepstatin A inhibitor control.

Results

Conclusion