The potential of Moringa oleifera Lam. to manage HIV-1 infections and its positive pharmaco-synergy with antiretroviral therapies

Despite the wide availability of antiretroviral therapy (ART), a number of people living with HIV still opt to adopt self-care practices or combinational therapies of ART and traditional medicines. Moringa oleifera Lam. (Moringaceae) is one such functional crop rich in protein, calcium, iron and vitamin C, used in the management of several medical and lifestyle conditions, including management of HIV infections. The crop is used either as self-care or combinational therapy to manage these conditions. This study was designed to investigate the utility of Moringa oleifera leaf powder in management of HIV infections and possible interactions with ART (lamivudine, zidovudine, lopinavir and ritonavir) when used as self-care or combinational therapy. Moringa oleifera sourced from different geographical regions as follows: Tanzania, South Africa and Thailand. It was grown under the same conditions in Pretoria, South Africa. Extracts were investigated for their ability to inhibit HIV-1 reverse transcriptase (RT) as single or combinational therapies. The results showed potential of the extracts as strong HIV-1 RT inhibitors with IC₅₀ values ranging from 9 µg/ml to 79 µg/ml for water and 50% methanol extracts. A strong synergistic and additive interaction with ART was observed with Fractional Inhibitory Concentration (FIC) indices below 0.5 and within 0.5 and 1.0 for all extracts. Isobolograms constructed from the IC₅₀ values yielded concave curves characteristic for strong pharmaco-synergism. In most cases, the IC₅₀ values of the ART drugs used in the study decreased by two-fold when combined 1:1 with the extracts of Moringa oleifera. As such, the combinational therapy of Moringa oleifera leaf powder and ART agents represents an attractive prospect for the development of new products for managing HIV-1 infections. Studies to investigate the potentially herb-drug pharmacokinetic and/or pharmacodynamic interactions, toxicity and interactions with antibiotics are underway.

Acknowledgements: Department of Science and Technology- IK-based Tech Innovation-South Africa, National Research Foundation, Pretoria (Grants Nos. 93185, 95662 and 104353), Ms Maria Mothoa and Mr Ndileka Mahlangu are acknowledged for technical support.

Keywords: Combinational therapies, Moringa oleifera, self-care therapy, pharmaco-synergy.