Cytotoxicity of Medicinal Plant Species Used by Traditional Healers in Treating People Suffering From HIV/AIDS in Uganda

Abstract

Introduction: Many people living with HIV/AIDS (PLHIV) in Uganda widely use herbal medicines. However, their toxicity and safety have not been investigated. The use of these plants can potentially cause harmful effects to the health of patients. The purpose of this study was to determine the cytotoxicity of some commonly used medicinal plant species used by PLHIV.Methods: The cytotoxicity of the plant extracts was determined with the AlamarBlue cell viability assay using the human glioblastoma cell line U87.CD4.CXCR4. The cells were treated with varying concentrations of extracts of Warburgia ugandensis, Erythrina abyssinica, Cryptolepis sanguinolenta, Albizia coriaria, Psorospermum febrifugium, Gymnosporia senegalensis, Zanthoxylum chalybeum, Securidaca longipendunculata, Vachellia hockii, Gardenia ternifolia, and Bridelia micrantha reconstituted with ethanol and dimethyl sulfoxide (DMSO). Using regression analysis, the half maximal cytotoxic concentration (CC50) of the plant extracts were calculated from exponential curve fits, since they provided the highest coefficient of determination, R2.Results: The ethanol extracts of W. ugandensis (CC50 = 7.6 μg/ml) and A. coriaria (CC50 = 1.5 μg/ml) as well as the DMSO-reconstituted extracts of W. ugandensis (CC50 = 6.4 μg/ml) and A. coriria (CC50 = < 4 μg/ml) were highly cytotoxic. The cytotoxicity of W. ugandensis and A. coriaria compared well with the indigenous traditional knowledge of the toxic effects experienced when the plants were not used correctly. However, the cytotoxicity of most of the plant extracts (15/22) was low to moderate (CC50 = 21–200 μg/ml).Conclusion: Most of the plant species tested in this study had low to moderate cytotoxicity against U87.CD4.CXCR4 cells, except W. ugandensis and A. coriria which were highly cytotoxic.

Medicinal plants used for treatment of malaria by indigenous communities of Tororo District, Eastern Uganda

“…Abruquinone B was cytotoxic towards KB & BC cell lines (IC 50 :13.0 ± 19.8 μg/ml) [ 42 – 44 ] Albizia coriaria Welw. ex Oliver Stem bark Methanol 15.2 (D6); 16.8 (W2) Triterpenoids, lupeol, lupenone Cytotoxic to the human glioblastoma cell line U87 CD4 CXCR4 (CC 50 = 6.4 and 14.9 μg/ml for ethanol and DMSO extracts [ 45 , 46 ] Azadirachta indica A. Juss Leaves Water, methanol 17.9 (D6); 43.7 (W2) Terpenoids, isoprenoids, gedunin, limonoids: khayanthone, meldenin, nimbinin Cytotoxicity LD 50 of 101.26 and 61.43 µg/ml for water and methanol extracts [ 47 – 51 ] Bidens pilosa L Leaves Dichloromethane, water, methanol 8.5, 5, 11, 70 (D10) No reports Hydro and ethanol extracts are not toxic in mice (LD 50 = 12.3 and 6.2 g/kg bw), respectively. Safe in humans [ 52 – 54 ] Carica papaya L Leaves Ethyl acetate 2.96 (D10), 3.98 (DD2), 0.2 uM (carpaine) Carpaine Carpaine has high selectivity (106) and is nontoxic to normal red blood cells and rat skeletal myoblast (L6) cells [ 55 – 57 ] Cissampelos mucronata A.…”

Antiviral activity of Ugandan medicinal plants against human immunodeficiency virus type-1 (HIV-1)

“…The crude ethanol extract E. abyssinica exhibited antiviral activity against HIV-1 with a SI of 11. chalybeum also exhibited antiviral activity against the measles virus (Edmonston strain) 67 Studies on W. ugandensis against the measles virus found the extracts to be highly toxic to the VERO cell lines used. Similarly, the crude extracts of W. ugandensis have been shown to be highly cytotoxic to the U87.CD4.CXCR4 cell used in this study 42,68 .…”

“…Using the laboratory protocol described in Anywar et al 42 and the World Health Organisation guidelines on the use of cell culture in virology for developing countries in the South-East Asia Region 43 , the cells were retrieved from storage under vapour phase of liquid nitrogen at − 196 o C. Then, a 1 ml cell aliquot was quickly thawed in a water bath at 37 o C. The cells were transferred to 9 ml warm Dulbecco's Modi ed Eagles Medium (DMEM) supplemented with 10% foetal calf serum (FCS) and 1% antibiotics ( nal concentration 100 U/ml Penicillin, 100 µg/ml Streptomycin, Gibco, Thermo Fisher, Life Technologies Ltd, UK) in 15 ml conical tube and gently mixed. The cells were centrifuged at 1,200 rpm for 5 minutes to form pellet.…”

“…The cytotoxicity of the plant extracts for the U87.CD4.CXCR4 human glioblastoma cells was determined using the AlamarBlue cell viability assay (Thermo Scienti c, USA) as described in Anywar el al 42 . The Alamar Blue test is a colorimetric assay that measures reduction of the chemical resazurin by the mitochondrial enzymes NADH or NADPH dehydrogenase as an indicator system for cellular metabolism.…”

“…Traditional herbal remedies are usually used because of the perception that they are safe since they are of natural origin 42,72 . Herbs can potentially interact with HIV drug metabolising enzymes and other ARV in the body.…”