Nutri-medicinal plants used in the management of HIV/AIDS opportunistic infections in western Uganda : documentation, phytochemistry and bioactivity evaluation

Abstract: As a result of the AIDS epidemic, many people are immunocompromised and opportunistic infections are common. Medicinal plants constitute one of the fundaments of HIV treatment and are commonly used in management of HIV–related ailments, and also to counteract the side effects of antiretroviral therapy. This study documents and evaluates nutri-medicinal plants traditionally used in the management of opportunistic infections associated with HIV/AIDS in western Uganda. A six-stage process of documentation, evaluation and analysis of results was conducted: (1) ethnobotanical studies leading to identification and documentation of medicinal and nutritional plants most frequently used in the treatment of opportunistic infections of HIV/AIDS  (2) Collection of plant samples and preparation of the extracts of each of the selected plants needed for bioactivity evaluation; (3) Phytochemical analysis of crude plant extracts (qualitative and GC/MS analysis); (4) pharmacological evaluation of the crude plant extracts (antimicrobial, antioxidant and mineral nutrient evaluation); (5) safety evaluation of the active extracts using animal models, and (6) Statistical analysis of the results.The study recorded 324 plant species distributed in 75 families, with potential to treat ailments associated with immuno-compromised people living with HIV/AIDS in western Uganda. The study revealed that folk medicine is still widely practiced. Fidelity level values indicated the most preferred plant species for particular ailments. The high consensus values indicated that there was high agreement in the use of plants for various ailments. The selected preferred plant species were subjected to chemical screening to ascertain their pharmacological activities and they could be prioritized for conservation. The study allows for identifying high value medicinal plants indicating high potential for economic development.Phytochemical screening of the aqueous and ethanol extracts of selected twenty plant species revealed the presence of tannins, saponins, flavonoids, anthocyanins, coumarins and steroid glycosides. Some of the major chemical compounds identified by gas chromatography mass spectrometry of the essential oils include α- phellandrene, linalool, carvacrol, geraniol, β-eudesmene, β-cubebene, α-caryophyllene, 1-8 cineole and caryophyllene oxide. The essential oils of Plectranthus amboinicus, Erlangea tomentosa, Plunchea ovalis and Crassocephalum vitellinum were highly active against Candida albicans and Cryptococcus neoformans. One of the essential oil fractions of Crassocephalum vitellinum (1.56 mg/ml) was highly active against Cryptococcus neoformans. Antioxidant activities of the plant species were also tested. The antioxidant activity of Pseudarthria hookeri (43.68%) and the ferric reducing power of Symphytum officinale (10.48 Mm/L) were the highest values. The ability of the plant extracts to scavenge free radicals may partly justify the traditional use of these plants to boost immunity in HIV/AIDS patients. Mineral nutrient analysis revealed high amounts of iron in Plectranthus amboinicus (5.8 mg/kg dry weight), zinc in Pseudarthria hookeri (6.9 mg/kg dry weight) and selenium in Plunchea ovalis (1.14 mg/kg dry weight). These elements are essential in maintenance of the immune system. Hematological analysis of the aqueous extract of Plectranthus amboinicus showed that the plant has immunostimulating properties by increasing the number of lymphocytes in the test animals. Further ethnopharmacological studies are needed for the documented plants particularly the most active ones.