Wilfred Mbeng Otang

Phytochemical studies and antioxidant activity of two South African medicinal plants traditionally used for the management of opportunistic fungal infections in HIV/AIDS patients

BackgroundIt has been observed that perturbations in the antioxidant defense systems, and consequently redox imbalance, are present in many tissues of HIV-infected patients. Hence, the exogenous supply of antioxidants, as natural compounds that scavenge free radicals, might represent an important additional strategy for the treatment of HIV infection. The aim of this study was therefore to analyse the phytochemical constituents and antioxidant potential of Gasteria bicolor Haw and Pittosporum viridiflorum Sims., two South African plants traditionally used for the management of opportunistic fungal infections (OFIs) in AIDS patients.MethodsThe in vitro antioxidant properties of the two plants were screened through DPPH (1,1-diphenyl-2-picrylhydrazyl), NO (nitric oxide), H2O2 (hydrogen peroxide) radical scavenging effects and reducing power assays. Phytochemical studies were done by spectrophotometric techniques.ResultsThere were no significant differences in the flavonoid and proanthocyanidins contents between the leaves and bark extracts of Gasteria bicolor and Pittosporum viridiflorum respectively, while the total phenolic content of the bark extract of P. viridiflorum was significantly higher than that of G. bicolor leaf. The acetone extracts of both plants indicated strong antioxidant activities.ConclusionThe results from this study indicate that the leaves and stem extracts of Gasteria bicolor and Pittosporum viridiflorum respectively possess antioxidant properties and could serve as free radical inhibitors, acting possibly as primary antioxidants. Since reactive oxygen species are thought to be associated with the pathogenesis of AIDS, and HIV-infected individuals often have impaired antioxidant defenses, the inhibitory effect of the extracts on free radicals may partially justify the traditional use of these plants in the management of OFIs in HIV patients in South Africa.

Antifungal activity of Arctotis arctotoides (L.f.) O. Hoffm. and Gasteria bicolor Haw. against opportunistic fungi associated with human immunodeficiency virus/acquired immunodeficiency syndrome.

Background: In South Africa where many patients are immunocompromised as a result of the AIDS pandemic, opportunistic fungal infections such as candidiasis caused mainly by Candida albicans are common. Arctotis arctotoides and Gasteria bicolor are two plants which are frequently and commonly used in traditional medicine in the treatment of HIV patients. Aim: The aim of this study was to investigate the antifungal activity of A. arctotoides and G. bicolor against opportunistic fungi common in HIV/AIDS patients. Materials and Methods: The agar diffusion and micro-dilution methods were used to determine the antifungal activities of the medicinal plant extracts against 10 opportunistic fungi. Results: All the hexane and acetone extracts were active against at least one of the fungi with zones of inhibition varying from 8 to 32 mm, while none of the aqueous extracts was active against any of the fungi. The inhibitory activity of the active extracts, based on the overall mean inhibition diameters, was in the order: A. arctotoides (hexane) > A. arctotoides (acetone) > G. bicolor (hexane) > G. bicolor (acetone). The most susceptible fungi, based on the overall mean diameter of growth inhibition, were Candida glabrata, C. krusei, and Microsporum canis, while Cyptococcus neoformans, Trycophyton tonsurans, and Microsporum gypseum were not susceptible to any of the extracts even at 5 mg/ml which was the highest concentration used. Conclusion: This study validates the use of these plants in traditional medicine in the treatment of secondary fungal infections in HIV/AIDS patients.

The Effect of the acetone extract of Arctotis arctotoides (Asteraceae) on the growth and ultrastructure of some opportunistic fungi associated with HIV/AIDS.

In this study, the effect of the acetone extract of Arctotis arctotoides (L.f.) O. Hoffm. (Asteraceae) on the growth and ultrastructure of some opportunistic fungi associated with HIV/AIDS was analyzed by means of scanning electron microscope (SEM). Remarkable morphological alterations in the fungal mycelia which were attributed to the loss of cell wall strength ranged from loss of turgidity and uniformity, collapse of entire hyphae to evident destruction of the hyphae. The elements responsible for giving the fungi their characteristic virulence were detected and quantified by energy dispersive X-ray microanalysis techniques. X-ray microanalysis showed the specific spectra of sodium, potassium and sulfur as the principal intersection of the four pathogenic fungi studied. Since these ions have the potential of fostering fungal invasion by altering the permeability of hosts’ membranes, their presence was considered inherent to the pathogenicity of the opportunistic fungi. Hence, these findings indicate the potential of the crude extract of A. arctotoides in preventing fungal invasion and subsequent infection of host’s membranes.

Prevalence, perceived benefits and effectiveness of herbal medicine in the management of symptoms of opportunistic fungal infections in HIV/AIDS patients in the Eastern Cape, South Africa

It has been reported that about 75% of HIV-infected patients use remedies from complementary or African traditional medicine in South Africa. The multiplicity of these medicines led not only to potentially severe side effects, but also to clinically significant interactions with antiretrovirals (ARVs) and other medicines. The aim of this study was to evaluate the prevalence, perceived benefit and efficacy of herbal medicine in the management of opportunistic fungal infections (OFIs) in HIV/AIDS patients. This study is part of a larger study which includes the evaluation of the antifungal activity and toxicity of medicinal plants in the management of opportunistic fungal infections in HIV/AIDS patients in the Eastern Cape of South Africa. Following Ethics Committee approval, 101 HIV/AIDS patients were recruited through convenience sampling into an anonymous cross-sectional questionnaire study. More than one-third (39.6%, 40/101) was reported to be using herbal medicine for treating signs/symptoms of OFIs. Close to half (21, 52.5%) of the 40 HIV/AIDS patients who used herbal medicine reported that the herbal medicine did not help their condition, while 13 (32.5%) patients disclosed that the herbal medicine had a significant and great contribution towards the management of their signs/symptoms of OFIs. Six themes were identified as regards the rationale behind the use of herbal medicine by the HIV/AIDS patients.

A survey of plants responsible for causing irritant contact dermatitis in the Amathole district, eastern cape, South Africa

ETHNOPHARMACOLOGICAL RELEVANCE Potentially harmful plants grow almost everywhere, hence, it is not practical to eradicate them all. However, a basic understanding of adverse cutaneous reactions and the common plants that cause each type can enable vulnerable individuals to discover the source of their dermatitis and thus prevent re-exposure. The aim of this study therefore, was to document the plants responsible for irritant contact dermatitis (ICD) in the Eastern Cape, along with their respective irritants and clinical presentations. MATERIALS AND METHODS Study participants (161) in 12 locations were selected by convenient sampling with particular focus on local people who regularly interact with plants or plant products. Interview questions were focused on the local names of plants that contain irritating chemicals and physical characteristics that cause ICD. RESULTS Forty four plant species distributed in 24 families and 34 genera were reported as causative agents of irritant contact dermatitis. Herbs constituted 67.35%, trees 24.49% and shrubs 8.16%. Mechanical ICD was reported to be caused by 23 species, closely followed by chemical ICD (20 species) and mechanico-chemical ICD (6 species). Species with the highest frequency of citations were Allium cepa, Acacia karroo, Capsicum annuum, Citrus limon and Zea mays. The most representative families were Euphorbiaceae (for chemical ICD), Urticaceae (for mechanico-chemical ICD), Fabaceae and Rutaceae for mechanical ICD. Most of the classes of chemical compounds identified as being responsible for chemical ICD were restricted to plants of specific genera such as the diterpenes in Euphorbia spp., disulphides in Allium spp., terpenes in Citrus spp. and isothiocyanates in Brassica spp. Thorns and hairs were reported for causing Mechanical ICD in 6 plant species each, including widely cultivated plants such as Acacia karoo and Citrus reticulata. CONCLUSION Irritant contact dermatitis is a common cutaneous disorder in individuals exposed to plants in the Eastern Cape, especially among workers of the food and flower industries. Health practitioners should therefore consider the possible work-related causes of dermatitis, especially in cases associated with a clear history of symptoms.