The effects of Rooibos (Aspalathus linearis) supplementation on the pancreas, liver, and kidney of male Wistar rats following antiretroviral treatment

[摘要] ENGLISH ABSTRACT : The health burden of human immunodeficiency virus (HIV) has improved with the introduction of antiretroviral therapy (ART). Near perfect adherence to ART is needed to ensure the maximum benefits of the drugs. Adherence is compromised by side effects and adverse drug reactions (ADRs) which may, in part, be due to drug induced oxidative stress. Rooibos (Aspalathus linearis) is a shrub-like bush native to South Africa and is cultivated primarily as an herbal tea. Rooibos contains various polyphenols that add to its overall antioxidant capabilities. Aspalathin, the most abundant polyphenol present in rooibos, has shown potent antioxidant capabilities in vitro, providing an attractive model for therapy. The following study questions whether the histological observable effects of ART can be attenuated with the introduction of rooibos tea in vivo. The study aimed to assess the effects of combination ART, and rooibos tea on the histology of the pancreas, liver, and kidney in a HIV-negative rat model.Rats (n=40) were subcatogorised into four groups namely: control (C), control ART (C-ART), control rooibos (C-R), and experimental (ART+R) groups. The C-ART and ART+R groups were administered a dose of combination ART consisting of 200 mg Emtricitabine (EMT), 600 mg Efavirenz (FTC) and 300 mg Tenofovir (TDF). A 2% (w/v) rooibos tea solution was administered ad libitum to C+R and ART+R groups. Samples of rooibos tea were analysed using liquid chromatography-mass spectrometry techniques to determine whether rats received the same concentrations of polyphenols throughout the investigation. Samples from the pancreas, liver, and kidney underwent standard histological processing. Routine haematoxylin and eosin stains and appropriate immunohistochemical and tinctorial techniques were conducted. Detailed morphometric measurements on pancreatic islet size, number and percentage of α and β-cells were performed. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were evaluated to test liver function. Changes in size of the glomerular corpuscle, glomeruli and proximal convoluted tubules (PCT) in the kidney were measured. Organ architecture, cellular structure and associated pathology were analysed in each organ, scored, and confirmed by a histopathologist.The size and number of pancreatic islets and the percentage of α and β-cells did not vary significantly from the control group. Serum AST and ALT levels did not vary significantly from controls indicating normal liver function. Glomerular corpuscle, glomeruli and PCT size remained constant compared to controls. No overt histopathology was present indicative of ART induced pancreatic toxicity, hepatotoxicity or nephrotoxicity. The results indicated no major changes between the various tea solutions indicating that the rats received similar concentrations of rooibos polyphenols throughout the week. The study maintains that ART, when given to rats, does not cause significant changes to organ histomorphometry. While rooibos tea administration did not worsen, or improve organ histomorphometry.

[发布机构] Stellenbosch University