Browsing by Author "Layman, Jodie"

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    A histomorphometric study of the effect of Afriplex GRT(TM) on the pancreas, liver and kidney of rats fed a high-fat diet
    (Stellenbosch : Stellenbosch University, 2018-12) Layman, Jodie; Kotze, Sanet; Chellan, Nireshni; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Biomedical Sciences: Anatomy and Histology.
    ENGLISH ABSTRACT: Obesity causes a wide range of disorders including insulin resistance, hepatic steatosis as well as renal glomerular and tubular pathology. These disorders are typically associated with oxidative stress and inflammation. Rooibos, Aspalathus linearis, is a South African plant which has antioxidative, anti-inflammatory, antilipidemic, and antihyperglycemic properties as shown in vivo and in vitro. Afriplex GRT™ is an unfermented green rooibos extract which is postulated to have enhanced effects compared to fermented rooibos, mostly due to its high aspalathin content. The present study aimed to determine the ameliorative effects of Afriplex GRT™ on the histomorphometry of the pancreas liver and kidney in a diet-induced obese rat model. Male Wistar rats (N=28) were randomly sorted into four study groups (n=7) namely, control (C), GRT fed control (GRT), high-fat diet (HFD) and HFD supplemented with GRT (HFDGRT). Animals were either fed a control feed or a HFD which contained fat, cholesterol and fructose. Animals in the GRT and HFD-GRT groups were supplemented with Afriplex GRT™ at a concentration of 60 mg per kg body mass per day. Body mass, and pancreatic, liver and kidney mass were determined after which samples were processed to wax. Tissues were sectioned at 4 – 5 µm in thickness and stained using haematoxylin and eosin for analysis by a histopathologist. Immunohistochemistry using anti-insulin and anti-glucagon double antibody labelling was performed on the pancreas. Other staining techniques included Masson’s trichrome, Gordon and Sweet’s reticulin impregnation and periodic acid Schiff. Additionally, frozen sections of the liver and pancreas were stained using Oil red O for lipid infiltration. Morphometric techniques included area, diameter, radii, point counting and ratios. Body mass significantly decreased in the HFD-GRT group compared to the HFD group. Pancreas and kidney mass decreased significantly in the HFD-GRT group compared to the Cgroup, however liver mass significantly increased in both HFD groups. Islet area and β-cell area significantly decreased in the HFD-GRT group compared to all three control groups however, a greater number of islets was observed. Hepatic steatosis and liver pathology were reduced in the HFD-GRT group compared to the HFD group. Renal space and the proximal convoluted tubules were decreased in the HFD-GRT compared to C-group as indicated by trends. Additionally, a trend was observed in the arcuate artery media to lumen ratio which was increased in the GRT group compared to the HFD group. Similar to the present study, a decrease in body mass has been observed with fermented rooibos and its polyphenols in HFD-fed animals. In the HFD-GRT group, increased islets per section area and smaller islet areas are associated with increased insulin secretion, which suggests improved glucose tolerance. This study suggests that Afriplex GRT™ may effectively reduce hepatic steatosis, an effect previously seen in studies on fermented rooibos and rooibos polyphenols. More in-depth studies on the effects of Afriplex GRT™ in the kidney are needed, potentially for a longer study period. Therefore, Afriplex GRT™ has observable ameliorative effects on the histomorphology of the liver and the pancreas; the effects on the kidney requires further investigation.