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The effect of Rooibos on trace elements absorption and biochemical parameters-Amurine model
Over the past few decades, it has been shown that various critical diseases including heart disease, cancer, and diabetes associated with free radical generation and low endogenous antioxidant capacity, lead to oxidative stress and cell injury. In recent years, numerous studies have also reported that antioxidants, present in various beverages, vegetables and some foods have attracted a significant research interest due to their potential benefits to human health. However, epidemiological evidence shows a correlation between the intake of food rich in antioxidants and the reduced incidence of some mortality of chronic diseases, certain cancers and coronary heart disease. The aims of this study were to determine the effects of rooibos teas (fermented and unfermented) and green tea as a comparison on the biochemical parameters and the trace element absorption in a rat model. In this study 4 groups of experimental animals were used. All groups had ad libitum access to standard rat chow. Group A, the controls (11 animals), were fed with tap water; group B (11 animals) were fed with the liquid extract of fermented rooibos tea; group C (9 animals) were fed with the liquid extracts of unfermented rooibos and group D (9 animals) were fed with the liquid extract of green tea. All groups were fed for a period of 10 weeks. After the feeding period, the animals were sacrificed by euthanization with intraperitoneal injections of pentobarbital. Blood was sampled by cardiac puncture and centrifuged to obtain the serum. Some elemental analyses were performed with X-ray emission and backscattering. ICP-OES was used to determine the magnesium content. For X-ray emission, backscattering and ICP-OES analyses, 100 μL of each serum sample in a group were added to 2 mL freeze-drying tube. Of the combined specimen, 100 μL was used for the magnesium determination by ICP-OES. The remainder of the combined serum specimens for each group were freeze-dried at -80 ºC and then pressed into a pellet. The pellet was coated with carbon and analyzed using X-ray emission and backscattering. The elemental X-rays of P, S, Ca, Mn, Fe, Cu, Co, Zn, Mo, Ca and Se emitted were quantified to obtain the respective concentrations. Biochemical chemistry analyses were performed on each serum sample of each animal. The biochemical parameters tested for were total protein, albumin, globulin, total bilirubin, lactate dehydrogenase, blood urea nitrogen, uric acid, total cholesterol, aspartate aminotransferase, alanine aminotransferase, creatine phosphokinase and creatinine. The P concentration increased (p=0.028) when fed with the fermented rooibos tea liquid extract and S content increased when fed with the - the unfermented tea liquid extract (p=0.041). The concentrations of Cl and Cr were not affected (p>0.05) by any of tea liquid extracts. The unfermented rooibos tea liquid extract and the green tea indicated a decrease in the concentrations of Fe (p=0.031 and p=0.032, respectively) and Mn (p=0.041 and p=0.034, respectively). The concentrations of Fe, Zn and Cu in the serum increased when feeding with fermented rooibos tea liquid extract (p=0.024; p=0.030 and p=0.015, respectively) while Se, Mo and Mg concentrations were decreased by the liquid extracts of the fermented, unfermented and green teas (p=0.014, p=0.017 and p=0.011; p=0.024, p=0.026 and p=0.019; p=0.031, p=0.034 and p=0.025, respectively). Concerning the biochemical parameters, the total protein, globulin and the uric acid contents in the serum sample were slightly affected with the green tea extract (p=0.041, p=0.039 and p=0.047 respectively). The albumin, lactate dehydrogenase, blood urea nitrogen, the total cholesterol, the alanine aminotransferase and the aspartate aminotransferase concentrations were not affected (p>0) by any of the tea liquid extracts. However, the total bilirubin content was decreased (p=0.012) when feeding with the fermented rooibos group while the creatine phosphokinase and the creatinine contents were decreased (p=0.042 and p=0.033, respectively) when feeding with the unfermented rooibos tea liquid extract.