ABSTRACT
Green tea, a non-fermented tea, has been shown to demonstrate a variety of potential health benefits. However, studies have shown that it may induce hypokalemia, iron deficiency anaemia and liver damage especially when excessively consumed. This study is aimed at investigating the effects of administration of green tea (Camellia sinensis) on the haematological and hepato-renal functions of male Sprague-Dawley rats. Proximate analysis of Green tea extract was done using GC-Mass Spectrometer. Rats where divided into four groups, viz; - Control group (no green tea extract was administered), group 2 (administered 100mg/kg body weight of extract daily and served as low dose group), group 3 (administered 300mg/kg body weight of extract daily and served as average dose group) and group 4 (administered 500mg/kg body weight of extract daily and served as high dose group). Administration was through oral gavage daily for 42 days. A total of 5ml of blood was collected through cardiac puncture into EDTA containers (for full blood count) and plain containers (for biochemical analysis). Haematological indices such as WBC count, lymphocytes, neutrophils, MID, platelets, RBC count, Hb, PCV, MCV, MCH, MCHC and MPV were determined using Sysmex automated analyser while renal indices (electrolytes - Na+, Cl-, K+ and HCO3- were assayed by ion selective electrode method, urea and creatinine determined by spectrophotometric method and N-acetylgucosaminidase (NAG) (determined by Enzyme Linked Immunosorbent Assay (ELISA). Liver function assessments such as bilirubin, total protein, albumin, AST, ALT and ALP were determined using spectrophotometric method. Also, lipid profile (total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), and low-density lipoprotein (LDL) was investigated using spectrophotometric method. Gene (paraoxonase-1) study was assessed on the liver tissue using polymerase chain reaction. The liver and kidney morphology were also assessed histologically. Statistical analysis was done using Graph Pad Prism version 8.0.1. Results were presented as Mean ± SEM for all parameters. P < 0.05 were considered statistically significant. Proximate analysis revealed the following: caffeine (19.27%), heptadecane 2, 6, 10, 14- tetramethyl (9.44%), undecane (8%), oxirane (0.01%), tetradecanoic acid, 2-hydroxy-methyl ester (0.11%), beta-myrcene (0.39%). There were no significant differences observed in the mean values of WBC, lymphocytes, neutrophils, platelets, RBC count, Hb, PCV, MCV, MCH and MPV in controls compared with every other groups and within groups, but MCHC showed significant increase across the test groups when compared with the control (P < 0.05, respectively). Also, there was no significant difference observed in the mean values of renal indices such as Na+, Cl-, K+ and HCO3- , urea and creatinine in controls compared with other groups while NAG showed significant increase in group 3 and 4 (300mg/kg and 500mg/Kg body weight respectively, P < 0.05). The liver indices were relatively stable in all the groups and the control. Furthermore, Lipid profile, exhibited a significant decrease in total cholesterol level (P < 0.05) in high dose treated group when compared with control, while triglyceride, HDL and LDL showed no significant difference. Histological analysis of the kidney showed that high dose of green tea administration caused a mild aggregation of tubular cells but with no remarkable effect at low and moderate doses while the Liver morphology was relatively unchanged. Correlation analysis showed a significant positive correlation between potassium and NAG (R=; 0.9851; P < 0.05). In conclusion, relatively stable haematological and Liver indices coupled with increased activity of NAG and reduced total cholesterol could be associated with green tea intake while altered renal tubular architecture demonstrated histologically are possible confirmatory features of the increased NAG activity especially at higher dosage.
