The effects of crude ficus thonningii stem-bark extract on high-fructose diet fed growing sprague dawley rats
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Date
2020
Authors
Mhosva, Yvonne
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Abstract
The consumption of fructose-rich diets is one of the causes of the global increase in the prevalence of obesity and metabolic derangements (MD) in children. Pharmacological agents used to manage MD are expensive, inaccessible and elicit side effects. Communities, therefore, depend on plant-derived ethnomedicines for primary healthcare. Ficus thonningii extracts contain phytochemicals with hypoglycaemic, hypolipidaemic and anti-oxidant effects. I investigated the prophylactic potential of methanolic F. thonningii stem-bark extracts (MEFT) to protect against high-fructose diet (HFD) induced MD in growing Sprague Dawley (SD) rats mimicking children fed obesogenic diets.
Eighty 21-day old SD rat pups (40 males; 40 females) were randomly allocated and administered the following treatment regimens: group 1 – standard rat chow (SRC) + water (W); group 2 - SRC + 20% (w/v) fructose solution (FS); group 3: SRC + FS + fenofibrate at 100 mg/kg bwt/day (FEN); group 4 – SRC + FS + low dose MEFT (LDMEFT) at 50 mg/kg bwt/day and group 5 – SRC + FS + high dose MEFT (HDMEFT) at 500 mg/kg bwt/day for 8 weeks. Body mass was measured twice weekly. At the end of the 8-week experimental period, the rats were subjected to an oral glucose tolerance test. Forty-eight hours later, the rats were then fasted overnight and fasting blood glucose and triglyceride concentration and haematocrit were determined. Thereafter the rats were euthanised. Plasma insulin concentration and surrogate markers of health were determined. HOMA-IR was computed. Viscera macro- and micro-morphometry and hepatic lipid content were also determined. Consumption of the HFD did not affect (P>0.05) body mass, tolerance to an oral glucose load, HOMA-IR, haematocrit, viscera macro-morphometry, plasma insulin concentration, ALT and ALP activities as well as plasma BUN, cholesterol and creatinine concentrations of the rats. The HFD increased (P<0.05) plasma triglyceride concentration (P<0.05) in the rats but decreased (P<0.05) the liver lipid content of female rats compared to counterparts administered the control treatment regimen. The LDMEFT increased (P<0.05) liver lipid content of female rats. The HFD caused micro-steatosis and hepatic inflammation (P<0.05) in male and female rats but caused macro-steatosis (P<0.05) in females only. FEN, LDMEFT and HDMEFT protected against steatosis and inflammation in female rats (P<0.05). In males, both the LDMEFT and HDMEFT protected against both steatosis and inflammation but FEN protected only against micro-steatosis. In male rats, the HFD decreased (P<0.05) long bone density. FEN, LDMEFT and HDMEFT prevented the HFD-induced increased plasma
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triglyceride concentration. The HFD had no effect (P>0.05) on tibiae and femora indices of rats. FEN decreased (P<0.05) femora mass and density in males and the low dose MEFT decreased (P<0.05) femora density in females. The HDMEFT decreased (P<0.05) tibiae length of female rats. FEN increased (P<0.05) the liver mass in both rat sexes. The LDMEFT increased (P<0.05) liver lipid in female rats. FEN, LDMEFT and HDMEFT attenuated HFD diet-induced high plasma triglyceride concentration. The HFD elicited elements of MD in a sexually dimorphic manner. The crude MEFT stem bark extracts potentially could be used to prevent HDF diet-induced hypertriglyceridemia, hepatic steatosis and inflammation. It should be used with caution since it caused hepatic lipid accretion and compromised bone length and density in females.
Description
A dissertation submitted in fulfilment of the requirements for the degree of Master of Science in Medicine to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, 2020