Effect of Raw and Cooked Ginger (<i>Zingiber officinale</i> Roscoe) Extracts on Serum Cholesterol and Triglyceride in Normal and Diabetic Rats

Abstract

Dyslipidemia is a risk factor of concern in public health even in a state of anomaly in blood glucose level. The effect of different ginger extracts on body lipids has been reported, few scientific studies have documented the effect of raw ginger extracts while the effect of cooked ginger extract (the form in which the spice is commonly consumed) is yet to be explored. This experimental study was therefore designed to determine the effect of raw and cooked ginger extracts on serum triglycerides and total cholesterol in diabetic rats and compare this with that of non-diabetic rats. Fresh ginger rhizomes were washed peeled, washed, wet-milled (without addition of water) and sieved to give the raw extract. A portion of of the extract was boiled for one hour and cooled to give cooked ginger extract. Seventy male albino rats of weight range 155g-195g were divided into 7 groups (n=10) with 3 groups kept as normal or non-diabetic while the remaining 4 groups were rendered diabetic by intraperitoneal administration of 60mg/kg body weight of streptozocin (STZ) to mimic Type 1 diabetes mellitus. These were repeated with another set of seventy rats but diabetes was induced in the 4 diabetic groups here with a 12 week consumption of high-fat diet (HFD) to mimic Type 2 diabetes mellitus. Serum total cholesterol and triglyceride were determined before and after diabetes induction as well as at the 2nd and 4th weeks of extracts and diabetic drugs administration using standard methods. Mean data were compared using Least Significant Difference at p≤0.05.Raw and cooked ginger extracts significantly reduced serum total cholesterol and triglyceride in both medium (2 weeks) and long (4 weeks) terms administration in non diabetic rats. In STZ-induced diabetic rats only raw ginger extract lowered these parameters significantly while the cooked extracts and glybenclamide increased these significantly. However, in HFD-induced diabetic rats, raw, cooked ginger extracts and Metformin reduced both serum total cholesterol and triglyceride significantly. Ginger in both raw and cooked forms may therefore be useful in ameliorating hyperlipidemia which commonly associates diabetic state. Human trial is hereby recommended.