Effect of Hibiscus sabdariffa L., extract spiced with Piper nigrum L. and Zingiber officinale on lipid profile, liver function and oxidative stress indicators of alloxan-induced diabetic rats

Abstract

Background: Extensive studies have previously been carried out on the anti-diabetic activities of Hibiscus Sabdariffa extract (Zobo), However, little is known about its effect on diabetes when spiced with Zingiber officinale (ginger) and Piper nigrum (black pepper), as is the practice in traditional remedy.

Objective: This study evaluated the effect of a combined aqueous extract of Zobo with ginger and black pepper on liver function indicators and lipid profile of alloxan-induced diabetic rats.

Methods: Thirty (30) male Wistar rats (1 comprised of 24 diabetic and 30 - 138 g) 6 non-diabetic, were divided into five groups of six each and treated thus: Groups 1 and 2 – normal and diabetic controls received distilled water, Groups 3 received 500 mg/kg of metformin and groups 4 and 5 received 250 mg and 500 mg/kg each of Zobo drink combined with ginger and black pepper. The treatment lasted for 21 days during which blood glucose and body weight changes were measured. At the end of treatment whole blood was collected, serum prepared and used for assay of lipid profile, liver enzymes and liver oxidative stress indicators.

Results: The results obtained showed that the combined extracts lowered blood sugar levels progressively, over the treatment period and also maintained body weights of the rats. Serum cholesterol and triglyceride levels were found to decrease with a corresponding increase in High Density Lipoprotein (HDL) levels (p < 0.05). The liver enzyme (the aminotransferases) activities were both within the normal range of 40 U/L. Moreover, measured indicators of oxidative stress, malondialdehyde (MDA) and activities of superoxide dismutase (SOD) and catalase (CAT) were positively modulated.

Conclusions: Taken together, data obtained from the study suggest that Zobo drink, commonly consumed in Nigeria, when spiced with ginger and black pepper, can attenuate the vascular system positively in a diabetic condition, including protecting the liver from injury, hence a promising functional food for diabetics.