The Antidiabetic Activity of Nigella sativa and Propolis on Streptozotocin-Induced Diabetes and Diabetic Nephropathy in Male Rats

Abstract

This study was conducted to compare the ameliorative effect of Nigella sativa and propolis methanol extract on streptozotocin-induced diabetic male rats and treating diabetic nephropathy. Forty male Albino rats were divided into four groups; the first group was the negative control fed standard diet. The other 30 rats were injected with streptozotocin to induce diabetes by a single intravenous injection and then divided equally into three groups; the second group was the positive diabetic control; the third and the fourth groups were treated orally with 20% w/w Nigella sativa seeds methanol extract and propolis methanol extract (20% w/w), respectively. The rats of the second group showed increased glucose levels and lipid peroxide accompanied with reduction in superoxide dismutase, catalase, and glutathione-S-transferase enzyme activities compared with the negative control. Carboxymethyl lysine, interleukin-6, and immunoglobulins were also increased as a result of diabetes. Kidney function parameters were also elevated, while potassium and sodium levels were decreased. Moreover, tissues of kidney and pancreas showed severe histopathological changes. Treating the diabetic rats with Nigella sativa and propolis methanol extract in the third and fourth groups, respectively, ameliorated all altered biochemical and pathological examinations approaching the negative control. Propolis was more effective than Nigella sativa.

Figure 1

(a) Kidney of rats of the negative control group reveals the normal histological structure of renal tissue with normal parenchyma, normal blood vessels, and being interstitial with no histopathological changes, (b) kidney of rat from the positive control group showing collapsed glomerular tuft with marked tubular atrophy, interstitial inflammation, and interstitial hemorrhage, (c) kidney of diabetic rat treated with N. sativa methanol extract showing normal glomeruli and regenerated tubules with interstitial hemorrhage, and (d) kidney of diabetic rat treated with propolis methanol extract (G4) showing near normal renal cortical tissue. G: glomerulus (H&E stain ×200).

Figure 2

(a) Pancreas of control negative group showing normal pancreatic acini, Langerhans cells, and interductal glands. (b) Pancreas of control positive group showing mild degeneration of pancreatic acini cells with periductal inflammation, edema, and congestion. (c) Pancreas of Nigella sativa treated group showing improvement and degeneration of pancreatic tissues with nearly normal tissues. (d) Pancreas of propolis treated group showing restored pancreatic tissues to the normal with no evidence of inflammation in islets or around the large ducts. (H&E, ×200).