Effect of Nigella sativa oil on paracetamol-induced renal cortical damage in rats: light and electron microscopic study

Paracetamol or acetaminophen [IV-acetyl-p-aminophenol; APAP] is a widely used analgesic and antipyretic drug. Unfortunately, it is now reported as the most common cause of toxic ingestion in the world. Nigella sativa oil [NSO] is an extract of N. sativa having antioxidant properties. This study aimed to assess the possible role of NSO in ameliorating the toxic effect of APAP overdose on the rat renal cortical structure. Thirty male albino rats were divided into three equal groups. Group I was the control group. Group II comprised rats treated with APAP [750 mg/kg/day] orally for 7 days. Group III received NSO [2 ml/kg/day orally] 30 min before oral administration of APAP at the same dose as that of group II for 7 days. Kidney specimens were processed for light and electron microscopic study of the renal cortex. Plasma renin activity and arterial blood pressure were estimated. APAP-treated rats showed marked structural changes in the proximal convoluted tubules with dense nuclear staining, cytoplasmic vacuolization, increased peroxisomes, and partial loss of apical brush border and basal striations. Renal corpuscles revealed focal fusion of podocyte foot processes and irregular thickening of glomerular basement membranes. Juxtaglomerular cells contained few renin granules, reflecting an increase in renin exocytosis that coincided with increased plasma renin activity and increased arterial blood pressure. Concomitant administration of NSO with APAP revealed a noticeable amelioration of these histological and physiological changes. NSO exerted a protective effect against APAP-induced renal cortical damage

effect of Nigella sativa on the diabetic liver in male albino rats with a special focus on the role of hepatic oval cells

Liver-related complications are a significant cause of death in diabetes and are often unrecognized. This study was designed to evaluate the hepatoprotective properties of Nigella sativa [NS] in streptozotocin-induced diabetes in rats. Moreover, the effect of NS on hepatic oval cells in the liver of diabetic rats was determined. Rats were divided into three groups: group I was the control group; group II included diabetic rats [single intraperitoneal injection of streptozotocin [50 mg/kg body weight]]; and group III included diabetic rats treated with NS [300 mg/kg/day, administered orally] for 4 weeks. Liver sections were subjected to H and E, masson staining, and immunohistochemical staining of proliferating cell nuclear antigen, alpha-smooth muscle actin, and insulin protein. Plasma levels of aspartate aminotransferase, alanine aminotransferase, and albumin levels were measured. Liver hepatocyte growth factor gene expression was also measured by reverse transcription PCR. Compared with the untreated diabetic group, NS preserved the hepatic architecture in diabetic rats as assessed histologically and biochemically. NS has a significant effect on liver regeneration as indicated by a significant increase in liver hepatocyte growth factor gene expression and a significant increase in proliferating cell nuclear antigen immunohistochemical staining. Hepatic fibrosis in diabetic rats was reduced by NS treatment as shown by the significant decrease in collagen deposition and alpha-smooth muscle actin immunohistochemical staining. Moreover, NS maintains functional insulin-producing hepatic oval cells as indicated by immunohistochemistry. This study showed the hepatoprotective effect of NS in experimentally induced diabetes in rats. NS also maintained functional insulin-producing hepatic oval cells in the liver of diabetic-treated rats

Evaluation of the in vitro effect of Nigella sativa aqueous extract on blastocystis hominis isolates

The effect of Nigella sativa aqueous extract was evaluated against the in vitro growth of 2 different isolates of the intestinal protozoan parasite Blastocystis hominis. Different concentrations [10, 100, 500 microg/ml] of Nigella aqueous extract and metronidazole, an active standard drug for B. hominis, were incubated with B. hominis isolates in culture media at 37°C. Their possible effect on B. hominnis living cell count [LCC] was assessed on Day 1, 3 and 6. The aqueous extract of N. sativa at concentrations of 100 and 500 microg/ml showed a potent lethal effect on both B. hominis isolates, but with different extent. There is no significant difference between the inhibitory effect of N. sativa and metronidazole on the LCC on the 6[th] day. On assessment of living cell rate [LCR] which calculate percentage rate of living cell, N. sativa at 500 microg/ml concentration has a significant inhibitory effect on both isolates. So, it is considered as the most active concentration of Nigella aqueous extract. These results prove that N. sativa aqueous extract could be useful in the treatment of B. hominis