Oral administration of Nigella sativa oil attenuates arsenic-induced redox imbalance, DNA damage, metabolic distress, and histopathological alterations in rat intestine.

BACKGROUND: Exposure to arsenic, a widespread environmental toxin, produces multiple organ toxicity, including gastrointestinal toxicity. Nigella sativa (NS) has long been revered for its numerous health benefits under normal and pathological states. In view of this, the present study attempts to evaluate the protective efficacy of orally administered Nigella sativa oil (NSO) against arsenic-induced cytotoxic and genotoxic alterations in rat intestine and elucidate the underlying mechanism of its action. METHODS: Rats were categorized into the control, NaAs, NSO, and NaAs+NSO groups. After pre-treatment of rats in the NaAs+NSO and NSO groups daily with NSO (2 ml/kg bwt, orally) for 14 days, NSO treatment was further continued for 30 days, with and without NaAs treatment (5 mg/kg bwt, orally), respectively. Various biochemical parameters, such as enzymatic and non-enzymatic antioxidants, carbohydrate metabolic and brush border membrane marker enzyme activities were evaluated in the mucosal homogenates of all the groups. Intestinal brush border membrane vesicles (BBMV) were isolated, and the activities of membrane marker enzyme viz. ALP, GGTase, LAP, and sucrase were determined. Further, the effect on kinetic parameters viz KM (Michaelis-Menten constant) and Vmax of these enzymes was assessed. Integrity of enterocyte DNA was examined using the comet assay. Histopathology of the intestines was performed to evaluate the histoarchitectural alterations induced by chronic arsenic exposure and/or NSO supplementation. Arsenic accumulation in the intestine was studied by inductively coupled plasma-mass spectroscopy (ICP-MS). RESULTS: NaAs treatment caused substantial changes in the activities of brush border membrane (BBM), carbohydrate metabolism, and antioxidant defense enzymes in the intestinal mucosal homogenates. The isolated BBM vesicles (BBMV) also showed marked suppression in the marker enzyme activities. Severe DNA damage and mucosal arsenic accumulation were observed in rats treated with NaAs alone. In contrast, oral NSO supplementation significantly alleviated all the adverse alterations induced by NaAs treatment. Histopathological examination supported the biochemical findings. CONCLUSION: NSO, by improving the antioxidant status and energy metabolism, could significantly alter the ability of the intestine to protect against free radical-mediated arsenic toxicity in intestine. Thus, NSO may have an excellent scope in managing gastrointestinal distress in arsenic intoxication.

Thymoquinone supplementation mitigates arsenic-induced cytotoxic and genotoxic alterations in rat liver.

Arsenic, a widespread environmental toxin, produces multiple organ toxicity, including hepatotoxicity. Thymoquinone (TQ) is known to restore liver functions in several hepatic injury models. This study aims to assess the mitigative potential of TQ against sodium arsenate (NaAs)-induced cytotoxic and genotoxic alterations in the liver. Rats were randomly distributed to control, NaAs, TQ, and NaAs+TQ groups. NaAs+TQ and TQ group of rats were pre-treated with TQ (1.5 mg/kg bwt, orally) for 14 days, and the treatment was further continued for 30 days, with and without NaAs treatment (5 mg/kg bwt, orally), respectively. The deleterious histological alterations in the liver of arsenic intoxicated animals were accompanied by an upsurge in the activities of serum ALT and AST, the diagnostic indicators of liver injury. NaAs caused pronounced alterations in the activities of membrane marker and carbohydrate metabolic enzymes and the enzymatic and non-enzymatic components of hepatic antioxidant defense. Significant hepatocyte DNA damage and hepatic arsenic accumulation were also observed in arsenic-exposed rats. TQ supplementation alleviated these adverse alterations and improved the overall hepatic metabolic and antioxidant status in NaAs-administered rats. Prevention of oxidative injury could be the key mechanism of TQ-elicited protective effects. TQ may have an excellent scope as a dietary supplement in the management of arsenic-induced hepatic pathophysiology.

Oral Nigella sativa oil administration alleviates arsenic-induced redox imbalance, DNA damage, and metabolic and histological alterations in rat liver.

Arsenic, an omnipresent environmental contaminant, is regarded as a potent hepatotoxin. Nigella sativa oil (NSO) consumption has been shown to improve hepatic functions in various in vivo models of acute hepatic injury. The present study evaluates the protective efficacy of NSO against sodium arsenate (As)-induced deleterious alterations in the liver. Male Wistar rats were divided into four groups, namely, control, As, NSO, and AsNSO. After pre-treating rats in AsNSO and NSO groups with NSO (2 mL/kg bwt, orally) for 14 days, NSO treatment was further extended for 30 days, with and without As treatment (5 mg/kg bwt, orally), respectively. As induced an upsurge in serum ALT and AST activities indicating liver injury, as also confirmed by the histopathological findings. As caused significant alterations in the activities of membrane marker enzymes and carbohydrate metabolic enzymes, and in the vital components of antioxidant defense system. Marked DNA damage and hepatic arsenic accumulation were also observed in As-treated rats. Oral NSO administration ameliorated these deleterious alterations and improved overall hepatic antioxidant and metabolic status in As-treated rats. Prevention of oxidative damage could be the underlying mechanism of NSO-mediated protective effects. The results suggest that NSO could be a useful dietary supplement in the management of arsenic hepatotoxicity.