Mitigating role of thymoquinone rich fractions from Nigella sativa oil and its constituents, thymoquinone and limonene on lipidemic-oxidative injury in rats

Abstract

Therapeutic role of Nigella sativa (NS) seed oil fractions, methanolic extract (ME) and volatile oil (VO) and their constituents, thymoquinone (TQ) and limonene (LMN) in relation to lipidemic-oxidative stress in Wistar rats was determined. The total phenolic contents of NS seed oil and their ME and VO extracts were 320.00 ± 3.00, 300.12 ± 0.04 and 288.41 ± 0.01 mg gallic acid equivalents per 100 g of NS oil, respectively. Their Fe+2 chelating activities were 870.00 ± 2.00, 222.31 ± 5.80 and 38.59 ± 1.43 mg EDTA equivalents per 100 g of NS oil, respectively. These fractions and compounds exhibited strong antioxidant activities against 2,2-diphenyl-1-picryl hydrazyl, 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid, nitric oxide and hydroxyl radicals. Potential antiperoxidative effects of these fractions and compounds were also observed in liposome, and lipidemic-induced lipid peroxidation in atherogenic suspension fed rats, pretreated with 100 mg ME, 20 mg VO, 10 mg pure TQ or 200 mg LMN for 30 days. ME containing ω-6 linoleic acid and palmitic acid natural compounds was highly effective against lipidemic oxidative stress than VO extract possessing thymol and isothymol phenolic natural antioxidant compounds. TQ, principal compound shared to both the extracts. The test fractions and compounds effectively reduced the erythrocyte and liver lipid peroxidation markers, conjugated diene, lipid hydroperoxide and malondialdehyde to near normal levels in the order ME > TQ > VO > LMN, by directly counteracting free radicals as well as suppressing hepatic HMG-CoA reductase activity. Our findings demonstrated that these natural products, preferably ME possess significant antioxidant activities, and may be recommended as new potential sources of natural antioxidants.

Thymoquinone Lowers Blood Glucose and Reduces Oxidative Stress in a Rat Model of Diabetes

“…In addition, the present study found that HbA1c levels were significantly lower following the treatment of STZ-induced diabetic rats with TQ, while the levels of lipid peroxidase, NO, and TAC were better than untreated diabetic rats. These findings provide further confirmation of the potential beneficial effects of TQ on glycaemic control [55,56] and oxidative stress [57,58], despite the fact that most previous studies were mainly conducted using the plant N. sativa rather than the active ingredient TQ.…”

Mechanisms of the antihypertensive effects of Nigella sativa oil in L-NAME-induced hypertensive rats

“…Thymol acts as a singlet oxygen quencher whereas thymoquinone and dithymoquinone have superoxide dismutase (SOD)-like activity and also act as free radical scavengers 27 - 29 . Oxidative stress causes endothelial dysfunction, leading to a reduction in the release or production of NO 30 - 32 , the proliferation of vascular smooth muscle cells and collagen deposition, which causes a thickening of the tunica media, and a narrowing of the vascular lumen 28 , which in turn impairs vasodilation 30 - 32 . Apart from its antioxidant properties, the blood pressure-lowering effect of N. sativa may be attributed to its diuretic properties 33 , its anti-inflammatory effect 34 or its reno-protective effect 35 .…”

Hesperidin attenuates altered redox homeostasis in an experimental hyperlipidaemic model of rat

“…All animal care and exploratory methods were in conformity with the guidelines of the Control and Supervision of Experiments on Animals (CPCSEA) and Institutional Animal Ethics Committee (IAEC), University of Allahabad, India (# IAEC/AU/2017(1)/011). The atherogenic suspension administrated to the rodents was fundamentally made out of 0.5% cholesterol, 3% coconut oil, and 0.25% cholic acid, and arranged by blending in a homogenizer. The measure of hesperidin supplementation was fundamentally settled based on accessible reports.…”