Involvement of Nrf2, JAK and COX pathways in acetaminophen-induced nephropathy: Role of some antioxidants

ObjectivesAcetaminophen (APAP)-induced nephrotoxicity is detrimental consequence for which there has not been a standardized therapeutic regimen. Although, N-acetylcysteine (NAC) is a well-known antidote used in APAP-induced hepatotoxicity, its benefit in nephrotoxicity caused by APAP is almost lacking. This study aimed to compare the possible protective effect of thymoquinone (TQ), curcumin (CR), and α-lipoic acid (α-LA), either in solo or in combination regimens with that of NAC against APAP-induced renal injury.Design and methodRats were divided into nine groups; control group, APAP intoxicated group (1000 mg/kg; orally), and the remaining seven groups received, in addition to APAP, oral doses of NAC, TQ, CR, α-LA, CR plus TQ, TQ plus α-LA, or CR plus α-LA. The first dose of the aforementioned antioxidants was given 24 h before APAP, and then the second dose was given 2 h after APAP, whereas the last dose was given 10 h after administration of APAP.ResultsTreatment with APAP elevated kidney markers like serum uric acid, urea, and creatinine. In addition, it increased the serum level of tumor necrosis factor alpha (TNF-α), interleukin-1beta (IL-1β) and thiobarbituric acid reactive species (TBARS). Also, the protein expression of renal janus kinase (JAK) and cyclooxygenase (COX)-2 were all upregulated by APAP. In contrast, the expression of Nrf2 and the renal levels of superoxide dismutase and glutathione were downregulated. Treatment with the indicated natural antioxidants resulted in amelioration of the aberrated parameters through exhibiting anti-inflammatory, antioxidant and free radical-scavenging effects with a variable degree.ConclusionThe combined administration of CR and TQ exerted the most potent protection against APAP-induced nephrotoxicity through its anti-inflammatory and free radical-scavenging effects (antioxidant) which were comparable to that of NAC-treatment.     

Thymoquinone-induced relaxation of isolated rat pulmonary artery

Aim of the study

The effect of thymoquinone (TQ), the main constituent of the volatile oil of black seed (Nigella sativa L. family Ranunculaceae), on the isolated rat pulmonary arterial rings was investigated.

Materials and methods

Isolated rat pulmonary arterial rings were precontracted with phenylephrine and concentration–response curves to TQ were constructed. The effects of different receptors antagonists or enzyme inhibitors were examined.

Results

TQ caused a concentration-dependent decrease in the tension of the pulmonary arterial rings precontracted by phenylephrine. The effects of TQ were not influenced by pretreatment of the rings with propranolol (a non-selective β-blocker), atropine (a non-selective blocker for muscarinic receptors), theophylline (an adenosine receptor antagonist), indomethacin (a cyclooxygenase inhibitor), L-NAME (a NO synthase inhibitor), methylene blue (an inhibitor of soluble guanylyl cyclase) and nifedipine (a Ca²⁺ channel blocker). The effects of TQ were significantly potentiated by bosentan (an ET_A/ET_B receptor antagonist). The effects of TQ were slightly abolished by pretreatment of the rings with glibenclamide (a non-selective blocker of ATP-sensitive K+ channels). TQ totally abolished the pressor effects of serotonin and phenylephrine on the isolated rat pulmonary arterial rings.

Conclusion

The results of the present study suggest that TQ-induced relaxation of the precontracted pulmonary artery is probably mediated, at least in part, by activation of ATP-sensitive potassium channels and possibly by non-competitive blocking of serotonin, α1 and endothelin receptors.     

Thymoquinone Augments Cyclophosphamide-Mediated Inhibition of Cell Proliferation in Breast Cancer Cells

Objective: Cancer chemotherapy at the recommended doses is largely associated with toxicity, and also it is noteffective enough to reduce the advancement of the disease at lower doses. Thymoquinone (TQ) is an active compoundderived from black seeds (Nigella sativa) which exhibits anticancer activities. The aim of the present study was toinvestigate the synergistic effect of TQ alone and in combination with cyclophosphamide (cyclo), and to unravel therole of TQ in fatty acid synthase (FASN) mediated molecular signaling in Her2 + and Her2- breast cancer cell lines.Methods: The effect of TQ on the growth of Her2+ SKBR-3 and Her2- MDA-231 breast cancer lines were evaluatedas percent cell viability by cytotoxicity-based MTT assay. The analysis of cell cycle arrest was done through flowcytometryfollowed by Western blot and RT-PCR to detect signaling events in the cells. Results: The data showedthat TQ-cyclo (0.5mM-10μM) combination significantly inhibited the proliferation through the 5.49% and 57.72%accumulation of cells in sub-G1 and G1 respectively as 12% cells were shifted from G2/M phase in Her2+ breast cancercells. Similarly, TQ-cyclo (0.5mM-20μM) combination exhibited that the 16.6% cells were arrested in Sub-G1 and only3.54% cells were remained in G2/M phase as it was 22.89% in DMSO control in Her-2- breast cancers cells. ThoughTQ alone or in combination with cyclo alleviated the PI3K/Akt signaling by downregulating the phosphorylation of Aktand upregulating the PTEN, no changes was observed in FASN and Her-2 as well in both type of cells. The significantdecreased expression of cyclin D1 was found in TQ-cyclo combinations. Conclusion: The current findings suggestedthat TQ can alter the cell cycle progression and induce cell death independent of FASN mediated signaling. In terms ofclinical perspective, the present study clearly showed that TQ can broadly augment the effect of cyclo in breast cancercases irrespective of Her-2+ or Her-.     

Thymoquinone effectively alleviates lung fibrosis induced by paraquat herbicide through down-regulation of pro-fibrotic genes and inhibition of oxidative stress

The potential preventive and therapeutic effects of thymoquinone (TQ) and its molecular mechanism were evaluated in paraquat (PQ)-induced pulmonary fibrosis in mice. TQ was administered orally at the doses of 20 and 40 mg/kg during the course and after development of fibrosis. Pathological changes, expressions of genes involved in fibrogenesis, hydroxyproline (HP) and oxidative stress parameters were determined in the lung tissues. TQ dose-dependently recovered the pathological changes induced by PQ. TQ decreased hydroxyproline content, lipid peroxidation and restored the antioxidant enzymes to the normal values. In molecular level, expressions of TGF-β1, α-SMA, collagen 1a1 and collagen 4a1 genes were also returned to the control level by TQ. This study indicated that TQ has the preventive and therapeutic potentials for the treatment of lung fibrosis by inhibition of oxidative stress and down-regulation of profibrotic genes.     

百里醌对大鼠肠缺血再灌注损伤的保护作用

【摘要】 目的 观察百里醌对大鼠肠缺血再灌注损伤(IIRI)的保护作用。方法 45只健康雄性SD大鼠,随机分成3组：假手术对照组(A组)、肠缺血再灌注组（B组）和肠缺血再灌注+百里醌组（C组）。B组和C组分别建立大鼠肠缺血再灌注模型,C组在再灌注同时腹腔注射百里醌（50mg/kg )。方法 HE染色观察小肠组织形态学改变;测定丙二醛（MDA）、超氧化物岐化酶(SOD)含量;采用原位缺口末端标记检测肠黏膜上皮细胞凋亡指数（AI）;RT PCR检测小肠组织中的caspase 3、Bax和Bcl 2的表达情况。结果 B组可见肠绒毛排列紊乱,肠黏膜坏死等表现,经百里醌治疗后明显改善;A组、B组和C组的凋亡指数分别为(453±028)％、(2173±117)％、(953±096)％,SOD活性分别为(13537±334)、(7645±139)和(9513±164) U/mg蛋白,MDA含量分别为(283±036)、(923±078)和(497±045) nmol/mg蛋白;与A组比较,B组中Bax、caspase 3 mRNA表达水平明显增高,Bcl 2表达水平降低 (P＜005)。与B组比较,C组中Bcl 2表达水平增高,Bax、caspase 3表达水平减低(P＜0．05)。结论 百里醌可减轻氧化应激水平,发挥抗凋亡作用, 从而在肠IIRI过程中发挥保护作用。     

百里醌对兔骨关节炎模型关节软骨的保护作用及机制

目的探索关节腔内注射百里醌对兔骨关节炎模型关节软骨的保护作用及机制。方法选用新西兰大白兔构建动物模型,分为百里醌组、骨关节炎组和假手术组各20只,观察并记录实验大白兔6min内步行距离。术后9周处死动物取左膝关节标本进行大体组织学Gross评分,切片行苏木精-伊红（HE）染色、番红染色后进行组织病理学Mankin评分,采用RT-PCR检测3组大白兔关节软骨中基底金属蛋白酶-13（MMP-13）、基底金属蛋白酶抑制剂-1（TIMP-1）、聚集蛋白聚糖（Aggrecan）和2型胶原（CollagenⅡ）等靶基因表达水平。结果百里醌组大白兔的行走距离明显大于骨关节炎组（P＜0.05）;而Gross评分、Mankin评分均低于骨关节炎组（均P＜0.05）。与骨关节炎组比较,百里醌组MMP-13mRNA表达水平明显下降（P＜0.05）,TIMP-1、Aggrecan和CollagenⅡmRNA表达水平明显上升（均P＜0.05）。结论百里醌对兔骨关节炎模型的关节软骨具有保护作用,可以减少疼痛,延缓骨关节炎的进展。百里醌可能通过下调MMP-13mRNA表达,上调TIMP-1、Aggrecan和CollagenⅡmRNA表达的分子机制实现保护作用。     

Protective effect of thymoquinone against diazinon-induced hematotoxicity,genotoxicity and immunotoxicity in rats

Several studies have shown that oxidative stress and cell damage can occur in the very early stages of diazinon (DZN) exposure. The present study was designed to determine the beneficial effect of thymoquinone (Thy), the main component of Nigella sativa (black seed or black cumin) against DZN immunotoxicity, hematotoxicity and genotoxicity in rats. In the present experimental study, 48 male Wistar rats were randomly divided into six groups, (eight per group) as follows: control (receiving corn oil as the DZN solvent), DZN (20 mg/kg), Thy (10 mg/kg), Thy (2.5 mg/kg) + DZN, Thy (5 mg/kg) + DZN and Thy (10 mg/kg) + DZN. After four weeks of treatment, the hematological parameters of red blood cells (RBCs), white blood cells (WBCs), hemoglobin (Hb), hematocrit (Hct) and platelets (PLTs) were evaluated. The evaluation of genotoxicity was carried out using the micronucleus assay. For measurement of cytokine production, interferon gamma (IFN-γ), interleukin 10 (IL10) and interleukin 4 (IL4) were chosen as immunotoxicity indicators of DZN toxicity. DZN was found to decrease RBCs, WBCs, Hb, Hct, PLTs, butyrl- and acetyl-cholinesterase activity and I FN-γ and increased the micronucleus indices of IL10 and IL4 as compared with the control group. Treatment with Thy reduced DZN hematotoxicity and immunotoxicity, but, significantly, did not prevent genotoxicity. This study showed that Thy (without the significant effect on genotoxicity) decreased the hematological toxicity, immunotoxicity and butyrl and acetyl cholinesterase activity induced by DZN. The success of Thy supplementation against DZN toxicity can be attributed to the antioxidant effects of its constituents.     

Thymoquinone-entrapped chitosan-modified nanoparticles: formulation optimization to preclinical bioavailability assessments

The major limitation with the oral administration of most of the phytochemicals is their low aqueous solubility and bioavailability. Thymoquinone (THQ) is one of the most widely used phytochemicals used to treat a variety of diseases. However, strong lipophilic characteristics limit its clinical application. Therefore, this study was aimed to design novel chitosan (C) modified polycaprolactone (PL) nanoparticles (NPs) for improved oral bioavailability of THQ. THQ-CPLNPs was optimized 33-Box–Behnken design. After that, the optimized THQ-CPLNPs was characterized by different parameters. THQ-CPLNPs showed the size, PDI, and ZP of 182.32 ± 6.46 nm, 0.179 ± 0.012, and +21.36 ± 1.22 mV, respectively. The entrapment and loading capacity were found to be 79.86 ± 4.36%, and 13.45 ± 1.38%, respectively. THQ-CPLNPs exhibited burst release in initial 2 h followed by prolonged release up to 24 h in simulated intestinal fluids. THQ-CPLNPs showed excellent mucoadhesion properties which were further confirmed with the intestinal permeation study as well as confocal microscopy. The study revealed higher permeation of THQ-CPLNPs compared to neat THQ suspension (THQ-S). Moreover, in vivo gastric irritation study revealed good compatibility of THQ-CPLNPs with the gastric mucosa. Furthermore, pharmacokinetic results depicted ∼3.53-fold improved oral bioavailability of THQ from THQ-CPLNPs than THQ-S. Therefore, from the findings, it was concluded that the prepared polymeric NPs could be an effective delivery system for improved oral bioavailability of THQ.     

Effect of thymoquinone on the lung pathology and cytokine levels of ovalbumin-sensitized guinea pigs

Different pharmacological effects from Nigella sativa have been demonstrated in guinea pig tracheal chains in previous studies. In the present study, the prophylactic effects of thymoquinone on lung pathology as well as blood IL-4 and IFN-γ levels in sensitized guinea pigs were examined. Three groups of guinea pigs sensitized to ovalbumin were given drinking water alone (group S) or drinking water containing low (LTQ) or high (HTQ) concentrations of thymoquinone (groups S + LTQ and S + HTQ). The lung pathology as well as blood IL-4 and IFN-γ levels of the sensitized and the control guinea pigs were evaluated in three sensitized and one control group (n = 8, for all groups). The lungs of the S group showed significant pathological changes (p < 0.001). Blood IL-4 and IFN-γ levels were increased in the sensitized animals compared to those of controls (p < 0.01 and p < 0.001, respectively). Treatment of the S animals with thymoquinone significantly improved their pathological changes to the lung and decreased their IL-4 levels (p < 0.05 to p < 0.001) but increased their IFN-γ levels (p < 0.001). These results showed a preventive effect of thymoquinone on lung inflammation in sensitized guinea pigs.