Benzo(a)pyrene (B(a)P) is an environmental pollutant which causes various lung toxicities. The present study was designed to evaluate the protective effects of carvacrol, a monoterpenic phenol against B(a)P-induced lung toxicity. In this study, Swiss albino mice were pretreated with carvacrol (25 mg/kg and 50 mg/kg) orally for 7 consecutive days before administering oral B(a)P (125 mg/kg). Preventive efficacy of carvacrol was assessed in terms of membrane oxidation, antioxidant enzyme activities, histopathological changes, and inflammatory (iNOS, NF-κB, and COX-2) markers. Carvacrol pretreatment in the two doses restored B(a)P-induced lipid peroxidation and increased the activities of antioxidant enzymes. Protein expressions of iNOS, NF-κB, and COX-2 in the lung tissue were found to be upregulated by B(a)P. Carvacrol treatment, however, downregulated their expressions by decreasing the marker of positive stained cells and restored the histopathological architecture of lung tissue. Our results suggest that carvacrol can be used as a protective agent against B(a)P-induced lung toxicity and inflammation.

1,2-Dimethylhydrazine (DMH), an environmental toxicant specifically targets the colon. The present study was aimed to evaluate the efficacy of gallic acid (GA) against colon toxicity induced by DMH in Wistar rats. GA, a phenolic acid has numerous beneficial properties, which include antiviral, antifungal and antioxidant properties which help cells to overcome oxidative stress and balance the redox homeostasis. GA was administered orally at two doses (25 and 50 mg/kg body weight) once daily for 14 days and a single dose (40 mg/kg body weight) of DMH was administered subcutaneously on 14th day. Animals were sacrificed on the 15th day and we could find that GA at both the doses significantly ameliorates DMH-induced increased toxicity markers and also substantially increases the glutathione content level and activities of detoxifying enzymes. It also ameliorates the expression of proliferation, inflammation, apoptosis, goblet cell disintegration, and mucin depletion in the colon that was elevated upon administration of DMH. Histological alterations provide further confirmation of the protective role of GA against DMH-induced colon toxicity. The results of this study clearly indicate supplementation of GA is beneficial in ameliorating DMH-induced oxidative stress, inflammation, proliferation, apoptosis, mucin depletion, and goblet cell disintegration in colon of Wistar rats.

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Benzo(a)pyrene [B(a)P] is a well-known carcinogen present in the environment. In this study, we evaluated the protective potential of methanolic bark extract of Acacia catechu Willd. (MEBA) against the lung toxicity induced by B(a)P in Swiss albino mice. To determine the protective efficacy of MEBA, it was orally administered to the mice at two doses (200 and 400 mg/kg body weight) once daily for 7 days. Mice were also exposed (orally) to B(a)P at a dose of 125 mg/kg body weight on 7th day. Administration of B(a)P increased the activities of toxicity markers such as LDH, LPO, and XO with a subsequent decrease in the activities of tissue anti-oxidant armory (CAT, SOD, GST, GPx, GR, QR, and GSH). It also caused activation of the apoptotic and inflammatory pathway by upregulation of TNF-α, NF-kB, COX-2, p53, bax, caspase-3, and downregulating Bcl-2. Pretreatment with MEBA at two different doses (200 and 400 mg/kg body weight) significantly ameliorates B(a)P-induced increased toxicity markers and activities of detoxifying enzymes along with the levels of glutathione content. It also significantly attenuated expression of apoptotic and inflammatory markers in the lungs. Histological results further confirmed the protective role of MEBA against B(a)P-induced lung toxicity. The results indicate that MEBA may be beneficial in ameliorating the B(a)P-induced oxidative stress, inflammation, and apoptosis in the lungs of mice. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1566-1577, 2017.

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