Olive oil and its phenolic compounds (hydroxytyrosol and tyrosol) ameliorated TCDD-induced heptotoxicity in rats via inhibition of oxidative stress and apoptosis

Abstract

Context: Naturally occurring polyphenols including olive oil (OO) and its constituents hydroxytyrosol (HT) and tyrosol (TY), consumed in the Mediterranean diet, have shown to treat various ailments due to their remarkable antioxidant properties. Objective: The present study investigates the hepatoprotective effects of OO and its phenolic compounds HT and TY against TCDD-induced hepatotoxicity in male Wistar rats. Materials and methods: TCDD was administered at a dose of 100 ng/kg p.o. for 20 d. Administration of OO (10 ml/kg; oral), HT (0.5 mg/kg; oral), and TY (30 mg/kg; i.p) was started 5 d prior to TCDD administration, and continued for 25 d with or without TCDD administration. At the end of the experiment (25 d), blood was taken for biochemical analyses and liver for the measurement of macromolecular damages, antioxidant status, expressions of CYP1A1, and apoptotic factors. Results: TCDD administration resulted in significant (p50.05) increase in the level of hepatic stress markers ALT (101.6 ± 3.07 IU/l), AST (295.0 ± 3.0 IU/l), and ALP (266.66 ± 3.7 IU/l). Also, biochemical analyses of liver reported elevation in nitrite and protein carbonyl content and depletion of NQO1 and HO. However, OO, HT, and TY restored the antioxidant status. Protein expressions by Western Blot technique showed an increase in the level of CYP1A1 and Bax and a decreased level of Bcl-2 on TCDD treatment, and vice versa on OO, HT, and TY treatment. Discussion and conclusion: Our work concludes that dietary supplementation of OO, HT, and TY could serve as a potential preventive drug for TCDD-induced hepatotoxicity.

A Straightforward Access to New Families of Lipophilic Polyphenols by Using Lipolytic Bacteria

“…In particular, the polyphenols present in the virgin olive oil display a strong antioxidant activity in vitro [2] and in vivo [3,4], which has impelled a growing interest in these compounds, especially those that can be obtained from by-products of the food industry [5]. Several epidemiological studies have shown the beneficial health effects arising from consumption of foods rich in antioxidants, preventing the damage caused by prolonged oxidative stress in certain biomolecules (nucleic acids, lipids, proteins), which is associated with an increased risk of chronic diseases [6].…”

Hydroxytyrosol prevents reduction in liver activity of Δ-5 and Δ-6 desaturases, oxidative stress, and depletion in long chain polyunsaturated fatty acid content in different tissues of high-fat diet fed mice

“…Moreover, HT restored the intestinal barrier integrity and functions in mice fed high fat diet [55]. It is also possible that HT can modulate the absorption of lipids in the intestine, especially cholesterol [57], but this effect still requires further investigation. HT-induced enhancement in the antioxidative potential of the liver seems to be associated with activation of nuclear factor-erythroid related factor 2 (Nrf2), a transcription factor controlling the expression of SOD, CAT, GR, and GPX (Fig.…”

Toxicological evaluation of an olive extract, H35: Subchronic toxicity in the rat

“…Specifically, following treatment with the toxin TCDD in male Wistar rats, olive oil, hydroxytyrosol, or tyrosol treatment resulted in an ameliorated TCDD-induced hepatotoxicity. This was linked to inhibition of oxidative stress and apoptosis, with a decrease in Bax protein and an increase in Bcl-2 (Kalaiselvan et al, 2015). As Bax protein favors cell death and Bcl-2 has been shown to inhibit apoptosis (Yang et al, 2002), these results indicate a shift away from pro-apoptotic status.…”