Enhanced Therapeutic Benefit of Quercetin–Phospholipid Complex in Carbon Tetrachloride–Induced Acute Liver Injury in Rats: A Comparative Study

Quercetin is a typical flavonoid with diverse biological effects, attributable to its free radical scavenging activity. Bioavailability of quercetin aglycone and its glycosides is an important factor for its antioxidant activity in vivo. A severe limitation exists and is imputable to very poor absorption of quercetin when ad-ministered orally. To overcome this limitation, development of a value added herbal formulation in combi-nation with phospholipids has been made which has better absorption and utilization profiles. Free radical scavenging activity of quercetin–phospholipid complex (equivalent to quercetin 10mg and 20 mg/kg body wt.) and free quercetin (10 mg and 20 mg/kg body wt.) was evaluated in oxidative stress condition in al-bino rats induced by carbon tetrachloride intoxication. The degree of protection of liver was estimated by evaluating status of enzymes like super oxide dismutase (SOD), catalase; lipid peroxidation profile in terms of thiobarbituric acid reactive substances (TBARS), reduced glutathione, glutathione peroxidase, glutathione reductase and glutathione–S–transferase. Quercetin–phospholipid complex restored the re-duced enzyme levels of liver glutathione system as well as impaired levels of other enzymes which are significant with respect to carbon tetrachloride treated group (p < 0.05 and < 0.01). For all enzymes tested, the complex at different dose levels produced better effects than free quercetin at same doses. Thus the results obtained ascertain the superiority of quercetin–phospholipid complex over free quercetin in terms of better free radical scavenging activity.