The present study investigates the antioxidant and hepatoprotective effects of Capparis spinosa L. and Quercetin in tert-butyl hydroperoxide (t-BHP) induced acute liver damage. Different fractions of C. spinosa were examined for total phenolic content and antioxidant property. Among these fractions, hydroalcoholic extract was used to assess the hepatoprotective effect in tert-butyl hydroperoxide (t-BHP) induced hepatotoxicity model by determining serum biochemical markers, sleeping time and antioxidant assay such as reduced glutathione (GSH) as well as histopathological examination of liver tissues. The total phenolic and Quercetin contents of hydroalcoholic fraction were significantly higher than other fractions. It also showed high antioxidant activity. Pretreatment with hydroalcoholic fraction at the dose of 400 mg/kg and Quercetin at the dose of 20 mg/kg showed liver protection against t-BHP induced hepatic injury, as it was evident by a significant decrease in serum enzymes marker, sleeping time and MDA and an increase in the GSH, SOD and CAT activities confirmed by pathology tests. The final results ascertained the hepatoprotective and antioxidant effects of C. spinosa and Quercetin in a dose-dependent manner. Moreover, this study suggests that possible mechanism of this protection may be associated with its property of scavenging free radicals which may be due to the presence of phenolic compounds.

Postprandial hyperglycemia plays an important role in the development of type 2 diabetes. Inhibition of alpha-amylase was led to a delay in breaks down of starch and glycogen and prevented a rapid rise in blood sugar. Alpha-amylase was isolated by gel filtration chromatography Sephadex G-75 from bovine pancreas. Then, total methanolic extracts of plants were prepared and IC₅₀values of extracts on alpha-amylase were obtained and compared with acarbose IC₅₀. The polyphenolic content of extracts and antioxidant capacity were determined by Folin-Ciocalteu test and DPPH test, respectively. The specific activity of alpha-amylase was 48.2 U/mg. For inhibition of alpha-amylase, IC₅₀values ofH. persicum,Z. jujuba, and acarbose were 307, 827, and 113 μg/ml, respectively. For inhibition of DPPH radical, IC₅₀values of extracts were 235 and 701 μg/ml. Total phenolic contents of methanol extracts were73.8±3.2and44.2±1.8 μg tannic acid equivalent/mg extract. Acarbose causes gastrointestinal symptoms and liver toxicity, butH. persicumandZ. jujubadecrease these side effects and prevent gastrointestinal disorders. Due to the high polyphenolic content and antioxidant capacity of these plants and significant inhibitory effect of the plants on alpha-amylase, these plants can be proposed for treatment of diabetic patients.

Total phenolic and flavonoid contents and antioxidant activity of four Iranian herbs (Lamiaceae) were investigated. The antioxidant activity of methanol extracts of thyme (Thymus daenensis Celak.), Bakhtiari savory (Satureja bachtiarica Bung.), dragonhead (Dracocephalum multicaule Montbr & Auch), and woundwort (Stachys lavandulifolia Vahl.) was evaluated by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing/antioxidant power (FRAP), and trolox equivalent antioxidant capacity (TEAC). A comparison of all plant extracts in the DPPH assay indicated that dragonhead and thyme were the most effective free radical scavenging agents. Thyme demonstrated a relatively strong antioxidant activity in both the FRAP and TEAC assays. The total phenolic content of all the extracts ranged from 99 to 208 mg TAE/g extract with thyme exhibiting the highest phenolic content. The flavonoid content of the extracts, which ranged from 10.1 to 22.2 rutin equivalents/g of extract, was highest in dragonhead. A positive correlation was noted between the total phenolic content and antioxidant activity in both the FRAP and TEAC assays, while no significant correlation was observed between the DPPH, TEAC, and FRAP assay and total flavonoid, suggesting that the level of antioxidant activity in these plants varies greatly, but the total phenolic in the plant extracts provided a substantial antioxidant activity. Experimental results indicate that thyme and dragonhead extracts could be an important dietary source of phenolic compounds with high antioxidant capacity.