Chemical composition, antioxidant, anti-inflammatory and antitumor activities of Eucalyptus globulus Labill.

Eucalyptus globulus L. is used in folk medicine throughout the world and its essential oils are widely used in modern pharmaceutical, food, and cosmetic industries. In this study, E. globulus leaves were extracted using three solvents (methanol, chloroform and hexane). The polyphenolics were quantified with HPLC and the volatiles analyzed by GC/MS with antioxidant, anti-inflammatory and antitumor activities. Results have shown a hierarchy of antioxidant and anti-inflammatory activity for three extracts as hexane > chloroform > methanol extracts with DPPH, FRAP, and oxygen radical absorbance capacity, respectively. A similar order of results was observed for antitumor activity by potato disc and colorimetric assays. The GC/MS analysis led to the identification of 1, 8-cineole (eucalyptol) as a major constituent of methanol (48.2%), chloroform (35.5%), and hexane (5.8%) extracts. Different phenolic acids (gallic acid, ellagic acid, syringic acid, and vanillic acid) and flavonoids (quercetin, rutin, and catechin) were highly abundant in methanol extract. The methanol extract of E. globulus exhibited the maximum antioxidant, anti-inflammatory, and antitumor activities. These results demonstrate E. globulus leaf extracts may be used as a potential source of bioactive compounds with remarkable antioxidant, anti-inflammatory, and antitumor activities.

Purification and characterization of buffalo liver L-arginase and its kinetic properties with dihydropyrimidine and metal ions.

Arginase (L-arginine amidinohydrolase, EC.3.5.3.1) from animal tissues such as, liver and kidney has been partially characterized by many researchers. In this study, we purified arginase to homogeneity from buffalo liver with about ~2857 purification fold and a 20% recovery by chromatographic and spectroscopic analysis were obtained. The molecular mass determined by gel filtration and SDS-PAGE was found to be 118 kDa and 47 kDa, respectively. The optimal pH and temperature of the arginase was 9.5 and 40°C, respectively. Kinetic parameters (Km and Vmax) showed activation of arginase in the reaction medium with decrease in Km (7.14, 5.26, 4.0 and control 3.22 mM) and Vmax (0.05, 0.035, 0.027 and control 0.021 mg/mL/min), while co-factor activity of arginase was optimized using metal ions like Mn2+ and Mg2+ at 2 mM, which revealed an increase in Vmax values (0.011, 0.013, 0.015 and control 0.010 mg/mL/min) and a decrease in Km values (2.22, 2.12, 1.88 and control 1.66 mM). The kinetic data suggested that the arginase activity is enhanced in the presence of dihydropyrimidine derivative and metal ions, indicating essential mode of activation.

Screening of ferulic acid related compounds as inhibitors of xanthine oxidase and cyclooxygenase-2 with anti-inflammatory activity

Abstract The ferulic and gallic acid related compounds from natural origin were studied against xanthine oxidase and cyclooxygenase-2 along with their anti-inflammatory activity. The compounds gallic acid, ferulic acid, caffeic acid and p-coumaric acid revealed promising anti-inflammatory activity (30–40% TNF-α and 60–75% IL-6 inhibitory activity at 10 µM). Bioavailability of compounds were checked by in vitro cytotoxicity using CCK-8 cell lines and confirmed to be nontoxic, but found toxic at higher concentration (50 µM). Gallic, ferulic, caffeic acid was demonstrated potential dual inhibition toward xanthine oxidase and cyclooxygenase-2 as calculated by IC50: 68, 70.2, and 65 µg/ml (xanthine oxidase) and 68.5, 65.2, and 62.5 µg/ml (cyclooxygenase-2), respectively. The structure activity relationship and in silico drug relevant properties (HBD, HBA, PSA, c Log P, ionization potential, molecular weight, EHOMO and ELUMO) further confirmed that the compounds were potential candidates for future drug discovery study, which was expected for further rational drug design against xanthine oxidase and cyclooxygenase.

Determination of polyphenols and antioxidant activity of Vitis labrusca cv. baile berries.

Grape juice and grape skin extracts are important commercial source of polyphenolic compounds which exert different functional properties such as color potential, antimicrobial, antioxidant activity, and health benefits. In this paper we describe a sensitive and specific assay for determination of bioactive polyphenolic compounds in Campbell Early (Vitis labrusca cv. baile). Five polyphenolic components were separated on an Agilent Zorbax Extend C18 Column (250 mm × 4.6 mm × 5 μm) and detected by a diode array detector. The mobile phase was composed of (a) aqueous phosphoric acid (0.2%, v/v); and (b) acetonitrile using a gradient elution. Analytes were performed at 25°C with a flow rate of 0.8 ml/min and UV detection at 280, 360, and 520 nm. All calibration curves showed good linear regression (r2 ≥ 0.9999) within tested ranges. Overall intra- and inter-day variations were less than 1.90%, and the average recoveries were 95.5-105% for analytes. The antioxidant activity determined by DPPH radical assay, ranged from 86-105 for extracts, and 165-252 for studied standards (µM trolox/100 g dry wt.). The proposed method would be sensitive enough and reliable for quality control in functional food and modernization of Campbell Early (Vitis labrusca cv. baile) as potent antioxidant agent.