Centella asiatica and Its Fractions Reduces Lipid Peroxidation Induced by Quinolinic Acid and Sodium Nitroprusside in Rat Brain Regions.

Oxidative stress has been implicated in several pathologies including neurological disorders. Centella asiatica is a popular medicinal plant which has long been used to treat neurological disturbances in Ayurvedic medicine. In the present study, we quantified of compounds by high performance liquid chromatography (HPLC) and examined the phenolic content of infusion, ethyl acetate, n-butanolic and dichloromethane fractions. Furthermore, we analyzed the ability of the extracts from C. asiatica to scavenge the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) radical as well as total antioxidant activity through the reduction of molybdenum (VI) (Mo(6+)) to molybdenum (V) (Mo(5+)). Finally, we examined the antioxidant effect of extracts against oxidant agents, quinolinic acid (QA) and sodium nitroprusside (SNP), on homogenates of different brain regions (cerebral cortex, striatum and hippocampus). The HPLC analysis revealed that flavonoids, triterpene glycoside, tannins, phenolic acids were present in the extracts of C. asiatica and also the phenolic content assay demonstrated that ethyl acetate fraction is rich in these compounds. Besides, the ethyl acetate fraction presented the highest antioxidant effect by decreasing the lipid peroxidation in brain regions induced by QA. On the other hand, when the pro-oxidant agent was SNP, the potency of infusion, ethyl acetate and dichloromethane fractions was equivalent. Ethyl acetate fraction from C. asiatica also protected against thiol oxidation induced by SNP and QA. Thus, the therapeutic potential of C. asiatica in neurological diseases could be associated to its antioxidant activity.

Scutia buxifolia Reissek essential oil: in vitro antioxidant and antimicrobial activities.

The volatile oil from the stem bark of Scutia buxifolia (Rhamnaceae) has been obtained by hydrodistillation and analyzed by GC-MS. Twenty-one components were identified representing 99.93 % of the total oil composition, spathulenol (35.87%), ß-cubebene (17.26%), germacrene D (6.43%), linalool (5.19%), carvacrol (4.05%) were the main components of S. buxifolia essential oil. Antioxidant and antimicrobial properties of the essential oil were evaluated by free radical scavenging (DPPH) assay and micro broth dilution method, respectively. S. buxifolia essential oil presented interesting radical scavenging activity (IC50 = 15.03 ± 0.11 µg/mL). The antibacterial assay showed that S. buxifolia stem bark essential oil was moderately active against the Staphylococcus aureus and Micrococcus sp. (MIC = 500 µg/mL) and Escherichia coli (250 µg/mL). To the best of our knowledge, this is the first study on the composition, antioxidant and antimicrobial activities of essential oil from the S. buxifolia collected from Brazil.

Phytochemical analysis and antioxidant capacity of Tabernaemontana catharinensis A. DC. Fruits and branches.

The antioxidant capacity of the crude extract and fractions of Tabernaemontana catharinensis fruits and branches, was evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method and the content of polyphenols, flavonoids, alkaloids and condensed tannins were determined by the spectrophotometric method. The ethyl acetate fraction of the fruits and the n-butanol fraction of the branches showed IC50 of 181.82 µg/mL and 78.19 µg/mL, respectively. All fractions were analyzed by high performance liquid chromatography (HPLC), in the branches were quantified chlorogenic acid in the chloroform (8.96 mg/g), ethyl acetate (4.31 mg/g) and n-butanol (3.33 mg/g) fractions; caffeic acid in the ethyl acetate (5.24 mg/g) and n-butanol (1.81 mg/g); gallic acid (0.52 mg/g) in the n-butanol. In the fruits, chlorogenic acid in the chloroform (1.67 mg/g); rutin in the ethyl acetate (3.45 mg/g) and n-butanol (8.98 mg/g) fractions. The present study showed that these quantified compounds can contribute to antioxidant capacity which was higher in the branches than in the fruits.