Optimization of the Green Chemistry-like Extraction of Phenolic Compounds from Grape (Vitis labrusca L.) and Blackberry (Rubus fruticosus L.) Seeds with Concomitant Biological and Antioxidant Activity Assessments.

The objective of this work was to determine the phenolic composition, chemical and cellular antioxidant activity, cytotoxicity in human cells, and peroxidative inhibition of the defatted fraction of grape (Vitis labrusca) and blackberry (Rubus fruticosus) seeds. Soxhlet extraction (Sox) was used to extract the fat and obtain the degreased material. A statistical optimization study was developed to maximize the extraction of bioactive compounds and antioxidant activity from defatted grape and blackberry seeds. Simultaneous optimization was applied with a combination of 35.9 min of extraction and a solid-to-solvent ratio of 1 g of defatted grape seed to 61.28 mL of an extracting solvent (60% ethanol) and 62.1 min of extraction and a solid-to-solvent ratio of 1 g of defatted blackberry seed to 64.1 mL of an extracting solvent (60% ethanol). In the cell viability assay, HepG2 cancer cells seemed more sensitive to grape and blackberry extracts, while Ea.hy926 hybrid cells showed more resistance to their effects. In general, the extracts presented low/no cytotoxicity, exhibited a protective effect against H2O2-induced ROS production, and demonstrated antioxidant activity and a protective effect on the erythrocytes when subjected to hypotonic and isotonic conditions not presenting hemolytic behavior (5.0 to 10.0 µg GAE/mL). Thus, the results provided a broad assessment of the bioactivity of the extracts obtained using a simple and low-cost process developed by employing non-toxic solvents and with the potential to be used in technological applications.

Selina-1,3,7(11)-trien-8-one and Oxidoselina-1,3,7(11)-trien-8-one from Eugenia uniflora Leaf Essential Oil and Their Cytotoxic Effects on Human Cell Lines.

The sesquiterpenes selina-1,3,7(11)-trien-8-one and oxidoselina-1,3,7(11)-trien-8-one were isolated from the essential oil of Eugenia uniflora L. leaves. The structures were elucidated using spectrometric methods (UV, GC-MS, NMR, and specific optical rotation). The relationship between antioxidant activity, as determined by DPPH assay, and the cytotoxic effect was evaluated using tumor cells, namely lung adenocarcinoma epithelial cells (A549) and human hepatoma carcinoma cells (HepG2), as well as a model of normal human lung fibroblast cells (IMR90). Both compounds did not show prominent free-radical scavenging activity according to DPPH assay, and did not inhibit lipid peroxidation in Wistar rat brain homogenate. The isolated compounds showed pro-oxidative effects and cytotoxicity in relation to the IMR90 cell line.

Hydroalcoholic Myrciaria dubia (camu-camu) seed extracts prevent chromosome damage and act as antioxidant and cytotoxic agents.

The camu-camu seeds, which comprehend about 20% of the fruit weight, is discarded without taking benefit of their chemical components and potential application by the industry. In the current study, we characterized the phenolic composition, the in vitro chemical antioxidant effects, cytotoxic activity, and the inhibition of induced-cisplatin chromosomal aberrations of five camu-camu seed extracts obtained with different proportions of water (H2O) and ethyl alcohol (EtOH). The 50% H2O + 50% EtOH was the most promising extract because it presented higher total phenolic content (4802 mg GAE/100 g), antioxidant capacity (DPPH = 3694 mg AAE/100 g; FRAP = 6604 mg AAE/100 g; FCRC = 4918 mg GAE/100 g) and inhibited the cell growth of four cancer cell lines (GI50 = 7.49 µg GAE/mL A549; 13.3 µg GAE/mL Caco-2; 15.57 µg GAE/mL HepG2 and 14.89 µg GAE/mL HCT8) without cytotoxic effects against normal cells (GI50 IMR90 > 43.2 µg GAE/mL). The cytotoxic effects presented high correlation with the (-)-epicatechin and methylvescalagin contents, while gallic and 2,5-dihydroxybenzoic acids were associated with cytoprotective effects of HCT8 cancer cell line. The 50% H2O + 50% EtOH extract also presented protective effect by decreasing 37% of the induced-cisplatin chromosomal breaks index, suggesting its antimutagenic potential, which may be associated to its antioxidant and cytotoxic activities.