Antioxidant effects and phytochemical analysis of crude and chromatographic fractions obtained from Eucalyptus globulus bark

Eucalyptus globulus is extremely used in traditional medicine in Algeria and its leaf extract is included as one of the antioxidant in the list of existing food additives in Japan. In the present study, the crude extract from bark of this plant and its fractions obtained by Sephadex LH-20 column were studied to quantify their levels of  phenolic compounds and their antioxidant activity (ferric reducing power, 1,1-diphenyl-2-picryl hydroxyl  (DPPH•) radical scavenging activity and scavenging of hydrogen peroxide). All extracts exhibited a reducing  power effect higher than that of á-tocopherol. It was observed that crude extract displayed the highest DPPH• scavenging ability (IC50115.40 ìg/ml) followed by á- tocopherol (IC50 233.78 ìg/ml). Crude extract also  displayed the highest ability to neutralize hydrogen peroxide at 65 ìg/ml (75.55%), followed by á-tocopherol  (20.07%) at the same concentration. The results show that fractions b and c exhibited lower antioxidant  activities for the three antioxidant tests comparatively to that of crude extract. Fraction a exhibited the lowest antioxidant capacity.Key words: Eucalyptus globulus, bark extract, phenolic compounds, antioxidant effect, Sephadex LH-20 column

Antioxidant, Anti-Inflammatory and Anti-Proliferative Properties of <i>Stachys circinata</i> on HepG2 and MCF7 Cells

According to the WHO, the overall age-standardized cancer rate keeps declining, and the number of cases diagnosed each year increases, remaining among the leading causes of death in 91 out of 172 recorded countries. In this context, novel cancer prediction and therapeutic protocols are compulsory. The effect of a Stachys circinata L’Hér dichloromethane extract (ScDME) on cell redox homeostasis and tumor proliferation was investigated. HepG2 cell feedback mechanisms to oxidative stress exposure were evaluated by determining catalase (CAT) and reduced glutathione (GSH), following the supply with ScDME (0.0–5.7 µg/µL). Cytotoxicity of ScDME against the human umbilical vein endothelial cell (HUVEC) and two human cancer cell lines (breast: MCF7; liver: HepG2) was evaluated by the MTT assay. H2O2-stressed HepG2 cells supplied with the S. circinata extracts exhibited significantly increased CAT and GSH activity as compared to unsupplied ones. The anti-inflammatory activity of the extracts was evaluated by real time-qPCR on IL-1, IL-6 and TNF-α expression. As a result, this research points out that S. circinata dichloromethane extract owns anti-inflammatory and anti-proliferative properties against MCF7 and HepG2 cells and activates CAT and GSH of the HepG2 cells’ antioxidant enzyme system