Chemopreventive effect of troxerutin against hydrogen peroxide-induced oxidative stress in human leukocytes through modulation of glutathione-dependent enzymes

Ethanolic extract from leaves of tithonia diversifolia induces apoptosis in HCT-116 cells through oxidative stress

Tithonia diversifolia is a perennial bushy plant found in South America with significant ethnopharmacological importance as an antimalarial, antidiabetic, antibacterial, and anticancer agent. The aim of the present study was to determine the cytotoxicity of the ethanolic extract from leaves of T. diversifolia (TdE) on human cancer cell lines (HCT-116, SNB-19, NCIH-460 and MCF-7), as well as the mechanism of action involved in cell death and cellular modulation of oxidative stress. The TdE exhibited significant activity with IC50 values ranging from 7.12 to 38.41 μg/ml, with HCT-116 being the most sensitive cell line. Subsequent experiments were conducted with HCT-116 cell line. TdE decreased the number of viable cells, followed by induction of apoptotic events, increase in mitochondrial membrane permeabilization, and enhanced G2/M phase of the cell cycle. Pro-oxidative effects including elevated acidic vesicular organelle formation, lipid peroxidation, and nitric oxide by-products, as well as reduced levels of intracellular glutathione and reactive oxygen species production were also observed following incubation with TdE, which may lead to DNA damage followed by apoptotic cell death. These results demonstrate the potential of TdE ethanolic leaf extraction for biological activity and enhance the importance of continuing to study natural sources of plants for the development of anticancer agents.

In vivo assessment of antioxidant, antigenotoxic, and antimutagenic effects of bark ethanolic extract from Spondias purpurea L

Medicinal plants have always been used for therapeutic purposes; however, some plants may contain toxic and mutagenic substances. The aim of this study was to assess the cytotoxic, genotoxic, mutagenic, antioxidant, antigenotoxic, and antimutagenic effects of the bark ethanolic extract of Spondias purpurea L. using male and female Swiss albino mice. To determine the protective effects of the extract, benzo[a]pyrene (B[a]P) and cyclophosphamide (CP) were selected as cell damage inducers. The extract was examined at doses of 500, 1000, or 1500 mg/kg body weight (BW)via gavage alone or concomitant with B[a]P or CP. Oxidative stress was measured by quantification of blood catalase activity (CAT), reduced glutathione (GSH) levels in total blood, liver, and kidney, and concentrations of malondiadehyde (MDA) in liver and kidney. Genotoxicity and antigenotoxicity were evaluated by the comet assay using peripheral blood. Cytotoxicity, mutagenicity, and antimutagenicity were determined utilizing the micronucleus test in bone marrow and peripheral blood. The S. purpurea L extract increased CAT activity and GSH levels accompanied by a decrease in MDA levels after treatment with B[a]P and CP. No genotoxic, cytotoxic, or mutagenic effects were found in mice exposed only to the extract. These results indicate that the extract of S. purpurea exhibited protective effects against oxidative and DNA damage induced by B[a]P and CP.