(−)-Epicatechin is a phenolic compound with antioxidant activity that is present in natural food and drinks, such as cocoa and red wine. Evidence suggests that (−)-epicatechin exhibits anticancer activity; however, its mechanism of action is poorly understood. Here, we investigated the anticancer effects of (−)-epicatechin and its mechanism of action in breast cancer cells. We assessed the anticancer activity by cell proliferation assays, apoptosis by DNA fragmentation and flow cytometry. The expression of proteins associated with apoptosis was analyzed by the human apoptosis array. MitoSOX^TM Red and biomarkers of oxidative damage were used to measure the effect of (−)-epicatechin on mitochondrial reactive oxygen species (ROS) and cellular damage, respectively. (−)-Epicatechin treatment caused a decreasing in the viability of MDA-MB-231 and MCF-7 cells. This cell death was associated with DNA fragmentation and an apoptotic proteomic profile. Further, (−)-epicatechin in MDA-MB-231 cells upregulated death receptor (DR4/DR5), increased the ROS production, and modulated pro-apoptotic proteins. In MCF-7 cells, (−)-epicatechin did not involve death receptor; however, an increase in ROS and the upregulation of pro-apoptotic proteins (Bad and Bax) were observed. These changes were associated with the apoptosis activation through the intrinsic pathway. In conclusion, this study shows that (−)-epicatechin has anticancer activity in breast cancer cells and provides novel insight into the molecular mechanism of (−)-epicatechin to induce apoptosis.

Candida albicans is an opportunistic fungus that is part of the normal microflora commonly found in the human digestive tract and the normal mucosa or skin of healthy individuals. However, in immunocompromised individuals, it becomes a serious health concern and a threat to their lives and is ranked as the leading fungal infection in humans worldwide. As existing treatments for this infection are non-specific or under threat of developing resistance, there is a dire necessity to find new targets for designing specific drugs to defeat this fungus. Some authors reported the presence of the transglutaminase activity in Candida and Saccharomyces, but its identity remains unknown. We report here the phenotypic effects produced by the inhibition of transglutaminase enzymatic activity with cystamine, including growth inhibition of yeast cells, induction of autophagy in response to damage caused by cystamine, alteration of the normal yeast division pattern, changes in cell wall, and inhibition of the yeast-to-mycelium transition. The latter phenomenon was also observed in the C. albicans ATCC 26555 strain. Growth inhibition by cystamine was also determined in other Candida strains, demonstrating the importance of transglutaminase in these species. Finally, we identified enolase 1 as the cell wall protein responsible for TGase activity. After studying the inhibition of enzymatic activities with anti-CaEno1 antibodies and through bioinformatics studies, we suggest that the enolase and transglutaminase catalytic sites are localized in different domains of the protein. The aforementioned data indicate that TGase/Eno1 is a putative target for designing new drugs to control C. albicans infection.

Introduction: Caralluma tuberculata holds significant importance as a medicinal plant due to its abundance of bioactive metabolites, which offer a wide range of therapeutic potentials. However, the sustainable production of this plant is challenged by overexploitation, changes in natural conditions, slow growth rate, and inadequate biosynthesis of bioactive compounds in wild populations. Therefore, the current study was conducted to establish an in vitro based elicitation strategy (nano elicitors and light regimes) for the enhancement of biomass and production of secondary metabolites. Methods: Garlic clove extract was employed as a stabilizing, reducing, or capping agent in the green formulation of Selenium nanoparticles (SeNPs) and various physicochemical characterization analyses such as UV visible spectroscopy, scanning electron microscopy (SEM), energy dispersive X-Ray (EDX) Spectroscopy, fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were performed. Furthermore, the effects of phytosynthesized SeNPs at various concentrations (0, 50, 100, 200, and 400 µg/L on callus proliferation and biosynthesis of medicinal metabolites under different light regimes were investigated.Results and discussion: Cultures grown on Murashige and Skoog (MS) media containing SeNPs (100 µg/L), in a dark environment for two weeks, and then transferred into normal light, accumulated maximum fresh weight (4,750 mg/L FW), phenolic contents (TPC: 3.91 mg/g DW), flavonoid content (TFC: 2.04 mg/g DW) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) antioxidant activity (85%). Maximum superoxide dismutase (SOD: 4.36 U/mg) and peroxide dismutase activity (POD: 3.85 U/mg) were determined in those cultures exposed to SeNPs (100 µg/L) under complete dark conditions. While the callus cultures proliferate on media augmented with SeNPs (200 µg/L) and kept under dark conditions for two weeks and then shifted to normal light conditions exhibited the highest catalase (CAT: 3.25 U/mg) and ascorbate peroxidase (APx: 1.93 U/mg) activities. Furthermore, LC-ESI-MS/MS analysis confirmed the effects of SeNPs and light conditions that elicited the antidiabetic metabolites (cumarins, gallic acid, caffeic acid, ferulic acid, catechin, querctin and rutin). This protocol can be scaled up for the industrial production of plant biomass and pharmacologically potent metabolites using in vitro callus cultures of C. tuberculata.