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Ripe rot is one of the most important bunch diseases of grapes in the highlands of southern Brazil and a matter of concern for winegrowers. Sixty‐one strains isolated from berries of Vitis labrusca and V. vinifera varieties with symptoms were classified by phylogenetic analysis of the sequences of β‐tubulin, glyceraldehyde‐3‐phosphate dehydrogenase, D1/D2 domain of 28S rDNA, and rDNA internal transcribed spacer. They were also characterized by morphology, and their pathogenicity was evaluated. The combined molecular data allowed identification of six Colletotrichum species: C. fructicola, C. kahawae and C. viniferum (gloeosporioides complex), C. limitticola, C. nymphaeae (acutatum complex), and C. karstii (boninense complex). This is the first report of C. karstii and C. limitticola associated with the ripe rot of grapes. Morphological characteristics varied within and among species, confirming their separation at the complex level. Pathogenicity tests on V. vinifera berries showed that the most prevalent species, C. viniferum (37.8%) and C. fructicola (36.1%), were more virulent than the less prevalent species C. limitticola and C. karstii. Our findings indicate that there is a high diversity of Colletotrichum species associated with ripe rot disease of grapes in Brazil. There were no clear differences in the distribution of Colletotrichum species between V. labrusca and V. vinifera varieties. The determination of fungal species responsible for grape ripe rot in Brazilian vineyards may contribute to further epidemiological studies and the development of more efficient prophylactic methods for ripe rot management.

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Captan is one of the most widely used broad-spectrum fungicide applied to control several early and late diseases of grapes, apples, and other fruits and vegetables, and as other phthalimide fungicides is defined as a multisite compound with thiol-reactivity. Captan can affect non-target organisms as yeasts, modifying microbial populations and fermentation processes. In this study, we asked whether Captan thiol-reactivity and other mechanisms are involved in acute Captan-induced cell death on aerobic growing Saccharomyces cerevisiae. Thus for, we analyze cellular protein and non-protein thiols, cell membrane integrity, reactive oxygen species accumulation, phosphatidylserine externalization, and apoptotic mutants behavior. The results showed that when submitted to acute Captan treatment most cells lost their membrane integrity and died by necrosis due to Captan reaction with thiols. However, part of the cells, even maintaining their membrane integrity, lost their culture ability. These cells showed an apoptotic behavior that may be the result of non-protein thiol depletion and consequent increase of reactive oxygen species (ROS). ROS accumulation triggers a metacaspase-dependent apoptotic cascade, as shown by the higher viability of the yca1-deleted mutant. Together, necrosis and apoptosis are responsible for the high mortality detected after acute Captan treatment of aerobically growing cells of S. cerevisiae.

Background/Aim: Colorectal cancer is a common type of cancer with reported resistance to treatment, in most cases due to loss of function of apoptotic and cell-cycle proteins. Piperlongumine (PPLGM) is a natural alkaloid isolated from Piper species, with promising anti-cancer properties. This study investigated whether PPLGM is able to induce cell death in colorectal carcinoma HCT 116 cells expressing wild-type or deficient in Bax, p21 or p53. Materials and Methods: PPLGM was extracted from roots of Piper tuberculatum. Cell viability was determined by reduction of 3-(4,5-dimethilthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and clonogenic assay. Cell death was evaluated by acridine orange/ethidium bromide staining and flow cytometry. Plasmid cleavage activity and circular dichroism DNA interaction were also analyzed. Results: PPLGM induced selective cell death in all cell lines (IC 50 range from 10.7 to 13.9 μM) with an increase in the number of late apoptotic cells and different profiles in cell-cycle distribution. Plasmid DNA analysis showed that PPLGM does not interact directly with DNA. Conclusion: This paper suggests that PPLGM may be a promising candidate in colorectal cancer therapy. According to the last GLOBOCAN publication (2012), colorectal cancer is the third most common malignancy in men and the second in women worldwide. Chemotherapeutic resistance and toxicity found in this type of cancer reinforce the need for alternative therapies. Extracts from Piper plants have been used in the treatment of different pathologies for centuries (1). Piperlongumine (PPLGM) is an alkaloid obtained from Piper species with promising anticancer activity. Raj et al. in 2011 (2), reported that PPLGM induces cancer-selective cell death by elevating reactive oxygen species (ROS) levels, through inhibition of the antioxidant enzyme glutathione S-transferase. As cancer cells have increased ROS levels compared to normal cells, they were more susceptible to cell death induced by oxidative stress (3, 4). This therapeutic strategy has been extensively studied to selectively kill cancer cells (5, 6). Cell death induced by PPLGM has been related to apoptotic signals such as increased p53 and PUMA expression, cleaved caspase-3, decreased bcl-2 expression and DNA fragmentation (1, 7). However, some studies show that PPLGM activates autophagy in the presence of apoptotic inhibitors (8, 9). In colon cancer cell lines, PPLGM seems to work, at least in part, through the JNK and MEK/ERK pathways, by activating JNK and ERK, which can induce apoptotic enzymes or phosphorylate transcription factors that regulate the expression of pro-apoptotic genes (10, 11). Apoptosis is a programmed cell death mechanism that occurs through two major pathways: the extrinsic pathway induced by extracellular stress signals and propagated by specific transmembrane receptors, and the intrinsic pathway, mediated by mitochondrial outer membrane permeabilization (12). p53 is a tumor-suppressor protein that induces cellcycle arrest, apoptosis or senescence ...

Cumulative evidence from research studies has shown that the shiitake culinary-medicinal mushroom, Lentinus edodes, is an excellent source of natural antitumor agents and is capable of inhibiting cancer cell growth. However, the cell signaling pathway that leads tumor cells to apoptosis is not well understood because many chemical compounds may be acting. This study investigated the chemopreventive effects of an L. edodes aqueous extract on human HEp-2 epithelial larynx carcinoma cells and normal human MRC-5 lung fibroblasts by identifying proliferative and apoptotic pathways. The chemical characterization of the dry powder was assessed by high-performance liquid chromatography. Antiproliferative and proapoptotic effects induced by the extract were evaluated by assessing proliferative markers, cell sorting through flow cytometry, and expression levels of apoptotic proteins with Western blotting. The results suggest that inhibition of cell proliferation was more prominent in HEp-2 than in MRC-5 cells. Cell death analysis showed the appearance of cell populations in the sub-G1 phase, with late apoptotic signal increased in a dose-dependent manner. In addition, the aqueous extract induced depolarization of mitochondria, activating the generation of intracellular reactive oxygen species in HEp-2 cells. These observations suggest that L. edodes extract may exert a chemopreventive effect, regulating mitotic induction of apoptogenic signals. These findings highlight the mushroom's pharmacological potential in cancer treatment.