Natural products and health foods have recently received a lot of attention both by health professionals and the common population for improving overall well-being, as well as in the prevention of diseases including cancer. In this line, all types of fruits and vegetables have been re-evaluated and recognized as valuable sources of nutraceuticals. The great number of potentially active nutrients and their multifunctional properties make cactus pear (Opuntia spp.) fruits and cladodes perfect candidates for the production of health-promoting food and food supplements. Although traditionally appreciated for its pharmacological properties by the Native Americans, cactus pear is still hardly recognized because of insufficient scientific information. However, recent studies on Opuntia spp. have demonstrated cactus pear fruit and vegetative cladodes to be excellent candidates for the development of healthy food. Therefore, this review summarizes current knowledge on the chemical composition of Opuntia cacti with particular emphasis in its use as food and medicine.

Background: Male infertility is a major problem for mammalian reproduction. However, molecular details including the underlying mechanisms of male fertility are still not known. A thorough understanding of these mechanisms is essential for obtaining consistently high reproductive efficiency and to ensure lower cost and time-loss by breeder. Results: Using high and low fertility bull spermatozoa, here we employed differential detergent fractionation multidimensional protein identification technology (DDF-Mud PIT) and identified 125 putative biomarkers of fertility. We next used quantitative Systems Biology modeling and canonical protein interaction pathways and networks to show that high fertility spermatozoa differ from low fertility spermatozoa in four main ways. Compared to sperm from low fertility bulls, sperm from high fertility bulls have higher expression of proteins involved in: energy metabolism, cell communication, spermatogenesis, and cell motility. Our data also suggests a hypothesis that low fertility sperm DNA integrity may be compromised because cell cycle: G₂/M DNA damage checkpoint regulation was most significant signaling pathway identified in low fertility spermatozoa. Conclusion: This is the first comprehensive description of the bovine spermatozoa proteome. Comparative proteomic analysis of high fertility and low fertility bulls, in the context of protein interaction networks identified putative molecular markers associated with high fertility phenotype.

Background: Cancer chemoprevention is a new approach in cancer prevention, in which chemical agents are used to prevent cancer in normal and/or high-risk populations. Although chemoprevention has shown promise in some epithelial cancers, currently available preventive agents are limited and the agents are costly, generally with side effects. Natural products, such as grape seed, green tea, and certain herbs have demonstrated anti-cancer effects. To find a natural product that can be used in chemoprevention of cancer, we tested Arizona cactus fruit solution, the aqueous extracts of cactus pear, for its anti-cancer effects in cultured cells and in an animal model. Method: Aqueous extracts of cactus pear were used to treat immortalized ovarian and cervical epithelial cells, as well as ovarian, cervical, and bladder cancer cells. Aqueous extracts of cactus pear were used at six concentrations (0, 0.5, 1, 5, 10 or 25%) to treat cells for 1, 3, or 5 days. Growth inhibition, apoptosis induction, and cell cycle changes were analyzed in the cultured cells; the suppression of tumor growth in nude mice was evaluated and compared with the effect of a synthetic retinoid N-(4-hydroxyphernyl) retinamide (4-HPR), which is currently used as a chemoprevention agent. Immunohistochemistry staining of tissue samples from animal tumors was performed to examine the gene expression. Results: Cells exposed to cactus pear extracts had a significant increase in apoptosis and growth inhibition in both immortalized epithelial cells and cancer cells in a dose- and time-dependent manner. It also affected cell cycle of cancer cells by increasing G1 and decreasing G2 and S phases. Both 4-HPR and cactus pear extracts significantly suppressed tumor growth in nude mice, increased annexin IV expression, and decreased VEGF expression. Conclusion: Arizona cactus pear extracts effectively inhibited cell growth in several different immortalized and cancer cell cultures, suppressed tumor growth in nude mice, and modulated expression of tumor-related genes. These effects were comparable with those caused by a synthetic retinoid currently used in chemoprevention trials. The mechanism of the anti-cancer effects of cactus pear extracts needs to be further studied.

Quercetin, a flavonoid found in many fruits and vegetables, belongs to an extensive class of polyphenolic compounds. Previous studies reported that quercetin inhibits the proliferation of various cancer cells and tumor growth in animal models. We investigated the growth inhibition and colony formation of quercetin on three bladder cancer cells (EJ, J82 and T24). The expression of tumor suppressor genes and oncogenes such as P53, Survivin, PTEN, as well as the methylation status of these genes was also evaluated. We observed that quercetin induced apoptosis in bladder cancer cells in a time- and dose-dependent manner. Quercetin (100 micromolars) significantly inhibited EJ, T24 and J82 cell growth accompanied by an increase in the G0/G1 phase. In all cell lines, quercetin decreased the expression of mutant P53 and Survivin proteins. However, there was no change in the level of PTEN protein. Moreover, the DNA methylation levels of the estrogen receptor (Er-beta), P16INK4a and RASSF1A were strongly decreased (from 35 to 70%) in the quercetin-treated group compared to the control. In conclusion, our study suggested that quercetin inhibits growth, colony formation and hypermethylation of bladder cancer cell lines. Quercetin-induced apoptosis might be associated with a decrease in mutant P53 and Survivin proteins.