phytosterols and taraxasterol

Substantial attention has been given to primary cancer prevention in daily life. Dietary factors are through to contribute to as much as one-third of the factors influencing the development of cancer. Ones of the components of a plant-based diet are beta-sitosterol and taraxasterol, compounds attracting our specific attention. This review summarizes the biological activities of presented phytosterols (anti-inflammatory, cholesterol-lowering, anti-microbial, anti-bacterial, anti-fungal effects). Our interest has been focussed especially on their anti-tumor and chemopreventive activity. They have been shown experimentally to inhibit colon and breast cancer development. They act at various stages of tumor development, including inhibition of tumorigenesis, inhibition of tumor promotion, and induction of cell differentiation. They effectively inhibit invasion of tumor cells and metastasis. With regard to toxicity, no obvious side effects of phytosterols have been observed in studies to date, with the exception of individuals with phytosterolemia. The exact mechanism by which dietary phytosterols act is not fully understood. However, some mechanisms have been offered. Therefore, they have a bright future in clinical application. Further investigation to explore their potential in tumor treatment may prove to be worthwhile.

Topics: Animals; Anti-Inflammatory Agents; Anticarcinogenic Agents; Antineoplastic Agents; Antioxidants; Breast Neoplasms; Colonic Neoplasms; Diet; Drugs, Chinese Herbal; Female; Humans; Phytosterols; Sitosterols; Sterols; Triterpenes

Suspension-cultured cells of Solanum lycopersicum cv Micro-Tom were used to evaluate the effect of methyl jasmonate and cyclodextrins, separately or in combination, on the induction of defense responses. An extracellular accumulation of two sterols (isofucosterol and β-sitosterol) and taraxasterol, a common tomato fruit cuticular triterpene, were observed. Their levels were higher in Micro-Tom tomato suspension cultured cells elicited with cyclodextrins than in control and methyl jasmonate-treated cells. Also, their accumulation profiles during the cell growth phase were markedly different. The most striking feature in response to cyclodextrin treatments was the observed enhancement of taraxasterol accumulation. Likewise, the exogenous application of methyl jasmonate and cyclodextrins induced the accumulation of pathogenesis-related proteins. Analysis of the extracellular proteome showed the presence of amino acid sequences homologous to pathogenesis-related 1 and 5 proteins, a cationic peroxidase and a biotic cell death-associated protein, which suggests that methyl jasmonate and cyclodextrins could play a role in mediating defense-related gene product expression in S. lycopersicum cv Micro-Tom.

Topics: Acetates; Cyclodextrins; Cyclopentanes; Oxylipins; Phytosterols; Plant Proteins; Solanum lycopersicum; Sterols; Triterpenes