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Protective effects of Allium vegetables against cancers have been shown extensively in experimental animals and epidemiologic studies. We investigated cell proliferation and the induction of apoptosis by onion oil extracted from Allium cepa, a widely consumed Allium vegetable, in human lung cancer A549 cells. GC/MS analysis suggested that propyl sulfides but not allyl sulfides are major sulfur-containing constituents of onion oil. Onion oil at 12.5 mg/L significantly induced apoptosis (13% increase of apoptotic cells) as indicated by sub-G1 DNA content. It also caused cell cycle arrest at the G2/M phase; 25 mg/L onion oil increased the percentage of G2/M cells almost 6-fold compared with the dimethyl sulfoxide control. The action of onion oil may occur via a reactive oxygen species-dependent pathway because cell cycle arrest and apoptosis were blocked by the antioxidants N-acetylcysteine and exogenous glutathione. Marked collapse of the mitochondrial membrane potential suggested that dysfunction of the mitochondria may be involved in the oxidative burst and apoptosis induced by onion oil. Expression of phospho-cdc2 and phospho-cyclin B1 were downregulated by onion oil, perhaps accounting for the G2/M arrest. Overall, these results suggest that onion oil may exert chemopreventive action by inducing cell cycle arrest and apoptosis in tumor cells. KEY WORDS: * onion * allium * cell cycle * apoptosis * chemoprevention

The activity of soluble invertase, and the variation in glucose, fructose and sucrose contents in onion bulbs (Allium cepa) during long-term storage at 10[degrees]C and 20[degrees]C were investigated. Invertase activity increased progressively after 8 weeks to 0.084 and 0.092 nkat/g fresh weight (FW), then sharply to 0.29 and 0.35 nkat/g FW at 20[degrees]C and 10[degrees]C, respectively, and remained high during 5 weeks. Then, activity decreased abruptly to 0.039 and 0.041 nkat/g, and remained low during the last 8 weeks and close to that observed initially. Glucose increased to 17.73 and 14.62 mg/g FW after 4 weeks at 20[degrees]C and 10[degrees]C, respectively, then decreased sharply between week 5 and week 7 to 4.13 and 4.91 mg/g FW, respectively, and remained rather stable ranging from 9 and 10 mg/g FW at both temperatures. Fructose showed a similar pattern and was 14.8 and 21.68 mg/g FW at 20[degrees]C and 10[degrees]C, respectively. Between week 10 and week 24, fructose ranged from 5 and 6 mg/g FW, and from 6 and 7 mg/g FW at 20[degrees]C and 10[degrees]C, respectively. Sucrose increased to 19.63 and 14.43 mg/g FW at 20[degrees]C and 10[degrees]C, respectively, decreased during 3 weeks, and then increased randomly from 5.69 to 9.42 mg/g FW at 20[degrees]C, but remained in a steady state at 10[degrees]C ranging 5.03 [+ or -] 0.78 mg/g FW. During the last 6 weeks, the sucrose content was higher at 20[degrees]C than at 10[degrees]C. The fructose-glucose ratio varied during the first 8 weeks but remained at a steady level during the last 16 weeks. The (glucose + fructose)/sucrose ratio increased randomly at 10[degrees]C, whereas at 20[degrees]C the ratio increased during 10 weeks then decreased progressively during the final 14 weeks.

Byline: Gholamali. Jelodar, M. Maleki, M. Motadayen, S. Sirus BACKGROUND: Many traditional treatments have been recommended in the alternative system of medicine for treatment of diabetes mellitus; however, the mechanism [...]

A small clinical trial (five patients) conducted at Johns Hopkins University School of Medicine, Baltimore, MD, showed that a pill combining chemicals found in curries and onions reduced both the [...]

Researchers at the University of Bern in Switzerland have identified a compound in the popular vegetable that appears to decrease bone loss in laboratory studies using rat bone cells. It is suggested that eating onions might help prevent bone loss and osteoporosis, a disease, which predominantly affects older women.