Molecular nutrition & food research
-
Matrix metalloproteinase (MMP) plays an important role in the invasion and metastasis of cancer cells. The inhibitory effects of bergamottin, a cytochrome P450 inhibitor from Citrus paradis (grapefruit), on tumor invasion and migration and the possible mechanisms involved in this inhibition were investigated in human fibrosarcoma HT-1080 cells. Bergamottin reduced phorbol-12-myristate-13-acetate (PMA)-induced activation of MMP-9 and MMP-2 and further inhibited cell invasion and migration. ⋯ Furthermore, bergamottin strongly repressed the PMA-induced phosphorylation of p38 mitogen-activated protein kinase and c-Jun N-terminal kinase (JNK), which are dependent on the protein kinase C-delta pathway. In conclusion, we demonstrated that the anti-invasive effects of bergamottin might occur through inhibition of protein kinase C-delta, p38 mitogen-activated protein kinase, and JNK phosphorylation and reduction of NF-kappaB activation, leading to downregulation of MMP-9 expression. These results suggest that the suppression of MMP expression contributes, at least in part, to the antitumor activity of bergamottin.
-
Pyrrolizidine alkaloids (PAs) are secondary plant constituents that comprise about 400 different structures and occur in two major forms, a tertiary form and the corresponding N-oxide. PAs containing a 1,2-double bond are pre-toxins and metabolically activated by the action of hepatic P-450 enzymes to toxic pyrroles. Besides the acute toxic effects, the genotoxic and tumorigenicity potential of PAs was demonstrated in some eukaryotic model systems. ⋯ In numerous studies the potential threat to human health by PAs is stated. In pharmaceuticals, the use of these plants is regulated. Considering the PA concentrations observed especially in authentic honey from PA producing plants and pollen products, the results provoke an international regulation of PAs in food.
-
Epidemiological studies have shown marked variations in prostate cancer incidence and mortality across different geographic regions, leading to the rising interest in the role of nutrition in prostate cancer risk. There is also a large body of evidence that a diverse diet, rich in vegetables, can reduce the risk of prostate cancer. In this review, the role of various kinds of vegetables and their bioactive compounds associated with prostate cancer risk, and the underlying mechanisms of these associations are summarized. ⋯ Evidence on the effect of pulses or soy consumption on prostate cancer risk was limited but suggestive of decreased risk with increased pulses or soy consumption. However, the role of vitamin C, vitamin E, allium vegetables, and cruciferous vegetables on prostate cancer risk remains to be determined due to limited evidence. Although the impact on prostate cancer risk differs among various vegetables and their constituent nutrients, the overall benefits of plant based diet on cancer prevention and other diet-related diseases should be promoted.
-
Recently, contamination of honey with pyrrolizidine alkaloids (PA) has been reported as potential health risk. Therefore, it was of interest to develop a reliable tool for selective and quantitative determination of PA in honey. Sample preparation of the novel method comprises strong cation exchange SPE (SCX-SPE), followed by two reduction steps using zinc and LiAlH(4), as well as subsequent silylation. ⋯ The reported method facilitates the selective determination of PA without the need to identify each individual PA independently. The PA contamination of honey is expressed in terms of a single sum parameter and no background information such as foraged plants and pollen analysis is necessary. The LOQ is 0.01 ppm with a S/N of 7:1.
-
Garlic (Alllium sativum L., Fam Liliaceae) is used medicinally mainly for the treatment of hypercholesterolemia and prevention of arteriosclerosis. Clinical trials have consistently shown that "garlic breath" and body odor are the most common (and well-documented) complaints associated to garlic intake. ⋯ Consumption of garlic by nursing mothers modifies their infant's behavior during breast-feeding. Finally, garlic may enhance the pharmacological effect of anticoagulants (e. g. warfarin, fluindione) and reduce the efficacy of anti-AIDS drugs (i. e. saquinavir).