ABSTRACT
A field litterbag experiment was conducted to investigate dynamics of total phenols and condensed tannin in the mixed leaf litter of Pinus massoniana (P) with other three broad-leaved species, i.e., Sassafras trumu (S), Cinnamomum camphora (C), Toona sinensis (T) during decomposition in low hilly lands, Sichuan Province, China. The mass ratio of P. massoniana : S. trumu (PS) was 6:4, 7:3, 8:2, P. massoniana : C. camphora (PC) was 6:4, 7:3, 8:2 and P. massoniana : T. sinensis (PT) was 6:4, 7:3, 8:2, respectively. The results showed that the degradation rate of condensed tannin in pure P. massoniana litter was 84.4%, being significantly lower than that in the mixed litters after 180 d. The degradation rate of condensed tannin and total phenols were the highest in PC 6:4, with 90.3% and 68.6%, respectively. The mixed litters promoted the decomposition of condensed tannin and total phenols in the P. massoniana litter. With decomposition time, the degradation rate of condensed tannin in mixed litters between P. massoniana and broad-leaved species initial increased, and then remained stable. The degradation rate of total phenols in pure P. massoniana litter, PT 7:3 and all the PC treatments increased significantly and then decreased during the 90 d decomposition. The degradation rate of total phenols in all the PS, PT 6:4 and 8:2 treatments increased with the decomposition time. The dynamics of total phenols and condensed tannin were closely related to litter quality, and the enzyme activities of polyphenol oxidase, peroxidase and leucine aminopeptidase.
Subject(s)
Phenols/metabolism , Plant Leaves/chemistry , Proanthocyanidins/metabolism , China , Pinus , Plant Leaves/enzymology , TreesABSTRACT
Epidemiological studies were inconsistent on the association between soy food intake and risk of gastric cancer (GC). This study aimed to determine the role of soy food intake in the development of GC.A systematic search was conducted in PubMed and Web of Science to identify all relevant studies. Study-specific relative risks (RRs) and 95% confidence intervals (CIs) were pooled using a random-effects model, and the dose-response relationship between soy food intake and GC risk was also assessed.Thirteen prospective studies were identified with a total of 517,106 participants and 5800 cases. Among 11 types of soy food, high intake of total soy food (the highest vs the lowest category: RR: 0.78, 95% CI: 0.62-0.98) and nonfermented soy food (RR: 0.63, 95% CI: 0.50-0.79) were inversely associated with GC risk, while high intake of miso soup was associated with the risk in male (RR: 1.17, 95% CI: 1.02-1.36). In dose-response meta-analysis, total soy food intake (0-150âg/day) showed no significant association with GC risk, while high intake of nonfermented soy food was inversely related, especially an intake of more than 100âg/day. In male, miso soup intake (1-5âcups/day) was significantly associated with GC risk.High intake of nonfermented soy food might reduce the risk of GC, while miso soup intake might increase the risk in male.