Effect of NaFeEDTA-Fortified Soy Sauce on Anemia Prevalence in China: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

OBJECTIVE: To assess the effect of sodium iron ethylenediaminetetraacetate (NaFeEDTA)-fortified soy sauce on anemia prevalence in the Chinese population. METHODS: A systematic review was performed to identify potential studies by searching the electronic databases of PubMed, Cochrane Library, WHO Library, HighWire, CNKI, and other sources. The selection criteria included randomized controlled trials that compared the efficacy of NaFeEDTA-fortified soy sauce with that of non-fortified soy sauce. Anemia rates and hemoglobin levels were the outcomes of interest. Inclusion decisions, quality assessment, and data extraction were performed by two reviewers independently. A total of 16 studies met the inclusion criteria for anemia rate analysis, of which 12 studies met the inclusion criteria for hemoglobin analysis. All included studies assessed the effect of NaFeEDTA-fortified soy sauce on anemia rates and hemoglobin concentrations. RESULTS: After the intervention, the hemoglobin concentration increased and anemia rates decreased significantly as compared with the non-fortified soy sauce groups. For anemia rates, data from 16 studies could be pooled, and the pooled estimate odds ratio was 0.25 (95% CI 0.19-0.35). For hemoglobin concentrations, data from 12 studies could be pooled, and the pooled weighted mean difference was 8.81 g/L (95% CI 5.96-11.67). CONCLUSION: NaFeEDTA-fortified soy sauce has a positive effect on anemia control and prevention in the at-risk population.

Efficacy of different iron fortificants in wheat flour in controlling iron deficiency.

OBJECTIVE: To observe the different impacts of electrolytic iron, FeSO4, and NaFeEDTA on body iron store of anemic school students. METHODS: Four hundreds anemic students at the age of 11-18 years were divided into four groups. Of which, three consumed different iron fortificants from wheat flour as food vehicle for six months and one consumed non-fortified flour (control). The fortification level of electrolytic iron, FeSO4, and NaFeEDTA was 60 mg Fe/kg, 30 mg Fe/kg, and 20 mg Fe/kg, respectively. Blood samples were collected at 0, 2, 4, and 6 months and hemoglobin (Hb), serum ferritin (SF), and transferrin receptor (TfR) were measured. RESULTS: The hemoglobin levels in three intervention groups increased, the increments of Hb in the NaFeEDTA group were significantly higher than that in the other groups. SF and TfR levels increased in the tested groups and body iron store in the NaFeEDTA group was higher than that in the other groups. These parameters did not show any significant changes in the control group. CONCLUSION: NaFeEDTA and FeSO4 fortified wheat flour has positive impacts on iron status in anemic students and NaFeEDTA is more effective than FeSO4, while electrolytic iron is less effective in improving iron store in anemic students.

NaFeEDTA fortified soy sauce showed higher iron absorption rate in Chinese females.

OBJECTIVE: NaFeEDTA was considered as a promising iron fortificant for controlling iron deficiency anemia. Soy sauce is a suitable food carrier for iron fortification and is a popular condiment in China. Iron absorption rates of NaFeEDTA and FeSO4 were observed and compared in adult female subjects. METHODS: The stable isotope tracer method was used in Chinese females consuming a typical Chinese diet. Ten healthy young Chinese women were selected as subjects in the 15-day study. A plant-based diet was used based on the dietary pattern of adult women in the 1992 National Nutrition Survey. Six milligram of 54Fe in 54FeSO4 soy sauce and 3 mg 58Fe in Na58FeEDTA soy sauce were given to the same subjects in two days. Food samples and fecal samples were collected and analyzed. RESULTS: Iron absorption rates of NaFeEDTA and FeSO4 were 10.51% +/- 2.83 and 4.73% +/- 2.15 respectively. The 58Fe (NaFeEDTA) absorption was significantly higher than that of 54Fe (FeSO4) (P < 0.01). The iron absorption rate from NaFeEDTA was 1.2 times higher than that from FeSO4 in Chinese adult women consuming a typical Chinese diet. CONCLUSION: The higher absorption rate of NaFeEDTA suggested that NaFeEDTA would be a better iron fortificant used in soy sauce for the controlling of iron deficiency anemia in China.

Tea pigments induce cell-cycle arrest and apoptosis in HepG2 cells.

AIM: To investigate the molecular mechanisms by which tea pigments exert preventive effects on liver carcinogenesis. METHODS: HepG2 cells were seeded at a density of 5X10(5)/well in six-well culture dishes and incubated overnight. The cells then were treated with various concentrations of tea pigments over 3 d, harvested by trypsinization, and counted using a hemocytometer. Flow cytometric analysis was performed by a flow cytometer after propidium iodide labeling. Bcl-2 and p21(WAF1) proteins were determined by Western blotting. In addition, DNA laddering assay was performed on treated and untreated cultured HepG2 cells. RESULTS: Tea pigments inhibited the growth of HepG2 cells in a dose-dependent manner. Flow-cytometric analysis showed that tea pigments arrested cell cycle progression at G1 phase. DNA laddering was used to investigate apoptotic cell death, and the result showed that 100 mg/L of tea pigments caused typical DNA laddering. Our study also showed that tea pigments induced upregulation of p21(WAF1) protein and downregulation of Bcl-2 protein. CONCLUSION: Tea pigments induce cell-cycle arrest and apoptosis. Tea pigments may be used as an ideal chemopreventive agent.

[Effects of tea polyphenols and tea pigments on apoptosis in HepG2 cell line].

OBJECTIVE: To investigate the effect of tea polyphenols and tea pigments on apoptosis in HepG2 cells. METHODS: HepG2 cells were seeded at a density of 5 x 10(5)/well in six-well culture dishes. The cells were then treated with 50 or 100 mg/L tea pigments and harvested at 48h by trypsinization. Agrose electrophoresis was applied to investigate DNA-LADDER, Bcl-2 and Bax protein expression were detected by Western blot. RESULTS: Tea polyphenols and tea pigments induced the appearance of DNA-LADDER; Western blot analysis demonstrated that Bcl-2 expression was significantly inhibited and the expression of Bax was significantly induced by tea polyphenols and tea pigments. CONCLUSION: Induction of apoptosis may be an important mechanism of cancer chemoprevention by tea.

[Effects of tea polyphenols and tea pigments on telomerase activity of HepG2 cells].

OBJECTIVE: This study is to investigate the effect of tea polyphenols and tea pigments on telomerase activity of human liver cancer cell line, HepG2 cells. METHODS: TRAP-PCR-ELISA was applied to investigate the telomerase activity. RESULTS: Telomerase was positive in tea polyphenols treated groups, tea pigments treated groups and blank control group. Telomerase activities (A(450 approximately 690) values) were 1.56 and 1.46 in 50 mg/L and 100 mg/L tea polyphenols-treated groups, 1.55 and 1.49 in 50 mg/L and 100 mg/L tea pigments-treated groups, respectively. The results showed that telomerase activity was significantly inhibited by tea polyphenols and tea pigments treatment as compared with the blank control group (A(450 approximately 690) = 2.11). CONCLUSIONS: Tea polyphenols and tea pigments could significantly inhibit telomerase activity of HepG2 cells, and telomerase activity may be a useful biomarker for cancer chemoprevention.

Direct reduction of N-acetoxy-PhIP by tea polyphenols: a possible mechanism for chemoprevention against PhIP-DNA adduct formation.

The chemopreventive effect of tea against 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-DNA adduct formation and its mechanism were studied. Rats were exposed to freshly prepared aqueous extracts of green tea (3% (w/v)) as the sole source of drinking water for 10 days prior to administration with a single dose of PhIP (10 mg/kg body weight) by oral gavage. PhIP-DNA adducts in the liver, colon, heart, and lung were measured using the 32P-postlabelling technique. Rats pre-treated with tea and given PhIP 20 h before sacrifice had significantly reduced levels of PhIP-DNA adducts as compared with controls given PhIP alone. The possible mechanism of protective effect of tea on PhIP-DNA adduct formation was then examined in vitro. It was found that an aqueous extract of green and black tea, mixtures of green and black tea polyphenols, as well as purified polyphenols could strongly inhibit the DNA binding of N-acetoxy-PhIP, a putative ultimate carcinogen of PhIP formed in vivo via metabolic activation. Among these, epigallocatechin gallate was exceptionally potent. HPLC analyses of these incubation mixtures containing N-acetoxy-PhIP and the tea polyphenols each revealed the production of the parent amine, PhIP, indicating the involvement of a redox mechanism. In view of the presence of relatively high levels of tea polyphenols in rat and human plasma after ingestion of tea, this study suggests that direct reduction of the ultimate carcinogen N-acetoxy-PhIP by tea polyphenols is likely to be involved in the mechanism of chemoprotection of tea against this carcinogen.