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Protective Effect of Folic Acid on Oxidative DNA Damage: A Randomized, Double-Blind, and Placebo Controlled Clinical Trial.
Guo, X, Cui, H, Zhang, H, Guan, X, Zhang, Z, Jia, C, Wu, J, Yang, H, Qiu, W, Zhang, C, et al
Medicine. 2015;(45):e1872
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Abstract
Although previous reports have linked DNA damage with both transmissions across generations as well as our own survival, it is unknown how to reverse the lesion. Based on the data from a Randomized, Double-blind, Placebo Controlled Clinical Trial, this study aimed to assess the efficacy of folic acid supplementation (FAS) on DNA oxidative damage reversal.In this randomized clinical trial (RCT), a total of 450 participants were enrolled and randomly assigned to 3 groups to receive folic acid (FA) 0.4 mg/day (low-FA), 0.8 mg/day (high-FA), or placebo (control) for 8 weeks. The urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and creatinine (Cr) concentration at pre- and post-FAS were measured with modified enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC), respectively. A multivariate general linear model was applied to assess the individual effects of FAS and the joint effects between FAS and hypercholesterolemia on oxidative DNA damage improvement. This clinical trial was registered with ClinicalTrials.gov, number NCT02235948.Of the 438 subjects that received FA fortification or placebo, the median (first quartile, third quartile) of urinary 8-OHdG/Cr for placebo, low-FA, and high-FA groups were 58.19 (43.90, 82.26), 53.51 (38.97, 72.74), 54.73 (39.58, 76.63) ng/mg at baseline and 57.77 (44.35, 81.33), 51.73 (38.20, 71.30), and 50.65 (37.64, 76.17) ng/mg at the 56th day, respectively. A significant decrease of urinary 8-OHdG was observed after 56 days FA fortification (P < 0.001). Compared with the placebo, after adjusting for some potential confounding factors, including the baseline urinary 8-OHdG/Cr, the urinary 8-OHdG/Cr concentration significantly decreased after 56 days FAS [β (95% confidence interval) = -0.88 (-1.62, -0.14) and P = 0.020 for low-FA; and β (95% confidence interval) = -2.68 (-3.42, -1.94) and P < 0.001 for high-FA] in a dose-response fashion (Ptrend < 0.001). Test of interaction between hypercholesterolemia and FA supplementation on urinary 8-OHdG reduction was significant (P = 0.001).The present study demonstrates that FA fortification is independently linked to the reduction of urinary 8-OHdG/Cr in a dose-related pattern, which suggests that FA is beneficial to protect against oxidative damage to DNA. This effect is apparently stronger in those with hypercholesterolemia. The authors provide a new insight into the prevention and reversal of oxidative DNA damage.
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[Clinical efficacy of vitamin support in lung adenocarcinoma patients treated with pemetrexed second-line chemotherapy].
Zeng, X, Zhou, C, Ouyang, M, Qin, Y, Yang, H, Peng, Y, Liu, S
Zhonghua zhong liu za zhi [Chinese journal of oncology]. 2015;(11):868-72
Abstract
OBJECTIVE To analyze the clinical efficacy and toxicity of vitamin support in lung adenocarcinoma patients treated with pemetrexed second-line chemotherapy. METHODS Two hundred and eighty-three patients with stage 3/4 lung adenocarcinoma treated at our hospital from August 2010 to August 2013 were included in this study. The lung adenocarcinomas in all the 283 patients were confirmed by pathology or cytology, all were EGFR-negative, and all patients received pemetrexed second line chemotherapy. The 283 patients were randomly divided into two groups: the improved treatment group (142 cases) and the conventional treatment group (141 cases). The patients of conventional treatment group received 400 µg folic acid per os daily for 7 days before the first dose of pemetrexed, and continued until 21 days after the last dose of pemetrexed. Besides, they received 1000 µg vitamin B12 injection at 7 days before the first dose of pemetrexed, and once per cycle of pemetrexed for 3 cycles after the last dose of pemetrexed. The patients of the improved treatment group took 400 µg folic acid daily per os from the day before the first dose to 21 days after the last dose of pemetrexed. They also received 500 µg vitamin B12 by injection one day before the first dose, and one day before each therapy cycle of pemetrexed therapy. RESULTS The mean number of cycles of pemetrexed chemotherapy was 4 in both groups. In the 142 patients of improved treatment group, complete response (CR) was observed in two cases, partial remission (PR) in 28, stable disease (SD) in 21, and progressive disease (PD) in 91 cases, with a total effective rate of 21.1%. While in the conventional treatment group, CR was observed in one case, PR in 27 cases, SD in 23 cases, and PD in 90 cases, with a total effective rate of 19.9%. The median progression-free survival (PFS) was 3.8 months in the improved treatment group and 4.2 months in the conventional treatment group (P=0.143). The toxicity of chemotherapy was mild in both groups, with no significant difference between the two groups (P>0.05). The most common side effects of hematological system were leukopenia and neutropenia, and the most common side effects of non-blood system were nausea and vomiting. The most common grade 3-4 toxic reaction in both groups was leukopenia and neutropenia, with no significant difference between the two groups (P>0.05). Multivariate analysis showed that the age of patients was an independent factor of grade 3-4 chemotherapy toxic reaction (P<0.05), while gender, the baseline level of PS score or blood system had no significant effect on the grade 3-4 chemotherapy toxic reaction (P>0.05). CONCLUSIONS Compared with the conventional treatment scheme, the improved treatment scheme has similar therapeutic effects and could be used more conveniently, while the toxic effects of chemotherapy are not increased at the same time. Our results indicate that pemetrexed-based chemotherapy does not need to delay the chemotherapy because of vitamin support treatment.