Antioxidant drugs to prevent post-endoscopic retrograde cholangiopancreatography pancreatitis:What does evidence suggest?

AIM:To determine whether or not the use of antioxidant supplementation aids in the prevention of post-endoscopic retrograde cholangiopancreatography pancreatitis.METHODS:A systematic review of randomized controlled trials(RCTs) was made to evaluate the preventive effect of prophylactic antioxidant supplementation in post-endoscopic retrograde cholangiopancreatography pancreatitis(PEP).The inclusion criteria included:acute post-endoscopic retrograde cholangiopancreatography pancreatitis in adults; randomized clinical trials with the use of any antioxidant as an intervention compared with placebo,to reduce PEP.The outcome measure was the incidence and severity of PEP.Twelve RCTs involving 3110 patients since 1999 wereincluded.The antioxidants used were selenite,β-carotene,and pentoxifylline(each one in one trial),N-acetylcysteine(NAC) in three trials,and allopurinol in six trials.The group of patients treated with NAC received different doses; either oral or intravenous,and allopurinol-treated patients received five different oral doses in two different administration periods.The results are expressed with raw numbers,proportions,as well as mean and standard deviations.The incidence of pancreatitis between groups was analyzed with Pearson's χ2 test or Fisher's exact test(F).The main outcome is expressed as relative risks and 95%CI.RESULTS:The incidence of pancreatitis in all antioxidant treatment groups was 8.6%,whereas it was 9.7% in the control group.The antioxidants used were selenite,β-carotene,and pentoxifylline(each one in one trial),NAC in three trials,and allopurinol in six trials.In allopurinol trials,three different dosifications were used; two trials reported a low dosage(of less than 400 mg),two trials reported a moderate dose(600 mg) and the remaining two employed higher doses(more than 900 mg).Supplementation was not associated with a significant reduction in the incidence of PEP [relative risk(RR) = 0.93; 95%CI:0.82-1.06; P = 0.28].In addition,the incidences of PEP in patients treated with allopurinol and those treated with other antioxidants were similar to that observed in patients who received the placebo(RR for trials with allopurinol,0.92; 95%CI:0.78-1.08; P = 0.31) and,with the use of other antioxidants,the incidence of PEP was 8.9%,whereas it was 9.7% in the control group(RR = 0.95; 95%CI:0.77-1.18; P = 0.19).CONCLUSION:Antioxidant supplementation shows no beneficial effect on the incidence of PEP.There is a lack of robust trials to support the use of antioxidants for prevention.

6种药用食物多糖清除活性氧及对全血化学发光的抑制作用

目的 :研究 6种药用食物多糖对全血化学发光和活性氧的抑制作用。方法 :从黑芝麻、黑豆、黑木耳、海带、紫菜和红枣中分别提取多糖 ,运用化学发光分析方法测定多糖清除活性氧及抑制全血化学发光的作用。结果 :6种多糖对全血化学发光有较强的抑制作用 ,而对非细胞体系产生的活性氧的清除能力较弱。结论 :黑木耳多糖和海带多糖对白细胞的吞噬功能有免疫抑制作用 ,黑豆、黑芝麻、紫菜和红枣 4种多糖对白细胞的吞噬功能也有一定的抑制作用 ,6种多糖有间接清除活性氧的作用。