Passion fruit (Passiflora edulis) leaf extract modulates the oxidative metabolism of rat peritoneal neutrophils in a model of inflammation

This study was conducted to evaluate the effect of extracts of Passiflora edulis Sims leaves on the oxidative metabolism of rat peritoneal neutrophils using a model of acute inflammation. The extract was obtained by maceration in 70% ethanol, evaporation under reduced pressure and lyophilisation. Total phenolic content (TP) was determined by the Folin-Ciocalteu assay. The P. edulis extract, in different doses, was administered by gavage 1 h prior to inflammation induction by carrageenan (8 mg/kg, i.p.); five hours later, the neutrophils were obtained by intraperitoneal lavage. The tests performed in neutrophils were cytochrome C and chemiluminescence assay as well as myeloperoxidase (MPO), superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) activities. The administration of the extract reduced the number of neutrophils recruited to the site of inflammation; however, the extract did not alter the activity of NADPH oxidase as well as SOD activity in these cells. The MPO and CAT activities in peritoneal neutrophils of rat treated with extract was lower than in the control group, and the GPx activity was increased. Based on the experimental model utilised, the anti-inflammatory potential of P. edulis leaf extract could be related to the presence of phenolic compounds in the extract.

本研究借助急性炎症模型，探究西番莲（Passiflora edulis Sims）叶提取物对大鼠腹腔中性粒细胞氧化代谢的影响。该提取物采用70%乙醇浸渍、减压蒸发及冷冻干燥法制备。总酚含量（TP）采用福林-酚（Folin-Ciocalteu）法测定。以不同剂量的西番莲提取物在角叉菜胶（carrageenan，8 mg/kg，腹腔注射）诱导炎症前1小时经灌胃给药；诱导炎症5小时后，通过腹腔灌洗获取中性粒细胞。针对中性粒细胞开展的检测包括细胞色素C检测、化学发光分析法，以及髓过氧化物酶（MPO）、超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GPx）和过氧化氢酶（CAT）活性测定。给予西番莲提取物可减少募集至炎症部位的中性粒细胞数量，但该提取物并未改变中性粒细胞内烟酰胺腺嘌呤二核苷酸磷酸氧化酶（NADPH oxidase）及超氧化物歧化酶的活性。西番莲提取物给药组大鼠腹腔中性粒细胞内的髓过氧化物酶与过氧化氢酶活性低于对照组，而谷胱甘肽过氧化物酶活性则有所升高。基于本研究所用的实验模型，西番莲叶提取物的抗炎潜力可能与其所含酚类化合物有关。