刺苞菜蓟叶的营养价值、抗氧化及抗菌特性

Biochemistry Department, Federal University of Technology, Akure, Nigeria.

J Med Food. 2006 Summer;9(2):276-80. doi: 10.1089/jmf.2006.9.276.

Struchium sparganophora leaf is a green leafy vegetable popularly used in soup preparations in processed and unprocessed forms in Nigeria. Fresh leaves of S. sparganophora were soaked overnight to remove its bitterness, before determination of the nutrient and antinutrient content, while sun-dried S. sparganophora leaves were extracted with rectified spirit. The antioxidant and antimicrobial properties of the extracts were subsequently determined. The result of the study revealed that the fresh leaf has high nutrient (protein, fat, crude fiber, and mineral) but low antinutrient (tannin and phytate) content. However, processing of the S. sparganophora leaf caused a significant decrease (P < .05) in both the nutrient and antinutrient contents. The ethanolic extract of the leaf contains alkaloids, tannin, saponins, phlobatannin, anthraquinone, and glycosides; furthermore, the extract has high antioxidant activity as typified by its high total phenol (5.4 g/100 g) content, reducing power (2.50 OD(700)), and free radical scavenging ability (65.2%). In addition, the extract (1.0 mg/mL) inhibited the growth of some pathogenic bacteria [Shigella dysenteriae (zone of inhibition 17.0 mm), Staphylococcus aureus (11.0 mm)] and fungi [Candida albicans (18.0 mm), Penicillium sp. (14.0 mm), Saccharomyces cerevisiae (15.0 mm)]. The inhibition of the bacterial and fungal growth was dose dependent. However, the same concentration of the extract did not inhibit the growth of Escherichia coli, Proteus sp., Pseudomonas aeruginosa, and Klebsiella sp., as well as the growth of the following fungi: Aspergillus fumigatus, Fusarium solani, and Aspergillus flavus. It could therefore be inferred that the leaf of S. sparganophora is promising both nutritionally and medicinally because of its high nutrient content, low antinutrient content, and arrays of pharmaceutically active phytochemicals with high levels of antioxidant and antimicrobial activity.

刺芋叶是一种绿叶蔬菜，在尼日利亚，无论是经过加工还是未加工的刺芋叶，都广泛用于汤品制作。在测定刺芋的营养成分和抗营养成分之前，将其新鲜叶子浸泡过夜以去除苦味，而将晒干的刺芋叶用精馏酒精进行提取。随后测定提取物的抗氧化和抗菌特性。研究结果表明，新鲜叶子营养成分（蛋白质、脂肪、粗纤维和矿物质）含量高，但抗营养成分（单宁和植酸盐）含量低。然而，刺芋叶的加工导致营养成分和抗营养成分均显著降低（P < 0.05）。叶的乙醇提取物含有生物碱、单宁、皂苷、鞣红、蒽醌和糖苷；此外，该提取物具有较高的抗氧化活性，其总酚含量高（5.4 g/100 g）、还原力强（2.50 OD(700)）、自由基清除能力高（65.2%）便是例证。此外，该提取物（1.0 mg/mL）抑制了一些病原菌的生长，如痢疾志贺氏菌（抑菌圈直径17.0 mm）、金黄色葡萄球菌（11.0 mm）以及真菌，如白色念珠菌（18.0 mm）、青霉菌（14.0 mm）、酿酒酵母（15.0 mm）。对细菌和真菌生长的抑制作用呈剂量依赖性。然而，相同浓度的提取物并未抑制大肠杆菌、变形杆菌、铜绿假单胞菌和克雷伯氏菌的生长，也未抑制以下真菌的生长：烟曲霉、茄病镰刀菌和黄曲霉。因此可以推断，由于刺芋叶营养成分含量高、抗营养成分含量低且含有一系列具有高抗氧化和抗菌活性的药用植物化学物质，其在营养和药用方面都具有潜力。