Oboh G
Biochemistry Department, Federal University of Technology, P.M.B. 704, Akure, Ondo State, Nigeria.
Nutr Health. 2006;18(2):151-60. doi: 10.1177/026010600601800207.
Vernonia amygdalina (Bitter leaf) is popularly consumed in many homes in Nigeria as a vegetable in soup preparation, while the infusion is used in folk medicine in the treatment of malaria fever. In this study, fresh leaves of Vernonia amygdalina were subjected to abrasion (to remove the bitter taste) as is normally done in soup preparation, subsequently the nutrient, anti-nutrient and zinc bioavailability of the processed and unprocessed leaf were determined. The heamolytic effect of the leaf infusion on human erythrocytes (Genotype-SS, AS, AA) was also determined.
The study revealed that Vernonia amygdalina leaf has high protein (33.3%), fat (10.1%), crude fibre (29.2%), ash (11.7%), mineral (Na, K, Ca, Mg, Zn & Fe), phytate (1015.4mg/100g) and tannin (0.6%) content, while it contain low cyanide (1.1mg/kg). Abrasion of the leaf caused a significant decrease (P<0.05) in both the nutrient and antinutrient content of the leaf except in carbohydrate where there was a significant increase (P<0.05) and Mg where there was no significant change (P>0.05). The result of the calculated [Ca][phytate]/ [Zn] molar ratio (the best index for the prediction of Zn bioavailability) indicated that the phytate content of both the processed and unprocessed Vernonia amygdalina leaf will not reduce the Zn content to a critical level (0.5mol./kg). Further studies on the leaf revealed that the infusion induced the haemolysis of human erythrocyte (In vitro). Human genotype-SS (1024) were highly susceptible to haemolysis induced by Vernonia amygdalina infusion, genotype-AS moderately susceptible (512) while genotype-AA (256) is highly resistant to haemolysis induced by the same infusion.
Bitter leaf has high nutrient and antinutrient content, however, abrasion will bring about a significant decrease (P<0.05) in both. The infusion of the Vernonia amygdalina leaf induces the haemolysis of mammalian erythrocyte in vitro, with Human-SS having the highest susceptibility.
在尼日利亚,许多家庭普遍将扁桃斑鸠菊(苦叶)作为蔬菜用于煮汤,而其浸剂在民间医学中用于治疗疟疾发热。在本研究中,扁桃斑鸠菊的新鲜叶子按照煮汤时通常的做法进行研磨(以去除苦味),随后测定了加工前后叶子的营养成分、抗营养成分及锌的生物利用度。还测定了叶子浸剂对人体红细胞(基因型SS、AS、AA)的溶血作用。
研究表明,扁桃斑鸠菊叶含有高蛋白(33.3%)、脂肪(10.1%)、粗纤维(29.2%)、灰分(11.7%)、矿物质(钠、钾、钙、镁、锌和铁)、植酸盐(1015.4毫克/100克)和单宁(0.6%),而氰化物含量较低(1.1毫克/千克)。叶子研磨后,除碳水化合物含量显著增加(P<0.05)和镁含量无显著变化(P>0.05)外,叶子的营养成分和抗营养成分均显著降低(P<0.05)。计算得出的[钙][植酸盐]/[锌]摩尔比(预测锌生物利用度的最佳指标)结果表明,加工前后的扁桃斑鸠菊叶中的植酸盐含量不会将锌含量降低到临界水平(0.5摩尔/千克)。对该叶子的进一步研究表明,浸剂在体外会诱导人体红细胞溶血。人类基因型SS(1024)对扁桃斑鸠菊浸剂诱导溶血高度敏感,基因型AS中度敏感(512),而基因型AA(256)对相同浸剂诱导的溶血高度抗性。
苦叶含有高营养成分和抗营养成分,然而,研磨会使两者都显著降低(P<0.05)。扁桃斑鸠菊叶浸剂在体外会诱导哺乳动物红细胞溶血,其中人类SS型敏感性最高。