Direct toxicity of amyloid beta peptide on rat brain mitochondria: preventive role of Mangifera indica and Juglans regia

Role of mitochondrial dysfunction and oxidative stress has been well documented in various cognitive-related disorders such as Alzheimer's disease (AD). Evidence indicates that Aß formation impairs mitochondrial function and that mitochondrial dysfunction is an early event in the pathogenesis of AD. The present study was, therefore, designed to investigate the direct toxicity of Aß peptide on isolated mitochondria obtained from rat brain. Various mitochondrial toxicity/integrity parameters such as succinate dehydrogenase activity, reactive oxygen species (ROS) formation, mitochondrial membrane potential collapse (MMP), mitochondrial swelling, and cytochrome c release were measured following the addition of Aß peptide on isolated mitochondria and then, mitoprotective effect of aqueous extracts of Mangifera indica and Juglans regia against mitochondrial toxicity endpoints parameters induced by Aß peptide were assessed. Our results showed that exposure to Aß peptide (30 nM) in isolated brain mitochondria induced mitochondrial ROS formation, MMP collapse, mitochondrial swelling, and cytochrome c release which is the starting point of apoptosis signaling. All these mitochondrial toxic endpoints induced by Aß peptide inhibited by aqueous extracts of Mangifera indica (100–400 µg/ml) and Juglans regia (200–400 µg/ml). To our knowledge, this is one of the first apparent studies to claim directly targeting of brain mitochondria and induction of apoptosis by Aß peptide as a new hypothesis for etiology of AD and other related neurodegenerative diseases as well as mitopreventive role of common antioxidant nutritional products including walnut and mango.     

三台核桃授粉特性研究

本文研究表明三台核桃可自花授粉、异花授粉、不交自育;花粉传播的水平距离可达350m。     

三台核桃结实特性研究

研究表明:草果核桃是优良的栽培品种,早熟核桃结实性状表现最差;果枝粗是影响座果率的最重要性状。     

三台核桃开花的生物学特性

本文观察了三台核桃芽的特性、开花物候期、开花习性、花期分析、落花情况等生物学特性。     

喀斯特特有植物罗甸小米核桃幼苗对光照强度的可塑性响应

研究光照强度对1年生喀斯特特有植物罗甸小米核桃幼苗可塑性的影响,探讨其在个体定居初期如何响应不同光照强度的变化及其生态适应策略.设置约为自然光100％、75％、50％和25％的光照强度处理材料,4个月后收获,比较分析罗甸小米核桃幼苗的形态、生物量分配和生理性状在不同光照强度处理下的差异,并对可塑性指标进行综合评价.结果...     

历山山核桃群落物种多样性特征

采用Patrick指数、Simpson指数、Shannon指数、Pielou指数、Alatalo指数等5个多样性指数,结合TWINSPAN分类,研究历山自然保护区山核桃(Juglans mandshurica)群落的物种多样性与群落类型、结构及环境因子的关系.结果表明:TWINSPAN分类将35个样方分为7个群丛,各群丛的物种丰富度指数、多样性指数和均匀度指数之间存在差异,各群丛乔木层、灌木层和草本层之间的丰富度指数和均匀度指数也存在差异,山核桃群落物种多样性受其所处的坡向、坡度、土壤类型等物理微环境及群落物种组成、干扰等共同影响.方差分析结果表明:各群丛间丰富度指数、多样性指数和均匀度指数差异不显著,各群丛乔木层、灌木层和草本层之间的丰富度指数和均匀度指数也差异不显著,这说明山核桃群落生境异质性小,物种对地带性气候有相似的适应特征以及相似的资源利用方式.