Aging attenuates the protective effect of ischemic preconditioning against endothelial ischemia-reperfusion injury in humans

Item does not contain fulltextReperfusion is mandatory after ischemia but also triggers ischemia-reperfusion (I/R) injury. Ischemic preconditioning (IPC) can limit endothelial I/R injury. Nonetheless, translation of IPC to the clinical arena is often disappointing. Since application of IPC typically relates to older patients, efficacy of IPC may be attenuated with aging. Our objective was to examine the impact of advanced age on the ability of IPC to protect against endothelial dysfunction due to I/R injury. We included 15 healthy young (20-25 yr) and 15 older (68-77 yr) men. We examined brachial artery endothelial function using flow-mediated dilation (FMD) before and after arm I/R (induced by inflation of an upper-arm blood pressure cuff for 20 min and 15 min of reperfusion). In a randomized order, I/R was preceded by IPC or a control intervention consisting of three cycles of 5 min upper-arm cuff inflation to 220 or 20 mmHg, respectively. As a result, in young men, FMD decreased significantly after I/R (6.4 +/- 2.7 to 4.4 +/- 2.5%). This decrease was not present when I/R was preceded by IPC (5.9 +/- 2.3 to 5.6 +/- 2.5%). IPC-induced protection appeared to be significantly reduced in the elderly patients (P = 0.04). Although FMD decreased after I/R in older men (3.5 +/- 1.7 to 2.5 +/- 1.0%), IPC could not prevent this (3.7 +/- 2.1 to 2.2 +/- 1.1%). In conclusion, this study is the first to observe in humans in vivo that older age is associated with an abolished effect of IPC to protect against endothelial dysfunction after I/R in the brachial artery. This provides a possible explanation for the problematic translation of strategies that reduce I/R injury from preclinical work to the clinical arena

Natural compounds extracted from Moringa oleifera and their agricultural applications

Natural bio-active compounds synthesized by plants as secondary metabolites are well known and established. Today, their application in various fields such as medicine in the form of drugs and biopesticides in agriculture is well documented. In recent times, the delivery of such compounds is achieved through nanodelivery technology, which is gaining acceptability in both field of drugs and agrochemical industries. The bio-active compounds with chemical diversity are obtained from nature either as homogenous plant crude extracts or as purified compounds. Crude plant extracts exist as a combination of different bio-active compounds with various polarities, and their partition remains a challenge in the process of characterization and identification. Extraction of these compounds from plant species is achieved by different solvents and extraction methods. Analytical methods like HPLC have commonly been utilized with GC-MS and LC-MS/MS chromatography methods to identify the compounds. Crude extracts from different morphological parts of plant species including Moringa oleifera are increasingly becoming important in the context of agricultural pest management and human medicine. M. oleifera is a medicinal plant that synthesizes such metabolites which include phenolic acids, carotenoids, quinones, antraquinones, flavonoids, flavonols, flavones, tannins, alkaloids, coumarins, terpenoids, amines, cyanogenic glycosides, triterpenoids, non-protein amino acids, glucosinolates, polyacetylenes, polyketides, phenylpropanes, steroids and saponins. They exert biological activities and can potentially be used to retard microbial activities. Other uses of M. oleifera are medicinal uses and other purposes such as water purification, fertilizer, biogas and biopesticides. The aim of this chapter is to highlight the uses and profiling of bio-active compounds of M. oleifera, their mode of action and prospects in commercial biopesticides for agricultural applications