Resveratrol is a dietary polyphenolic compound widely used in medicine, food, and cosmetic products. The glycoside form of resveratrol, piceid, is also present in several plant materials but is less bioavailable. In this study, enzymatic transformation of piceid into resveratrol using inexpensive cellulase was investigated. Response surface methodology was used to evaluate the effect of reaction parameters, including reaction temperature, reaction time, enzyme amount and pH. The optimal conditions for biotransformation of piceid to resveratrol are: a reaction temperature of 50 °C, reaction time of 4.75 h, enzyme amount of 2.5 fungal β-glucanase (FBG) units and pH of 4.3. In addition, the extracts from Polygonum cuspidatum root contained high amounts of piceid were treated with cellulase in order to deglycosylation that increased resveratrol yield. After treatment, the resveratrol yield significantly increased from 2.72 to 9.49 mg/g, while the piceid contents decreased from 8.60 to 0 mg/g. The result provides an efficient method to convert piceid in the extracts of P. cuspidatum root into resveratrol by cellulase. Full article

Ischemia-reperfusion injury resulting from arterial occlusion or hypotension in patients leads to tissue hypoxia with glucose deprivation, which causes endoplasmic reticulum (ER) stress and neuronal death. A proteomic approach was used to identify the differentially expressed proteins in the brain of rats following a global ischemic stroke. The mechanisms involved the action in apoptotic and ER stress pathways. Rats were treated with ischemia-reperfusion brain injuries by the bilateral occlusion of the common carotid artery. The cortical neuron proteins from the stroke animal model (SAM) and the control rats were separated using two-dimensional gel electrophoresis (2-DE) to purify and identify the protein profiles. Our results demonstrated that the SAM rats experienced brain cell death in the ischemic core. Fifteen proteins were expressed differentially between the SAM rats and control rats, which were assayed and validated in vivo and in vitro. Interestingly, the set of differentially expressed, down-regulated proteins included catechol O-methyltransferase (COMT) and cathepsin D (CATD), which are implicated in oxidative stress, inflammatory response and apoptosis. After an ischemic stroke, one protein spot, namely the calretinin (CALB2) protein, showed increased expression. It mediated the effects of SAM administration on the apoptotic and ER stress pathways. Our results demonstrate that the ischemic injury of neuronal cells increased cell cytoxicity and apoptosis, which were accompanied by sustained activation of the IRE1-alpha/TRAF2, JNK1/2, and p38 MAPK pathways. Proteomic analysis suggested that the differential expression of CALB2 during a global ischemic stroke could be involved in the mechanisms of ER stress-induced neuronal cell apoptosis, which occurred via IRE1-alpha/TRAF2 complex formation, with activation of JNK1/2 and p38 MAPK. Based on these results, we also provide the molecular evidence supporting the ischemia-reperfusion-related neuronal injury. Full article

Hericium erinaceus, an edible mushroom, has been demonstrated to potentiate the effects of numerous biological activities. The aim of this study was to investigate whether H. erinaceus mycelium could act as an anti-inflammatory agent to bring about neuroprotection using a model of global ischemic stroke and the mechanisms involved. Rats were treated with H. erinaceus mycelium and its isolated diterpenoid derivative, erinacine A, after ischemia reperfusion brain injuries caused by the occlusion of the two common carotid arteries. The production of inflammatory cytokines in serum and the infracted volume of the brain were measured. The proteins from the stroke animal model (SAM) were evaluated to determine the effect of H. erinaceus mycelium. H. erinaceus mycelium reduced the total infarcted volumes by 22% and 44% at a concentration of 50 and 300 mg/kg, respectively, compared to the SAM group. The levels of acute inflammatory cytokines, including interleukin-1β, interleukin-6 and tumor necrosis factor á, were all reduced by erinacine A. Levels of nitrotyrosine-containing proteins, phosphorylation of p38 MAPK and CCAAT enhancer-binding protein (C/EBP) and homologous protein (CHOP) expression were attenuated by erinacine A. Moreover, the modulation of ischemia injury factors present in the SAM model by erinacine A seemed to result in the suppression of reactive nitrogen species and the downregulation of inducible NO synthase (iNOS), p38 MAPK and CHOP. These findings confirm the nerve-growth properties of Hericium erinaceus mycelium, which include the prevention of ischemic injury to neurons; this protective effect seems to be involved in the in vivo activity of iNOS, p38 MAPK and CHOP. Full article

In this study the phenolic compounds piceid, resveratrol and emodin were extracted from P. cuspidatum roots using ultrasound-assisted extraction. Multiple response surface methodology was used to optimize the extraction conditions of these phenolic compounds. A three-factor and three-level Box-Behnken experimental design was employed to evaluate the effects of the operation parameters, including extraction temperature (30–70 °C), ethanol concentration (40%–80%), and ultrasonic power (90–150 W), on the extraction yields of piceid, resveratrol, and emodin. The statistical models built from multiple response surface methodology were developed for the estimation of the extraction yields of multi-phenolic components. Based on the model, the extraction yields of piceid, resveratrol, and emodin can be improved by controlling the extraction parameters. Under the optimum conditions, the extraction yields of piceid, resveratrol and emodin were 10.77 mg/g, 3.82 mg/g and 11.72 mg/g, respectively. Full article

Wax esters are long-chain esters that have been widely applied in premium lubricants, parting agents, antifoaming agents and cosmetics. In this study, the biocatalytic preparation of a specific wax ester, cetyl octanoate, is performed in n-hexane using two commercial immobilized lipases, i.e., Lipozyme^® RMIM (Rhizomucor miehei) and Novozym^® 435 (Candida antarctica). Response surface methodology (RSM) and 5-level-4-factor central composite rotatable design (CCRD) are employed to evaluate the effects of reaction time (1–5 h), reaction temperature (45–65 °C), substrate molar ratio (1–3:1), and enzyme amount (10%–50%) on the yield of cetyl octanoate. Using RSM to optimize the reaction, the maximum yields reached 94% and 98% using Lipozyme^® RMIM and Novozym^® 435, respectively. The optimum conditions for synthesis of cetyl octanoate by both lipases are established and compared. Novozym^® 435 proves to be a more efficient biocatalyst than Lipozyme^® RMIM. Full article