Molecular mechanism underlying anti-apoptotic and anti-inflammatory effects of Mamao (Antidesma thwaitesianum Müll. Arg.) polyphenolics in human breast epithelial cells

There has been increasing interest in finding natural antioxidants to prevent free radical damage and retard the progress of chronic inflammatory diseases. Our previous data demonstrated the strong antioxidant properties of polyphenolics in Mamao seed (MS) and Mamao marc (MM) extracts. In this study we further investigated the effect of MS and MM polyphenolics on hydrogen peroxide (H₂O₂)-induced apoptosis and tumour promoter 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation, using human breast epithelial (MCF10A) cells. MS and MM extracts conferred dose-dependent protection against H₂O₂-induced apoptosis by inhibiting PARP/caspase-3 cleavage, inducing anti-apoptotic Bcl-2 expression, and down-regulating pro-apoptotic Bax. Moreover, MS and MM polyphenolics inhibited TPA-induced COX-2 and NF-κB activation by blocking the degradation of cytoplasmic IκBα, as well as subsequent nuclear translocation of p65 and attenuation of the activation of ERK, but not JNK and p38. These data establish the molecular mechanism for the anti-apoptotic and anti-inflammatory effects of MS and MM polyphenolics.     

Evaluation of heat treatment regimes and their influences on the properties of powder‐printed high‐density polyethylene bone implant

A two‐step heat treatment was utilized as a means to improve the mechanical properties of a high‐density polyethylene structure which was fabricated using the three‐dimensional printing technique. It was found that the relationship between structure and properties was strongly influenced by heat treatment conditions including treatment times (15–60 min) and treatment temperatures (140–180 °C) of both primary and secondary steps. The use of primary heating at 180 °C for 15 min and secondary heating at 160 °C for 60 min resulted in the highest tensile modulus and strength, 0.7 GPa and 14.8 MPa, respectively. The changes in both shrinkage and tensile properties were governed by the level of residual porosity and quality of polyethylene interface in samples which were both influenced by the degree of thermally induced densification and binder degradation. Empirical correlations between porosity and shrinkage or tensile properties were found to be power functions. Copyright © 2010 Society of Chemical Industry     

Influence of alcohol addition on properties of bio-oil produced from fast pyrolysis of eucalyptus bark in a free-fall reactor

Fast pyrolysis of eucalyptus bark was carried out in a free-fall pyrolysis unit at different temperatures ranging from 400 to 550 °C to produce bio-oil, char and gas. The bio-oil produced at optimum temperature was mixed with alcohols with an aim to improve its properties. The results showed that the maximum bio-oil yield of 64.65 wt% on dry biomass basis could be obtained at the pyrolysis temperature of 500 °C. The addition of a small proportion (2.5–10%) of alcohol into the bio-oil could improve its viscosity, stability and heating value. These effects were further enhanced when increasing the alcohol.     

Antioxidant Activities of Polyphenolic Compounds Isolated from Antidesma thwaitesianum Müll. Arg. Seeds and Marcs

ABSTRACT: Antidesma thwaitesianum Müll. Arg. or mao is widely used as commercial products of juice and wine in Thailand. As a result, waste products from the mao plant, such as mao seeds (MS) and mao marcs (MM), are plentiful. We aimed to purify and analyze polyphenolic content in both MS and MM and to investigate the radical scavenging activities of these polyphenolics against 1,1‐diphenyl‐2‐picryl‐hydrazyl (DPPH) and 2,2′‐Azinobis (3‐ethylbenzothiazoline 6‐sulphonate) (ABTS) radicals and thiobarbituric acid reactive products (TBARP). The results showed MS and MM to be an abundant source of polyphenols (97.32 to 130 mg gallic acid equivalents [GAE]/g) and proanthocyanidins. The radical scavenging activities of MS/MM against DPPH and ABTS radicals (IC₅₀ of 0.85 to 1.21 μg/mL) were significantly higher (P < 0.05) than that of standard trolox (IC₅₀ of 5.05 μg/mL). Activity of MS/MM extracts were 3.74 and 3.80 μg/mL trolox eq/g f.w. for the DPPH and ABTS assays, respectively. The oxidation of erythrocyte membranes using 2‐thiobarbituric acid demonstrated that the protective effect of MS/MM on lipid peroxidation is as strong as grape seed proanthocyanidin extract. These findings suggest that polyphenolic compounds and proanthocyanidins isolated from these mao extracts had much higher antioxidant activities than those of standard trolox and exhibited similar antioxidant potential to grape seed proanthocyanidin extract. These findings may also increase value of mao waste products and allow development of commercial health products.