Jen-Min Kuo

6‐Shogaol induces apoptosis in human colorectal carcinoma cells via ROS production, caspase activation, and GADD 153 expression

Ginger, the rhizome of Zingiber officinale, is a traditional medicine with anti-inflammatory and anticarcinogenic properties. This study examined the growth inhibitory effects of the structurally related compounds 6-gingerol and 6-shogaol on human cancer cells. 6-Shogaol [1-(4-hydroxy-3-methoxyphenyl)-4-decen-3-one] inhibits the growth of human cancer cells and induces apoptosis in COLO 205 cells through modulation of mitochondrial functions regulated by reactive oxygen species (ROS). ROS generation occurs in the early stages of 6-shogaol-induced apoptosis, preceding cytochrome c release, caspase activation, and DNA fragmentation. Up-regulation of Bax, Fas, and FasL, as well as down-regulation of Bcl-2 and Bcl-X(L )were observed in 6-shogaol-treated COLO 205 cells. N-acetylcysteine (NAC), but not by other antioxidants, suppress 6-shogaol-induced apoptosis. The growth arrest and DNA damage (GADD)-inducible transcription factor 153 (GADD153) mRNA and protein is markedly induced in a time- and concentration-dependent manner in response to 6-shogaol.

Purification and characterization of a fish scale-degrading enzyme from a newly identified Vogesella sp.

The objective of the present study is to purify and characterize the fish scale-degrading enzyme from Vogesella sp.7307-1, which was newly identified and isolated from fish scales. The enzyme from Vogesella sp.7307-1 was assayed with casein and confirmed as a protease. Crude protease was extracted, isolated, and purified 35.7-fold with 19.6% recovery using 20-80% saturation of ammonium sulfate fractionation, Q FF ion exchange chromatography, and Superdex 200 gelfiltration. The molecular weight of the purified enzyme was 119 kDa. The Km and Vmax were 0.067 mM and 425.5 U/mg-min, respectively using azo-casein as substrate. The optimum pH of the purified enzyme was 7.5, and the optimum temperature was 50 °C. The enzyme was stable at temperatures below 55 °C and pH range 7.5 to 9.0. The enzyme activity of the purified protease was completely inhibited by EDTA (ethylene diamine teraacetates), indicating the enzyme was a metalloprotease. Hydrolysates from fish scales treated with protease 7307-1 were found having low molecular weight peptides (<1 kDa). The protease 7307-1 is a promising enzyme for preparing smaller peptides from fish scales.

Feather Keratin Hydrolysis by an Aquatic Bacterium Meiothermus I40 from Hot Spring Water

After undergoing keratinase digestion, feather wastes could have a great potential as a source of proteins and amino acids for many applications. In this study, the fermentation conditions of feather-degrading Meiothermus sp. strain I40 (I40) were optimized to enhance the biodegradation of chicken feather to hydrolysates. Initially, the factors essential for I40 keratinase production in submerged fermentation were screened, whereas response surface methodology (RSM) was then employed to evaluate the interactions among the effective factors. At first stage, eight fermentation parameters were screened using a Plackett-Burman (PB) design. Four effective factors identified by PB screening, namely feather concentration, tryptone concentration, yeast extract concentration, and incubation temperature, were further investigated their effects on keratinase production by RSM using central composite design (CCD). The I40 fermentation conditions for maximal keratinase activity were as follows: tryptone concentration 0.16 percent (w/v), yeast extract concentration 0.27 percent (w/v), feather concentration 0.08 percent (w/v), and incubation temperature at 51.7°C for 72 hr under 120 rev/min shaking. Compared to the initial stage, a 13.3-fold increase in keratinase activity was achieved when I40 incubated in the optimized conditions.