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Crude proteins of cultured mycelia and fruiting bodies of Ganoderma lucidum were investigated for antioxidant, antibacterial and DNA protective activities. It was found that the half maximal inhibitory concentration (IC 50 ) of the mycelia protein and fruiting bodies protein extracts against 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) radical (ABTS •+ ) were 2.47±0.01 and 2.77±0.11 μg protein/ml and against 2,2-diphenylpicrylhydrazyl radical (DPPH • ) were 2.5 ±0.01 and 3.42±0.01 μg protein/ml, respectively. The ferric reducing-antioxidant power (FRAP) values of those samples were 1.73±0.01 and 2.62±0.01 μmole trolox/μg protein respectively. Protein hydrolysates prepared by pronase exhibited a weaker antioxidant activity. Both crude proteins showed antibacterial activity, whereas only the mycelia protein extract could protect DNA damage by hydroxyl (• OH) radicals. This protein extract was partial purified by Diethyl amino ethyl (DEAE)-Sepharose column and Sulfopropyl (SP)-Sepharose column, obtained major protein with molecular weight about 45 kilo Dalton (kDa). In conclusion, G. lucidum protein extracts have promise potential for applications as antioxidant and antibacterial agents.

Abstract. The aim of the present study was to investigate the molecular mechanisms underlying Cratoxylum formosum (CF) Dyer-induced cancer cell death and antimigratory effects in HepG2 liver cancer cells. The cytotoxic, antiproliferative and antimigratory effects of CF leaf extract on human liver cancer HepG2 cell lines were evaluated using sulforhodamine B, colony formation, and wound healing assays. In addition, apoptosis induction mechanisms were investigated via reactive oxygen species (ROS) formation, caspase 3 activities, and mitochondrial membrane potential (ΔΨm) disruption. Gene expression and apoptosis-associated protein levels were measured by reverse transcription-quantitative polymerase chain reaction and western blotting. CF induced HepG2 cell death in a time-and dose-dependent manner with half maximal inhibitory concentration values of 219.03±9.96 and 124.90±6.86 µg/ml at 24 and 48 h, respectively. Treatment with CF caused a significant and dose-dependent decrease in colony forming ability and cell migration. Furthermore, the present study demonstrated that CF induced ROS formation, increased caspase 3 activities, decreased the ΔΨm, and caused HepG2 apoptosis. CF marginally decreased the expression level of the cell cycle regulatory protein, ras-related C3 botulinum toxin substrate 1 (rho family, small GTP binding protein Rac1) and the downstream protein, cyclin dependent kinase 6. Additionally, CF significantly enhanced p21 levels, reduced cyclin D1 protein levels and triggered cancer cell death. CF leaf extracts induced cell death, stimulated apoptosis and inhibited migration in HepG2 cells. Thus, CF may be useful for developing an anticancer drug candidate for the treatment of liver cancer. IntroductionMedicinal plants and their active compounds have been reported to exert potent cytotoxic activity against various types of cancer cell (1). Numerous plants are consumed as food and are claimed by practitioners of traditional medicine to promote health (2-4). Northeast Thai vegetables, such as Cratoxylum formosum (CF) Dyer may have an affect on human health by exerting antioxidant and anticancer effects. CF belongs to the Guttiferae family and is a plant of the tropics, cultivated in many Southeast Asian countries, including Thailand (5). It is a local dietary and herbal plant, and its leaves are usually consumed fresh. CF has been adopted in folk medicine for the treatment of fever, coughs, stomach ache and peptic ulcers (6,7). CF produces various secondary metabolites, including phenolic compounds, triterpenoids, flavonoids (6,8), xanthones, anthraquinones (7), chlorogenic acid, dicaffeoylquinic acids, and ferulic acid (5). Kukongviriyapan et al (9) detected potent antioxidant activity in aqueous extracts of CF leaves. Other bioactivities demonstrated by CF include anti-inflammatory (10), antibacterial (11), antimicrobial (12) and anticancer (13). Various parts of the plant have been found to exert anticancer effects, including the roots, bark and leaves (14-16).CF inhibits the proliferation of v...

We isolated several thermotolerant Acetobacter species of which MSU10 strain, identified as Acetobacter pasteurianus, could grow well on agar plates at 41 degrees C, tolerate to 1.5% acetic acid or 4% ethanol at 39 degrees C, similarly seen with A. pasteurianus SKU1108 previously isolated. The MSU10 strain showed higher acetic acid productivity in a medium containing 6% ethanol at 37 degrees C than SKU1108 while SKU1108 strain could accumulate more acetic acid in a medium supplemented with 4-5% ethanol at the same temperature. The fermentation ability at 37 degrees C of these thermotolerant strains was superior to that of mesophilic A. pasteurianus IFO3191 strain having weak growth and very delayed acetic acid production at 37 degrees C even at 4% ethanol. Alcohol dehydrogenases (ADHs) were purified from MSU10, SKU1108, and IFO3191 strains, and their properties were compared related to the thermotolerance. ADH of the thermotolerant strains had a little higher optimal temperature and heat stability than that of mesophilic IFO3191. More critically, ADHs from MSU10 and SKU1108 strains exhibited a higher resistance to ethanol and acetic acid than IFO3191 enzyme at elevated temperature. Furthermore, in this study, the ADH genes were cloned, and the amino acid sequences of ADH subunit I, subunit II, and subunit III were compared. The difference in the amino acid residues could be seen, seemingly related to the thermotolerance, between MSU10 or SKU1108 ADH and IFO 3191 ADH.

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