Oleic acid prevents apoptotic cell death induced by <Emphasis Type="Italic">trans</Emphasis>10, <Emphasis Type="Italic">cis</Emphasis>12 isomer of conjugated linoleic acid via p38 MAP kinase dependent pathway

Our previous study indicated that oleic acid prevented apoptotic cell death induced by trans10, cis12 (t10, c12)-conjugated linoleic acid in rat hepatoma dRLh-84 cells. The intracellular mechanism of action oleic acid is still unknown. Here, we showed that p38 mitogen-activated protein kinase (MAPK) inhibition using its specific inhibitor SB203580 cancelled the ameliorative effect of oleic acid on the cytotoxicity of t10, c12-conjugated linoleic acid. In addition, SubG1 cell population analysis showed that p38 MAPK played an essential role in the prevention of apoptotic cell death by oleic acid. In fact, p38 phosphorylation level was upregulated in cells treated with oleic acid irrespective of t10, c12-conjugated linoleic acid stimulation. Interestingly, t10, c12-conjugated linoleic acid increased intracellular triglyceride accumulation. However, oleic acid completely inhibited this effect. These observations indicated the involvement of blockade of a p38 MAPK pathway in the ameliorative effect of oleic acid on apoptosis induced by t10, c12-conjugated linoleic acid.     

In vitro effects of gossypol on testicular lactic dehydrogenase-X and other dehydrogenases

Thein vitro inhibition of several rat testis dehydrogenases by gossyPol was examined. Inclusion of the coenzyme (substrate for NADP⁺-isocitrate dehydrogenase) in the Preincubation mixture containing the enzyme and gossyPol, Protected the enzymes against inhibition by gossyPol. Lactic dehydrogenase-X was amongst the least Protected enzymes. This, couPled with its lowK _i for gossyPol makes it one of the most vulnerable target enzymesin vivo for gossyPol action. The inhibition kinetics for lactic dehydrogenase-X were comPetitive when NADH was Present during Preincubation, but non-comPetitive when the coenzyme was excluded during Preincubation. In the latter condition, the enzyme seems to undergo Progressive inactivation with time causing a nonreversible tyPe of inhibition.     

Cloning and expression of MPT83 gene from Mycobacterium tuberculosis in E. coli BL21 as vaccine candidate of tuberculosis: A preliminary study

The appearance of Mycobacterium tuberculosis strains leading to drug resistance has caused new problems in TB treatment in various parts of the world and forces WHO to declare TB as a global emergency. With the increase of TB drug resistance, it is convinced that a more effective vaccine development will stop the epidemic of TB. Some M. tuberculosis antigens, one of which is MPT83, have been examined as TB vaccine candidate. MPT83 antigen, which is very immunogenic in lipoprotein micro bacteria, is identified as surface cell interrelated to antigen with cytometry circulation. Having TB resistance from BCG vaccine, MPT83 is considered TB vaccine candidate that can protect people against TB at adult age. The purpose of this research is to conduct amplification of MPT83 antigen cloning, and expression of its antigen on E. coli bacteria. From the result of the research, it is expected that raw material to produce TB vaccine as well as a high-quality antigen can be obtained. The band of DNA in PCR product is 660?bp, while the one in pGEMT-Easy-Mpt83 recombinant plasmid is 3678?bp. This is expressed in E. coli BL21 strain and produces 48?kDa protein as well as GST-MPT83 fusion protein.     

Aspergillus parasiticus growth and aflatoxin production on black and white pepper and the inhibitory action of their chemical constituents

Aspergillus parasiticus Speare NRRL 2999 growth and aflatoxin production in black and white pepper and the penetration of the fungus in black pepper corn over various incubation periods were studied. Also, the effects of piperine and pepper oil on growth and aflatoxin production were studied. Under laboratory conditions, black and white pepper supported aflatoxin production (62.5 and 44 ppb (ng/g), respectively) over 30 days of incubation. Fungal growth measured in terms of chitin was considerably less in white pepper than in black pepper. A histological study of black pepper corn showed the fungus penetrating up to the inner mesocarp and establishing itself in the middle mesocarp. Piperine and pepper oil were found to inhibit fungal growth and toxin production in a dose-dependent manner. Thus, both black and white pepper could be considered as poor substrates for fungal growth and aflatoxin production.