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Showing papers by "Pallu Reddanna published in 2003"


Journal ArticleDOI
TL;DR: This C-PC induced apoptosis in RAW 264.7 cells appears to be mediated by the release of cytochrome c from mitochondria and independent of Bcl-2 expression, and may be due to reduced PGE(2) levels as a result of COX-2 inhibition.

174 citations


Journal Article
TL;DR: Phycocyanin-induced apoptotic death in AK-5 cells is demonstrated, which is inhibited by Bcl-2 expression through the regulation of free radical generation.
Abstract: C-phycocyanin, which is a major biliprotein of the blue-green algae, has been shown to possess cyclooxygenase-2 inhibitory activity. We have studied the effect of phycocyanin on a rat histiocytic tumor line. AK-5 cells are induced into apoptotic death program when treated with phycocyanin, which involves the activation of caspase-3. Phycocyanin-mediated apoptotic death is induced through the generation of reactive oxygen radicals. Free radical scavengers inhibited phycocyanin-induced apoptotic death in AK-5 cells. Bcl-2, an inhibitor of apoptosis, is shown to regulate ROS generation. Bcl-2 gene-transfected AK-5 cells are resistant to phycocyanin-induced death. Overexpression of Bcl-2 inhibited the production of ROS in phycocyanin-treated AK-5 cells. Thus, our observations demonstrate phycocyanin-induced apoptotic death in AK-5 cells, which is inhibited by Bcl-2 expression through the regulation of free radical generation. Phycocyanin, a natural product, could therefore be a possible chemotherapeutic agent through its apoptotic activity against tumor cells. (Mol Cancer Ther. 2003;2:1165–1170)

101 citations


Journal ArticleDOI
TL;DR: Cell cultures of Plumbago rosea were immobilized in calcium alginate and cultured in Murashige and Skoog's basal medium containing 10 mM CaCl(2) for the production of plumbagin, an important medicinal compound, and the impact of immobilization on the increased accumulation of this secondary metabolite was carried out.

94 citations


Journal ArticleDOI
TL;DR: During chemical carcinogenesis because of jun/fos oncogenes (AP-1) regulatory elements, specifically GST-π is expressed in liver, and could be used as marker protein for the detection of chemical toxicity and carcinogenesis.
Abstract: Glutathione S-transferases (GSTs, EC 2.5.1.18) are multifunctional and multigene products. They are versatile enzymes and participate in the nucleophilic attack of the sulphur atom of glutathione on the electrophilic centers of various endogenous and xenobiotic compounds. Out of the five, alpha, micro, pi, sigma and theta, major classes of GSTs, GST-pi has significance in the diagnosis of cancers as it is expressed abundantly in tumor cells. This protein is a single gene product, coded by seven exons, that is having 24 kDa mass and pI value of 7.0. Four upstream elements such as two enhancers, and one of each of AP-1 site and GC box regulate pi gene. During chemical carcinogenesis because of jun/fos oncogenes (AP-1) regulatory elements, specifically GST-pi is expressed in liver. Therefore this gene product could be used as marker protein for the detection of chemical toxicity and carcinogenesis.

68 citations


Journal ArticleDOI
TL;DR: The combination of fungal elicitor plus cyclodextrin was the most effective elicitor treatment, followed by methyl jasmonate plus cyclodesxtrin in inducing sesquiterpenes and LOX metabolites.
Abstract: Potato (Solanum tuberosum) hairy root cultures, established by infecting potato tuber discs with Agrobacterium rhizogenes, were used as a model system for the production of antimicrobial sesquiterpenes and lipoxygenase (LOX) metabolites. Of the four sesquiterpene phytoalexins (rishitin, lubimin, phytuberin and phytuberol) detected in elicitor-treated hairy root cultures, rishitin (213 micrograms g-1 dry wt) was the most predominant followed by lubimin (171 micrograms g-1 dry wt). The elicitors also induced LOX activity (25-fold increase) and LOX metabolites, mainly 9-hydroxyoctadecadienoic acid and 9-hydroxyoctadecatrienoic acid, in potato hairy root cultures. The combination of fungal elicitor plus cyclodextrin was the most effective elicitor treatment, followed by methyl jasmonate plus cyclodextrin in inducing sesquiterpenes and LOX metabolites.

54 citations


Journal ArticleDOI
TL;DR: The present study describes the constitutive expression of Cox-2 in immature and mature rat testis, primarily localized in the spermatogonial cells, and reports the presence ofcox-2 on the chromatin and also in cytosol, apart from nuclear and endoplasmic reticular membranes.
Abstract: Cyclooxygenase, the rate-limiting enzyme in the production of prostaglandins, exists in two isoforms, the constitutive cyclooxygenase 1 (Cox-1) and the inducible cyclooxygenase 2 (Cox-2). Cox-1 is involved in homeostatic functions while Cox-2 is implicated in various pathological processes such as inflammation and cancer. The present study describes the constitutive expression of Cox-2 in immature and mature rat testis, primarily localized in the spermatogonial cells. An interesting observation is the presence of Cox-2 on the chromatin and also in cytosol, apart from nuclear and endoplasmic reticular membranes. The significance of this observation is not yet clear, though its presence in the nucleus raises the possibility of Cox-2 having a more direct role in gene regulation than was thought earlier. In addition, the Cox-2 mRNA in testis is the smaller (2.8 kb) of the two isoform transcripts reported for Cox-2. Further hormone treatment regimes (testosterone/follicle stimulating hormone) increased the levels of Cox-2 protein within 6 h after treatment, suggesting that the sustained levels of Cox-2 protein in testis can be further influenced by gonadotrophins and androgens.

32 citations


Journal ArticleDOI
TL;DR: Evidence is presented that bovine pancreatic carboxypeptidase A (CPA), which shares significant sequence homology with CPA in mast cell granules, catalyzes the conversion of LTC( 4) to LTF(4) via the hydrolysis of an amide bond, and it appears that the physiological significance of this single-step transformation may point toward a major cellular homeostatic mechanism of metabolizing LTC

22 citations