Pallu Reddanna

Bio: Pallu Reddanna is an academic researcher from University of Hyderabad. The author has contributed to research in topics: Arachidonic acid & Lipoxygenase. The author has an hindex of 43, co-authored 190 publications receiving 5909 citations. Previous affiliations of Pallu Reddanna include Sri Venkateswara University & Yahoo!.

Identification of a developmentally and hormonally regulated Delta-Class glutathione S-transferase in rice moth Corcyra cephalonica.

Abstract: Glutathione S-transferases (GSTs) are a large family of multifunctional enzymes, known for their role in cellular detoxification. Here we report a cytosolic GST with optimal activity at alkaline pH (8.3) from the visceral fat body of late-last instar (LLI) larvae of a lepidopteran insect rice moth Corcyra cephalonica. All previously known GSTs are active between pH 6.0 to 6.5. Purification and characterization revealed the Corcyra cephalonica GST (CcGST) as a 23-kDa protein. HPLC and 2D analysis showed a single isoform of the protein in the LLI visceral fat body. Degenerate primer based method identified a 701-nucleotide cDNA and the longest open reading frame contained 216 amino acids. Multiple sequence and structural alignment showed close similarity with delta-class GSTs. CcGST is present mainly in the fat body with highest activity at the late-last instar larval stage. Juvenile hormone (JH) negatively inhibits the CcGST activity both ex vivo and in vivo. We speculate that high expression and activity of CcGST in the fat body of the late-last instar larvae, when endogenous JH titer is low may have role in the insect post-embryonic development unrelated to their previously known function.

Isoorientin, a Selective Inhibitor of Cyclooxygenase-2 (COX-2) from the Tubers of Pueraria tuberosa.

Abstract: Bioassay-guided fraction of the methanol extract of the roots of Pueraria tuberose DC yielded puerarin, an isoflavone C-glycoside (PT-1), isoorientin, a flavone C-glycoside (PT-2) and mangiferin, a xanthone C-glycoside (PT-3). The extracts and the isolated compounds were screened for potent anti-inflammatory components inhibiting the cyclooxygenases (COX-1 and COX-2) and 5-lipoxygenase (5-LOX), the target enzymes of inflammation, by employing spectroscopic/polorographic methods. Among these, isoorientin was found to be a potent inhibitor of COX-2with an IC50 value of 39 μM. Docking studies were carried out to understand the interactions of isorientin (PT-2) with COX-2.The structures of the isolates were determined by mass spectrometry and 2D-NMR techniques including HSQC, HMBC, NOESY and 1H-1H COSY experiments. Although isoorientin and mangiferin have been reported from several plant sources, this is the first report of their isolation from a Pueraria species.

Lipid profiles among fish-consuming coastal and non-fish-consuming inland populations.

Abstract: Serum lipid profiles were examined in 100 individuals of fish-consuming coastal and 109 individuals of non-fish-consuming inland populations. The fish-consuming population showed lower mean serum cholesterol, triacylglycerols and significantly higher levels of HDL cholesterol and phospholipids. The bleeding time and clotting time were significantly prolonged in the fish-eating population. Thus the fish-consuming population showed lower risk factors of coronary heart disease when compared to the non-fish-consuming population.

Arterial pressures in fish-consuming and non-fish- consuming populations of coastal south India

Abstract: It has been suggested that fish-consuming populations have lower blood pressure levels. The aim of this study was to determine and compare the mean blood pressure levels among fish-consuming populations with those among populations who do not consume fish, as a risk marker for cardiovascular disease. A cross-sectional study was conducted among 1000 healthy Indian adult men and women (aged >=20 years) randomly chosen from two representative age and sex-matched samples, one of which was fish-consuming (n = 500) and the other of which was non-fish-consuming (n = 500). The systolic and diastolic blood pressures and pulse rates were studied. The mean systolic and diastolic blood pressures and pulse rates were found to be lower in older men and women who were fish consumers in comparison with those who were non-fish consumers, and the levels increased with advancing age. The population and sex differences were significant for certain age groups. The percentile cut-off values for diagnosis of systolic hypertension showed lower prevalence in fish consumers than in non-fish consumers. The results indicate that people who ate fish regularly appeared to have a better cardiovascular risk profile than did non-fish consumers, which is of public health significance. The relationship between fish consumption and blood pressure deserves further studies in normotensive and hypertensive populations.

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

Abstract: In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure flux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation, it is imperative to target by gene knockout or RNA interference more than one autophagy-related protein. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways implying that not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular assays, we hope to encourage technical innovation in the field.

Lipid peroxidation: production, metabolism, and signaling mechanisms of malondialdehyde and 4-hydroxy-2-nonenal.

Abstract: Lipid peroxidation can be described generally as a process under which oxidants such as free radicals attack lipids containing carbon-carbon double bond(s), especially polyunsaturated fatty acids (PUFAs). Over the last four decades, an extensive body of literature regarding lipid peroxidation has shown its important role in cell biology and human health. Since the early 1970s, the total published research articles on the topic of lipid peroxidation was 98 (1970–1974) and has been increasing at almost 135-fold, by up to 13165 in last 4 years (2010–2013). New discoveries about the involvement in cellular physiology and pathology, as well as the control of lipid peroxidation, continue to emerge every day. Given the enormity of this field, this review focuses on biochemical concepts of lipid peroxidation, production, metabolism, and signaling mechanisms of two main omega-6 fatty acids lipid peroxidation products: malondialdehyde (MDA) and, in particular, 4-hydroxy-2-nonenal (4-HNE), summarizing not only its physiological and protective function as signaling molecule stimulating gene expression and cell survival, but also its cytotoxic role inhibiting gene expression and promoting cell death. Finally, overviews of in vivo mammalian model systems used to study the lipid peroxidation process, and common pathological processes linked to MDA and 4-HNE are shown.

The glutathione S-transferase supergene family: regulation of GST and the contribution of the isoenzymes to cancer chemoprotection and drug resistance.

Abstract: The glutathione S-transferases (GST) represent a major group of detoxification enzymes. All eukaryotic species possess multiple cytosolic and membrane-bound GST isoenzymes, each of which displays distinct catalytic as well as noncatalytic binding properties: the cytosolic enzymes are encoded by at least five distantly related gene families (designated class alpha, mu, pi, sigma, and theta GST), whereas the membrane-bound enzymes, microsomal GST and leukotriene C, synthetase, are encoded by single genes and both have arisen separately from the soluble GST. Evidence suggests that the level of expression of GST is a crucial factor in determining the sensitivity of cells to a broad spectrum of toxic chemicals. In this article the biochemical functions of GST are described to show how individual isoenzymes contribute to resistance to carcinogens, antitumor drugs, environmental pollutants, and products of oxidative stress.A description of the mechanisms of transcriptional and posttranscriptional regulat...