Surendra Kumar Bansal

Antihyperglycemic and hypolipidemic activity of aqueous extract of Cassia auriculata L. leaves in experimental diabetes.

ETHNOPHARMACOLOGICAL RELEVANCE Cassia auriculata L. (Caesalpiniaceae) is widely used from ancient period to treat diabetes mellitus. The leaves of Cassia auriculata are having potential in the development of drug for diabetes due to its antihyperglycemic and lipid-lowering activity. AIM OF THE STUDY The present study was to evaluate antihyperglycemic and hypolipidemic activity of aqueous extract of Cassia auriculata leaves (CLEt) in streptozotocin (STZ)-induced mild diabetic (MD) and severe diabetic (SD) rats. MATERIALS AND METHODS Male Albino rats were rendered diabetic by STZ (45 mg/kg, intraperitoneally). CLEt was orally administered to MD and SD rats at 100, 200 and 400 mg/kg doses for 1 day to determine antihyperglycemic activity. The 400 mg/kg dose was administered daily for 3 weeks to assess glycemic control and hypolipidemic effect. RESULTS CLEt showed dose dependant fall in fasting blood glucose (FBG). After 5h of extract administration at 400mg/kg dose, FBG was reduced by 13.9% and 17.4% in MD and SD rats respectively. After 3 weeks treatment, CLEt produced significant reduction in FBG and glycosylated haemoglobin (GHb) in both MD and SD rats. Serum lipid levels were reversed towards normal in extract fed MD and SD rats. CONCLUSIONS The results demonstrate that CLEt possesses potent antihyperglycemic and hypolipidemic activity in both MD and SD rats.

Elucidation of mechanism of action of Cassia auriculata leaf extract for its antidiabetic activity in streptozotocin-induced diabetic rats.

Cassia auriculata traditionally has been used to treat diabetes from ancient times. The objective of the present study was to investigate the mechanism of action for the antidiabetic activity of aqueous leaf extract of C. auriculata (CLEt) in streptozotocin-induced mildly diabetic (MD) and severely diabetic (SD) rats. CLEt was orally administered to MD and SD rats at a dose of 400 mg/kg once a day for 15 days. CLEt-treated MD and SD rats showed significant reduction in fasting blood glucose. Assessment of plasma insulin and C-peptide following treatment with CLEt revealed significant elevation in their levels. Administration of CLEt enhanced the activity of hepatic hexokinase and phosphofructokinase and suppressed glucose-6-phosphatase and fructose-1,6-bisphosphatase in both MD and SD rats. A significant rise in glycogen content was also observed in both liver and muscles of CLEt-fed MD and SD rats. Histopathological examination of pancreatic sections revealed increased number of islets and beta-cells in CLEt-treated MD as well as SD rats. The findings of the study suggest that the antidiabetic effect of CLEt could be due to its insulinogenic action. In addition, impaired glucose homeostasis was improved by feeding the extract through amelioration in the carbohydrate metabolic pathways. Thus, the extract may exert an antidiabetic effect through pancreatic as well as extrapancreatic action.

Serum interleukin-1β as a marker for differentiation of asthma and chronic obstructive pulmonary disease

Asthma and chronic obstructive pulmonary disease (COPD) are diseases of airway inflammation with clinical and physiological similarities, making their differentiation difficult. Airway inflammatory changes are associated with systemic changes. However, no serum marker is known for their differentiation. Therefore, serum interleukin (IL)-1β levels were determined. Out of a total of 1023 patients screened, we included in the study ten patients each with atopic asthma, non-atopic asthma and COPD and ten healthy subjects. Skin prick tests with 14 inhalant allergens were performed on each patient. Blood was collected in the symptomatic and asymptomatic phases of the diseases and serum IL-1β and IgE levels were determined. Our results showed that in the symptomatic phase in asthmatics, serum IL-1β levels were higher (P<0.05) than in patients with COPD. Serum IgE levels were higher (P<0.05) in atopic asthmatics than in non-atopic asthmatics and in COPD patients. We conclude that serum IL-1β level determination during the symptomatic phase of the diseases may help to differentiate asthmatics from patients with COPD. Serum IgE levels may differentiate atopic asthmatics from non-atopic asthmatics and COPD patients.

Lipids of Erythrocyte Membranes of COPD Patients: A Quantitative and Qualitative Study

Abstract Chronic obstructive pulmonary disease (COPD) is characterized by inflammation of lung parenchyma and pulmonary hypoxemia with a proven systemic component. Tobacco smoke is the most important risk factor and plasma membrane plays a major role in the disease pathology and progression. The properties of biological membranes are a function of their lipid composition. Any change in its composition may lead to the pathophysiology. In COPD research, erythrocytes are emerging as a new therapeutic venture, as their shape and properties change in the disease. Therefore we studied the lipid composition of the erythrocyte membranes of COPD patients. The study included 30 patients having COPD, 10 healthy smokers and 10 non-smokers. Erythrocytes were separated from peripheral blood and their membranes prepared, followed by estimation of proteins, cholesterol and phospholipids. Individual phospholipids were identified and separated by TLC and fatty acid composition determined by gas chromatography. The data were analyzed statistically and P < 0.05 was considered significant. Our results demonstrate that in very severe COPD, proteins decrease, whereas phospholipids and cholesterol contents increase significantly, which showed a consistent negative correlation with FEV1%. The fatty acid analysis showed preponderance towards saturated fatty acids mainly arachidic and behenic acid, suggesting a decrease in membrane fluidity or a closer packing of lipid rafts. We are the first to report about preponderance of saturated fatty acids in plasma membrane of erythrocytes of COPD patients which may decrease the membrane fluidity and possibly impair the functions of the plasma membrane in the disease.

Genomic Profiling Identifies Novel Mutations and SNPs in ABCD1 Gene: A Molecular, Biochemical and Clinical Analysis of X-ALD Cases in India

X-linked adrenoleukodystrophy (X-ALD) affects the nervous system white matter and adrenal cortex secondary to mutations in the ABCD1 gene that encode the peroxisomal membrane protein. We conducted a genomic and protein expression study of susceptibility gene with its clinical and biochemical analysis. To the best of our knowledge this is the first preliminary comprehensive study in Indian population that identified novel mutations and SNPs in a relatively large group. We screened 17 Indian indigenous X-linked adrenoleukodystrophy cases and 70 controls for mutations and SNPs in the exonic regions (including flanking regions) of ABCD1 gene by direct sequencing with ABI automated sequencer along with Western blot analysis of its endogenous protein, ALDP, levels in peripheral blood mononuclear cells. Single germ line mutation was identified in each index case in ABCD1 gene. We detected 4 novel mutations (2 missense and 2 deletion/insertion) and 3 novel single nucleotide polymorphisms. We observed a variable protein expression in different patients. These findings were further extended to biochemical and clinical observations as it occurs with great clinical expression variability. This is the first major study in this population that presents a different molecular genetic spectrum as compared to Caucasian population due to geographical distributions of ethnicity of patients. It enhances our knowledge of the causative mutations of X-ALD that grants holistic base to develop effective medicine against X-ALD.

Calreticulin transacetylase catalyzed modification of the TNF-α mediated pathway in the human peripheral blood mononuclear cells by polyphenolic acetates

Polyphenols, coumarin (1,2-benzopyrone) and chromone (1,4-benzopyrone), are naturally occurring constituent of variety of plant species. They have attracted immense interest because of their diverse pharmacological activities. Not much was known about biological activities of acetyl derivative (polyphenolic acetates) of parent polyphenols. In previous investigations, we have conclusively established calreticulin transacetylase catalyzed activation of endothelial nitric oxide synthase (eNOS) by polyphenolic acetates. In the present work, calreticulin transacetylase of human peripheral blood mononuclear cells was characterized with respect to specificity for various polyphenolic acetates and its role in the activation of TNF-alpha induced nitric oxide synthase (iNOS). Peripheral blood mononuclear cells incubated with a model polyphenolic acetate, 7,8-diacetoxy-4-methylcoumarin (DAMC), along with L-arginine caused activation of NOS. The incubation of peripheral blood mononuclear cells with TNF-alpha and DAMC resulted in increased production of NO as compared to TNF-alpha alone. This increased NO production was attenuated by l-Nomega-nitro-L-arginine methyl ester (L-NAME), a well known non-specific inhibitor of NOS, and 1400W (N-[3-(aminomethyl) benzyl] acetamidine), a specific inhibitor of human iNOS. These results substantiate the CRTAase catalyzed activation of iNOS. Further, expression of NOS isoforms by semi-quantitative PCR and real-time RT-PCR confirms the preponderance of iNOS in TNF-alpha treated peripheral blood mononuclear cells over the untreated one. It was also observed that polyphenolic acetates inhibit TNF-alpha mediated release of IL-6 from peripheral blood mononuclear cells.

Changes in Protein Profile of Erythrocyte Membrane in Bronchial Asthma

Objectives. Erythrocyte membrane proteins reflect the prototype of multifunctional proteins of various erythroid and non-erythroid cells, which demonstrate various cellular functions. The protein profile of cells changes in various diseases. Therefore, the objective of this study was to understand the changes in protein profile of erythrocyte membranes in bronchial asthma. Methods. The study included 20 patients of bronchial asthma and 20 healthy subjects. Erythrocytes were isolated from peripheral blood, membranes were prepared followed by the determination of protein contents, and protein profile was assessed using SDS-PAGE. Results. In bronchial asthma, the protein contents of erythrocyte membranes in asthmatic patients were significantly higher (p < .005) than in healthy controls. Analysis of protein profile showed absence of the proteins, namely, band 4.2 and adducin subunit-II, and appearance of protein bands of molecular weights corresponding to galectin-3, glyceraldehyde 3-phosphate dehydrogenase, β-actin, dematin, band 4.1, and adducin (subunit-I) in asthmatic patients when compared with healthy controls. Conclusions. In asthma, there are quantitative and qualitative changes in proteins of erythrocyte membranes. The absence of band 4.2 protein may cause impairment of the erythrocyte membrane integrity, and presence of galectin-3 may lead to the activation of various inflammatory cells. The altered protein profile may possibly lead to altered response of the inflammatory cells to the asthmogenic stimuli, which may be responsible for pathophysiology and manifestation of the symptoms of bronchial asthma.

Sphingomyelin metabolism in erythrocyte membrane in asthma

Background. Sphingomyelin (SM), a major lipid constituent of outer leaflet of plasma membranes, with cholesterol, constitutes microdomains, which are termed as lipid rafts. These rafts provide support to proteins, receptors, enzymes, and so on and organize and orient them to conduct cellular functions including transmembrane signaling to substances in external milieu. The SM contents are regulated by its metabolism, changes in which may affect the composition of lipid rafts and cell response to the triggers of asthma which may lead to the pathophysiology. For studying changes in membranes, erythrocytes, which contain lipid rafts, are considered to be the best cell type. Hence, this study was conducted on plasma membrane of erythrocytes of asthmatic patients. Objective. The objective is to understand the changes in SM metabolism in asthma. Methods. The study included 50 subjects (25 asthmatics and 25 healthy subjects). Erythrocytes were isolated from the peripheral blood and membrane prepared. This was followed by determination of total cholesterol, phospholipids, SM, and sphingomyelinase activity. P < .05 was considered significant. Results and conclusions In asthmatics, there was a significant decrease in cholesterol contents (p < .05), decrease in total phospholipid contents (p < .005), increase in SM (p < .01), decrease in cholesterol: SM ratio (p < .001) and increase in sphingomyelinase activity (p < .001) in erythrocyte membranes. We conclude that in asthma, the increase in SM contents is associated with increased sphingomyelinase activity which shows an imbalance in SM metabolism, directed toward its accumulation. The ratio of cholesterol to SM, critical for maintenance of lipid rafts, was significantly lower in asthmatics. This indicates changes in structure of lipid rafts which may lead to the pathophysiology and development of asthma. Regulation of SM metabolism may help in disease regulation and its control.

Calreticulin transacetylase (CRTAase): Identification of novel substrates and CRTAase-mediated modification of protein kinase C (PKC) activity in lymphocytes of asthmatic patients by polyphenolic acetates

Earlier reports from our laboratory established the acetyl transferase function of calreticulin (CRT), enabling CRT to transfer acetyl groups from the acetoxy groups of polyphenolic acetates (PAs) to certain receptor proteins. We have in this paper documented the ability of CRT to catalyze the possible transfer of acetyl moiety from 7-acetamido-4-methylcoumarin (7-N-AMC) to the proteins, glutathione S-transferase (GST), and NADPH cytochrome c reductase, leading to the modification of their catalytic activities. 7-Acetoxy-4-methylthiocoumarin (7-AMTC) compared to 7-acetoxy-4-methylcoumarin (7-AMC) when used as a substrate for calreticulin transacetylase (CRTAase) yielded significantly higher catalytic activity. PM3-optimized geometries suggested that the availability of electrons on the sulfur atom of the thiocarbonyl group of the thiocoumarin may render the substrate binding more favorable to the active site of the enzyme as compared to its oxygen analog. Further CRTAase activity was characterized in the human blood lymphocytes. There was no appreciable difference in CRTAase activity of lymphocytes of asthmatic patients as compared to those of normal subjects. The results presented here highlight for the first time the irreversible inhibition of human blood lymphocytes protein kinase C (PKC) by 7,8-diacetoxy-4-methylcoumarin (DAMC) possibly by way of acetylation. The activity of PKC in lymphocytes of asthmatic patients was found to proportionally increase with the severity of the disease. When PA was incubated with lymphocytes of normal patients, PKC was inhibited marginally. On the other hand, lymphocyte PKC of severe asthmatic patients was inhibited drastically. Several PAs inhibited PKC of asthmatic patients in tune with their specificity to CRTAase. DAMC was found to exert maximum inhibitory action on PKC, while 7,8-dihydroxy-4-methylcoumarin (DHMC), the deacetylated product of DAMC, failed to inhibit PKC. These observations clearly describe DAMC as the novel irreversible inhibitor of PKC, and DAMC may be found useful in the control of inflammation and may serve as a potential drug candidate in the therapy of asthma.

Novel mutation in ATP-binding domain of ABCD1 gene in adrenoleucodystrophy

gene in Indian population. The diagnosis was basedon clinical symptoms, substantial increase in plasma, verylong-chain fatty acids and typical MRI pattern. MRI of thepatient showed peritrigonal and cerebellar semioval whitematter hypodensities and hyperintense areas (T2/fluid atten-uated inversion recovery) in bilateral cerebral white mat-ter, predominantly in parieto–occipital region. The molecu-lar analysis by direct sequencing of the