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Biomedical subjects

Ashok Kumar

Publications and source records attributed to Ashok Kumar.

At least 91 records · Page 5Linked to original sources

Association of angiotensinogen gene polymorphisms with essential hypertension in African-Americans and Caucasians.

OBJECTIVE: Molecular variants of angiotensinogen (AGT) have been linked to essential hypertension, and promoter variants have been shown to alter the transcription rate of AGT in vitro. We employed a case-control study to determine whether single nucleotide polymorphisms (SNPs) in the promoter region of AGT were associated with hypertension in African-Americans and Caucasians. METHODS: The frequencies of the variants at base positions -6, -20, -217, -793, and -776, both alone and in combination (haplotypes), were compared between cases and controls in samples stratified based on race and sex. A logistic regression model was applied to test whether AGT genotypes were significant predictors of the disease while adjusting for race, sex, and age. RESULTS: Subjects with the AA or AG genotype at locus -793 were significantly more likely to have the disease (OR = 1.88, 95% CI = 1.12-3.15). Additionally, the differences in haplotype frequency distributions between cases and controls were significant at the 7% level for all four subgroups (stratified by race and sex) after adjusting for multiple testing. Based on the odds ratios for each individual haplotype, the haplotype AAAAT (nucleotide sequences at base positions -6, -20, -217, -793, -776) in African-American males, African-American females, and Caucasian females may confer susceptibility to the disease in these population subsets. CONCLUSION: Overall, the present report provides statistical evidence for the association of AGT with essential hypertension.

Black or African American↗

A comparative analysis of antibody repertoire against Staphylococcus aureus antigens in patients with deep-seated versus superficial staphylococcal infections.

Immunoblot and an enzyme-linked immunosorbent assays were used to evaluate and compare IgG antibodies against S. aureus whole cell lysate, cell wall peptidoglycan and lipoteichoic acid to discriminate between deep-seated and superficial S. aureus infection. Serum samples were examined from patients with deep-seated (n = 25) and superficial (n = 25) S. aureus infections and 15 healthy controls. Patients with deep-seated infections exhibited a large number of immuno-reactive bands in their IgG immunoblot profile as compared to those with superficial infections and healthy controls. Anti-staphylococcal IgG antibodies that reacted with two antigens of apparent molecular weight 110 and 98 kDa were specifically present in 96% (24/25) of patients with deep-seated infections, and were absent in, superficial and control sera. Moreover other Gram-positive and Gram-negative bacteria did not share these two unique antigens. The ELISA assays revealed significantly elevated levels of IgG antibodies to peptidoglycan (PG) in 18 of 25 (72%) patients with deep infection and 15 of 25 (60%) patients with superficial staphylococcal infection. The elevated levels of IgG antibodies to teichoic acid (TA) antigen were detected in all (100%) deep-seated group patients and among 40% (10/25) patients with superficial infection. An increase in levels of antibodies to PG showed a positive correlation trend with levels of IgG antibodies to TA only in deep infection group. Thus immunoblot detection of these two unique antigens as well as detection of elevated antibodies against PG and TA may be useful for the discrimination of staphylococcal deep-seated and superficial infection in humans.

Journal Article↗

Toll-like receptor 2-mediated expression of beta-defensin-2 in human corneal epithelial cells.

We previously showed that human corneal epithelial cells (HCECs) express Toll-like receptors (TLRs), which recognize gram-positive bacteria and respond to Staphylococcus aureus infection by the expression and secretion of proinflammatory cytokines and beta-defensin-2 (hBD2). In this study, we further elucidated the underlying mechanisms regulating hBD-2 expression and its role in innate defense in HCECs in response to S. aureus challenge. Exposure of HUCL cells, a telomerase-immortalized HCEC line, to S. aureus, its exoproducts (1:10 dilution), or synthetic lipopeptide Pam3Cys (10 microg/ml) resulted in the up-regulation of hBD-2, but not hBD1 and hBD3. Similar to HUCL cells, primary HCECs responded to S. aureus-exoproducts and Pam3Cys challenge by expressing hBD2 mRNA and secreting hBD2 into the culture media. Furthermore, these stimuli induced the expression of TLR2 at both mRNA and protein levels. Consistently with its role as a major pattern-recognizing receptor, TLR2 was located at the cell surface by cell surface biotinylation. The treatment of HUCL cells with TLR2 neutralizing antibody resulted in a significant decrease in Pam3Cys-induced hBD2 production as well as IL-6, IL-8, and TNF-alpha secretion. The Pam3Cys-induced hBD2 expression was completely blocked by NF-kappaB inhibitors and partially inhibited by p38 MAP kinase and the JNK inhibitors. Conditioned media derived from HCECs challenged with S. aureus-exoproducts or Pam3Cys exhibited antibacterial activity against S. aureus, Pseudomonas aeruginosa and Escherichia coli. These findings suggest that S. aureus induces hBD2 production through TLR2-mediated pathways in HCECs and that pathogen-challenged, TLR-activated HCECs possess antimicrobial activity. Thus, the epithelium might play a role in innate defense against bacterial infection by directly killing bacteria in the cornea.

Cells, Cultured↗

Distinct role of calmodulin and calmodulin-dependent protein kinase-II in lipopolysaccharide and tumor necrosis factor-alpha-mediated suppression of apoptosis and antiapoptotic c-IAP2 gene expression in human monocytic cells.

Exposure of phagocytic cells to bacterial endotoxin (lipopolysaccharide; LPS) or inflammatory cytokines confers antiapoptotic survival signals; however, in the absence of the appropriate stimulus, monocytes are programmed to undergo apoptosis. Macrophage survival may thus influence inflammatory and immune responses and susceptibility to microbial pathogens. Herein, we demonstrate that LPS and the proinflammatory cytokine, tumor necrosis factor-alpha (TNF-alpha), enhance monocytic cell survival through the induction of the antiapoptotic c-IAP2 gene in a human promonocytic THP-1 cell line. We also investigated the role of upstream signaling molecules including the mitogen-activated protein kinases, phosphatidylinositol 3-kinase, and the calcium signaling pathways in the regulation of c-IAP2 expression and eventual survival of monocytic cells. Our results suggest that LPS and TNF-alpha-induced c-IAP2 expression was regulated by calmodulin (CaM) through the activation of calmodulin-dependent protein kinase-II (CaMKII). In addition, CaM and CaMKII regulated c-IAP2 expression in LPSand TNF-alpha-stimulated cells through NF-kappaB activation. Moreover, the CaM/CaMKII pathway also regulated LPS- and TNF-alpha-mediated inhibition of apoptosis in these cells. Taken together, these results suggest that LPS- and TNF-alpha-induced c-IAP2 expression and its associated antiapoptotic survival signals in THP-1 cells are regulated selectively by CaM/CaMKII through NF-kappaB activation.

Apoptosis↗

Application of GC-EI-MS for the identification and investigation of positional isomer in primaquine, an antimalarial drug.

A major impurity associated with primaquine drug samples obtained from European Pharmacopoeia (EP) and other commercial sources was detected and identified using HPLC, photo diode array (PDA), LC-MS/MS and gas chromatograph-electron impact-mass spectrometer (GC-EI-MS). PDA and LC-ESI-MS/MS data provided an evidence for it being isomeric in nature. However, spectral data obtained from the newly developed GC-EI-MS method has been utilised for structural elucidation and found to be conclusive to characterize this impurity as positional isomer, i.e. 8-(4-amino-4-methylbutyl amino)-6 methoxyquinoline. The structure of this impurity has been confirmed by its synthesis. Precursor of primaquine was also investigated using GC-EI-MS. The data obtained confirmed the origin of isomeric impurity in precursor.

Antimalarials↗

Pregnancy-associated plasma protein-A regulates myoblast proliferation and differentiation through an insulin-like growth factor-dependent mechanism.

Pregnancy-associated plasma protein-A (PAPP-A), a member of the metalloproteinase superfamily, is an important regulator of mammalian growth and development. However, the role of PAPP-A and its mechanism of action in various cellular processes remain unknown. In this study, we have investigated the role of PAPP-A in skeletal myogenesis using C2C12 myoblasts. Recombinant PAPP-A was purified from the conditioned medium of HT1080 cells overexpressing PAPP-A. Treatment of C2C12 myoblasts with PAPP-A increased their proliferation in a dose- and time-dependent manner. Addition of exogenous PAPP-A also increased the myotube formation and the activity of creatine kinase in C2C12 cultures. Transient overexpression of the full-length PAPP-A-(1-1547), but not truncated protease-inactive N-terminal PAPP-A-(1-920) or C-terminal PAPP-A-(1100-1547), significantly enhanced the proliferation of C2C12 myoblasts. In vitro and in situ experiments demonstrated that PAPP-A cleaves insulin-like growth factor-binding protein (IGFBP)-2, but not IGFBP-3, in the conditioned medium of C2C12 myoblasts. Overexpression of PAPP-A led to degradation of the IGFBP-2 produced by C2C12 myoblasts and increased free IGF-I concentrations without affecting total IGF-I concentrations. Addition of protease-resistant IGFBP-4 completely abolished the PAPP-A-induced proliferation of C2C12 myoblasts. Our results demonstrate that 1) PAPP-A increases the proliferation and differentiation of myoblasts, 2) the stimulatory effect of PAPP-A on myogenesis is governed by its proteolytic activity, and 3) PAPP-A promotes skeletal myogenesis by increasing the amount of free IGFs via specific degradation of IGFBP-2 produced by myoblasts.

Animals↗

Synthesis of acridinyl-thiazolino derivatives and their evaluation for anti-inflammatory, analgesic and kinase inhibition activities.

Variety of N-(4-phenyl-3-(2',3',4'(un)substituted phenyl)thiazol-2(3H)-ylidene)-2,4(un)substituted acridin-9-amine (4a-o) and 1-[(2,4-(un)substituted acridin-9-yl)-3-(4-phenyl-3-(2',3',4'(un)substituted phenyl)thiazol-2(3H)-ylidene)]isothiourea (5a-h) derivatives have been synthesized by condensation of 4-phenyl-3-(2',3',4'(un)substituted phenyl)thiazol-2(3H)-imine (3a-g) with 9-chloro-2,4-(un)substituted acridine (1a-c) and 9-isothiocyanato-2,4-(un)substituted acridine (2a-d), respectively. All these compounds were characterized by correct 1H NMR, FT-IR, MS and elemental analyses. These compounds were screened for anti-inflammatory, analgesic and kinase (CDK1, CDK5 and GSK3) inhibition activities. Some compounds exhibited good anti-inflammatory (25-32%) and potent analgesic (50-75%) activities, at 50 mg/kg p.o. A compound, 4o (R1 = H, R2 = OCH3, R3 = CH3, R4 = CH3, R5 = H) exhibited moderate CDK1 (IC50 = 8.5 microM) inhibition activity.

Acridines↗

STAT-1 mediates the stimulatory effect of IL-10 on CD14 expression in human monocytic cells.

IL-10, an anti-inflammatory cytokine, has been shown to exhibit stimulatory functions including CD14 up-regulation on human monocytic cells. CD14-mediated signaling following LPS stimulation of monocytic cells results in the synthesis of proinflammatory cytokines. Our results show that LPS-induced CD14 expression on monocytic cells may be mediated by endogenously produced IL-10. To investigate the molecular mechanism by which IL-10 enhances CD14 expression, both human monocytes and the promyelocytic HL-60 cells were used as model systems. IL-10 induced the phosphorylation of PI3K and p42/44 ERK MAPK. By using specific inhibitors for PI3K (LY294002) and ERK MAPKs (PD98059), we demonstrate that LY294002 either alone or in conjunction with PD98059 inhibited IL-10-induced phosphorylation of STAT-1 and consequently CD14 expression. However, IL-10-induced STAT-3 phosphorylation remained unaffected under these conditions. Finally, STAT-1 interfering RNA inhibited IL-10-induced CD14 expression. Taken together, these results suggest that IL-10-induced CD14 up-regulation in human monocytic cells may be mediated by STAT-1 activation through the activation of PI3K either alone or in concert with the ERK MAPK.

Adult↗

Synthesis, spectral characterization and biological studies of some organotin(IV) complexes of L-proline, trans-hydroxy-L-proline and L-glutamine.

New organotin(IV) complexes of the general formula R3Sn(L) (where R=Me, n-Bu and HL=L-proline; R=Me, Ph and HL=trans-hydroxy-L-proline and L-glutamine) and R2Sn(L)2 (where R=n-Bu, Ph and HL=L-proline; R=Ph, HL=trans-hydroxy-L-proline) have been synthesized by the reaction of RnSnCl(4-n) (where n=2 or 3) with sodium salt of the amino acid (HL). n-Bu2Sn(Pro)2 was synthesized by the reaction of n-Bu2SnO with L-proline under azeotropic removal of water. The bonding and coordination behavior in these complexes have been discussed on the basis of IR and 119Sn Mössbauer spectroscopic studies in the solid-state. Their coordination behavior in solution has been discussed with the help of multinuclear (1H, 13C and 119Sn) NMR spectral studies. The 119Sn Mössbauer and IR studies indicate that L-proline and trans-hydroxy-L-proline show similar coordination behavior towards organotin(IV) compounds. Pentacoordinate trigonal-bipyramidal and hexacoordinate octahedral structures, respectively, have been proposed for the tri- and diorganotin(IV) complexes of L-proline and trans-hydroxy-L-proline, in which the carboxylate group acts as bidentate group. L-glutamine shows different coordination behavior towards organotin(IV) compounds, it acts as monoanionic bidentate ligand coordinating through carboxylate and amino group. The triorganotin(IV) complexes of L-glutamine have been proposed to have trigonal-bipyramidal environment around tin. The newly synthesized complexes have been tested for their antiinflammatory and cardiovascular activities. Their LD50 values are >1000 mg kg-1.

Animals↗

New triorganotin (IV) derivatives of dipeptides as models for metal-protein interactions: synthesis, structural characterization and biological studies.

New non-electrolytic triorganotin(IV) derivatives of dipeptides with general formulae R3Sn(HL), where R = Ph and HL = monoanion of glycylisoleucine (H2L-1), valylvaline (H2L-2), alanylvaline (H2L-3), leucylalanine (H2L-4), leucylleucine (H2L-5); R = n-Bu and HL = monoanion of glycylisoleucine (H2L-1) and leucylalanine (H2L-4); and R = Me and HL = monoanion of leucylalanine (H2L-4) have been synthesized and characterized on the basis of infrared, multinuclear 1H, 13C and 119Sn NMR and 119Sn Mössbauer spectroscopic studies. These investigations suggest that all the ligands in R3Sn(HL) act as monoanionic bidentates coordinating through the COO- and NH2 groups. The 119Sn Mössbauer studies, together with the NMR data, indicate that, for these polymeric derivatives, the polyhedron around tin in R3Sn(HL) is a trigonal-bipyramid with the three organic groups in the equatorial positions, while the axial positions are occupied by a carboxylic oxygen and the amino nitrogen atom from the adjacent molecule. The anti-inflammatory and cardiovascular activities and toxicity of all these compounds have been determined. Four of the complexes have also been screened against some of the chosen bacterial and fungal strains. The Ph3Sn(IV) compounds exhibit better anti-inflammatory and cardiovascular activities in comparison to the Me3Sn(IV) and n-Bu3Sn(IV) analogues. n-Bu3Sn(Gly-Ile) and Ph3Sn(Ala-Val) exhibit good antibacterial activity against all the chosen strains.

Animals↗

Differential involvement of calmodulin-dependent protein kinase II-activated AP-1 and c-Jun N-terminal kinase-activated EGR-1 signaling pathways in tumor necrosis factor-alpha and lipopolysaccharide-induced CD44 expression in human monocytic cells.

CD44 plays a crucial role in cell migration, inflammation, and immune responses. Alteration in the levels of CD44 expression on monocytic cells by endotoxins and immunoregulatory cytokines may modulate the migration of immune cells to inflammatory sites and the development of immune responses. Lipopolysaccharide (LPS) and the proinflammatory cytokine, tumor necrosis factor-alpha (TNF-alpha), act as important regulators of CD44 expression in human monocytic cells. We previously demonstrated that the c-Jun N-terminal kinase (JNK), a mitogen-activated protein kinase (MAPK), differentially regulated LPS- but not TNF-alpha-induced CD44 expression in monocytic cells. In this study, our results suggest that the calcium signaling pathway, in particular calmodulin (CaM) and CaM-dependent protein kinase II (CaMK-II), is involved in TNF-alpha- but not LPS-induced CD44 expression. CD44 promoter analysis suggested the participation of distinct transcription factors AP-1 and Egr-1 in TNF-alpha- and LPS-induced CD44 expression, respectively. Furthermore, TNF-alpha-induced CD44 expression was regulated by AP-1 through the activation of the CaMK-II pathway, whereas LPS-induced CD44 transcription was regulated specifically by Egr-1 through JNK activation. Overall, the results suggest the involvement of two distinct and independent signaling pathways involved in the regulation of CD44 transcription that may represent potential targets for anti-inflammatory agents capable of inhibiting CD44-mediated cell migration.

Calcium Signaling↗

Prodynorphin knockout mice demonstrate diminished age-associated impairment in spatial water maze performance.

Dynorphins, endogenous kappa-opioid agonists widely expressed in the central nervous system, have been reported to increase following diverse pathophysiological processes, including excitotoxicity, chronic inflammation, and traumatic injury. These peptides have been implicated in cognitive impairment, especially that associated with aging. To determine whether absence of dynorphin confers any beneficial effect on spatial learning and memory, knockout mice lacking the coding exons of the gene encoding its precursor prodynorphin (Pdyn) were tested in a water maze task. Learning and memory assessment using a 3-day water maze protocol demonstrated that aged Pdyn knockout mice (13-17 months) perform comparatively better than similarly aged wild-type (WT) mice, based on acquisition and retention probe trial indices. There was no genotype effect on performance in the cued version of the swim task nor on average swim speed, suggesting the observed genotype effects are likely attributable to differences in cognitive rather than motor function. Young (3-6 months) mice performed significantly better than aged mice, but in young mice, no genotype difference was observed. To investigate the relationship between aging and brain dynorphin expression in mice, we examined dynorphin peptide levels at varying ages in hippocampus and frontal cortex of WT 129SvEv mice. Quantitative radioimmunoassay demonstrated that dynorphin A levels in frontal cortex, but not hippocampus, of 12- and 24-month mice were significantly elevated compared to 3-month mice. Although the underlying mechanisms have yet to be elucidated, the results suggest that chronic increases in endogenous dynorphin expression with age, especially in frontal cortex, may adversely affect learning and memory.

Age Factors↗

Mitogenic and anti-proliferative activity of a lectin from the tubers of Voodoo lily (Sauromatum venosum).

A new lectin with the potent mitogenic and in vitro anti-proliferative activity was isolated from the tubers of a wild monocotyledonous plant Sauromatum venosum (Schott), from the family Araceae, by affinity chromatography on the asialofetuin linked amino-activated silica beads. The apparent native molecular mass of S. venosum lectin (SVL), as determined by gel filtration chromatography, was 54 kDa. In HPLC, size exclusion and cation exchange chromatography, SVL gave a single peak and also a single band of 13.5 kDa in SDS-PAGE, pH 8.3, under reducing and non-reducing conditions, indicating that the lectin is composed of four identical subunits. S. venosum lectin agglutinated rabbit, rat, sheep and guinea pig erythrocytes but reacted with goat erythrocytes after the neuraminidase treatment. However, SVL was unable to agglutinate human ABO blood group erythrocytes even after treatment with neuraminidase. SVL was inhibited by N-acetyl-D-Lactosamine (LacNAc), which is an important marker in various carcinomas and a complex desialylated glycoprotein, asialofetuin. The amino acid composition showed that lectin contained a high amount of aspartic acid and glycine but totally devoid of cysteine. However, trace amounts of methionine was present. The lectin showed a potent mitogenic response towards BALB/c splenocytes and human lymphocytes. As the mitogenic stimulation was more than that of Con A, a standard well-known plant mitogen and the response of this lectin was almost double than that of Con A. This lectin is endowed with proliferation of T cells as revealed by IL-2 bioassay but showed no production of immunoglobulins thus indicating the non-stimulation of B cells. SVL significantly inhibited the proliferation of murine cancer cell-lines, i.e., WEHI-279 to 84.6%, J774 to 81%, P388D1 to 74% and A-20 to 47%. In addition, the in vitro anti-proliferative activity of SVL was also evaluated against nine human cancer cell lines representing different organs and tissues namely, T-47D (breast), SiHa (cervix), SK-N-MC (CNS), SK-N-SH (CNS), SW-620 (colon), HT-29 (colon), HEP-2 (liver), OVCAR-5 (ovary) and PC-3 (prostate). SVL showed a significant inhibition towards the entire cell lines except the cell lines from CNS, which showed partial response in comparison to a standard anticancer drug adriamycin which was used at a concentration of 5 x 10(-5) M. Thus the anti-proliferative ability of SVL may be helpful in identification of new lectin probes that can lead to better understanding in the detection and study of certain types of cancer.

Animals↗

Studies on synthesis and evaluation of quantitative structure-activity relationship of 5-[(3'-chloro-4',4'-disubstituted-2-oxoazetidinyl)(N-nitro)amino]-6-hydroxy-3-alkyl/aryl[1,3]azaphospholo[1,5-a]pyridin-1-yl-phosphorus dichlorides.

A new series of 5-[(3'-chloro-4',4'-disubstituted-2-oxoazetidinyl)(N-nitro)amino]-6-hydroxy-3-alkyl/aryl[1,3]azaphospholo[1,5-a]pyridin-1-yl-phosphorus dichlorides has been synthesized and subjected to acute antibacterial and antifungal screening studies. All the derivatives belonging to this series delineated remarkable activity as compared to standard drugs (ampicillin and clotrimazole). Compounds are quantitatively analyzed in relation to their different physicochemical parameters. Significant correlations were obtained between biological activity and polarizability parameter (MR).

Anti-Bacterial Agents↗

Intracellular calcium stores contribute to increased susceptibility to LTD induction during aging.

Release of Ca(2+) from intracellular Ca(2+) stores (ICS) is involved in age-related changes in the induction of long-term potentiation. However, the role of this Ca(2+) source for the increased susceptibility to long-term depression (LTD) with advanced age is unknown. Extracellular excitatory postsynaptic field potentials were recorded from CA3-CA1 synaptic contacts from hippocampal slices obtained from young (5-8 months) and aged (22-24 months) male Fischer 344 rats. Blockade of Ca(2+)-release from ICS by cyclopiazonic acid, thapsigargin, or ryanodine blocked LTD induction in aged rats. Impaired LTD was not simply due to a loss of a Ca(2+) source. The idea that ICS may play prominent role in regulating synaptic modifiability through regulation of cell excitability and the timing of pre and postsynaptic activity is discussed.

Aging↗

A single-nucleotide polymorphism in human angiotensinogen gene is associated with essential hypertension and affects glucocorticoid induced promoter activity.

Hypertension is a serious health problem particularly for African-Americans. Previous studies have suggested that angiotensinogen (AGT) gene locus is involved in human essential hypertension. We have recently shown that an A/G polymorphism at -217 in the promoter of the AGT gene is associated with essential hypertension especially in African-Americans. We report here that A/G polymorphism at -217 affects the glucocorticoid-induced promoter activity of the human AGT gene. We show that recombinant glucocorticoid receptor (GR) binds strongly to the AGT gene promoter when nucleoside A is present at -217, and dexamethasone treatment increases the interleukin 6 induced promoter activity of reporter constructs containing nucleoside A at -217. Similarly cotransfection of GR and C/EBP beta or C/EBP delta increases the promoter activity of reporter construct containing nucleoside A at -217. Since AGT is an acute phase protein, we propose that increased expression of -217A allele of the AGT gene by glucocorticoids and C/EBP family of transcription factors may be involved in essential hypertension.

Angiotensinogen↗

New triorganotin(IV) derivatives of dipeptides as anti-inflammatory-antimicrobial agents.

New triorganotin(IV) derivatives of dipeptides with general formulae R(3)Sn(HL), where R = Me and/or n-Bu and/or Ph and HL is the monoanion of glycylglycine (H(2)L-1), glycylvaline (H(2)L-2), glycylleucine (H(2)L-3), glycyltryptophane (H(2)L-4) and glycyltyrosine (H(2)L-5) have been synthesized and characterized on the basis of infrared, multinuclear NMR and (119)Sn Mossbauer spectroscopic studies. All the newly synthesized compounds were examined for their in vivo anti-inflammatory activity (using the carrageenan-induced paw edema bioassay in rats), acute toxicity (LD(50)) and cardiovascular activity. These compounds were also screened for their in vitro antimicrobial activity against Staphylococcus aureus Mau (29/58) and (78/71), Bacillus subtilis (18/64), Escherichia coli (326/71), Candida albicans (Pn-10), Microsporum gypseum and Euglena gracillis. The results revealed that triphenyltin(IV) derivatives exhibited anti-inflammatory activity comparable to that of phenylbutazone with high safety margin (LD(50) > 500 mg kg(-1)). Further Ph(3)Sn(Gly-Val) displays a potent cardiovascular activity. Moreover, most of the compounds displayed appreciable antibacterial activities when compared with ampicillin and norfloxacin. Compounds Ph(3)Sn(Gly-Gly) and Ph(3)Sn(Gly-Val) are the most distinctive derivatives identified in the present study because of their promising in vivo anti-inflammatory activity and in vitro antibacterial activity against gram-positive and -negative bacteria.

Animals↗