Subacute 28 days oral toxicity study of kaempferol and biochanin-A in the mouse model.

The present study was undertaken to investigate the safety of kaempferol (KEM) and biochanin-A (BCA) following subacute exposure in mice. KEM and BCA were administered in three different doses by oral administration for 28 days. Evaluation of general toxicity parameters by examining the clinical signs, body weight, organ weights, haematological, biochemical, oxidative stress parameters, and histopathology was done. Administration of KEM and BCA for 28 days did not show any clinical signs of toxicity, nor any treatment-related changes in body weight and organ weights in comparison to control. The haematological parameters such as red blood cell, white blood cell, platelets count, haemoglobin (Hb) level, haematocrit, mean corpuscular haemoglobin concentration, red cell distribution width, and platelet distribution width did not show any change in the treated groups and control. Furthermore, different biochemical parameters like markers of the liver (alanine aminotransferase and aspartate aminotransferase), kidney (creatinine and urea), and heart (creatinine kinase-myocardial band and lactate dehydrogenase) injury along with other biochemical parameters showed nonsignificant differences between treated groups and control. Results of oxidative stress parameters in treated groups showed insignificant variations with control. The level of antioxidant enzymes such as superoxide dismutase and catalase were markedly increased in the treated groups; however, these were nonsignificant in comparison to control. In histopathology, evaluation of all vital organs, such as liver, kidney, heart, and lungs, did not show any morphological abnormalities and lesions in treated groups and control. The present study suggests that KEM and BCA have no adverse effects on the general physiology in mice.

Circulating oxidative stress caused by Psoroptes natalensis infestation in Indian water buffaloes.

The present study reports the circulating oxidative stress associated with Psoroptes natalensis infestation in Indian water buffaloes. Three non-descriptive water buffaloes, age ranging between 4 and 9 years, presented to Referral Veterinary Polyclinic, IVRI, for treatment served as clinical subject. The infested animals were treated with Ivermectin subcutaneously and Amitraz topically along with antioxidant like ascorbic acid, Vitamin E and selenium. The level of lipid peroxidase was significantly higher (3.94 ± 0.34) in Psoroptes infested buffalo and was reduced significantly (P ≤ 0.05) after treatment (1.56 ± 0.40). The significantly higher levels of MDA before treatment signify the role of lipid peroxide mediated skin lesions in P. natalensis infested buffaloes. Similarly the activities of the body antioxidant like GSH and CAT were significantly higher (P ≤ 0.05) after treatment. The less level of the body antioxidant (GSH) and reduced activities of the antioxidant enzymes like CAT and SOD before treatment imply that Psoroptes mite-infested buffaloes were in a state of significant oxidative stress. The study provides information on oxidative stress indices in P. natalensis infested buffaloes and gives additional insight regarding the pathogenesis of the disease and its management.

Alteration in Oxidative/nitrosative imbalance, histochemical expression of osteopontin and antiurolithiatic efficacy of Xanthium strumarium (L.) in ethylene glycol induced urolithiasis.

Xanthium strumarium has traditionally been used in the treatment of urolitiasis especially by the rural people in India, but its antiurolithiatic efficacy was not explored scientifically till now. Therefore, the present study was designed to validate the ethnic practice scientifically, and explore the possible antiurolithiatic effect to rationalize its medicinal use. Urolitiasis was induced in hyperoxaluric rat model by giving 0.75% ethylene glycol (EG) for 28days along with 1% ammonium chloride (AC) for first 14days. Antiurolithiatic effect of aqueous-ethanol extract of Xanthium strumarium bur (xanthium) was evaluated based on urine and serum biochemistry, oxidative/nitrosative stress indices, histopathology, kidney calcium and calcium oxalate content and immunohistochemical expression of matrix glycoprotein, osteopontin (OPN). Administration of EG and AC resulted in hyperoxaluria, crystalluria, hypocalciuria, polyurea, raised serum urea, creatinine, erythrocytic lipid peroxidise and nitric oxide, kidney calcium content as well as crystal deposition in kidney section in lithiatic group rats. However, xanthium treatment significantly restored the impairment in above kidney function test as that of standard treatment, cystone. The up-regulation of OPN was also significantly decreased after xanthium treatment. The present findings demonstrate the curative efficacy of xanthium in ethylene glycol induced urolithiasis, possibly mediated through inhibition of various pathways involved in renal calcium oxalate formation, antioxidant property and down regulation of matrix glycoprotein, OPN. Therefore, future studies may be established to evaluate its efficacy and safety for clinical use.

Trypanosoma evansi infection in a German shepherd dog - Apparent successful treatment using serial low dose of diminazene aceturate.

The present study reports a new case of Trypanosoma evansi infection in a dog possibly due to oral transmission from a wild antelope, Nilgai. A four year old male German shepherd dog presented to the Referral Veterinary Polyclinic with history of inappetance, persistent fever, ocular discharge, standing for prolong periods and head pressing. Physical examination revealed corneal opacity, absence of menace reflex and partial blindness. The blood smear examination revealed the presence of Trypanosoma species. T. evansi infection was confirmed by RoTat 1.2 T. evansi specific Polymerase Chain Reaction (PCR). Haemato-biochemical examination showed anaemia, leukopenia, neutrophilia, a mild increase in concentration of alanine aminotransferase, blood urea nitrogen, and creatinine, and a decrease in concentration of blood glucose level. The dog was treated with diminazene aceturate at 3.5mg/kg body weight by deep intramuscular for 5days along with supportive therapy. Marked recovery in clinical signs as well as restoration of normal organ function and oxidant/antioxidant equilibrium was observed after two weeks of treatment. The dog was followed up to 6month and was negative for T. evansi by microscopy and PCR. The present treatment of a consecutive five dose regime of diminazene aceturate along with supportive therapy may help clinicians to overcome the hurdle of relapsing parasitaemia due to T. evansi and successful recovery in clinical cases.

Modified Boytchev procedure for recurrent anterior dislocation of shoulder.

PURPOSE. To evaluate results of the modified Boytchev procedure for recurrent anterior dislocation of the shoulder in 60 patients. METHODS. Medical records of 45 men and 15 women aged 20 to 44 years who underwent the modified Boytchev procedure for recurrent anterior dislocation of the right (n=44) and left (n=16) shoulders were reviewed. The mean number of dislocations was 14. Outcome was evaluated using the Burkhead and Rockwood criteria. RESULTS. The mean follow-up period was 56 months. Outcome was excellent in 32 patients, good in 21, and fair in 7. None had poor outcome. The mean external rotation deficit at 0º and 90º of abduction improved from 14º to 7º (p=0.04) and 18º to 7º (p=0.03), respectively. Two patients had fragmentation of the coracoid process, which was fixed with non-absorbable suture. Two patients had traction injury to the musculocutaneous nerve, which recovered after 6 months. One patient had recurrent dislocation that ruled out the chance of revision surgery. CONCLUSION. The modified Boytchev procedure is a viable and simple treatment for recurrent anterior shoulder dislocation.

Development of pyrazolone and isoxazol-5-one cambinol analogues as sirtuin inhibitors.

Sirtuins are a family of NAD(+)-dependent protein deacetylases that play critical roles in epigenetic regulation, stress responses, and cellular aging in eukaryotic cells. In an effort to identify small molecule inhibitors of sirtuins for potential use as chemotherapeutics as well as tools to modulate sirtuin activity, we previously identified a nonselective sirtuin inhibitor called cambinol (IC50 ≈ 50 µM for SIRT1 and SIRT2) with in vitro and in vivo antilymphoma activity. In the current study, we used saturation transfer difference (STD) NMR experiments with recombinant SIRT1 and 20 to map parts of the inhibitor that interacted with the protein. Our ongoing efforts to optimize cambinol analogues for potency and selectivity have resulted in the identification of isoform selective analogues: 17 with >7.8-fold selectivity for SIRT1, 24 with >15.4-fold selectivity for SIRT2, and 8 with 6.8- and 5.3-fold selectivity for SIRT3 versus SIRT1 and SIRT2, respectively. In vitro cytotoxicity studies with these compounds as well as EX527, a potent and selective SIRT1 inhibitor, suggest that antilymphoma activity of this compound class may be predominantly due to SIRT2 inhibition.

Targeted inhibition of cell-surface serine protease Hepsin blocks prostate cancer bone metastasis.

The development of effective therapies inhibiting prostate cancer progression and metastasis may substantially impact prostate cancer mortality and potentially reduce the rates of invasive treatments by enhancing the safety of active surveillance strategies. Hepsin (HPN) is a cell surface serine protease amplified in a subset of human sarcomas (7.2%), as well as in ovarian (10%), lung adeno (5.4%), lung squamous cell (4.5%), adenoid cystic (5%), breast (2.6%), uterine (1.7%) and colon (1.4%) carcinomas. While HPN is not amplified in prostate cancer, it is one of the most prominently overexpressed genes in the majority of human prostate tumors and genetic experiments in mice indicate that Hepsin promotes prostate cancer metastasis, particularly metastasis to the bone marrow. We report here the development, analysis and animal trial of the small-molecule Hepsin inhibitor HepIn-13. Long-term exposure to HepIn-13 inhibited bone, liver and lung metastasis in a murine model of metastatic prostate cancer. These findings indicate that inhibition of Hepsin with small-molecule compounds could provide an effective tool for attenuation of prostate cancer progression and metastasis.

Role of viscosupplementation in osteo-arthritis of knee joint.

Osteo-arthritis is the chronic degenerative disease associated with joint pain and loss of joint function. It is caused by 'wear and tear' on a joint. Knee is the most commonly Involved joint. Disease is so crippling that patient is unable to walk independently from bed to bathroom. The major causes of osteo-arthritis are age, gender, obesity, medical condition and hereditary. The signs and symptoms of osteo-arthritis are pain, joint stiffness, joint swelling, and loss of function. No blood tests are helpful in diagnosing osteo-arthritis. Management of osteo-arthritis includes non-pharmacological, pharmacological and surgical. A relatively new procedure is viscosupplementation, in which a preparation of hyaluronic acid is injected into the knee joint. Hyaluronic acid is a naturally occurring substance found in the synovial fluid. It acts as a lubricant to enable bones to move smoothly over each other and a shock absorber for joint loads. The decrease in the elastic and viscous properties of synovial fluid in osteo-arthritis results from both a reduced molecular size and a reduced concentration of hyaluronic acid in the synovial fluid. Viscosupplementation may be a therapeutic option for individuals with osteo-arthritis of the knee. Viscosupplementation has been shown to relieve pain in many patients who cannot get relief from non-medicinal measures or analgesic drugs. This article is to know the mechanism of action, patients' selection criteria, rationale and efficacy of viscosupplimentation in the management of osteo-arthritis of knee.

Ferrous iron-dependent delivery of therapeutic agents to the malaria parasite.

BACKGROUND: The malaria parasites Plasmodium falciparum and Plasmodium vivax generate significant concentrations of free unbound ferrous iron heme as a side product of hemoglobin degradation. The presence of these chemically reactive forms of iron, rare in healthy cells, presents an opportunity for parasite-selective drug delivery. Accordingly, our group is developing technologies for the targeted delivery of therapeutics to the intra-erythrocytic malaria parasite. These so-called 'fragmenting hybrids' employ a 1,2,4-trioxolane ring system as an iron(II)-sensing 'trigger' moiety and a 'traceless' retro-Michael linker to which a variety of partner drug species may be attached. After ferrous iron-promoted activation in the parasite, the partner drug is released via a ß-elimination reaction. METHODS: In this report, we describe three orthogonal experimental approaches that were explored in order to generate in vitro proof-of-concept for ferrous iron-dependent drug delivery from a prototypical fragmenting hybrid. CONCLUSION: Studies of two fragmenting hybrids by orthogonal approaches confirm that a partner drug species can be delivered to live P. falciparum parasites. A key advantage of this approach is the potential to mask a partner drug's intrinsic bioactivity prior to release in the parasite.

"Nora lesion" - Bizarre parosteal osteochondromatous proliferation.

Nora lesion is a rare benign parosteal osteochondromatous proliferation involving feet and hand. Aggressive features on imaging and confusing results on histopathological studies make its diagnosis difficult. Since the time of its discovery, only few cases have been reported in the literature. Authors report a case of Nora's lesion on the planto-medial aspect of metatarsal head of great toe of left foot. The diagnosis was suspected by imaging characteristic features and was confirmed by histopathology. Treatment was surgical, with complete excision. There are no clinical or radiological signs of recurrence on further review 1 year post-operatively.

Investigating the antimalarial action of 1,2,4-trioxolanes with fluorescent chemical probes.

The 1,2,4-trioxolanes are a new class of synthetic peroxidic antimalarials currently in human clinical trials. The well-known reactivity of the 1,2,4-trioxolane ring toward inorganic ferrous iron and ferrous iron heme is proposed to play a role in the antimalarial action of this class of compounds. We have designed structurally relevant fluorescent chemical probes to study the subcellular localization of 1,2,4-trioxolanes in cultured Plasmodium falciparum parasites. Microscopy experiments revealed that a probe fluorescently labeled on the adamantane ring accumulated specifically in digestive vacuole-associated neutral lipid bodies within the parasite while an isosteric, but nonperoxidic, congener did not. Probes fluorescently labeled on the cyclohexane ring showed no distinct localization pattern. In their subcellular localization and peroxidative effects, 1,2,4-trioxolane probes behave much like artemisinin-based probes studied previously. Our results are consistent with a role for adamantane-derived carbon-centered radicals in the antimalarial action of 1,2,4-trioxolanes, as hypothesized previously on the basis of chemical reactivity studies.

Sirtuin modulators.

Members of the sirtuin family including the founding protein Sir2 in Saccharomyces cerevisiae have been linked to lifespan extension in simple organisms. This finding prompted evaluation of the role of Sir2 orthologues in many aging-associated conditions including neurodegeneration, type II diabetes and cancer. These studies have demonstrated that genetic and pharmacologic manipulation of sirtuin activity have beneficial effects in a surprisingly broad spectrum of aging-associated conditions suggesting that the Sir2-family of enzymes presents an attractive target for the development of pharmacological agents. While the initial model favored pharmacological activators of sirtuins as calorie restriction mimetics, it now appears that either activation or inhibition of sirtuins may be desirable for ameliorating disease depending on the pathological condition and the target tissue. In this chapter we review the development of pharmacological small molecule activators and inhibitors of the sirtuin family of enzymes.

Dinoxin B, a withanolide from Datura inoxia leaves with specific cytotoxic activities.

A new withanolide, dinoxin B (12,21-dihydroxy-1-oxowitha-2,5,24-trienolide-27-O-ß-D-glucopyranoside, 1), was isolated from a methanol extract of Datura inoxia leaves, using bioassay-guided fractionation. The structure was determined by spectroscopic techniques, including (1)H, (13)C, and 2D NMR experiments as well as by HRMS. Extracts and the purified compound were tested for their antiproliferative activities toward a panel of human normal and cancer cell lines. Dinoxin B (1) and its aglycone (2) exhibited submicromolar IC(50) values against multiple human cancer cell lines. Among the most sensitive were several breast cancer cell lines. Dinoxin B (1) was found only in D. inoxia and was not detected in D. metel or D. stramonium. The accumulation of this compound was limited largely to leaf tissue, with little to none detected in extracts from the flowers, fruits, roots, or stems of D. inoxia.

Optimization of bivalent glutathione S-transferase inhibitors by combinatorial linker design.

Dimeric glutathione S-transferases (GSTs) are pharmacological targets for several diseases, including cancer. Isoform specificity has been difficult to achieve due to their overlapping substrate selectivity. Here we demonstrate the utility of bivalent GST inhibitors and their optimization via combinatorial linker design. A combinatorial library with dipeptide linkers emanating symmetrically from a central scaffold (bis-3,5-aminomethyl benzoic acid, AMAB) to connect two ethacrynic acid moieties was prepared and decoded via iterative deconvolution, against the isoforms GSTA1-1 and GSTP1-1. The library yielded high affinity GSTA1-1 selective inhibitors (70-120-fold selectivity) and with stoichiometry of one inhibitor: one GSTA1-1 dimer. Saturation Transfer Difference (STD) NMR with one of these inhibitors, with linker structure (Asp-Gly-AMAB-Gly-Asp) and K(D) = 42 nM for GSTA1-1, demonstrates that the Asp-Gly linker interacts tightly with GSTA1-1, but not P1-1. H/D exchange mass spectrometry was used to map the protein binding site and indicates that peptides within the intersubunit cleft and in the substrate binding site are protected by inhibitor from solvent exchange. A model is proposed for the binding orientation of the inhibitor, which is consistent with electrostatic complementarity between the protein cleft and inhibitor linker as the source of isoform selectivity and high affinity. The results demonstrate the utility of combinatorial, or "irrational", linker design for optimizing bivalent inhibitors.

Bivalent inhibitors of glutathione S-transferase: the effect of spacer length on isozyme selectivity.

Glutathione S-transferases (GSTs) are cytosolic enzymes that catalyze the conjugation of glutathione with a variety of exogenous and endogenous electrophiles. High affinity, isozyme-specific inhibitors of GST are required for use as pharmacological tools as well as potential therapeutics. The design of selective inhibitors is hindered due to the broad substrate binding capabilities of the GST enzymes. GSTs are dimeric enzymes, and therefore offer a unique discriminator for achieving inhibitor selectivity: the distance between binding sites on each monomer unit as a function of its quaternary organization. Bivalent analogs of the non-selective GST inhibitor ethacrynic acid were prepared, and selectivity for the GST A1-1 isozyme over GST P1-1 (IC50 values of 13.7 vs 1022 nM, respectively) was achieved through the optimization of the spacer length between the ethacrynic acid ligand domains.

Glutathione S-transferase P1-1 expression modulates sensitivity of human kidney 293 cells to photodynamic therapy with hypericin.

Photodynamic therapy (PDT) relies on light-dependent, tissue-targeted, oxidative stress in tumors that have accumulated a photosensitizing drug. Glutathione S-transferases (GSTs) are often up-regulated in tumors and they modulate oxidative stress by several isoform-dependent mechanisms. GSTs, therefore, are potential confounding factors in PDT. Therefore, we examined this possibility in human kidney 293 cells transfected with a plasmid encoding either green fluorescent protein alone (pIRES-GFP) or both GFP and GSTP1-1 (pIRES-GFP-GSTP). Cells were cultured and treated with light alone, the sensitizer hypericin (HYP) alone, or light and HYP. Cells harboring pIRES-GFP-GSTP exhibited a modest 2-fold increase in GSTP1-1 expression over control cells. On the basis of flow cytometry and microscopy, the light-dependent toxicity of HYP was reduced in cells over-expressing GSTP1-1. Paradoxically, the decreased toxicity in the cells with GSTP1-1 over-expression occurred concomitantly with a modest approximately 2-fold increase in cellular uptake of the drug. Immunoprecipitation of HYP and Western analysis indicated that GSTP1-1 is a major intracellular-binding site for HYP. These results are the first to demonstrate GST expression as a confounding variable of photodynamic therapy. Further, a high-affinity GST inhibitor reversed the GSTP1-1-dependent resistance, suggesting the possible utility of pharmacological strategies to optimize PDT.

A glutathione-based hydrogel and its site-selective interactions with water.

Glutathione (gamma-glutamyl-cysteinyl-glycine; GSH) is ubiquitous biological tripeptide with multiple functions and possible therapeutic uses. The oxidized disulfide form (GSSG) self-assembles into fibrillar aggregates and gels in organic solvents, but not in solvent mixtures with high water content. Here, the disulfide bond has been replaced with a pyrenyl moiety in order to test the ability of GSH to direct noncovalent self-assembly in H2O, when combined with a hydrophobic driving force for aggregation. The resulting GSH-pyrene forms gels in 95% H2O:5% DMSO. The gamma-glutamyl group is critical for gelation, as it is with GSSG organo-gels, inasmuch as neither S-(pyrenyl)-cysteinyl-glycine nor the iodo-acetamido-pyrene precursor gels under any conditions studied. Circular dichroism and fluorescence spectroscopy indicate that the pyrene moieties cluster within the gels. Scanning and transmission electron microscopy reveal fibrous networks with individual strands of approximately 50-100 nm diameter. Saturation transfer difference (STD) NMR studies demonstrate that water interacts strongly with GSH-borne protons in both solution and gel states, but only the gels include water-pyrenyl interactions with significant residence times.

Adenylylation and catalytic properties of Mycobacterium tuberculosis glutamine synthetase expressed in Escherichia coli versus mycobacteria.

Bacterial glutamine synthetases (GSs) are complex dodecameric oligomers that play a critical role in nitrogen metabolism, converting ammonia and glutamate to glutamine. Recently published reports suggest that GS from Mycobacterium tuberculosis (MTb) may be a therapeutic target (Harth, G., and Horwitz, M. A. (2003) Infect. Immun. 71, 456-464). In some bacteria, GS is regulated via adenylylation of some or all of the subunits within the aggregate; catalytic activity is inversely proportional to the extent of adenylylation. The adenylylation and deadenylylation of GS are catalyzed by adenylyl transferase (ATase). Here, we demonstrate via electrospray ionization mass spectrometry that GS from pathogenic M. tuberculosis is adenylylated by the Escherichia coli ATase. The adenylyl group can be hydrolyzed by snake venom phosphodiesterase to afford the unmodified enzyme. The site of adenylylation of MTb GS by the E. coli ATase is Tyr-406, as indicated by the lack of adenylylation of the Y406F mutant, and, as expected, is based on amino acid sequence alignments. Using electrospray ionization mass spectroscopy methodology, we found that GS is not adenylylated when obtained directly from MTb cultures that are not supplemented with glutamine. Under these conditions, the highly related but non-pathogenic Mycobacterium bovis BCG yields partially ( approximately 25%) adenylylated enzyme. Upon the addition of glutamine to the cultures, the MTb GS becomes significantly adenylylated ( approximately 30%), whereas the adenylylation of M. bovis BCG GS does not change. Collectively, the results demonstrate that MTb GS is a substrate for E. coli ATase, but only low adenylylation states are accessible. This parallels the low adenylylation states observed for GS from mycobacteria and suggests the intriguing possibility that adenylylation in the pathogenic versus non-pathogenic mycobacteria is differentially regulated.