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Etoposide, a semi-synthetic derivative of podophyllotoxin, is one of the most active and useful antineoplastic agent used routinely in firstline combination chemotherapy of testicular cancer, small-cell lung cancer and non-Hodgkin's lymphoma. Etoposide displays narrow therapeutic index, erratic pharmacokinetics and dose individualization that needs to be achieved for overcoming inter- and intra-patient variability (25-80%), so as to maintain proper drug exposure within a therapeutic range. Etoposide posses high plasma protein binding (97%) and is degraded via complex metabolic pathways. The main pharmacokinetic determinants of etoposide are still not completely defined in order to optimize the pharmaco-therapeutic parameters including dose, therapeutic schedule and route of administration. Much research has been done to determine drug-drug and herb-drug interactions for improving the bioavailability of etoposide. The present article gives insight on pharmaceutical and pharmacological attempts made from time to time to overcome the erratic inter- and intra-patient variability for improving the bioavailability of etoposide. [ABSTRACT FROM AUTHOR]

The present study was designed to investigate the anti-allergic effects of ethanolic extract of Alternanthera sessilis (AS-1) in rat basophilic leukemia (RBL-2H3) cells. It significantly reduced the β-hexosaminidase release from anti-DNP-IgE sensitized RBL-2H3 cells. AS-1also inhibited the IgE antibody-induced increase in Interleukin-6 (IL-6), TNF-α, IL-13 and IL-4 production in these cells. The inhibitory effect of AS-1 on these cytokine was found to be nuclear factor-KB (NF-kB) dependent, as it attenuated the degradation of IKBa and nuclear translocation of NFkB. In addition, AS-1 significantly attenuated the DNP HAS-induced intracellular Ca2+ release from these cells, which makes us speculate strongly that the decreased intracellular Ca2+ is involved in the inhibitory effect of AS-1 on β-hexoaminidase release. Taken together, anti-allergic effects of AS-1 suggest possible therapeutic application of this extract in allergic diseases. [ABSTRACT FROM AUTHOR]

Abstract: In the present investigation, adjuvant potential of two novel lipidated tripeptide lysine derivatives (KKSM and KKSMB) was evaluated using various in vitro and animal-derived models of humoral and cell-mediated immune events in response to hepatitis B surface antigen (HBsAg). The results were compared with alum adjuvanted with HBsAg. Both these molecules were found to stimulate anti-HBsAg IgG and neutralizing (IgG1 and IgG2a) antibody titres in mice sera. The two molecules stimulated the proliferation of T-lymphocyte sub-sets (CD4/CD8) as well as the production of soluble mediators of Th1 (IL-2 and IFN-γ) and Th2 response (IL-4) in spleen cell culture supernatant. Furthermore, the two lipidated tripeptides enhanced the CD4, CD8, CD3 and CD19 cell populations as well as CD4/CD8 derived IL-2, IL-4, IFN-γ and TNF-α in whole blood of treated mice. There was found to be the significant enhancement in the release of IL-12, IFN-γ and nitrite content in macrophage supernatant. Moreover, the two lipidated tripeptides enhanced the population of CD80 and CD86 in spleen-derived macrophages and did not show any hemolytic effect on rabbit RBCs. Taken together, these results suggest that both these molecules are the potent enhancers of anti-HBsAg immune response via augmenting Th1/Th2 response in a dose dependent manner. [Copyright &y& Elsevier]

Abstract: An efflux pump inhibitor, SK-20 (5-(3,4-methylenedioxyphenyle)-4 ethyl-2E,4E-pentadienoic acid piperidide), was assessed for its toxicity at three different pharmacological profiles: acute, sub-acute and general pharmacology with pharmacokinetics. In acute study, the SK-20 was found safe up to a dose of 2000mg/kg (b.wt.); and at sub-acute, dosages of 50 and 100mg/kg (b.wt.) were found to be safe. However, dosages of 200mg or above per kg (b.wt.) showed some morphological alterations in cellular architecture of both liver and kidneys in both sexes, viz., mild vascular congestion along with sporadic hemorrhages and infiltration into renal and hepatic parenchyma by mononucleate cell. General pharmacological studies did not result into any alterations in analgesic, convulsions, rectal temperatures and in the rhythm or the rate of the intestinal motility or the secretion of the bile. While the respiratory and the cardiac rate remained normal, the only parameter to show was the blood pressure, which at all the doses tested, showed a tendency toward reduction. Characteristically, the SK-20 at all doses influenced pentobarbital-induced hypnosis positively and negatively to spontaneous motor activity in a dose dependent manner. Pharmacokinetics of SK-20 revealed it to have retention time at 10.2min and half life 2.47h. [Copyright &y& Elsevier]

Background: A specific and sensitive UPLC-qTOF-MS/MS method has been developed for the simultaneous determination of curcuminoids. These Curcuminoids comprises of curcumin, a principal curcuminoid and other two namely, demethoxycurcumin, and bisdemethoxycurcumin obtained from rhizomes of Curcuma longa an ancient Indian curry spice turmeric, family (Zingiberaceae). Methods: These analytes were separated on a reverse phase C18 column by using a mobile phase of acetonitrile: 5% acetonitrile in water with 0.07% acetic acid (75:25 v/v), flow rate of 100 μL/min was maintained. The qTOF-MS was operated under multiple reaction monitoring (MRM) mode using electro-spray ionization (ESI) technique with positive ion polarity. The major product ions in the positive mode for curcuminoids were at m/z 369.1066, 339.1023 and 309.0214 respectively. The recovery of the analytes from mouse plasma was optimized using solid phase extraction technique. Results: The total run time was 5 min and the peaks of the compounds, bisdemethoxycurcumin, demethoxycurcumin and curcumin occurred at 2.06, 2.23 and 2.40 min respectively. The calibration curves of bisdemethoxycurcumin, demethoxycurcumin and curcumin were linear over the concentration range of 2-1000 ng/mL (r2, 0.9951), 2-1000 ng/mL (r2, 0.9970) and 2-1000 ng/mL (r2, 0.9906) respectively. Intra-assay and inter-assay accuracy in terms of % bias for curcumin was in between -7.95to +6.21, and ?7.03 to + 6.34; for demethoxycurcumin was μ6.72 to +6.34, and -7.86 to +6.74 and for bisdesmetoxycurcumin was -8.23 to +6.37 and μ8.47 to +7.81. The lower limit of quantitation for curcumin, demethoxycurcumin and bisdemethoxycurcumin was 2.0 ng/mL. Analytes were stable under various conditions (in autosampler, during freeze-thaw, at room temperature, and under deep-freeze conditions). This validated method was used during pharmacokinetic studies of curcumin in the mouse plasma. [ABSTRACT FROM AUTHOR]

Purpose: To develop and validate a sensitive HPLC method for the separation and simultaneous estimation of two ingredients in a composition comprising of rifampicin and a flavonoid glycoside (an enhancer of oral bioavailability of rifampicin). Methods: Reverse phase (RP) chromatographic separation and estimation was achieved using a Shimadzu HPLC system. RP-18 column was used at the following optimised conditions: mobile phase, acetonitrile:phosphate buffer, 50 mM, pH 5.0 in a ratio of 60:40 v/v; oven temperature, 40 °C; flow rate, 0.8 ml min-1; detection wavelength, 340 nm; and total run time, 15 min. Results: The developed method was validated in terms of linearity, range, accuracy, precision, limit of detection, limit of quantification, robustness and specificity. Good linearity was observed (r2 > 0.999) over the study range of both ingredients. The precision values for rifampicin and the flavonoid glycoside were in the range 1.08-2.77 and 1.14-2.98 %, respectively, while the limit of quantification was 0.10 and 0.05μg mL-1 respectively. The method was found to be robust and specific for both ingredients. Conclusion: The developed method has a potential application in preclinical and clinical studies. [ABSTRACT FROM AUTHOR]

Aim: Biochemical characterization of long-term toxic manifestations of anti-tubercular (anti-TB) drugs – rifampicin (RIF), isoniazid (INH) and pyrazinamide (PZA) – individually and in two combinations: (i) RIF + INH, and (ii) RIF + INH + PZA in Wistar rats. Methods: Animals received anti-TB drugs – alone or in combination – once daily p.o. for up to 90 days (doses, in mg/kg: RIF, 250; INH, 50; PZA, 100). Assays for alanine aminotransferase (ALT), alkaline phosphatase (ALP), bilirubin (serum) and lipid peroxidation (LPO), glutathione (GSH), glutathione peroxidase (GPx), catalase, Na+K+-ATPase and CYP 2E1 (liver) were performed to assess liver toxicity. Clinical biochemistry was done by commercial kits. Determinations were made at 0, 15, 30 and 90 days of treatment schedule. Results: Anti-TB drugs-treated animals showed abnormal rises or falls (>1.5–2 fold) in the serum/liver parameters. Mild hyperlipidemia, hypercholesterolemia and hyperuricemia were the other pathologies. Of all the treated groups, INHalone or in combination with other drugs produced a progressive enhancement of toxicity over 15–90 days. The in vivo results were further supported by in vitro results (MTT assay, GSH and LPO) in primary cultures of rat hepatocyte. Results indicated that anti-TB drugs in combination: (i) caused membrane damage resulting in leakage of ALT, ALP and bilirubin; (ii) caused imbalance in endogenous enzymatic oxidant–antioxidant defense via increased lipid peroxidation and in glutathione homeostasis; and (iii) enhanced the CYP 2E1-mediated bioactivation mechanism. Conclusion: Toxicity manifestations seemed to be heptocytic injury targeted at hepatocytes, bile ducts or sinusoidal cells related to hepatitis and primary biliary cholestasis. [ABSTRACT FROM AUTHOR]

Abstract: In the present study, the biochemical manifestations of liver toxicity caused by co-administration of anti-TB drugs, rifampicin (RIF), isoniazid (INH) and pyrazinamide (PZA), in a sub-chronic mode (12 weeks), were investigated. Significant alterations were revealed in (a) increased levels of alanine aminotrasferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) and a high bilirubin content in serum; (b) elevated lipid peroxidation (LPO), intracellular calcium [Ca2+]i and CYP4502EI activity in liver; and (c) decreased glutathione (GSH) content, glutathione peroxidase (GPx) and catalase activities in liver. Silymarin reversed these abnormal alterations. The biochemical changes were supported by histological observations. [Copyright &y& Elsevier]