Probing Microscale Structuring-Induced Phase Separation with Fluorescence Recovery Diffusion Dynamics in Poly(ethylene glycol) Solutions.

Apart from biocompatibility, poly(ethylene glycol) (PEG)-based biomedical constructs require mechanical tunability and optimization of microscale transport for regulation of the release kinetics of biomolecules. This study illustrates the role of inhomogeneities due to aggregates and structuring in the PEG matrix in the microscale diffusion of a fluorescent probe. Comparative analysis of fluorescence recovery after photobleaching (FRAP) profiles with the help of diffusion half-time is used to assess the diffusion coefficient (D). The observations support a nontrivial dependence of diffusion dynamics on polymer concentration (volume fraction, φ) and that of fillers carboxymethyl cellulose (CMC) and nanoclay bentonite (B). D values follow the Rouse scaling D ∼ φ-0.54 in PEG solutions. The diffusion time of the fluorescent probe in the PEG+bentonite matrix reveals the onset of depletion interaction-induced phase separation with an increase in bentonite concentration in the PEG matrix beyond 0.1 wt %. Beyond this concentration, structure factors obtained from prebleach FRAP images show a rapid increase at low Q. The two-phase system (PEG-rich and bentonite-rich) was characterized by the hierarchical structural topology of bentonite aggregates, and aggregate sizes were obtained at different length scales with phase contrast imaging, small-angle neutron scattering, and small-angle X-ray scattering. The microscale transport detection presented captures sensitively the commencement of phase separation in the PEG + bentonite matrix, as opposed to the PEG or PEG + CMC matrix, which are observed to be one-phase systems. This method of diffusion half-time and prebleach image analysis can be used for the fast, high-throughput experimental investigation of microscale mechanical response and its correlation with structuring in the polymer matrix.

Glabridin plays dual action to intensify anti-metastatic potential of paclitaxel via impeding CYP2C8 in liver and CYP2J2/EETs in tumor of an orthotopic mouse model of breast cancer.

In spite of unprecedented advances in modern cancer therapy, there is still a dearth of targeted therapy to circumvent triple-negative breast cancer (TNBC). Paclitaxel is the front-line therapy against TNBC, but the main constraints of its treatment are dose-related adverse effects and emerging chemoresistance. In this context, glabridin (phytoconstituent from Glycyrrhiza glabra) is reported to hit multiple signalling pathways at the in-vitro level, but hardly any information is known at the in-vivo level. We aimed here to elucidate glabridin potential with an underlying mechanism in combination with a low dose of paclitaxel using a highly aggressive mouse mammary carcinoma model. Glabridin potentiated the anti-metastatic efficacy of paclitaxel by substantially curtailing tumor burden and diminishing lung nodule formation. Moreover, glabridin remarkably attenuated epithelial-mesenchymal transition (EMT) traits of hostile cancer cells via up-regulating (E-cadherin & occludin) and down-regulating (Vimentin & Zeb1) vital EMT markers. Besides, glabridin amplified apoptotic induction effect of paclitaxel in tumor tissue by declining or elevating pro-apoptotic (Procaspase-9 or Cleaved Caspase-9 & Bax) and reducing anti-apoptotic (Bcl-2) markers. Additionally, concomitant treatment of glabridin and paclitaxel predominantly lessened CYP2J2 expression with marked lowering of epoxyeicosatrienoic acid (EET)'s levels in tumor tissue to reinforce the anti-tumor impact. Simultaneous administration of glabridin with paclitaxel notably enhanced plasma exposure and delayed clearance of paclitaxel, which was mainly arbitrated by CYP2C8-mediated slowdown of paclitaxel metabolism in the liver. The fact of intense CYP2C8 inhibitory action of glabridin was also ascertained using human liver microsomes. Concisely, glabridin plays a dual role in boosting anti-metastatic activity by augmenting paclitaxel exposure via CYP2C8 inhibition-mediated delaying paclitaxel metabolism and limiting tumorigenesis via CYP2J2 inhibition-mediated restricting EETs level. Considering the safety, reported protective efficacy, and the current study results of boosted anti-metastatic effects, further investigations are warranted as a promising neoadjuvant therapy for crux paclitaxel chemoresistance and cancer recurrence.

Rottlerin renders a selective and highly potent CYP2C8 inhibition to impede EET formation for implication in cancer therapy.

CYP2C8 is a crucial CYP isoform responsible for the metabolism of xenobiotics and endogenous molecules. CYP2C8 converts arachidonic acid to epoxyeicosatrienoic acids (EETs) that cause cancer progression. Rottlerin possess significant anticancer actions. However, information on its CYP inhibitory action is lacking in the literature and therefore, we aimed to explore the same using in silico, in vitro, and in vivo approaches. Rottlerin showed highly potent and selective CYP2C8 inhibition (IC50 < 0.1 µM) compared to negligible inhibition (IC50 > 10 µM) for seven other experimental CYPs in human liver microsomes (HLM) (in vitro) using USFDA recommended index reactions. Mechanistic studies reveal that rottlerin could reversibly (mixed-type) block CYP2C8. Molecular docking (in silico) results indicate a strong interaction could occur between rottlerin and the active site of human CYP2C8. Rottlerin boosted the plasma exposure of repaglinide and paclitaxel (CYP2C8 substrates) by delaying their metabolism using the rat model (in vivo). Multiple-dose treatment of rottlerin with CYP2C8 substrates lowered the CYP2C8 protein expression and up-regulated & down-regulated the mRNA for CYP2C12 & CYP2C11 (rat homologs), respectively, in rat liver tissue. Rottlerin substantially hindered the EET formation in HLM. Overall results of rottlerin on CYP2C8 inhibition and EET formation insinuate further exploration for cancer therapy.

Design, Synthesis, and Pharmacological Evaluation of Embelin-Aryl/alkyl Amine Hybrids as Orally Bioavailable Blood-Brain Barrier Permeable Multitargeted Agents with Therapeutic Potential in Alzheimer's Disease: Discovery of SB-1448.

The complex and multifaceted nature of Alzheimer's disease has brought about a pressing demand to develop ligands targeting multiple pathways to combat its outrageous prevalence. Embelin is a major secondary metabolite of Embelia ribes Burm f., one of the oldest herbs in Indian traditional medicine. It is a micromolar inhibitor of cholinesterases (ChEs) and ß-site amyloid precursor protein cleaving enzyme 1 (BACE-1) with poor absorption, distribution, metabolism, and excretion (ADME) properties. Herein, we synthesize a series of embelin-aryl/alkyl amine hybrids to improve its physicochemical properties and therapeutic potency against targeted enzymes. The most active derivative, 9j (SB-1448), inhibits human acetylcholinesterase (hAChE), human butyrylcholinesterase (hBChE), and human BACE-1 (hBACE-1) with IC50 values of 0.15, 1.6, and 0.6 µM, respectively. It inhibits both ChEs noncompetitively with ki values of 0.21 and 1.3 µM, respectively. It is orally bioavailable, crosses blood-brain barrier (BBB), inhibits Aß self-aggregation, possesses good ADME properties, and protects neuronal cells from scopolamine-induced cell death. The oral administration of 9j at 30 mg/kg attenuates the scopolamine-induced cognitive impairments in C57BL/6J mice.

Design, synthesis, and structure-activity relationship of caffeine-based triazoles as dual AChE and BACE-1 inhibitors.

Natural products have significantly contributed to drug discovery for neurodegenerative diseases. Caffeine is one of the well-known central nervous system(CNS)-active natural products. Besides its CNS stimulant properties, it is a mild inhibitor of acetylcholinesterase (AChE) and possesses memory-enhancing properties. The present work aimed to improve the AChE inhibition activity of the caffeine. The rationally designed caffeine-based triazoles were synthesized and evaluated in vitro for cholinesterase and ß-site amyloid precursor protein cleaving enzyme-1 (BACE-1) inhibitory activities. The attachment of triazole to the caffeine enhances its AChE inhibition activity from half-maximal inhibitory concentration (IC50 ) of 129 µM to 0.49 µM (derivative, 6l). The caffeine core interacts with the peripheral anionic site, whereas the benzyl triazole occupies the catalytic anionic site located at the bottom of the active site gorge. The structure-activity relationship revealed that the four-atom ester linker is superior to shorter linkers for connecting the caffeine core to the triazole. The 2,6-difluorobenzyl triazole-linked caffeine derivative, 6d, exhibits dual inhibition of AChE and BACE-1 with IC50 values of 1.43 and 10.9 µM, respectively. The derivative 6d inhibits AChE via a mixed-type mode with an inhibition rate constant (Ki ) value of 2.35 µM, which was corroborated by docking studies. The triazole 6d has an acceptable stability profile in human liver microsomes (t1/2 = 54 min) and was found to possess CNS permeability when evaluated using the parallel artificial membrane permeability blood-brain barrier assay. The results presented herein warrant investigating caffeine-based triazoles in preclinical models of Alzheimer's disease.

Assessment of the CYP1A2 Inhibition-Mediated Drug Interaction Potential for Pinocembrin Using In Silico, In Vitro, and In Vivo Approaches.

Pinocembrin, a bioflavonoid, is extensively used in complementary/alternative medicine. It turns out as a promising candidate against neurodegenerative diseases because of its multifaceted pharmacological action toward neuroprotection. However, literature evidence is still lacking for its inhibitory action on CYP1A2, which is responsible for xenobiotic metabolism leading to the generation of toxic metabolites and bioactivation of procarcinogens. In the present study, our aim was to evaluate the CYP1A2 inhibitory potential of pinocembrin via in silico, in vitro, and in vivo investigations. From the results of in vitro studies, pinocembrin is found to be a potent and competitive inhibitor of CYP1A2. In vitro-in vivo extrapolation results indicate the potential of pinocembrin to interact with CYP1A2 substrate drugs clinically. Molecular docking-based in silico studies demonstrate the strong interaction of pinocembrin with human CYP1A2. In in vivo investigations using a rat model, pinocembrin displayed a marked alteration in the plasma exposure of CYP1A2 substrate drugs, namely, caffeine and tacrine. In conclusion, pinocembrin has a potent CYP1A2 inhibitory action to cause drug interactions, and further confirmatory study is warranted at the clinical level.

Effect of Myricetin on CYP2C8 Inhibition to Assess the Likelihood of Drug Interaction Using In Silico, In Vitro, and In Vivo Approaches.

Myricetin, a bioflavonoid, is widely used as functional food/complementary medicine and has promising multifaceted pharmacological actions against therapeutically validated anticancer targets. On the other hand, CYP2C8 is not only crucial for alteration in the pharmacokinetics of drugs to cause drug interaction but also unequivocally important for the metabolism of endogenous substances like the formation of epoxyeicosatrienoic acids (EETs), which are considered as signaling molecules against hallmarks of cancer. However, there is hardly any information known to date about the effect of myricetin on CYP2C8 inhibition and, subsequently, the CYP2C8-mediated drug interaction potential of myricetin at the preclinical/clinical level. We aimed here to explore the CYP2C8 inhibitory potential of myricetin using in silico, in vitro, and in vivo investigations. In the in vitro study, myricetin showed a substantial effect on CYP2C8 inhibition in human liver microsomes using CYP2C8-catalyzed amodiaquine-N-deethylation as an index reaction. Considering the Lineweaver-Burk plot, the Dixon plot, and the higher α-value, myricetin is found to be a mixed type of CYP2C8 inhibitor. Moreover, in vitro-in vivo extrapolation data suggest that myricetin is likely to cause drug interaction at the hepatic level. The molecular docking study depicted a strong interaction between myricetin and the active site of the human CYP2C8 enzyme. Moreover, myricetin caused considerable elevation in the oral exposure of amodiaquine as a CYP2C8 substrate via a slowdown of amodiaquine clearance in the rat model. Overall, the potent action of myricetin on CYP2C8 inhibition indicates that there is a need for further exploration to avoid drug interaction-mediated precipitation of obvious adverse effects as well as to optimize anticancer therapy.

Glabridin attenuates paracetamol-induced liver injury in mice via CYP2E1-mediated inhibition of oxidative stress.

CYP2E1 plays a crucial role in the bio-activation of toxic substances leading to liver damage. In this context, CYP2E1 converts paracetamol (PCM) to N-acetyl-p-benzoquinone imine (NAPQI), which is prone to cause hepatotoxicity. Hence, we aimed to explore the protective effect of glabridin on widely used PCM-induced liver injury model in the present study and, after that, correlated with the role of CYP2E1 toward its efficacy. Glabridin was isolated from Glycyrrhiza glabra and characterized before the investigation in an in-vivo mice model of PCM-induced liver injury. Glabridin after oral treatment at 5-20 mg/kg showed a considerable improvement in serum biochemical parameters (ALT and AST) and oxidative stress markers (MDA, GSH, SOD, and catalase) in comparison to only PCM-treatment. Histopathological examination of the liver depicted that glabridin exhibited substantial protection from PCM-induced liver injury compared to the disease control group. Significant down-regulation of CYP2E1 protein and its mRNA expression levels were observed in the glabridin-treated groups compared to PCM-induced respective elevation of CYP2E1. Moreover, activation of NF-κB was significantly inhibited by glabridin. Therefore, glabridin has the potential to protect PCM-induced liver injury through CYP2E1 inhibition-mediated normalization of oxidative stress. Further research is warranted to establish glabridin as a phytotherapeutics for liver protection for which no effective and safe oral drug is available to date.

Molecular and micro-scale heterogeneities in Raman modes of a relaxing polymer glass.

We have used Raman spectroscopy to study relaxation dynamics at two different length scales, molecular level and micro-scale in order to probe the presence of cooperative rearranging regions in a polymer glass. Response to slow thermal cycles and fast quench through the glass transition temperature (Tg) is analyzed for film and unprocessed forms of polyvinyl acetate (PVAc). In PVAc film, enhanced disorder and molecular mobility lead to peak broadening by about a factor of 10 compared to unprocessed PVAc. Thermal cycles (10 K min-1) produce hysteresis in integrated Raman peak intensity (loop areaAINTI).AINTIvalues of film are two orders of magnitude more than unprocessed, indicating more configurational mosaics with higher interfacial energy dissipations. Ageing after 60 K min-1quench manifests as heterogeneous molecular dynamics of film Raman modes with significant peak-width variations, differentiating high mobility and low mobility modes. Two-dimensional mapping of film Raman modes after quench reveal micro-scale clusters of average size ≈250 molecules having fractal boundaries with fractal dimensiondf= 1.5, resemblingdfof percolation clusters below percolation threshold. During thermal cycling and relaxation after a quench, cooperative segmental dynamics with large correlations between skeletal C-C stretch and side branch modes is observed. The observations are analyzed in the context of the random first order transition theory of glasses, which attributes heterogeneous relaxations in glasses to the presence of clusters of variable configurational states.

Glabridin ameliorates methotrexate-induced liver injury via attenuation of oxidative stress, inflammation, and apoptosis.

Despite unprecedented advances in modern medicine, no safe and effective drug is available to date for oral administration to combat drug-induced liver injury, which is a vital concern nowadays. The present study deals with the hepatoprotective effect of pure glabridin, a key phytoconstituent from Glycyrrhiza glabra with mechanistic investigations using an in-vivo methotrexate-induced liver injury model as there is no such precedent. The study was performed in the Swiss mice model where a single dose of methotrexate (40 mg/kg) was given on the 7th day through an intraperitoneal route to induce hepatotoxicity, and glabridin as a test compound was administered orally for eleven consecutive days at 10 to 40 mg/kg. Glabridin markedly improved serum biochemical parameters (SGPT, SGOT), proinflammatory cytokine (TNF-α) level, oxidative stress markers (MDA, GSH, SOD, CAT) as compared to methotrexate alone. Alterations in methotrexate-induced liver architecture were considerably prevented by glabridin treatment as suggested by liver histopathological examination and SEM investigation. Glabridin substantially prevented methotrexate-induced down-regulation of Nrf2, & activation of NF-κB, and caused up-regulation of BAX at different dose levels. Overall, glabridin is found to protect methotrexate-induced hepatotoxicity by improving important factors for oxidative stress, inflammation, and apoptosis.

Amalgamation of in-silico, in-vitro and in-vivo approach to establish glabridin as a potential CYP2E1 inhibitor.

CYP2E1 is directly or indirectly involved in the metabolism of ethanol and endogenous fatty acids but it plays a major role in the bio-activation of toxic substances that produce reactive metabolites leading to hepatotoxicity. Therefore, identification of CYP2E1 inhibitor from bioflavonoids class having useful pharmacological properties has dual benefit regarding avoidance of severe food-drug/nutraceutical-drug interaction and scope to develop a phytotherapeutics through an intended pharmacokinetic interaction.In the present study, we aimed to identify CYP2E1 inhibitor from experimental bioflavonoids which are unexplored for CYP2E1 inhibition till date using in-silico, in-vitro and in-vivo approaches.Results of in-vitro CYP2E1 inhibitory studies using CYP2E1-mediated chlorzoxazone 6-hydroxylation in human liver microsomes showed that glabridin have the highest potential than fisetin, epicatechin, nobiletin, and chrysin to inhibit CYP2E1 enzyme. Mechanistic investigations indicate that glabridin is a competitive CYP2E1 inhibitor. Molecular docking study results demonstrate that glabridin strongly interacted with the active site of human CYP2E1 enzyme. Pharmacokinetics of a CYP2E1 substrate in mice model indicates a significant alteration of chlorzoxazone and 6-hydroxychlorzoxazone plasma levels in the presence of glabridin. Further studies are needed to confirm the results at clinical level.Overall, glabridin is found to be a potential CYP2E1 inhibitor.

Effect of rutin on pharmacokinetic modulation of diclofenac in rats.

Diclofenac is an extensively used nonsteroidal anti-inflammatory drug, but gastrointestinal liabilities and cardiovascular complications take the shine away from such a widely prescribed drug. On the other hand, rutin, a dietary bioflavonoid, has quite a few pharmacological attributes to improve the efficacy and reduce the dose-related toxicities of diclofenac through the intended food-drug/herb-drug interaction. The aim of the present research work was to investigate the role of rutin on pharmacokinetic modulation and the consequent efficacy of diclofenac. At first, pharmacodynamics and pharmacokinetics of diclofenac as alone and in the presence of rutin were investigated orally in a rat model. Then, mechanistic studies were performed to explain the effect of rutin on improvement in oral exposure as well as the efficacy of diclofenac using a battery of in-vitro/in-situ/in-vivo studies. Results displayed that rutin enhanced efficacy as well as oral bioavailability of diclofenac in rats. A marked increase in permeability of diclofenac by rutin was displayed that is linked to inhibition of Breast Cancer Resistance Protein (BCRP) transporters. There was no significant effect of rutin on the modulation of intestinal transit, CYP2C9 inhibition in human liver microsomes, and CYP2C9/CYP2C11 expression in rat liver tissues to boost the oral exposure of diclofenac. Rutin is found to be an inhibitor for BCRP transporters and can act as an oral bioavailability enhancer for a drug like diclofenac.

Description of Druglike Properties of Safranal and Its Chemistry behind Low Oral Exposure.

Safranal, a plant secondary metabolite isolated from saffron, has been reported for several promising pharmacological properties toward the management of Alzheimer's disease. In the present study, we observe and report for the first time about several druglike attributes of safranal, such as adherence to Lipinski's rule of five; optimum lipophilicity; high permeability; low blood-to-plasma ratio; less to moderate propensity to interact with P-glycoprotein (P-gp) or breast cancer-resistant protein (BCRP) transporters; and high plasma protein binding as common to most of the marketed drugs using in vitro and ex vivo models. In spite of the above attributes, in vivo oral absorption was found to be very poor, which is linked to the structural integrity of safranal in simulated gastric fluid, simulated intestinal fluid, plasma, and liver microsomes. Moreover, the presence of unsaturated aldehyde moiety in safranal remains in equilibrium with its hydroxylated acetal form. Further research work is required to find out the stable oral absorbable form of safranal by derivatization of its aldehyde group without losing its potency.

Effect of Natural Phenolics on Pharmacokinetic Modulation of Bedaquiline in Rat to Assess the Likelihood of Potential Food-Drug Interaction.

Bedaquiline (TMC-207) is a recently approved drug for the treatment of multidrug-resistant tuberculosis (MDR-TB). Moreover, there is a present and growing concern for natural-product-mediated drug interaction, as these are inadvertently taken by patients as a dietary supplement, food additive, and medicine. In the present study, we investigated the impact of 20 plant-based natural products, typically phenolics, on in vivo oral bedaquiline pharmacokinetics, as previous studies are lacking. Three natural phenolics were identified that can significantly enhance the oral exposure of bedaquiline upon coadministration. We further investigated the possible role of all of the phytochemicals on in vitro P-glycoprotein (P-gp) induction and inhibition and CYP3A4 inhibition in a single platform as bedaquiline is the substrate for both P-gp and CYP3A4. In conclusion, curcumin, CC-I (3',5-dihydroxyflavone-7-O-ß-d-galacturonide-4'-O-ß-d-glucopyranoside), and 6-gingerol should not be coadministered with bedaquiline to avoid untoward drug interactions and, subsequently, its dose-dependent adverse effects.

Effect of IS01957, a para-coumaric acid derivative on pharmacokinetic modulation of diclofenac through oral route for augmented efficacy.

Diclofenac is one of the world's largest selling nonsteroidal anti-inflammatory drugs. The major concerns related to oral diclofenac therapy are gastrointestinal and cardiovascular side effects for which explicitly emphasis has been given to use it at lowest effective dose for the shortest duration. On the other hand, IS01957 has been designed under the purview of anti-inflammatory drug and bioavailability enhancer. IS01957 have dual action on inflammation and nociception with acceptable safety profile. In the quest for a suitable combination with improved therapeutic efficacy and better tolerability, pharmacodynamic and pharmacokinetic interaction studies were performed for diclofenac with or without IS01957 in mice model. Results showed that IS01957 enhanced both anti-inflammatory effect and plasma concentration of diclofenac upon concomitant oral administration. These interesting results steered to enumerate the possible role of IS01957 towards diclofenac pharmacokinetics through a panel of mechanistic investigations: (a) BCRP dependent ATPase activity was markedly interfered by IS01957; (b) IS01957 increased the intestinal permeability of diclofenac in the single pass in-situ perfusion model; (c) IS01957 inhibited the CYP2C9 catalyzed diclofenac 4-hydroxylation in human liver microsomes. Immunoblotting results suggest that diclofenac action was improved significantly in the presence of IS01957 involving MAPK pathways. Finally acute gastric damage study showed that IS01957 in combination with diclofenac was better to improve the desired PGE2 level as compare to alone. In nutshell, IS01957 have potential to augment the efficacy of diclofenac through pharmacokinetic modulation. Further investigations are required for dose reduction of diclofenac to combat its liabilities before going into clinical setting.

Assessment of preclinical drug interactions of bedaquiline by a highly sensitive LC-ESI-MS/MS based bioanalytical method.

A continuous effort has been given to find out a new drug that is effective against tuberculosis (TB) from both susceptible and resistant strains of Mycobacterium tuberculosis. Bedaquiline represents a recently approved anti-TB drug, which has a unique mechanism of action to fight against multi drug resistance (MDR). Some severe side effects and drug-drug interactions are associated with the treatment of bedaquiline. Moreover, World Health Organisation (WHO) has also been provided guidelines in the year of 2013 for the use of bedaquiline and encourages additional investigation into it. Hence, the pharmacokinetics of bedaquiline upon coadministration with the drug has to be explored in the preclinical model and for which a liquid chromatography tandem mass spectrometry (LC-MS/MS) based bioanalytical method for quantitation of bedaquiline will be useful. A simple, sensitive and rapid LC-MS/MS method was developed, validated and successfully applied to drug interactions of bedaquiline upon coadministration with cytochrome P450 3A4 (CYP3A4) inducers/inhibitors orally in Wistar rats. Results reveal that ciprofloxacin and fluconazole have marked effect to hinder the pharmacokinetics of bedaquiline but isoniazid, verapamil and carbamazepine have no significant effect on bedaquiline pharmacokinetics. Overall, this new bioanalytical method for estimation of bedaquiline in rat plasma was found to be helpful to assess the pharmacokinetics of bedaquiline and very much useful for evaluation of preclinical drug-drug interaction before considering costly and perilous clinical exploration.

Liquid Chromatography Based Methods for Analysis of Disease-Modifying Antirheumatic Drugs (DMARDs) in Biological Matrices.

Rheumatoid arthritis (RA) is a common chronic disease with inflammatory and immunological background where treatments can only improve the symptoms and slow down the progress of the disease. Although there are several drugs with different therapeutic targets available in the market for the treatment of RA, conventional synthetic disease-modifying antirheumatic drugs (DMARDs) are the most effective option to date. Methotrexate, azathioprine, hydroxychloroquine, sulfasalazine, leflunomide, minocycline are commonly prescribed DMARDs by rheumatologists but they have the limitations of severe toxicity for which therapeutic drug monitoring is necessary. Many chromatographic methods are available for analysis of these drugs including their metabolites. However, they have not been critically reviewed for pre-chromatographic sample preparation, chromatographic separation and sensitive detection. This review article can be handy for quantitation of DMARDs in diverse biological matrices as it provides comprehensive information on the reported liquid chromatographic methods for last three decades covering all the aspects required for preclinical and clinical studies.

Intervention of curcumin on oral pharmacokinetics of daclatasvir in rat: A possible risk for long-term use.

Curcumin, a natural diarylheptanoid, is extensively used as a food additive or dietary supplement on the regular basis. It is known to have potential to encumber the drug transporters and hepatic drug metabolizing enzymes that lead to pharmacokinetic interactions with drug or food. Daclatasvir is a new orally acting drug for the treatment of chronic Hepatitis C Virus infections. This is a substrate of P-glycoprotein and CYP3A4 that are involved in the major pharmacokinetic interaction. Hence, the studies' aim is to assess for any possible pharmacokinetic interactions. Pharmacokinetic studies of daclatasvir in presence or absence of curcumin were carried out in Wistar rats following oral administration. Parallelly, the oral pharmacokinetics of daclatasvir was also determined in the presence of ketoconazole or quinidine. Studies revealed that plasma level of daclatasvir was not altered significantly during concomitant single dose administration of curcumin, whereas significantly decreased upon pretreatment for 7 days with curcumin at high dose level. Ketoconazole and quinidine markedly increase daclatasvir exposure following concomitant administration with daclatasvir. It can be concluded that dose adjustment is unlikely to be required for intermittent use of curcumin at low dose but cautious for chronic and concomitant use of curcumin at a high dose.