Epicatechin exerts dual action to shield sickling and hydroxyurea-induced myelosuppression: Implication in sickle cell anemia management.

Hydroxyurea (HU) is the key drug to treat Sickle cell anemia (SCA). However, its treatment is associated with the liability of myelosuppression. The present study aimed to investigate the potential of epicatechin as a supplementation therapy for the symptomatic management of SCA under HU therapy. A panel of experiments were performed at first to observe epicatechin's effect on sickling and hemolytic behaviour using SCA patient's blood (ex vivo). Thereafter, the effect of HU in the presence or absence of epicatechin was investigated on cytokine inhibition in rat splenocytes (ex vivo) as well as alterations in hematological parameters and kidney function tests in rats (in vivo). Then, any effect of epicatechin on pharmacokinetic modulation of HU in rats was elucidated along with the underlying mechanism using a battery of in vitro and in vivo models. Epicatechin exhibited potent action on anti-sickling, polymerization inhibition, and erythrocyte membrane stability. It did not show any inherent hemolytic activity and reduced TNF-α level during concomitant administration with HU. Based on hematological changes in rats, epicatechin treatment aided to the beneficial effect of HU and prevented the treatment-linked disadvantageous effects of HU like neutropenia. The plasma exposure of HU was significantly augmented in rats upon simultaneous oral administration of epicatechin with HU. Down-regulation of Oatp1b2 and catalase possibly contributed to the pharmacokinetic interaction of HU. Epicatechin is found to be a promising candidate and should be explored at a reduced dose level of HU towards offsetting the dose-dependent myelosuppressive effect of HU under the frame of supplementation therapy in SCA.

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.

A highly sensitive UPLC-MS/MS method for hydroxyurea to assess pharmacokinetic intervention by phytotherapeutics in rats.

Hydroxyurea (HU) is the first-ever approved drug by the United States Food and Drug Administration (USFDA) for the management of sickle cell anemia (SCA). However, its treatment is associated with severe liabilities like myelosuppression. Therefore, the aim of the present investigation was to identify phytotherapeutics through assessment of the pharmacokinetic interaction of HU with dietary bioflavonoids followed by elucidation of the same phytoconstituents for their ability to protect HU-induced toxicity in hematological profile. In this direction, we developed a sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method to estimate HU in rat plasma at first and then validated as per USFDA guidelines as there is no such precedent in the literature. A simple plasma protein precipitation method was employed for plasma sample processing. The separation was achieved in gradient mode using Syncronis HILIC column (100 × 4.6 mm, 3 µm) with a mobile phase composition of water containing 0.1% (v/v) formic acid and acetonitrile. Ionization was carried out in positive heated-electrospray ionization (H-ESI) mode. Detection was done in selected reaction monitoring (SRM) mode with m/z 77.1 > 44.4 and m/z 75.1 > 58.2 for HU and methylurea (internal standard), respectively. All the validation parameters were within the acceptable criteria. This bioanalytical method was found to be useful in assessing the preclinical pharmacokinetic interaction of HU. Concomitant administration of chrysin or quercetin with HU in rats significantly enhanced the oral exposure of HU. Lowering of total red blood cells (RBC) and hemoglobin (Hb) level by HU in rats was significantly improved in the presence of chrysin, quercetin, and naringenin. Overall, both chrysin and quercetin showed potential to be a promising phytotherapeutics for concomitant therapy with HU to combat its dose-dependent side effects.

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.

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.

Physicochemical, pharmacokinetic, efficacy and toxicity profiling of a potential nitrofuranyl methyl piperazine derivative IIIM-MCD-211 for oral tuberculosis therapy via in-silico-in-vitro-in-vivo approach.

Recent tuberculosis (TB) drug discovery programme involve continuous pursuit for new chemical entity (NCE) which can be not only effective against both susceptible and resistant strains of Mycobacterium tuberculosis (Mtb) but also safe and faster acting with the target, thereby shortening the prolonged TB treatments. We have identified a potential nitrofuranyl methyl piperazine derivative, IIIM-MCD-211 as new antitubercular agent with minimum inhibitory concentration (MIC) value of 0.0072 µM against H37Rv strain. Objective of the present study is to investigate physicochemical, pharmacokinetic, efficacy and toxicity profile using in-silico, in-vitro and in-vivo model in comprehensive manner to assess the likelihood of developing IIIM-MCD-211 as a clinical candidate. Results of computational prediction reveal that compound does not violate Lipinski's, Veber's and Jorgensen's rule linked with drug like properties and oral bioavailability. Experimentally, IIIM-MCD-211 exhibits excellent lipophilicity that is optimal for oral administration. IIIM-MCD-211 displays evidence of P-glycoprotein (P-gp) induction but no inhibition ability in rhodamine cell exclusion assay. IIIM-MCD-211 shows high permeability and plasma protein binding based on parallel artificial membrane permeability assay (PAMPA) and rapid equilibrium dialysis (RED) assay model, respectively. IIIM-MCD-211 has adequate metabolic stability in rat liver microsomes (RLM) and favourable pharmacokinetics with admirable correlation during dose escalation study in Swiss mice. IIIM-MCD-211 has capability to appear into highly perfusable tissues. IIIM-MCD-211 is able to actively prevent progression of TB infection in chronic infection mice model. IIIM-MCD-211 shows no substantial cytotoxicity in HepG2 cell line. In acute toxicity study, significant increase of total white blood cell (WBC) count in treatment group as compared to control group is observed. Overall, amenable preclinical data make IIIM-MCD-211 ideal candidate for further development of oral anti-TB agent.

Pharmacokinetics, pharmacodynamics and safety profiling of IS01957, a preclinical candidate possessing dual activity against inflammation and nociception.

In spite of unprecedented advances in modern systems of medicine, there is necessity for exploration of traditional plant based secondary metabolites or their semisynthetic derivatives which may results in better therapeutic activity, low toxicity and favourable pharmacokinetics. In this context, computational model based predictions aid medicinal chemists in rational development of new chemical entity having unfavourable pharmacokinetic properties which is a major hurdle for its further development as a drug molecule. Para-coumaric acid (p-CA) and its derivatives found to be have promising antiinflammatory and analgesic activity. IS01957, a p-CA derivative has been identified as dual acting molecule against inflammation and nociception. Therefore, objective of the present study was to investigate pharmacokinetics, efficacy and safety profile based on in-silico, in-vitro and in-vivo model to assess drug likeliness. In the present study, it has excellent pharmacological action in different animal models for inflammation and nociception. Virtual pharmacokinetics related properties of IS01957 have resemblance between envision and experimentation with a few deviations. It has also acceptable safety pharmacological profile in various animal models for central nervous system (CNS), gastro intestinal tract (GIT)/digestive system and cardiovascular system (CVS). Finally, further development of IS01957 is required based on its attractive preclinical profiles.

Benzothiazole Derivative as a Novel Mycobacterium tuberculosis Shikimate Kinase Inhibitor: Identification and Elucidation of Its Allosteric Mode of Inhibition.

Mycobacterium tuberculosis shikimate kinase (Mtb-SK) is a key enzyme involved in the biosynthesis of aromatic amino acids through the shikimate pathway. Since it is proven to be essential for the survival of the microbe and is absent from mammals, it is a promising target for anti-TB drug discovery. In this study, a combined approach of in silico similarity search and pharmacophore building using already reported inhibitors was used to screen a procured library of 20,000 compounds of the commercially available ChemBridge database. From the in silico screening, 15 hits were identified, and these hits were evaluated in vitro for Mtb-SK enzyme inhibition. Two compounds presented significant enzyme inhibition with IC50 values of 10.69 ± 0.9 and 46.22 ± 1.2 µM. The best hit was then evaluated for the in vitro mode of inhibition where it came out to be an uncompetitive and noncompetitive inhibitor with respect to shikimate (SKM) and ATP, respectively, suggesting its binding at an allosteric site. Potential binding sites of Mtb-SK were identified which confirmed the presence of an allosteric binding pocket apart from the ATP and SKM binding sites. The docking simulations were performed at this pocket in order to find the mode of binding of the best hit in the presence of substrates and the products of the enzymatic reaction. Molecular dynamics (MD) simulations elucidated the probability of inhibitor binding at the allosteric site in the presence of ADP and shikimate-3-phosphate (S-3-P), that is, after the formation of products of the reaction. The inhibitor binding may prevent the release of the product from Mtb-SK, thereby inhibiting its activity. The binding stability and the key residue interactions of the inhibitor to this product complex were also revealed by the MD simulations. Residues ARG43, ILE45, and PHE57 were identified as crucial that were involved in interactions with the best hit. This is the first report of an allosteric binding site of Mtb-SK, which could largely address the selectivity issue associated with kinase inhibitors.