In Vitro Effect on Plasmodium falciparum and In Vivo Effect on Plasmodium berghei of Annomaal, an Oily Fraction Obtained from the Seeds of Annona squamosa.

Malaria remains a life-threatening health problem and is responsible for the high rates of mortality and morbidity in the tropical and subtropical regions of the world. The increasing threat of drug resistance to available artemisinin-based therapy warrants an urgent need to develop new antimalarial drugs that are safer, more effective, and have a novel mode of action. Natural plants are an excellent source of inspiration in searching for a new antimalarial agent. This research reports a systematic investigation for determining the antimalarial potential of the seeds of A. squamosa. The study shows that the crude seed extract (CSE), protein, saponin, and the oily fractions of the seeds were nontoxic at a 2000 mg/kg body weight dose when tested in Wistar rats, thus revealing high safety is classified as class 5. The oily fraction, Annomaal, demonstrated pronounced antimalarial activity with low IC50 (1.25 ± 0.183 µg/mL) against P. falciparum in vitro. The CSE and Annomaal significantly inhibited the growth of P. berghei parasites in vivo with 58.47% and 61.11% chemo suppression, respectively, while the standard drug artemether showed chemo suppression of 66.75%. Furthermore, the study demonstrated that oral administration of Annomaal at a daily dose of 250 mg/kg/day for 3 days was adequate to provide a complete cure to the P. berghei-infected mice. Annomaal thus holds promise as being patient-compliant due to the shorter treatment schedule, eliminating the need for frequent dosing for extended time periods as required by several synthetic antimalarial drugs. Further studies are needed to determine the active compounds in the oily fraction responsible for antimalarial activity.

Evaluation of piperine against cancer stem cells (CSCs) of hepatocellular carcinoma: Insights into epithelial-mesenchymal transition (EMT).

Cancer stem cells (CSCs) are involved in recurrent hepatocellular carcinoma (HCC), yet there is a lack of effective treatment that targets these CSCs. CD44+ and CD133+ CSCs are markedly expressed in HepG2 cells and were isolated and characterized using fluorescence-activated cell sorting (FACS) analysis. Since piperine is known as an effective molecule against metastasis, we thought to investigate the effect of piperine against CD44+/CD133+ CSCs. Herein, piperine was found to be active against these CSCs. Also, it was found appropriate to respite at the 'subG0/G1 and G0/G1' phase of the cell cycle analysis, respectively. TGF-ß activated epithelial-mesenchymal transition (EMT) has been involved in the invasion and metastasis of HepG2 cells in hepatocellular carcinoma. Therefore, we next investigated the effect of piperine on different biomarkers that remarkably takes part in the process of EMT using flow cytometric analysis. Piperine was found able to repress the epithelial marker (E-cadherin) but was unable to restore the level of Vimentin (mesenchymal marker) and SNAIL (EMT-inducing transcription factor). Therefore, the findings of this study revealed that piperine could be an effective treatment strategy for recurrent hepatocarcinogenesis.

Isolation, characterization and quantitative HPLC-DAD analysis of components of charantin from fruits of Momordica charantia.

Charantin, a steroidal glycoside, exists as a mixture of stigmasterol glucoside (STG) and ß-sitosterol glucoside (BSG) in the fruits of Momordica charantia. Charantin has anti-diabetic activity comparable to insulin. The present work discusses a method for separation of components of charantin namely STG and BSG by simple extraction technique followed by preparative HPLC. The identity of separated components was established by chromatographic as well as spectral techniques. Also reversed phase HPLC-DAD method was developed and validated for estimation of STG and BSG present in fruits of Momordica charantia. The method used C18 column (75 mm × 4.6 mm, 3.5 µm) as stationary phase and methanol: water (98:02, v/v) as mobile phase. Retention times of STG and BSG were found to be 10.707 min and 11.870 min, respectively. The validated method was applied to evaluate content of these components in different extracts and some commercial herbal formulations containing fruits of Momordica charantia.

Bioanalytical method development and its application to pharmacokinetics studies on Simvastatin in the presence of piperine and two of its synthetic derivatives.

Piperine has been widely used as a bioenhancer. Simvastatin belongs to a group of medicines known as statins. It acts by inhibiting HMG CoA reductase and acts primarily as a hypolipidemic agent. In this study some derivatives of Piperine were synthesized. They were studied for their bioenhencing effect (10 mg kg-1) and this effect was compared with that of Piperine. The pharmacokinectic profile of Simvastatin alone and in combination with Piperine and Piperine derivatives were investigated by validated HPLC method as per USFDA guidelines. It was seen that the two synthesized derivatives of Piperine significantly improved the bioavailability of Simvastatin in Wistar rats. The 5-(benzo) [1,3]dioxol-5-yl)-N-(pyridin-4-yl)penta-2,4-dienamide was better amongst the synthesized in increasing the bioavailability of Simvastatin in Wistar rat.

Enhanced HPLC-DAD Method for Fast Determination of Quercetin-3-O-ß-d-Glucoside in Extracts and Polyherbal Formulations Containing Azadirachta indica-Optimization and Validation.

Azadirachta indica has been used for its medicinal properties since time immemorial. Herbal medicines which are prepared using this medicinal tree are utilized to treat various diseases and disorders. No reports are available for marker-based standardization of these herbal medicines prepared from leaves of A. indica. Also existing HPLC methods for determination quercetin-3-O-ß-d-glucoside are time consuming. There is an obvious need for development of new HPLC method for quantification of quercetin-3-O-ß-d-glucoside which is fast enough to carry out analysis in stipulated time period. This article deals with the development, optimization and validation of fast HPLC-DAD method for the determination of quercetin-3-O-ß-d-glucoside in extracts containing A. indica for its successive application for marker-based standardization of herbal formulations containing A. indica. The retention time of quercetin-3-O-ß-d-glucoside was 11.213 min. The method was found to be linear in the range of 4.0-60 µg mL-1. Limit of detection and limit of quantitation of the proposed method were found to be 1.33 and 4.0 µg mL-1, respectively. The mean recoveries were found to be within 93.53-103.75%. The method can be used as quality control tool for routine analysis of herbal extracts and formulations containing A. indicia.

In silico optimization of pharmacokinetic properties and receptor binding affinity simultaneously: a 'parallel progression approach to drug design' applied to ß-blockers.

The present work exploits the potential of in silico approaches for minimizing attrition of leads in the later stages of drug development. We propose a theoretical approach, wherein 'parallel' information is generated to simultaneously optimize the pharmacokinetics (PK) and pharmacodynamics (PD) of lead candidates. ß-blockers, though in use for many years, have suboptimal PKs; hence are an ideal test series for the 'parallel progression approach'. This approach utilizes molecular modeling tools viz. hologram quantitative structure activity relationships, homology modeling, docking, predictive metabolism, and toxicity models. Validated models have been developed for PK parameters such as volume of distribution (log Vd) and clearance (log Cl), which together influence the half-life (t1/2) of a drug. Simultaneously, models for PD in terms of inhibition constant pKi have been developed. Thus, PK and PD properties of ß-blockers were concurrently analyzed and after iterative cycling, modifications were proposed that lead to compounds with optimized PK and PD. We report some of the resultant re-engineered ß-blockers with improved half-lives and pKi values comparable with marketed ß-blockers. These were further analyzed by the docking studies to evaluate their binding poses. Finally, metabolic and toxicological assessment of these molecules was done through in silico methods. The strategy proposed herein has potential universal applicability, and can be used in any drug discovery scenario; provided that the data used is consistent in terms of experimental conditions, endpoints, and methods employed. Thus the 'parallel progression approach' helps to simultaneously fine-tune various properties of the drug and would be an invaluable tool during the drug development process.

Establishment of inherent stability of pramipexole and development of validated stability indicating LC-UV and LC-MS method.

Pramipexole belongs to a class of nonergot dopamine agonist recently approved for the treatment of early and advanced Parkinson's disease. A validated specific stability indicating reversed-phase liquid chromatographic method has been developed for the quantitative determination of pramipexole in bulk as well as in pharmaceutical dosage forms in the presence of degradation products. Forced degradation studies were performed by exposition of drug to hydrolytic (acidic and basic), oxidative and photolytic stress conditions, as defined under ICH guideline Q1A (R2). Significant degradation was observed under hydrolytic, oxidative and photolytic conditions and the degradation products formed were identified by LC-MS.

LC-UV and LC-MS evaluation of stress degradation behavior of desvenlafaxine.

The objective of current study was to develop a validated specific stability indicating reversed-phase liquid chromatographic method for the quantitative determination of desvenlafaxine in bulk sample and pharmaceutical dosage form in the presence of degradation products. Forced degradation studies were performed on bulk sample of desvenlafaxine as per ICH prescribed stress conditions using acid, base, oxidative and photolytic degradation to show the stability indicating power of the method. Significant degradation was observed under acidic stress condition and the degradation product formed was identified by LC-MS and a degradation pathway for drug has been proposed. Successful separation of drug from degradation products formed under stress conditions was achieved on a SymmetryShield column C18 (5 µm, 250 mm×4.6 mm, i.d.) using the mobile phase consisting of a mixture of 0.2% (v/v) triethylamine in ammonium acetate (0.05 M; pH 6.5) and methanol using isocratic gradient.