Determination of permeability, plasma protein binding, blood partitioning, pharmacokinetics and tissue distribution of Withanolide A in rats: A neuroprotective steroidal lactone

Functionalized azirine based scaffolds as endothelin inhibitors for the selective anti-angiogenic activity

Anti-angiogenic therapy has long been used as an adjunct therapy for the resolution of tumor burden. The current findings describe the synthesis of novel marine-based azirine-containing compounds that exhibit anti-angiogenic mediated anti-tumor activity. Azirine-2-carboxylate inhibited HUVEC-mediated tubulogenesis without causing cell death in a dose-dependent manner. Ex-vivo CAM, in-vivo Matrigel implantation, and ear angiogenesis experiments have all shown that azirine-2-carboxylate effectively inhibits angiogenesis. Furthermore, azirine-2-carboxylate inhibits the migration of ECs without disrupting the preformed tubule network. Azirine-2-carboxylate had adequate intramuscular systemic exposure and inhibited tumor growth in a xenograft mouse model. DARTS analysis, competitive binding assay, and gene expression investigations revealed that azirine-2-carboxylate inhibits endothelin-1-mediated angiogenesis. Overall, the discovery of azirine-2-carboxylate demonstrated a potent inhibition of angiogenesis targeting ET1 and a possible application in anti-angiogenic therapy.

Pharmacokinetics and bioequivalence of Withania somnifera (Ashwagandha) extracts - A double blind, crossover study in healthy adults

Introduction

Withania somnifera (WS) or ashwagandha is an adaptogenic plant used extensively in traditional medicines and as a food supplement. Despite a long history of use and numerous clinical trials, the human pharmacokinetics of withanolides, the active phytochemicals in WS extracts, have not been fully evaluated. This study evaluated the oral pharmacokinetics and bioequivalence of active withanolides in human plasma after administration of a single dose of two commercial ashwagandha extracts containing equal amounts of total withanolides.

Methods

This randomized, double-blind, single-dose crossover study of 16 healthy human volunteers evaluated the acute oral bioavailability of withanolides and the bioequivalence of two WS extracts, WS-35 and WS-2.5. WS-35 was standardized to total withanolides not less than 40% comprising not less than 35% withanolide glycosides and WS-2.5 was standardized to 2.5% withanolides. The clinical dosages were normalized to 185 mg of total withanolide in each extract at the bioequivalent dosages. The pharmacokinetic parameters of withanolide A, withanoside IV, withaferin A, and total withanolides were quantified in the blood plasma using a validated LC-MS/MS method.

Results

The half-life, C-max, and mean residence time of the total withanolides were 5.18, 5.62 and 4.13 times significantly higher and had lower systemic clearance with WS-35 than with WS-2.5 extract. Considering the plasma AUC 0-inf of total withanolides per mg of each WS extract administered orally, WS-35 was 280.74 times more bioavailable than WS-2.5.

Conclusion

The results of this study highlight the importance of withanolide glycosides in improving the pharmacokinetics of WS extracts. Owing to its superior pharmacokinetic profile, WS-35, with 35% withanolide glycosides, is a promising candidate for further studies on Withania somnifera.

Clinical trial registration

CTRI/2020/10/028397 [registered on:13/10/2020] (Trial prospectively registered) http://ctri.nic.in/Clinicaltrials/pmaindet2.php?trialid=42149&EncHid=&userName=CTRI/2020/10/028397.

Simultaneous estimation of five biomarkers of neuroprotective herb Ashwagandha NMITLI-118R AF1 in rat plasma and brain using LC-ESI-MS/MS: Application to its pharmacokinetic and stability studies

Withania Somnifera (WS) is a popular nutritional supplement in the USA, Europe, and Asia, known for its pharmacological effects on neurological disorders. However, the bioanalytical method development, validation, and pharmacokinetics of WS NMITLI-118R AF1 biomarkers Withanolide A (WLD A), Withanone (WNONE), Withanolide B (WLD B), Withaferin A (WF A), and 12 Deoxywithastramonolide (12 DEOXY) in rats have not been comprehensively explored. This study aimed to develop and validate a sensitive and selective LC-ESI-MS/MS method for these biomarkers in male Sprague Dawley rats plasma and brain matrix. Rats were divided into eight groups, each containing five rats. A plant extract of NMITLI-118R AF1 at 50 mg/kg was orally administered to the rats for in-vivo pharmacokinetic investigation. All the analytes had a linear calibration curve (r2 > 0.999), and intra-day and inter-day precision (%) were found in the range of 2.46 - 13.71% and accuracy were within the acceptable range (±15%). The biomarkers of NMITLI-118R AF1 were found stable in in-vitro plasma and simulated gastro-intestinal fluids. The observed (Cmax) and (Tmax) values for the biomarkers in the systemic circulation were WLD A (5.59 ± 0.34 ng/mL, Tmax 1.00 ± 0.00 h), WNONE (6.28 ± 0.41 ng/mL, Tmax 0.95 ± 0.11 h), WLD B (6.45 ± 2.87 ng/mL, Tmax 0.95 ± 0.11 h), WF A (6.50 ± 0.27 ng/mL, Tmax 1.00 ± 0.00 h), and 12 DEOXY (5.68 ± 0.39 ng/mL, Tmax 1.00 ± 0.00 h). In contrast to the old method, our approach exhibits a lower limit of quantification (LLOQ), shorter run time (less than10 min), and enables the detection of WF A and WNONE in fresh rat plasma by other quantitative analysis of mass spectrometry (m/z) [M]+. Shows high sample volumes for both, larger plasma volumes, costlier sample collection techniques dried blood spot (DBS), more expensive solid phase extraction techniques (SPE) and longer analysis time 14 min. Moreover, our method requires a smaller sample volume 10 µL, offers faster analysis time 4 min, and achieves a higher sensitivity 1 ng/mL. This is the first report of a comprehensive study on in-vitro and in-vivo pharmacokinetics of NMITLI-118R AF1 biomarkers, which may aid in further pre-clinical and clinical trial investigations.

LC-MS/MS method for quantification of raspberry ketone in rat plasma: application to preclinical pharmacokinetic studies

Background: Raspberry ketone (RK), derived from red raspberry fruit (Rubus idaeus, family Rosaceae), is a reported potent antiobesity agent. This study aims to investigate method development, validation, and in vitro and in vivo pharmacokinetics in rats. Materials & methods: LC-MS/MS was used to conduct method development, validation, stability, and oral PK samples of RK in plasma analyses. Results: RK was highly soluble in Tris buffer and stable in gastrointestinal fluids as well as plasma. Rat liver microsomal stability of RK in phase I and II studies was 84.96 ± 2.39 and 69.98 ± 8.69%, respectively, after 60 min. Intestinal permeability was 4.39 ± 1.37 × 10^-5 cm/s. Maximal concentration was 1591.02 ± 64.76 ng/ml, which was achieved after 1 h (time to maximal concentration), and absolute oral bioavailability was 86.28%. Conclusion: Pharmacokinetic data serve as a keystone for preclinical and clinical adjuvant therapy.

Elucidation of plasma protein binding, blood partitioning, permeability, CYP phenotyping and CYP inhibition studies of Withanone using validated UPLC method: An active constituent of neuroprotective herb Ashwagandha

ETHNOPHARMACOLOGICAL RELEVANCE

Withanone (WN), an active constituent of Withania somnifera commonly called Ashwagandha has remarkable pharmacological responses along with neurological activities. However, for a better understanding of the pharmacokinetic and pharmacodynamic behavior of WN, a comprehensive in-vitro ADME (absorption, distribution, metabolism, and excretion) studies are necessary.

AIM OF THE STUDY

A precise, accurate, and sensitive reverse-phase ultra-performance liquid chromatographic method of WN was developed and validated in rat plasma for the first time. The developed method was successfully applied to the in-vitro ADME investigation of WN.

MATERIAL AND METHODS

The passive permeability of WN was assayed using PAMPA plates and the plasma protein binding (PPB) was performed using the equilibrium dialysis method. Pooled liver microsomes of rat (RLM) and human (HLM) were used for the microsomal stability, CYP phenotyping, and inhibition studies. CYP phenotyping was evaluated using the specific inhibitors. CYP inhibition study was performed using specific probe substrates along with WN or specific inhibitors.

RESULTS

WN was found to be stable in the simulated gastric and intestinal environment and has a high passive permeability at pH 4.0 and 7.0 in PAMPA assay. The PPB of WN at 5 and 20 μg/mL concentrations were found to be high i.e. 82.01 ± 1.44 and 88.02 ± 1.15%, respectively. The in vitro half-life of WN in RLM and HLM was found to be 59.63 ± 2.50 and 68.42 ± 2.19 min, respectively. CYP phenotyping results showed that WN was extensively metabolized by CYP 3A4 and1A2 enzymes in RLM and HLM. However, the results of CYP Inhibition studies showed that none of the CYP isoenzymes were potentially inhibited by WN in RLM and HLM.

CONCLUSION

The in vitro results of pH-dependent stability, plasma stability, permeability, PPB, blood partitioning, microsomal stability, CYP phenotyping, and CYP inhibition studies demonstrated that WN could be a better phytochemical for neurological disorders.

Induction of stress resistance and extension of lifespan in Chaenorhabditis elegans serotonin-receptor knockout strains by withanolide A

INTRODUCTION

Approximately 300 million people worldwide suffer from depression. The COVID-19 crisis may dramatically increase these numbers. Severe side effects and resistance development limit the use of standard antidepressants. The steroidal lactone withanolide A (WA) from Withania somnifera may be a promising alternative. Caenorhabditis elegans was used as model to explore WA's anti-depressive and anti-stress potential.

METHODS

C. elegans wildtype (N2) and deficient strains (AQ866, DA1814, DA2100, DA2109 and MT9772) were used to assess oxidative, osmotic or heat stress as measured by generation of reactive oxygen species (ROS), determination of lifespan, and mRNA expression of serotonin receptor (ser-1, ser-4, ser-7) and serotonin transporter genes (mod-5). The protective effect of WA was compared to fluoxetine as clinically established antidepressant. Additionally, WA's effect on lifespan was determined. Furthermore, the binding affinities and pKi values of WA, fluoxetine and serotonin as natural ligand to Ser-1, Ser-4, Ser-7, Mod-5 and their human orthologues proteins were calculated by molecular docking.

RESULTS

Baseline oxidative stress was higher in deficient than wildtype worms. WA and fluoxetine reduced ROS levels in all strains except MT9772. WA and fluoxetine prolonged survival times in wildtype and mutants under osmotic stress. WA but not fluoxetine increased lifespan of all heat-stressed C. elegans strains except DA2100. Furthermore, WA but not fluoxetine extended lifespan in all non-stressed C. elegans strains. WA also induced mRNA expression of serotonin receptors and transporters in wildtype and mutants. WA bound with higher affinity and lower pKi values to all C. elegans and human serotonin receptors and transporters than serotonin, indicating that WA may competitively displaced serotonin from the binding pockets of these proteins.

CONCLUSION

WA reduced stress and increased lifespan by ROS scavenging and interference with the serotonin system. Hence, WA may serve as promising candidate to treat depression.

Effects of Withania somnifera (Ashwagandha) on Stress and the Stress- Related Neuropsychiatric Disorders Anxiety, Depression, and Insomnia

BACKGROUND

Withania somnifera (WS), also known as Ashwagandha, is commonly used in Ayurveda and other traditional medicine systems. WS has seen an increase in worldwide usage due to its reputation as an adaptogen. This popularity has elicited increased scientific study of its biological effects, including a potential application for neuropsychiatric and neurodegenerative disorders.

OBJECTIVE

This review aims to provide a comprehensive summary of preclinical and clinical studies examining the neuropsychiatric effects of WS, specifically its application in stress, anxiety, depression, and insomnia.

METHODS

Reports of human trials and animal studies of WS were collected primarily from the PubMed, Scopus, and Google Scholar databases.

RESULTS

WS root and leaf extracts exhibited noteworthy anti-stress and anti-anxiety activity in animal and human studies. WS also improved symptoms of depression and insomnia, though fewer studies investigated these applications. WS may alleviate these conditions predominantly through modulation of the hypothalamic-pituitary-adrenal and sympathetic-adrenal-medullary axes, as well as through GABAergic and serotonergic pathways. While some studies link specific withanolide components to its neuropsychiatric benefits, there is evidence for the presence of additional, as yet unidentified, active compounds in WS.

CONCLUSION

While benefits were seen in the reviewed studies, significant variability in the WS extracts examined prevents a consensus on the optimum WS preparation or dosage for treating neuropsychiatric conditions. WS generally appears safe for human use; however, it will be important to investigate potential herb-drug interactions involving WS if used alongside pharmaceutical interventions. Further elucidation of active compounds of WS is also needed.

Withanolides from the genus Physalis: a review on their phytochemical and pharmacological aspects

Objectives

Withanolides are a group of modified C28 ergostane-type steroids with a C-22, C-26 δ-lactone side chain or a C-23, C-26 γ-lactone side chain. They enjoy a limited distribution in the plant kingdom and predominantly occur in several genera of Solanaceae. Of which, the genus Physalis is an important resource for this type of natural molecules. The present review aims to comprehensively illustrate the structural characteristics and classification of withanolides, and particularly focus on the progression on phytochemical and pharmacological aspects of withanolides from Physalis ranging from January 2015 to June 2019.

Key findings

Approximately 351 natural withanolides with novel and unique structures have so far been identified from genus Physalis, mainly isolated from the species of P. angulata and P. peruviana. Withanolides demonstrated diverse biological activity, such as anticancer, anti-inflammatory, antimicrobial, immunoregulatory, trypanocidal and leishmanicidal activity. Their observed pharmacological functions supported the uses of Physalis species in traditional or folk medicines.

Summary

Due to their unique structure skeleton and potent bioactivities, withanolides are regarded to be promising drug candidates, particularly for developing anticancer and anti-inflammatory agents. Further investigations for discovering novel withanolides of genus Physalis, exploiting their pharmacological values and evaluating their potency as therapeutic agents are significant work.

LC-ESI-MS/MS method for the simultaneous determination of isoformononetin, daidzein, and equol in rat plasma: Application to a preclinical pharmacokinetic study

Isoformononetin (methoxy isoflavone) is a potent osteogenic isoflavone abundantly present in Butea monosperma, Pisum sativum, Mung bean, Machaerium villosum, Medicago sativa, and Glycine max. In the current study, an LC-ESI-MS/MS method for the simultaneous evaluation of isoformononetin (IFN), daidzein (DZN) and equol (EQL) was developed and validated in rat plasma using biochanin A as an internal standard. IFN, DZN, and EQL separation was achieved by using acetonitrile and acetic acid (0.1%) in the ratio of 90:10 (% v/v) as mobile phase under isocratic conditions at a flow rate of 0.6 mL/min on Atlantis C₁₈ (4.6 × 250 mm, 5.0 μm) column. The achieved method was linear within the concentration range of 0.5-500 ng/mL. The method was effectively applied to investigate the permeability, protein binding estimation and pharmacokinetics studies of IFN in rats. The PAMPA permeability of IFN was found to be high at pH 4.0 and 7.0. The protein binding was found to be about 91% of IFN. The oral bioavailability of IFN was found to be poor (21.6%). IFN was found to have a moderate clearance (2.9 L/h/kg) and a large apparent volume of distribution (12.1 L/kg). The plasma half-life (t_1/2) and maximum attainable concentration (C_max) of IFN at systemic circulation was found to be 1.9 ± 0.6 h and 269.3 ± 0.4 after oral administration.

Leishmanicidal Activity of Withanolides from Aureliana Fasciculata var. Fasciculata

Leishmaniasis is the generic denomination to the neglected diseases caused by more than 20 species of protozoa belonging to the genus Leishmania. The toxic and parenteral-delivered pentavalent antimonials remain to be the first-line treatment. However, all the current used drugs have restrictions. The species Aureliana fasciculata (Vell.) Sendtner var. fasciculata is a native Brazilian species parsimoniously studied on a chemical point of view. In this study, the antileishmanial activity of A. fasciculata was evaluated. Among the evaluated samples of the leaves, the dichloromethane partition (AFfDi) showed the more pronounced activity, with IC₅₀ 1.85 µg/ml against promastigotes of L. amazonensis. From AFfDi, two active withanolides were isolated, the Aurelianolides A and B, with IC₅₀ 7.61 μM and 7.94 μM, respectively. The withanolides also proved to be active against the clinically important form, the intracellular amastigote, with IC₅₀ 2.25 μM and 6.43 μM for Aurelianolides A and B, respectively. Furthermore, withanolides showed results for in silico parameters of absorption, distribution, metabolism, excretion, and toxicity (ADMET) similar to miltefosine, the reference drug, and were predicted as good oral drugs, with the advantage of not being hepatotoxic. These results suggest that these compounds can be useful as scaffolds for planning drug design.