Withanoside V

Investigating 11 Withanosides and Withanolides by UHPLC-PDA and Mass Fragmentation Studies from Ashwagandha (Withania somnifera).[Pubmed:33163776]

ACS Omega. 2020 Oct 21;5(43):27933-27943.

Withania somnifera (WS), also known as ashwagandha or Indian ginseng, is known for its pharmacological significance in neurodegenerative diseases, stress, cancer, immunomodulatory, and antiviral activity. In this study, the WS extract (WSE) from the root was subjected to ultrahigh-performance liquid chromatography with photodiode array detection (UHPLC-PDA) analysis to separate 11 withanoside and withanolide compounds. The quantification validation was carried out as per ICHQ2R1 guidelines in a single methodology. The calibration curves were linear (r (2) > 0.99) for all 11 compounds within the tested concentration ranges. The limits of detection and quantification were in the range of 0.213-0.362 and 0.646-1.098 mug/mL, respectively. The results were precise (relative standard deviation, <5.0%) and accurate (relative error, 0.01-0.76). All compounds showed good recoveries of 84.77-100.11%. For the first time, Withanoside VII, 27-hydroxywithanone, dihydrowithaferin A, and viscosalactone B were quantified and validated along with bioactive compounds withanoside IV, Withanoside V, withaferin A, 12-deoxywithastramonolide, withanolide A, withanone, and withanolide B simultaneously in WS. This UHPLC-PDA method has practical adaptability for ashwagandha raw material, extract, and product manufacturers, along with basic and applied science researchers. The method has been developed on UHPLC for routine analysis. The 11 withanosides and withanolides were confirmed using the fragmentation pattern obtained by the combined use of electrospray ionization and collision-induced dissociation in triple-quadrupole tandem mass spectrometry (TQ-MS/MS) in the WSE.

Targeting COVID-19 (SARS-CoV-2) main protease through active phytochemicals of ayurvedic medicinal plants - Withania somnifera (Ashwagandha), Tinospora cordifolia (Giloy) and Ocimum sanctum (Tulsi) - a molecular docking study.[Pubmed:32851919]

J Biomol Struct Dyn. 2020 Aug 27:1-14.

COVID-19 (Coronavirus disease 2019) is a transmissible disease initiated and propagated through a new virus strain SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2) since 31(st) December 2019 in Wuhan city of China and the infection has outspread globally influencing millions of people. Here, an attempt was made to recognize natural phytochemicals from medicinal plants, in order to reutilize them against COVID-19 by the virtue of molecular docking and molecular dynamics (MD) simulation study. Molecular docking study showed six probable inhibitors against SARS-CoV-2 M(pro) (Main protease), two from Withania somnifera (Ashwagandha) (Withanoside V [10.32 kcal/mol] and Somniferine [9.62 kcal/mol]), one from Tinospora cordifolia (Giloy) (Tinocordiside [8.10 kcal/mol]) and three from Ocimum sanctum (Tulsi) (Vicenin [8.97 kcal/mol], Isorientin 4'-O-glucoside 2''-O-p-hydroxybenzoagte [8.55 kcal/mol] and Ursolic acid [8.52 kcal/mol]). ADMET profile prediction showed that the best docked phytochemicals from present work were safe and possesses drug-like properties. Further MD simulation study was performed to assess the constancy of docked complexes and found stable. Hence from present study it could be suggested that active phytochemicals from medicinal plants could potentially inhibit M(pro) of SARS-CoV-2 and further equip the management strategy against COVID-19-a global contagion. Highlights Holistic approach of Ayurvedic medicinal plants to avenge against COVID-19 pandemic. Active phytoconstituents of Ayurvedic medicinal plants Withania somnifera (Ashwagandha), Tinospora cordifolia (Giloy) and Ocimum sanctum (Tulsi) predicted to significantly hinder main protease (M(pro) or 3Cl(pro)) of SARS-CoV-2. Through molecular docking and molecular dynamic simulation study, Withanoside V, Somniferine, Tinocordiside, Vicenin, Ursolic acid and Isorientin 4'-O-glucoside 2''-O-p-hydroxybenzoagte were anticipated to impede the activity of SARS-CoV-2 M(pro). Drug-likeness and ADMET profile prediction of best docked compounds from present study were predicted to be safe, drug-like compounds with no toxicity. Communicated by Ramaswamy H. Sarma.

Identification of bioactive molecule from Withania somnifera (Ashwagandha) as SARS-CoV-2 main protease inhibitor.[Pubmed:32643552]

J Biomol Struct Dyn. 2020 Jul 8:1-14.

SARS-CoV-2 is the causative agent of COVID-19 and has been declared as pandemic disease by World Health Organization. Lack of targeted therapeutics and vaccines for COVID-2019 have triggered the scientific community to develop new vaccines or drugs against this novel virus. Many synthetic compounds and antimalarial drugs are undergoing clinical trials. The traditional medical practitioners widely use Indian medicinal plant Withania somnifera (Ashwagandha) natural constituents, called withanolides for curing various diseases. The main protease (M(pro)) of SARS-CoV-2 plays a vital role in disease propagation by processing the polyproteins which are required for its replication. Hence, it denotes a significant target for drug discovery. In the present study, we evaluate the potential of 40 natural chemical constituents of Ashwagandha to explore a possible inhibitor against main protease of SARS-CoV-2 by adopting the computational approach. The docking study revealed that four constituents of Ashwagandha; Withanoside II (-11.30 Kcal/mol), Withanoside IV (-11.02 Kcal/mol), Withanoside V (-8.96 Kcal/mol) and Sitoindoside IX (-8.37 Kcal/mol) exhibited the highest docking energy among the selected natural constituents. Further, MD simulation study of 100 ns predicts Withanoside V possess strong binding affinity and hydrogen-bonding interactions with the protein active site and indicates its stability in the active site. The binding free energy score also correlates with the highest score of -87.01 +/- 5.01 Kcal/mol as compared to other selected compounds. In conclusion, our study suggests that Withanoside V in Ashwagandha may be serve as a potential inhibitor against M(pro) of SARS-CoV-2 to combat COVID-19 and may have an antiviral effect on nCoV. Communicated by Ramaswamy H. Sarma.

Subcritical water extraction of withanosides and withanolides from ashwagandha (Withania somnifera L) and their biological activities.[Pubmed:31276745]

Food Chem Toxicol. 2019 Oct;132:110659.

Subcritical water extraction (SWE) applied to analyses the bioactives from ashwagandha (W. somnifera) at varying temperature (100-200 degrees C) and extraction time (10-30min). The effect of temperature and time has been investigated in terms of extraction yield (EY), total phenolic content (TPC), cytotoxicity, antioxidant, and enzyme inhibitory activities. The withanosides and withanolides responsible for various biological effects were quantified using high performance liquid chromatography (HPLC). The HPLC analysis revealed Withanoside V, Withanoside IV, 12-Deoxywithastramonolide, Withanolide A, and Withaferin A as a principle bioactive compounds in SWE, with high in concentration compared to microwave-assisted extraction (MAE), Soxhlet extraction (SE) and maceration (MC). For SWE the highest EY (65.6%; 200 degrees C for 30min), TPC (82.5mg GAE/g DE), antioxidant activity (DPPH: 80.3%, FRAP: 60.5% and ABTS: 78.9), and potent enzyme inhibitory effects were observed. The SWE and Withaferin A showed significant reduction in cell viability of cervical cancer (HeLa) cells, with IC50 values 10mg/ml and 8.5muM/ml, respectively but no cytotoxic effect for normal cells (MDCK). Thus, SWE can provide effective extraction for ashwagandha withanosides and withanolides compared MAE, SE and MC to conventional methods, which could be used for extraction of pharmacologically active fractions with therapeutic applications.

Elucidating the active interaction mechanism of phytochemicals withanolide and withanoside derivatives with human serum albumin.[Pubmed:30403672]

PLoS One. 2018 Nov 7;13(11):e0200053.

Withania somnifera (Ashwagandha) is an efficient medicinal plant known in Ayurveda and Chinese medicine since ancient times, whose extracts are consumed orally as food supplement or as a health tonic owing to its several restorative properties for various CNS disorders, inflammation, tumour, stress, rheumatism etc. In this study, we have analyzed the binding interaction of four derivatives of Withania somnifera (Withanolide A, Withanolide B, Withanoside IV and Withanoside V) with HSA because of their important pharmacological properties. To unravel the binding between derivatives of Withania somnifera and HSA, fluorescence spectroscopy was used. Binding studies were further studied by molecular docking and dynamics and results confirmed greater stability upon binding of derivatives with HSA. Circular dichroism data illustrated change in the secondary structure of protein upon interaction with these derivatives, particularly the helical structure was increased and beta-sheets and random coils were decreased. Furthermore, morphological and topological changes were observed using AFM and TEM upon binding of ligands with HSA indicating that HSA-withnoside/withanolide complexes were formed. All the results cumulatively demonstrate strong binding of withanosides and withanolides derivatives with serum albumin, which should further be explored to study the pharmacokinetics and pharmacodynamics of these derivatives.

Determination of Withanolides in Withania somnifera by Liquid Chromatography: Single-Laboratory Validation, First Action 2015.17.[Pubmed:27697094]

J AOAC Int. 2016 Nov 1;99(6):1444-1458.

An LC method was developed and validated in 2007 for analyzing Withania somnifera raw material (root) and dried extracts for withanolide content, including withanoside IV, Withanoside V, withaferin A, 12-deoxywithastromonolide, withanolide A, and withanolide B. The method involved the extraction of the analytes with methanol, their subsequent filtration, and then analysis on a C18 column with an acetonitrile gradient and UV detection. Single-laboratory validation yielded linearity generally in the range of 20 to 200 mug/mL for each analyte, with a repeatability precision of RSD < 3% in most cases, and recovery in the range of 90 to 105%. These results compare well with the performance criteria recently detailed in AOAC Standard Method Performance Requirement 2015.007. The method was shown to be rugged with respect to different analysts, equipment, and days of analysis, and the sample solution was shown to be stable for 24 h at room temperature after extraction. The method was reviewed by the AOAC Expert Review Panel on Dietary Supplements (Set 2 Ingredients) and approved for First Action Official MethodSM status.

Silencing of sterol glycosyltransferases modulates the withanolide biosynthesis and leads to compromised basal immunity of Withania somnifera.[Pubmed:27146059]

Sci Rep. 2016 May 5;6:25562.

Sterol glycosyltransferases (SGTs) catalyse transfer of glycon moiety to sterols and their related compounds to produce diverse glyco-conjugates or steryl glycosides with different biological and pharmacological activities. Functional studies of SGTs from Withania somnifera indicated their role in abiotic stresses but details about role under biotic stress are still unknown. Here, we have elucidated the function of SGTs by silencing SGTL1, SGTL2 and SGTL4 in Withania somnifera. Down-regulation of SGTs by artificial miRNAs led to the enhanced accumulation of withanolide A, withaferin A, sitosterol, stigmasterol and decreased content of Withanoside V in Virus Induced Gene Silencing (VIGS) lines. This was further correlated with increased expression of WsHMGR, WsDXR, WsFPPS, WsCYP710A1, WsSTE1 and WsDWF5 genes, involved in withanolide biosynthesis. These variations of withanolide concentrations in silenced lines resulted in pathogen susceptibility as compared to control plants. The infection of Alternaria alternata causes increased salicylic acid, callose deposition, superoxide dismutase and H2O2 in aMIR-VIGS lines. The expression of biotic stress related genes, namely, WsPR1, WsDFS, WsSPI and WsPR10 were also enhanced in aMIR-VIGS lines in time dependent manner. Taken together, our observations revealed that a positive feedback regulation of withanolide biosynthesis occurred by silencing of SGTLs which resulted in reduced biotic tolerance.

Ectopic overexpression of WsSGTL1, a sterol glucosyltransferase gene in Withania somnifera, promotes growth, enhances glycowithanolide and provides tolerance to abiotic and biotic stresses.[Pubmed:26518426]

Plant Cell Rep. 2016 Jan;35(1):195-211.

KEY MESSAGE: Overexpression of sterol glycosyltransferase (SGTL1) gene of Withania somnifera showing its involvement in glycosylation of withanolide that leads to enhanced growth and tolerance to biotic and abiotic stresses. Withania somnifera is widely used in Ayurvedic medicines for over 3000 years due to its therapeutic properties. It contains a variety of glycosylated steroids called withanosides that possess neuroregenerative, adaptogenic, anticonvulsant, immunomodulatory and antioxidant activities. The WsSGTL1 gene specific for 3beta-hydroxy position has a catalytic specificity to glycosylate withanolide and sterols. Glycosylation not only stabilizes the products but also alters their physiological activities and governs intracellular distribution. To understand the functional significance and potential of WsSGTL1 gene, transgenics of W. somnifera were generated using Agrobacterium tumefaciens-mediated transformation. Stable integration and overexpression of WsSGTL1 gene were confirmed by Southern blot analysis followed by quantitative real-time PCR. The WsGTL1 transgenic plants displayed number of alterations at phenotypic and metabolic level in comparison to wild-type plants which include: (1) early and enhanced growth with leaf expansion and increase in number of stomata; (2) increased production of glycowithanolide (majorly Withanoside V) and campesterol, stigmasterol and sitosterol in glycosylated forms with reduced accumulation of withanolides (withaferin A, withanolide A and withanone); (3) tolerance towards biotic stress (100 % mortality of Spodoptera litura), improved survival capacity under abiotic stress (cold stress) and; (4) enhanced recovery capacity after cold stress, as indicated by better photosynthesis performance, chlorophyll, anthocyanin content and better quenching regulation of PSI and PSII. Our data demonstrate overexpression of WsSGTL1 gene which is responsible for increase in glycosylated withanolide and sterols, and confers better growth and tolerance to both biotic and abiotic stresses.

RNAi-mediated gene silencing of WsSGTL1 in W.somnifera affects growth and glycosylation pattern.[Pubmed:26357855]

Plant Signal Behav. 2015;10(12):e1078064.

Sterol glycosyltransferases (SGTs) belong to family 1 of glycosyltransferases (GTs) and are enzymes responsible for synthesis of sterol-glucosides (SGs) in many organisms. WsSGTL1 is a SGT of Withania somnifera that has been found associated with plasma membranes. However its biological function in W.somnifera is largely unknown. In the present study, we have demonstrated through RNAi silencing of WsSGTL1 gene that it performs glycosylation of withanolides and sterols resulting in glycowithanolides and glycosylated sterols respectively, and affects the growth and development of transgenic W.somnifera. For this, RNAi construct (pFGC1008-WsSGTL1) was made and genetic transformation was done by Agrobacterium tumefaciens. HPLC analysis depicts the reduction of Withanoside V (the glycowithanolide of W.somnifera) and a large increase of withanolides (majorly withaferin A) content. Also, a significant decrease in level of glycosylated sterols has been observed. Hence, the obtained data provides an insight into the biological function of WsSGTL1 gene in W.somnifera.

Enhanced biosynthesis of withanolides by elicitation and precursor feeding in cell suspension culture of Withania somnifera (L.) Dunal in shake-flask culture and bioreactor.[Pubmed:25089711]

PLoS One. 2014 Aug 4;9(8):e104005.

The present study investigated the biosynthesis of major and minor withanolides of Withania somnifera in cell suspension culture using shake-flask culture and bioreactor by exploiting elicitation and precursor feeding strategies. Elicitors like cadmium chloride, aluminium chloride and chitosan, precursors such as cholesterol, mevalonic acid and squalene were examined. Maximum total withanolides detected [withanolide A (7606.75 mg), withanolide B (4826.05 mg), withaferin A (3732.81 mg), withanone (6538.65 mg), 12 deoxy withanstramonolide (3176.63 mg), withanoside IV (2623.21 mg) and Withanoside V (2861.18 mg)] were achieved in the combined treatment of chitosan (100 mg/l) and squalene (6 mM) along with 1 mg/l picloram, 0.5 mg/l KN, 200 mg/l L-glutamine and 5% sucrose in culture at 4 h and 48 h exposure times respectively on 28th day of culture in bioreactor. We obtained higher concentrations of total withanolides in shake-flask culture (2.13-fold) as well as bioreactor (1.66-fold) when compared to control treatments. This optimized protocol can be utilized for commercial level production of withanolides from suspension culture using industrial bioreactors in a short culture period.

Characterization of Withania somnifera leaf transcriptome and expression analysis of pathogenesis-related genes during salicylic acid signaling.[Pubmed:24739900]

PLoS One. 2014 Apr 16;9(4):e94803.

Withania somnifera (L.) Dunal is a valued medicinal plant with pharmaceutical applications. The present study was undertaken to analyze the salicylic acid induced leaf transcriptome of W. somnifera. A total of 45.6 million reads were generated and the de novo assembly yielded 73,523 transcript contig with average transcript contig length of 1620 bp. A total of 71,062 transcripts were annotated and 53,424 of them were assigned GO terms. Mapping of transcript contigs to biological pathways revealed presence of 182 pathways. Seventeen genes representing 12 pathogenesis-related (PR) families were mined from the transcriptome data and their pattern of expression post 17 and 36 hours of salicylic acid treatment was documented. The analysis revealed significant up-regulation of all families of PR genes by 36 hours post treatment except WsPR10. The relative fold expression of transcripts ranged from 1 fold to 6,532 fold. The two families of peroxidases including the lignin-forming anionic peroxidase (WsL-PRX) and suberization-associated anionic peroxidase (WsS-PRX) recorded maximum expression of 377 fold and 6532 fold respectively, while the expression of WsPR10 was down-regulated by 14 fold. Additionally, the most stable reference gene for normalization of qRT-PCR data was also identified. The effect of SA on the accumulation of major secondary metabolites of W. somnifera including Withanoside V, withaferin A and withanolide A was also analyzed and an increase in content of all the three metabolites were detected. This is the first report on expression patterns of PR genes during salicylic acid signaling in W. somnifera.

Optimization of elicitation conditions with methyl jasmonate and salicylic acid to improve the productivity of withanolides in the adventitious root culture of Withania somnifera (L.) Dunal.[Pubmed:22843063]

Appl Biochem Biotechnol. 2012 Oct;168(3):681-96.

Adventitious root cultures derived from leaf derived callus of Withania somnifera (L.) Dunal were treated with methyl jasmonate and salicylic acid independently. Biomass accumulation, culture age, elicitation period, and culture duration were optimized for higher withanolides production in the two best-responding varieties collected from Kolli hills (Eastern Ghats) and Cumbum (Western Ghats) of Tamil Nadu, India. Between the two elicitors, salicylic acid (SA) improved the production of major withanolides (withanolide A, withanolide B, withaferin A, and withanone) as well as minor constituents (12-deoxy withastramonolide, Withanoside V, and withanoside IV) in the Kolli hills variety. Treatment of root biomass (11.70 g FW) on 30-day-old adventitious root cultures with 150 muM SA for 4 h elicitor exposure period resulted in the production of 64.65 mg g(-l) dry weight (DW) withanolide A (48-fold), 33.74 mg g(-l) DW withanolide B (29-fold), 17.47 mg g(-l) DW withaferin A (20-fold), 42.88 mg g(-l) DW withanone (37-fold), 5.34 mg g(-l) DW 12-deoxy withastramonolide (nine fold), 7.23 mg g(-l) DW Withanoside V (seven fold), and 9.45 mg g(-l) DW withanoside IV (nine fold) after 10 days of elicitation (40th day of culture) when compared to untreated cultures. This is the first report on the use of elicitation strategy on the significant improvement in withanolides production in the adventitious root cultures of W. somnifera.