Withaferin A: A potential selective glucocorticoid receptor modulator with anti-inflammatory effect

Withania frutescens (L.) Pauquy, a valuable Mediterranean shrub containing bioactive withanolides

The bushy plant Withania frutescens (L.) Pauquy is well distributed in the West-Mediterranean area, notably in the south of Spain, Algeria and Morocco where is it is used traditionally for the treatment of various human diseases, including diabetes. Unlike the two major species W. somnifera and W. coagulans extensively studied, the genomically close species W. frutescens has been much less investigated. Nevertheless, this shrub species displays a comparable phytochemical profile and marked antioxidant and anti-inflammatory properties, at the origin of reported pharmacological effects and its traditional uses. Here we have analyzed the diversity of biological effects reported with leaves and root extracts of W. frutescens. Hydroalcoholic extracts prepared from the aerial parts of the plant have revealed antihyperglycemic and cell-protective activities along with antimicrobial and anticorrosive effects. The extracts contained diverse polyphenolic compounds and a few alkaloids (calystegines) but most of the observed effects have been attributed to the presence of withanolides which are modified C28 ergostane-type steroids. Our analysis focused in part on specific withanolides found in W. frutescens, in particular an unusual 3-O-sulfated withanolide considered as a potential pro-drug of the major active compound withaferin A (WA) and a lead compound for the development of a potential drug candidate. The mechanism of action of this sulfated WA analogue is discussed. Altogether, our unprecedented extensive analysis of W. frutescens highlighted the pharmacological potential of this atypical medicinal plant. By analogy with the major cultivated Withania species, the market potential of little-known plant is underlined.

Effects of Withania somnifera on Cortisol Levels in Stressed Human Subjects: A Systematic Review

BACKGROUND

Withania somnifera (WS), a popular medicinal plant of the Solanaceae family, contains active ingredients with antioxidant, anti-inflammatory, immunomodulatory, and anti-stress activities. However, its precise mechanisms of action and optimal use as a supplement are not yet fully understood. The objective of this systematic review is to assess the impact of WS supplementation on cortisol levels in stressed humans by analyzing clinical trials conducted prior to May 2023.

METHODS

The assessment was carried out following the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) by exploring the databases of EMBASE, PubMed, Google Scholar, CENTRAL, and Scopus.

RESULTS

Of the 4788 articles identified, only 9 studies met the selection criteria. The selected studies varied in terms of design, results, formulations, dosages, and treatment duration (30-112 days), and involved subjects with varying degrees of stress. WS supplementation decreases cortisol secretion with no significant adverse effects. Nonetheless, none of the studies evaluated the potential impact of cortisol reduction on adrenal function and long-term effects.

CONCLUSIONS

Brief-term supplementation with WS appears to have a stress-reducing effect in stressed individuals. However, since the long-term effects of WS supplementation are not yet fully understood, WS supplements should be used under medical supervision.