Bioactive metabolites reveal the therapeutic consistency of epimedii folium from multi-plant sources for the treatment of kidney-yang deficiency

Ethnopharmacological relevance: Epimedii Folium (Yin-yang-huo in Chinese), a traditional and commonly used herbal medicine (HM), is a representative of multi-plant sources. To date, little is known about the reasons for similar therapeutic effects of this HM from multi-plant sources.Aim of the study: To investigate the underlying reasons for the similar pharmacological effects of Epimedii Folium from two botanical sources (Epimedium koreanum Nakai and Epimedium wushanense T. S. Ying).Materials and methods: Firstly, the phytochemicals of the extracts of E. koreanum and E. wushanense were systematically analyzed. Meanwhile, their pharmacological effects on kidney-yang deficiency (KYD) syndrome were evaluated in rats induced by hydrocortisone. Subsequently, we proposed a combined effect index (CEI) to assess the effects of two plants on the secretion of testosterone by combing the system exposure of twelve active components in vivo with their regulation activities of testosterone production in vitro. Moreover, the label-free proteomics and Western blot analysis were conducted to evaluate the possible mechanism of Epimedii Folium from two botanical sources.Results: E. koreanum and E. wushanense exhibited similar pharmacological effects on KYD syndrome with promoting the mating behaviors and testosterone levels of rats, although there is a certain difference in the main components between two plants. The CEI analysis showed that there was no difference (P > 0.05) in the sum of CEIs of two Epimedium, indicating that their similar therapeutic effects are attributed to bioactive metabolites in vivo. Furthermore, Epimedii Folium can regulate testosterone production in rat Leydig cell via reversing expressions of key steroidogenic enzymes, such as steroidogenic acute regulatory protein (StAR) and 38-hydroxysteroid dehydrogenase (38-HSD).Conclusion: Our results supply critical evidence for the similar pharmacological effects of two Epimedium species, acting by consistent bioactive components directly exposing in vivo, not chemical compositions presenting in herbs. It provides a reasonable scientific basis for understanding of the HMs originated from multi-plant sources for the same clinical application.