Estrogenic activity of Sage (Salvia officinalis L.) aerial parts and its isolated ferulic acid in immature ovariectomized female rats

Abstract

Etnopharmacological relevance: Common sage (Salvia officinalis L., Lamiaceae), a medicinal plant of Mediterranean origin, has been traditionally applied in cases of excessive sweating, and in menopausal complaints, including hot flushes.

Aim of the study: This study aims to study the possible estrogenic effect of the aerial parts of S. officinalis ethanolic extract in immature ovariectomized female rats.

Materials and methods: The ethanolic extract was subjected to qualitative and quantitative HPLC analysis and phytochemical isolation. The estrogenic activity of S. officinalis ethanolic extract at oral doses of 50, 100 and 200 mg/kg b.wt. and its isolated ferulic acid at a dose of 50 mg/kg b.wt. for a week, was assessed on ovariectomized immature Wistar rats. The experiment was confirmed by luteinizing hormone (LH) and follicle stimulating hormone (FSH) serum levels determination, a histopathological examination and a histomorphometrical study.

Results: HPLC/PDA analysis revealed fourteen phenolic compounds the major constituents were methyl rosmarinate (24.86 mg/100 g) and ferulic acid (6.06 mg/100 g) together with five flavonoids where the major constituents were rutin, naringenin and quercetin. Two compounds were isolated from the polar fraction and identified as methyl rosmarinate (1) and ferulic acid (2). Oral administration of sage ethanolic extract and ferulic acid revealed a significant increase in the uterine weight compared to ovariectomized control rats. Moreover, S. officinalis and ferulic acid showed different phases of estrus cycle denoting estrogenic activity, and significantly decreased the serum levels of FSH and LH.

Conclusion: From these results it could be concluded that S. officinalis ethanolic extract and its content of ferulic acid could be useful as a safe natural source for estrogenic activity, supporting its traditional use to improve postmenopausal symptoms.

Keywords: Estrogen receptor; Estrogenic activity; HPLC; Immature female rats; Sage; Salvia officinalis.