Phytoecdysteroids (PEs) are naturally occurring steroid compounds, that have recently gained significant attention, due to their diverse biological activities and high therapeutic potential. The aim of the present study was to quantify some PEs including 20-hydroxyecdysterone (20-HE), ponasterone A (PA), and turkesterone (TU) in selected plant foods and Rhaponticum carthamoides extract. Furthermore, the effects of 20-HE, TU, and R. carthamoides extract, were investigated with in vitro methods using isolated smooth muscle tissues. The levels of 20-HE in the analyzed samples exhibited significant differences, with kaniwa seed extract containing the highest amount, followed by spinach leaf extract, quinoa seed extract, and asparagus stem extract. The in vitro analyses suggested that R. carthamoides extract exhibits dose-dependent cytotoxic effects on smooth muscle cells, with low doses promoting contraction and higher doses inducing relaxation. Additionally, the extract demonstrated a significant inhibitory effect on ACh-induced contractions, while 20-HE enhanced the contractile response. The current findings highlighted phytoecdysteroids’ potential for modifying gastrointestinal motility.

Salvia officinalis L. (S. officinalis) or common sage has long been valued in traditional medicine for its broad therapeutic properties. Our study explored the antioxidant potential, the cytotoxic activity and the effects on smooth muscle (SM) contractility of a traditionally prepared sage aqueous infusion. A chromatographic analysis revealed the major phenolic constituents of the infusion, rosmarinic acid being the most abundant compound (38.16 mg/mL), followed by rutin (3.58 mg/g), caffeic acid (3.00 mg/g) and hesperidin (1.84 mg/g). Three spectrophotometric methods were used to determine the antioxidant potential of the plant extract: a DPPH assay for radical scavenging activity (IC₅₀ 21.77 ± 0.98 µg/mL), a CUPRAC assay (2.32 ± 0.04 mmol Trolox equivalents/g) and a total reducing capacity assay (1.92 ± 0.01 mmol Trolox equivalents/g) for evaluating reducing properties. A cytotoxicity was assessed in primary SM cells (isolated from rat gastric tissue) using the xCELLigence real-time cell analysis system, where the infusion demonstrated dose-dependent cytotoxicity with an IC₅₀ of 0.34 ± 0.12 mg/mL. Concentrations of 0.37 mg/mL rapidly reduced viability, while lower concentrations showed mild or negligible effects. Functional experiments with isolated rat gastric SM cells revealed a dose-dependent enhancement of both tonic and phasic contractile activity. Our results showed that the serotonergic pathways were mainly implicated in mediating these effects, while the cholinergic pathways were not involved with them. Together, these findings validate the traditional use of S. officinalis and point to its role in modulating SM function and providing antioxidant benefits, warranting further investigation into its mechanisms and therapeutic potential.