Steviol glycosides affect functional properties and macromolecular expression of breast cancer cells

Biological activity and structural modification of isosteviol over the past 15 years

Isosteviol is a tetracyclic diterpenoid obtained by hydrolysis of stevioside. Due to its unique molecular skeleton and extensive pharmacological activities, isosteviol has attracted more and more attention from researchers. This review summarized the structural modification, pharmacological activity and microbial transformation of isosteviol from 04/2008 to 10/2023. In addition, the research history, structural characterization, and pharmacokinetics of isosteviol were also briefly reviewed. This review aims to provide useful literature resources and inspirations for the exploration of diterpenoid drugs.

Stevioside Improves Antioxidant Capacity and Intestinal Barrier Function while Attenuating Inflammation and Apoptosis by Regulating the NF-κB/MAPK Pathways in Diquat-Induced Oxidative Stress of IPEC-J2 Cells

As a natural sweetener, stevioside is extracted from Stevia rebaudiana Bertoni and possesses potent antioxidant activity. However, little information is known about its protective role in maintaining the intestinal epithelial cells health under oxidative stress. The aim of this study was to investigate the protective effects and underlying mechanisms of stevioside on alleviating inflammation, apoptosis, and improving antioxidant capacity in intestinal porcine epithelial cells (IPEC-J2) under oxidative stress by diquat. The results demonstrated that the pretreatment with stevioside (250 μM) for 6 h increased cell viability and proliferation and prevented apoptosis induced by diquat at 1000 μM for 6 h in IPEC-J2 cells, compared with the diquat alone-treated cells. Importantly, stevioside pretreatment significantly reduced ROS and MDA production as well as upregulated T-SOD, CAT, and GSH-Px activity. Moreover, it also decreased cell permeability and improved intestinal barrier functions by significantly upregulating the tight junction protein abundances of claudin-1, occludin, and ZO-1. At the same time, stevioside significantly down-regulated the secretion and gene expression of IL-6, IL-8, and TNF-α and decreased the phosphorylation levels of NF-κB, IκB, and ERK1/2 compared with the diquat alone group. Taken together, this study demonstrated that stevioside alleviated diquat-stimulated cytotoxicity, inflammation, and apoptosis in IPEC-J2 cells, protecting cellular barrier integrity and mitigating oxidative stress by interfering with the NF-κB and MAPK signaling pathways.

Steviol Glycosides from Stevia rebaudiana: An Updated Overview of Their Sweetening Activity, Pharmacological Properties, and Safety Aspects

This literature-based review synthesizes the available scientific information about steviol glycosides as natural sweeteners and molecules with therapeutic potential. In addition, it discusses the safety concerns regarding human consumption. Steviol glycosides exhibit a superior sweetener proficiency to that of sucrose and are noncaloric, noncariogenic, and nonfermentative. Scientific evidence encourages stevioside and rebaudioside A as sweetener alternatives to sucrose and supports their use based on their absences of harmful effects on human health. Moreover, these active compounds isolated from Stevia rebaudiana possess interesting medicinal activities, including antidiabetic, antihypertensive, anti-inflammatory, antioxidant, anticancer, and antidiarrheal activity. The described bioactivities of steviol glycosides deserve special attention based on their dose dependence and specific pathological situations. Further clinical research is needed to understand underlying mechanisms of action, therapeutic indexes, and pharmacological applications.