Stevioside fromStevia rebaudianaBertoni Increases Insulin Sensitivity in 3T3-L1 Adipocytes

Abstract

Stevioside from Stevia rebaudiana has been reported to exert antihyperglycemic effects in both rat and human subjects. There have been few studies on these effects in vitro. In this paper, radioactive glucose uptake assay was implemented in order to assess improvements in insulin sensitivity in 3T3-L1 cells by elevation of glucose uptake following treatment with stevioside. Oil Red-O staining and MTT assay were utilized to confirm adipocyte differentiation and cell viability, respectively. Findings from this research showed a significant increase in absorbance values in mature adipocytes following Oil Red-O staining, confirming the differentiation process. Stevioside was noncytotoxic to 3T3-L1 cells as cell viability was reduced by a maximum of 17%, making it impossible to determine its IC50. Stevioside increased glucose uptake activities by 2.1 times (p < 0.001) in normal conditions and up to 4.4 times (p < 0.001) in insulin-resistant states. At times, this increase was higher than that seen in positive control group treated with rosiglitazone maleate, an antidiabetic agent. Expressions of pY20 and p-IRS1 which were measured via Western blot were improved by stevioside treatment. In conclusion, stevioside has direct effects on 3T3-L1 insulin sensitivity via increase in glucose uptake and enhanced expression of proteins involved in insulin-signalling pathway.

Glycosides from Stevia rebaudiana Bertoni Possess Insulin‐Mimetic and Antioxidant Activities in Rat Cardiac Fibroblasts

“…Stevia rebaudiana Bertoni and its glycosides are known not only as natural, noncaloric sweeteners but also for their antihypertensive, anti-inflammatory, immune-modulatory, and antihyperglycaemic effects [ 9 ]. In particular, the hypoglycaemic, antidiabetic, and insulin-like properties of steviol glycosides have been investigated in 3T3-L1 adipocytes [ 40 ], in L6 myoblasts [ 21 ], and in cancer-derived cell lines [ 28 ].…”

Stevia rebaudiana Bertoni: health promoting properties and therapeutic applications

“…ions. Mohd-Radzman et al (2013) observed that stevioside has direct effects on 3T3-L1 insulin sensitivity via increase glucose uptake and enhanced expression of proteins involved in insulin-signaling pathway. Increased insulin secretion is connected with the closure of ATP-dependent potassium channels, which results in the depolarisation of pancreatic beta cells and activation of Ca 2?…”

Stevia rebaudiana Bertoni bioactive effects: From in vivo to clinical trials towards future therapeutic approaches

“…The report confirmed the stevioside noncytotoxicity and increased glucose uptake activity in insulin resistant states, sometimes greater than that observed in the treated group with antidiabetic agent. This S. rebaudiana extract was found to have direct effects on insulin sensitivity through an increase in glucose uptake and increased expression of proteins linked to the insulin signaling pathway (Mohd‐Radzman et al, ). Other authors have demonstrated a direct insulinotropic effect of glycoside stevioside (Jeppesen, Gregersen, Alstrup, & Hermansen, ).…”

“…Thus, it was concluded that S. rebaudiana extracts could mimic insulin effects by modulating PI3K/Akt pathway (Rizzo et al, ). Similarly, in another study, the radioactive glucose uptake assay was used to assess the progress of insulin sensitivity in 3T3‐L1 cells by elevation of glucose uptake, following treatment with stevioside (Mohd‐Radzman, Ismail, Jaapar, Adam, & Adam, ). The report confirmed the stevioside noncytotoxicity and increased glucose uptake activity in insulin resistant states, sometimes greater than that observed in the treated group with antidiabetic agent.…”