Schizandra arisanensis extract attenuates cytokine-mediated cytotoxicity in insulin-secreting cells

Figure 5 Ethanolic extract of Schizandra arisanensis treatment partially rescued the abolished insulin secretion in cytokine-treated BRIN-BD11 cells. A: Acute insulin release in response to glucose, KCl and Ca²⁺ in the presence or absence of the ethanolic extract of Schizandra arisanensis (SA-Et) was evaluated. Data are presented as the mean ± SE, n = 4. ^aP < 0.05, ^bP < 0.01 vs insulin released from cells treated with 1.1 mmol/L glucose; ^dP < 0.01 vs control cells under the same conditions; B: Cultured BRIN-BD11 cells were treated with the cytokine mixture in the presence or absence of the SA-Et. At 48 h post-treatment, treated cells were evaluated for glucose responsiveness. Data are presented as the mean ± SE, n = 4. ^bP < 0.01 vs insulin released from cells treated with 1.1 mmol/L glucose; ^dP < 0.01 vs SA-Et-treated cells under the same glucose conditions. C: In addition, a portion of the treated cells was harvested to measure insulin mRNA level using reverse transcription-polymerase chain reaction. Relative insulin gene expression was calculated by employing endogenous β-actin mRNA level as an internal control. ^aP < 0.05 vs control conditions (none); D: Protein level and cellular insulin content were independently measured by Western blot and enzyme-linked immunosorbent assay. Data are presented as the mean ± SE, n = 4. ^aP < 0.05, ^bP < 0.01 vs control conditions (none). IL-1β: Interleukin 1β; IFN-γ: Interferon-γ; ND: Not determined.