Fig. 1

Metformin improves the salivary flow rate and salivary gland inflammation. a Eleven-week-old mice were orally administered vehicle or 50 mg/kg metformin daily for 9 weeks. The salivary flow rate was measured for 7 min at 11, 13, 15, 17, and 20 weeks (n = 5 per group at each time point). Symbols indicate means, and bars indicate SEMs. Data are representative of the two independent experiments. b Histological analysis of the salivary glands from vehicle- and metformin-treated mice (at 20 weeks of age, n = 5 per group) was conducted by hematoxylin and eosin staining (original magnification, × 100) and immunohistochemical staining for IL-6, TNF-α, and IL-17 (original magnification, × 200; insets, × 400). Histological score and numbers of IL-6-, TNF-α-, and IL-17-expressing (positive) cells are shown; scale bar, 100 μm. c IL-6, TNF-α, and IL-17 mRNA levels in the salivary glands, as determined by real-time PCR. Data are means ± SEMs. Data are representative of three independent experiments (*p < 0.05, **p < 0.01)