The dried tuberous root of Ophiopogon japonicas Thunb. (Ophiopogonis Radix; Maidong in Chinese), is used in China as an herbal medicine for the treatment of diabetes. Maidong Fang (MDF), a Chinese medicinal formula, contains Ophiopogonis Radix (OR) and five other single Chinese medicinal herbs. Previous studies have demonstrated that these herbs have anti-diabetic effects, and they can promote glucose uptake in liver or skeletal muscle cells and reduce the plasma glucose levels in vivo. To explore the anti-diabetic effects of MDF in vitro and in vivo, we constructed insulin resistance (IR) cell models by insulin and palmitate induction in HepG2 cells and C2C12 cells, respectively, and in vivo mice model using high sugar- and high fat-diet followed by streptozocin (STZ) treatment. Our st...[ Read more ]

The dried tuberous root of Ophiopogon japonicas Thunb. (Ophiopogonis Radix; Maidong in Chinese), is used in China as an herbal medicine for the treatment of diabetes. Maidong Fang (MDF), a Chinese medicinal formula, contains Ophiopogonis Radix (OR) and five other single Chinese medicinal herbs. Previous studies have demonstrated that these herbs have anti-diabetic effects, and they can promote glucose uptake in liver or skeletal muscle cells and reduce the plasma glucose levels in vivo. To explore the anti-diabetic effects of MDF in vitro and in vivo, we constructed insulin resistance (IR) cell models by insulin and palmitate induction in HepG2 cells and C2C12 cells, respectively, and in vivo mice model using high sugar- and high fat-diet followed by streptozocin (STZ) treatment. Our study indicated that MDF treatment increased glucose uptake in IR HepG2 cells and IR C2C12 cells significantly, by stimulating the levels of two major GLUTs, upregulating the IRS1 protein level, downregulating the NF-κB protein expression, and activating Akt and AMPK-α in a dose-dependent manner. Furthermore, in the animal experiments, the blood glucose and insulin levels were determined and the insulin resistance index along with the insulin sensitivity index were calculated to reveal the hypoglycemic effects of MDF. These experiments demonstrated that similar to the commercial drug metformin, MDF treatment reduced insulin resistance and increased insulin sensitivity in comparison to the IR model group without drug treatment, while there was no significant difference in the insulin content among the control group, IR model group and drug treatment group. Our data suggest that MDF may have a good potential as an anti-diabetic medicine, particularly in patients with insulin resistance or reduced sensitivity to insulin.