Table 1.

Oral agents approved for treatment of type 2 diabetes

Class	Mechanism of action	Target organ site
Biguanides [57]	Decrease in hepatic glucose production; increase in muscle insulin sensitivity by activating AMPK	Liver and intestine
Thiazolidinediones (TZDs) [58]	Bind PPAR-γ, decrease insulin resistance and increase glucose utilization	Muscle, adipose tissue, and liver
Sulfonylureas [59]	Stimulates beta cell insulin secretion.	Islet cells of pancreas
α-glucosidase inhibitors [60]	Reduces absorption of dietary carbohydrate, by inhibiting the enzyme alpha-glucosidase	Intestine
Meglitinides (glinides) [61]	Stimulate the release of insulin from the pancreatic beta cells	Islet cells of pancreas
DPP-4 inhibitors [62]	Prevent degradation Of GLP-1	Intestine
SGLT-2 inhibitors [63]	Prevent glucose reabsorption and facilitate its excretion in urine by inhibiting SGLT-2	Kidney
GLP-1 receptor agonists [64]	Activate GLP-1 receptor, increase insulin secretion, decrease glucagon secretion	Islet cells of pancreas

AMPK, AMP-activated protein kinase; PPAR-γ, Peroxisome proliferator-activated receptor gamma; DPP-4, Dipeptidyl peptidase 4; GLP-1, SGLT-2, sodium-glucose cotransporter-2; Glucagon-like peptide-1