Objective: To show the preventive effect of Brazilian propolis on metabolic syndrome.Methods: Nine Brazilian propolis were examined for inhibition ofα-glucosidase, absorption of sugar in mice, and lipid accumulation, glycerol 3-phosphate dehydrogenase, and adiponection production in mouse 3T3-L1 cells.Results: In nine Brazilian propolis, AF-06, AF-19, and AFG-06 propolis inhibited rat internal α-glucosidase, and AF-06 propolis inhibited the absorption of sugar in mice. In 3T3-L1 cells, AF-06 and AF-08 propolis inhibited accumulation lipid, and inhibited glycerol 3-phosphate dehydrogenase.Conclusion: Brazilian propolis AF-06 and AF-08 are natural products which offer promise in the prevention of diabetes and metabolic syndrome. Incorporating dietary supplements into a treatment plan with medicines with similar effects requires further study.