Objective: To show the preventive effect of dietary supplements on metabolic syndrome.
Methods: Twenty dietary supplements were examined for inhibition of α-glucosidase, absorption of sugar in mice, lipids accumulation and adiponectin production in rat visceral adipocytes.
Results: In twenty dietary supplements, Bombyx mori and mulberry leaves inhibited rat intestinal α-glucosidase more than acarbose, and inhibited absorption of sugar in mice. In visceral adipocytes, Ganoderma lucidum, mate and Japanese yew inhibited accumulation of lipid and Artemisia Capillaris Flowers and Ground-ivy increased production of adiponectin in rat visceral adipocytes.
Conclusion: Mulberry leaves, Bombyx mori, Glechoma hederacea, Artemisia Capillaris Flowers 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.

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.