RESUMO
OBJECTIVE: To evaluate, in hyperglycemic tilapia [Oreochromis niloticus (O. niloticus)], the effect of this aqueous extract on blood glucose levels. METHODS: The hyperglycemia in O. niloticus was induced by adding glucose to fish pond water. An aqueous extract of Ocimum tenuiflorum (O. tenuiflorum) was prepared by boiling fresh leaves and the doses of 0, 40, 80, 200 and 400 mg per liter of pond water were tested. RESULTS: The blood sugar concentration for tilapia with hyperglycemic induced was an average of 50% higher than the control group. The blood glucose levels in tilapia after the induction of hyperglycemia were higher than the control group for 90 min after the treatment. The treatment with the aqueous extract of O. tenuiflorum dropped the serum glucose level of hyperglycemic tilapia until it was similar to that of the control group and was dose dependent. CONCLUSIONS: The results indicated that O. tenuiflorum was endowed with anti-hyperglycemic activity. To our knowledge, this is the first report on the use of fish as a diabetes model to test natural extracts from plants.