Jorge Ana Paula, Horst Heros, de Sousa Eliandra, Pizzolatti Moacir Geraldo, Silva Fátima Regina Mena Barreto
Departamento de Bioquímica, Centro de Ciências Biológicas, UFSC, Campus Universitário, Bairro Trindade. Cx. Postal 5069, CEP: 88040-970, Florianópolis, SC, Brazil.
Chem Biol Interact. 2004 Oct 15;149(2-3):89-96. doi: 10.1016/j.cbi.2004.07.001.
Bauhinia forficata is one of the Bauhinia species mostly used as an antidiabetic herbal remedy in Brazil. Kaempferitrin (kaempferol-3,7-O-(alpha)-L-dirhamnoside) is the predominant flavonol glycoside found in the B. forficata leaves. The aim of the present work was to study the long-term effect of kaempferitrin on glycaemia in diabetic rats, as well as the in vitro effect of this compound on 14C-D-glucose uptake and 14C-leucine incorporation into protein in normal rat soleus muscle. Kaempferitrin was found to have an acute lowering effect on blood glucose in diabetic rats and to stimulate the glucose uptake percentile, as efficiently as insulin in muscle from normal rats. This compound did not have any effect on glucosuria or on protein synthesis in muscle from normal and diabetic animals. However, the protein synthesis in the kaempferitrin-treated groups was maintained at the same level as the respective controls. Thus, the hypoglycaemic effect and the prompt efficiency of the kaempferitrin in stimulating [U-14C]-2-deoxi-D-glucose uptake in muscle -constitute the first evidence to indicate that the acute effect of this compound on blood glucose lowering may occur as a consequence of the altered intrinsic activity of the glucose transporter (Vmax or glucose transporters translocation?) not involving directly the synthesis of new carriers.
紫羊蹄甲是巴西最常被用作抗糖尿病草药的羊蹄甲属植物之一。山柰酚鼠李糖苷（山柰酚-3,7-O-α-L-二鼠李糖苷）是在紫羊蹄甲叶片中发现的主要黄酮醇糖苷。本研究的目的是研究山柰酚鼠李糖苷对糖尿病大鼠血糖的长期影响，以及该化合物对正常大鼠比目鱼肌中14C-D-葡萄糖摄取和14C-亮氨酸掺入蛋白质的体外影响。结果发现，山柰酚鼠李糖苷对糖尿病大鼠的血糖有急性降低作用，并能刺激葡萄糖摄取百分率，其效果与正常大鼠肌肉中的胰岛素一样有效。该化合物对正常和糖尿病动物的糖尿或肌肉中的蛋白质合成没有任何影响。然而，山柰酚鼠李糖苷处理组的蛋白质合成维持在与各自对照组相同的水平。因此，山柰酚鼠李糖苷的降血糖作用以及其在刺激肌肉中[U-14C]-2-脱氧-D-葡萄糖摄取方面的迅速有效性——构成了首个证据，表明该化合物对血糖降低的急性作用可能是由于葡萄糖转运蛋白内在活性改变（Vmax或葡萄糖转运蛋白易位？）所致，而不直接涉及新载体的合成。
