Buchang NaoXinTong capsule (NXT) is a Chinese
Materia Medica standardized product extracted from 16 Chinese traditional medical herbs and widely used for treatment of patients with cerebrovascular and
cardiovascular diseases in China. Formation of
microaneurysms plays an important role in the development of
diabetic retinopathy. In this study, we investigated if NXT can protect diabetic mice against the development of
diabetic retinopathy. The db/db mice (~6 weeks old), a diabetic animal model, were divided into two groups and fed normal chow or plus NXT for 14 weeks. During the treatment, fasting
blood glucose levels were monthly determined.
After treatment, retinas were collected to determine
retinal thickness, accumulation of
carbohydrate macromolecules, and
caspase-3 (CAS-3) expression. Our results demonstrate that administration of NXT decreased fasting
blood glucose levels. Associated with the decreased
glucose levels, NXT blocked the diabetes-induced shrink of multiple layers, such as photoreceptor layer and outer nuclear/plexiform layers, in the retina. NXT also inhibited the diabetes-induced expression of CAS-3
protein and
mRNA,
MMP-2/9 and TNFα
mRNA, accumulation of
carbohydrate macromolecules, and formation of acellular capillaries in the retina. Taken together, our study shows that NXT can inhibit the development of
diabetic retinopathy and suggests a new potential application of NXT in clinic.