Baicalin alleviates diabetes­associated cognitive deficits via modulation of mitogen-activated protein kinase signaling, brain­derived neurotrophic factor and apoptosis.

Baicalin is an important active component of the medicinal herb Scutellaria baicalensis Georgi and has shown a variety of pharmacological actions. The present study aimed to evaluate the neuroprotective effects of baicalin against diabetes­associated cognitive deficits (DACD) in rats and to elucidate the potential molecular mechanisms of action. A rat model of diabetes mellitus was prepared by intraperitoneal injection of streptozotocin. After the successful establishment of the diabetic rat model, baicalin (50, 100 and 200 mg/kg) or vehicle was administrated for seven weeks. Learning and memory function were assessed using the Morris water maze test. At the end of the experiment, the activities of acetylcholinesterase (AChE) and choline acetylase (ChAT) were determined using commercial kits. Furthermore, the expression of proteins involved in mitogen­activated protein kinase (MAPK) cascades [extracellular signal­regulated kinase (ERK), c­Jun N­terminal kinase (JNK) and p38], brain­derived neurotrophic factor (BDNF) and apoptosis­associated proteins [caspase­3, B-cell lymphoma 2 (Bcl­2) and Bcl-2-associated X protein (Bax)] were detected by western blot analysis. Caspase­3 activity was also analyzed using a commercial kit. The results demonstrated that diabetic rats exhibited decreases in body weight, decreases in the percentage of time spent in the target quadrant and the number of times of crossing the platform in the water maze test, as well as decreases in neuronal survival, ChAT, phosphorylated (p)ERK, BDNF and Bcl­2. Furthermore, diabetic rats showed increases in escape latency and mean path length in the water maze test, increases in the levels of hippocampal AChE, p­JNK, p­p38, caspase­3 and Bax as well as plasma glucose. However, in diabetic rats treated with baicalin, all of the abovementioned observations were obviously reversed. The findings suggested that baicalin exerts neuroprotective effects against DACD via modulation of MAPK cascades, BDNF and apoptosis.

The lactase gene -13910T allele can not predict the lactase-persistence phenotype in north China.

The frequency of lactase persistence varies widely in human populations. Study showed that the T allele of a C/T transition 13910bp upstream from exon 1 of lactase gene (LCT) was completely associated with lactase persistence in a Finnish population. To evaluate if the frequency of -13910T allele was in concordance with the lactase persistence in northern Chinese populations, in this study, we used Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) to detect the lactase -13910T allelic frequency in 5 northern Chinese populations for the first time. Results showed that the T allele frequency was low in these populations and that it did not match the lactase persistence phenotype in these populations. Therefore the -13910T allelic frequency can not serve as a predictor of the lactase persistence in these populations and this suggests the existence of other possible mechanisms of lactose tolerance in Chinese populations.