Effect of Berberine Isolated from Barberry Species by Centrifugal Partition Chromatography on Memory and the Expression of Parvalbumin in the Mouse Hippocampus Proper.

Neurodegenerative diseases associated with memory disturbances are important health issues occurring due to a prolonged life span. This article presents the results of a study targeting the emergence of a drug candidate with antiamnesic properties. The effect of berberine (BBR), an isoquinoline alkaloid isolated from the overground parts of Berberis sibirica Pall., on memory and expression of parvalbumin in the mouse hippocampus proper were determined. High-purity BBR was isolated by centrifugal partition chromatography from a methanolic extract from B. sibirica by using a methyl-tert-butyl ether and water (1:1 v/v) solvent system with 10 mmol/L of triethylamine and hydrochloric acid. In an in vivo study, we assessed the influence of the chronic administration of BBR on different stages of memory-related responses in mice. Our results indicated that the chronic administration of BBR in a higher dose (5 mg/kg) improves long-term memory acquisition in mice, as determined in the passive avoidance test. The hippocampal CA1-CA3 fields showed an increased number of parvalbumin-immunoreactive neurons (PV-IR) and nerve fibers as compared to the control. No significant changes in the dentate gyrus were observed between the groups. The HPLC-ESI-QTOF-MS/MS analysis of the biological material revealed the content of BBR as 363.4 ± 15.0 ng (4.11% of RSD) per brain, 15.06 ± 0.89 ng (5.91% of RSD) per hippocampus, and 54.45 ± 1.40 (4.05% of RSD) ng in 100 µL plasma. The study showed that BBR could be a factor influencing the expression of PV in hippocampal neurons. We speculate that BBR may modulate the level of Ca2+ in neurons and thus potentially act as a neuroprotective factor against neuronal damages.

Effects of alcohol on the levels of parvalbumin in rat hearts.

Chronic excessive alcohol administration has been reported to be associated with diastolic dysfunction. Parvalbumin (PV) is a calcium-binding protein present in cardiac myocytes and involved in mediating relaxation. Therefore, alteration of PV levels may affect relaxation in cardiac myocytes. This study investigated the effects of alcohol administration on the levels of PV in the rat heart. Male Wistar rats weighing 200-250 g were divided into 2 groups: control (C) and alcohol-treated groups. The control group was provided with distilled water and the alcohol groups were provided with either a low dose (LD, 2g/kg) or high dose of ethanol (HD, 5 g/kg) once daily for 21 days, 3 months or 6 months. The PV levels in the ventricles were investigated by immunohistochemistry and Western blot analysis. In the 21-day ethanol-treated groups, parvalbumin immunoreactivity (PV-ir) and protein levels were not different when compared to the C, LD and HD groups. In the 3-month ethanol-treated groups, PV-ir and PV protein levels were decreased in both the LD and HD groups compared to that of the control group. In the 6-month ethanol-treated groups, PV-ir and PV protein levels decreased significantly in both the LD and HD groups (P<0.05). This indicates that short-term ethanol treatment may not affect PV levels, whereas, long-term ethanol treatment clearly reduced PV levels. The decrease of PV was predominantly due to the direct toxic effects of alcohol rather than malabsorption caused by pathological changes in the duodenum and liver. The toxic effects of alcohol leading to a reduction of PV levels may lead to diastolic impairment.