ABSTRACT
Oligodendrocytes, the myelinating glial cells of central nervous system, are highly vulnerable to ischemic-induced excitotoxic insult, a phenomenon in which calcium overload triggers cell death. Berberine is an alkaloid extracted from medicinal herbs as Coptidis Rhizoma with several pharmacological effects like inhibition of neuronal apoptosis in cerebral ischemia. We examined the effects of berberine [0.5-4 microM] and glutamate receptors antagonists [MK-801 [10 microM] and NBQX [30 microM] on OLN-93 cell line [a permanent immature rat Oligodendrocyte] during [30, 60, 240 min] oxygen-glucose deprivation [OGD]/24 h reperfusion. The cells were cultured in 12-well plates. The cells were exposed to glucose-free medium and hypoxia in a small anaerobic chamber. Cell viability was evaluated by MTT [3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide] assay. The intracellular calcium levels also were evaluated by Ca[2+]-sensitive indicator Fura-2/AM in presence or absence of berberine [2 microM] during 30 min chemical OGD by NaN3 [20 mM]. Student's t-test and AN OVA were used for statistical analysis. Berberine, MK-801 and NBQX significantly increased Oligodendrocyte viability in all 3 time-scheduled oxygen-glucose deprivation/reperfusion. Berberine at 2 microM produced peak of protection, and increased cell viability to 83%, 77%, and 79% during 30, 60, 240 min ischemic experiments, respectively [P < 0.001]. Berberine significantly attenuated intracellular Ca[2+] rise induced by chemical ischemia, and this effect of berberine was significantly stronger than MK-801 and NBQX [P < 0.001]. We concluded that berberine protected OLN-93 Oligodendrocyte against ischemic induced excitotoxic injury. Attenuation of intracellular Ca[2+] overload by berberine may be the key mechanism that saved OLN-93 from excitotoxicity damage
ABSTRACT
Molecular imprinting is a method for synthesizing polymers with structure-selective adsorption properties with applications such as, selectivity binding, drug delivery systems and anti-bodies. The present study aims at optimizing the preparation of molecularly imprinted polymer [MIP] against 1-phenylalanine, in order to increase phenylalanine-binding in Enzymatic Intestinal Simulated Fluid [ESIF]. The MIP for 1-phenylalanine, as a water-soluble template, was successfully synthesized without derivatization. Synthesization was done by a UV polymerization method in which methacrylic acid [MAA], as a functional monomer, and ethylene glycol dimethacrylate [EGDMA], as a cross-linker, were used in the presence of five different porogenic solvents including; acetonitrile, tetrahydrofuran [THF], chloroform, toluene and dimethyl sulfoxide [DMSO]. The selectivity of the MIP was examined using 19 different amino acids in human serum and was evaluated by HPLC. In addition, morphological studies were conducted using SEM. The results showed that the obtained MIP with acetonitrile had the highest capacity and selectivity compared with other solvents. The data indicated that Phe-binding to MYS was significantly more than the former binding to NIP in EIS1 [p<0.05]. Moreover, in comparison wthNIP and control grouf MIP showed abetter selectivity and binding for Phe. This could be used for the reduction of Phe in human serum samples of Phenylketonuria. Our findings suggest that the MIP against PI prepared with acetonitrile, showed a good selectivity ai binding, which caused a reduction of blood Phe concentrati in enzymatic simulated intestinal fluid and human serum sam] of Phenylketonuria