Jeong Hwa Hong

Inhibitory Effects of Water Extract from Rice Bran Due to cAMP-dependent Phosphorylation of VASP (Ser 157 ) on ADP-induced Platelet Aggregation

In this study, we investigated the effect of water extract from rice bran (RB) on ADP (20 μM)-stimulated platelet aggregation. RB dose-dependently inhibited ADP-induced platelet aggregation, and its IC50 value was 224.0 μg/mL, which was increased by adenylate cyclase inhibitor SQ22536 and cAMP-dependent protein kinase (A-kinase) inhibitor Rp-8-Br-cAMPS. RB elevated the phosphorylation of VASP (Ser 157 ) which was also inhibited by SQ22536 and Rp-8-Br-cAMPS. It is thought that RB-elevated cAMP contributed to the phosphorylation of VASP (Ser 157 ) to inhibit ADP-induced platelet aggregation. Therefore, we demonstrate that RB has an antiplatelet effect via cAMP-dependent phosphorylation of VASP (Ser 157 ), and RB may have preventive or therapeutic potential for platelet aggregation-mediated diseases, such as thrombosis, myocardial infarction, atherosclerosis, and ischemic cerebrovascular disease.

Inhibitory Effects of Rice Bran Water Extract Fermented Lactobacillus plantarum due to cAMP-dependent Phosphorylation of VASP (Ser 157 ) on human Platelet Aggregation

In this study, we investigated the effect of rice bran water extract fermented with Lactobacillus plantarum KCCM-12116 (RBLp) on ADP (20 μM)-, collagen (10 μg/mL)-, and thrombin (0.2 U/mL)-stimulated platelet aggregation. RBLp dose-dependently inhibited ADP-, collagen-, and thrombin-induced platelet aggregation, with IC50 values of 501.1, 637.2, and > 2,000 μg/mL, respectively. The platelet aggregation induced by ADP plus RBLp (750 μg/mL) was increased by the adenylate cyclase inhibitor, SQ22536, and the cAMP-dependent protein kinase (A-kinase) inhibitor, Rp-8-Br-cAMPS. Treatment with RBLp increased the phosphorylation of VASP (Ser 157 ), an A-kinase substrate, which was also inhibited by SQ22536 and Rp-8-Br-cAMPS. It is thought that the RBLp-induced increases in cAMP contributed to the phosphorylation of VASP (Ser 157 ), which in turn resulted in an inhibition of ADP-induced platelet aggregation, thereby indicating that RBLp has an antiplatelet effect via cAMP-dependent phosphorylation of VASP (Ser 157 ). Thus, RBLp may have therapeutic potential for the treatment (or prevention) of platelet aggregation-mediated diseases, such as thrombosis, myocardial infarction, atherosclerosis, and ischemic cerebrovascular disease.

Neuroprotective effect of rice bran extract supplemented with ferulic acid in the rat model of ischemic brain injury

Cerebral ischemia is clinically characterized by a partial functional neurological deficit, which represents one of the leading causes of death. This study aimed to determine whether rice bran extract (RB), ferulic acid (FA), or rice bran extract supplemented with FA (RB + FA) promote functional recovery from ischemic injury. Focal cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) in rats. Four groups were studied, including (1) vehicle group, (2) RB 5%, 10%, and 20% groups, (3) FA group, and (4) RB + FA group. Animals were injected with RB or FA once a day for 3 days after MCAO. In this studys results, the RB 20% and FA groups significantly improved neurological functions compared with the vehicle group. The RB + FA group produced more recovery from functional deficits than the other groups. Moreover, the RB 20%, FA, and RB + FA groups enhanced the antiapoptotic effect in the cortex and neural cell densities in the hippocampal DG and CA1. The RB 20%, FA, and RB + FA groups stimulated not only the expression of neurotrophic factor and antioxidant genes but also neuronal nuclei (NeuN), synaptophysin, and glutamic acid decarboxylase 67 (GAD67) proteins. Our finding indicates that the combination of RB + FA treatment showed the most synergic effect in functional recovery with ischemic brain through the stimulation of the nuclear factor-E2-related factor 2, brain-derived neurotrophic factor NeuN, SYP, and GAD67 expressions.

Effects of Rice Bran Extracts Fermented with Lactobacillus plantarum on Neuroprotection and Cognitive Improvement in a Rat Model of Ischemic Brain Injury

This work aimed to study whether rice bran extract fermented with Lactobacillus plantarum (LW) promotes functional recovery and reduces cognitive impairment after ischemic brain injury. Ischemic brain injury was induced by middle cerebral artery occlusion (MCAO) in rats. Four groups were studied, namely the (1) sham, (2) vehicle, (3) donepezil, and (4) LW groups. Animals were injected with LW once a day for 7 days after middle cerebral artery occlusion. LW group showed significantly improved neurological function as compared to the vehicle group, as well as enhanced learning and memory in the Morris water maze. The LW group showed the greatest functional recovery. Moreover, the LW group showed an enhanced more survival cells anti-apoptotic effect in the cortex and neural cell densities in the hippocampal DG and CA1. In addition, this group showed enhanced expression of neurotrophic factors, antioxidant genes, and the acetylcholine receptor gene, as well as synaptophysin (SYP), Fox-3 (NeuN), doublecortin (DCX), and choline acetyltransferase (ChAT) proteins. Our findings indicate that LW treatment showed the largest effects in functional recovery and cognitive improvement after ischemic brain injury through stimulation of the acetylcholine receptor, antioxidant genes, neurotrophic factors, and expression of NeuN, SYP, DCX, and ChAT.