Research progress on mechanism of gastrodin and p-hydroxybenzyl alcohol on central nervous system / 中国中药杂志

Gastrodin(GAS) and p-hydroxybenzyl alcohol(HBA) are extracts of dried tubers of Gastrodia elata, which is the material basis for its efficacy and belongs to phenolic compounds. Modern pharmacology studies have shown that they have significant effects on central nervous system diseases, such as insomnia, convulsions, depression, ischemic stroke, anxiety, and cognitive impairment, and these diseases are closely related to neurotransmitters and cytokines. This paper described various mechanisms of GAS and HBA monomer components on the central nervous system. They alleviate hippocampal neuronal toxicity mainly by regulating a variety of neurotransmitters, such as acetylcholine, glutamic acid(GLU), γ-aminobutyric acid(GABA), serotonin(5-HT), dopamine(DA), norepinephrine(NE), 5-indoleacetic acid(5-HIAA), high vanillic acid(HVA) and dihydroxyphenylacetic acid(DOPAC), pro-inflammatory cell growth factors, such as IL-1β, IL-6 and TNF-α and relevant receptor functions, and exert neuropharmacological effects by effectively increasing mRNA expressions of brain neurotrophic factors, such as BDNF and GDNF, and further inhibiting the apoptosis of damaged neurons. This paper summarized various mechanisms on the central nervous system, which provides a scientific basis for the further research of the neuropharmacological mechanism of GAS and HBA and the development of new drugs and functional food.

Gastrodin induced HO-1 and Nrf2 up-regulation to alleviate H2O2-induced oxidative stress in mouse liver sinusoidal endothelial cells through p38 MAPK phosphorylation

Nuclear factor erythroid-related factor 2 (Nrf2) has been implicated in several detoxifying and antioxidant defense processes. Nrf2-mediated heme oxygenase-1 (HO-1) expression was demonstrated to play a key role against oxidative stress. Gastrodin (GSTD) is a well-known active compound isolated from the roots of Rhizoma gastrodiae, a plant used in ancient Chinese traditional medicine. The aim of this work was to investigate whether GSTD could alleviate H2O2-induced oxidative stress in mouse liver sinusoidal endothelial cells (LSECs). In LSECs exposed to 1 mM H2O2, treatment with GSTD (1, 10, or 50 µM) resulted in higher cell viability than the untreated control. Treated cells maintained a higher Bcl2/Bax ratio and suppressed caspase-9 expression compared with untreated cells, reducing cell apoptosis. GSTD was protective for H2O2-induced oxidative injury by reducing the generation of intracellular reactive oxygen species and malondialdehyde. HO-1 and Nrf2 expressions were synergistically upregulated by GSTD. Inhibition of HO-1 by 10 µM zinc protoporphyrin resulted in less protective effects on cell viability and malondialdehyde reduction by GSTD treatment in H2O2-exposed LSECs. Additionally, phosphorylated p38 in LSECs exposed to H2O2 was elevated by GSTD. Inhibition of p38 phosphorylation by SB203580 did not induce Nrf2 and HO-1 expression after 1 or 10 µM GSTD treatment and the protective effect on cell viability and malondialdehyde reduction in H2O2-exposed LSECs was reduced. The data conclusively demonstrated that GSTD-induced HO-1 and Nrf2 expression is involved in protection of LSECs from H2O2-induced oxidative injury, which may be regulated by p38 phosphorylation.

Gastrodia elata Blume and its pure compounds protect BV-2 microglial-derived cell lines against β-amyloid: The involvement of GRP78 and CHOP

Objectives: Gastrodia elata (GE) Blume (Orchidaceae) has been previously known for its therapeutic benefits against neurodegenerative diseases. Microglial activation and death have been implicated in the pathogenesis of a variety of neurodegenerative diseases, including Alzheimer's disease. In this study, GE and its pure components, gastrodin and 4-hydroxybenzyl alcohol (4HBA), were applied to β-amyloid-induced BV2 mouse microglial cells. Materials and Methods Cell viability was assessed by the MTT assay and Western blotting was also performed. Results: β-amyloid-induced cell death was shown to be induced time- and dose-dependently. To examine the cell death mechanism, we confirmed the involvement of ER stress signaling. C/EBP homologous protein (CHOP), a pro-apoptotic ER stress protein, was expressed at high levels but glucose-regulated protein 78 (GRP78), an anti-apoptotic ER stress protein with chaperone activity, was only slightly affected by treatment with β-amyloid. However, pretreatment with GE and its components inhibited the expression of CHOP but increased that of GRP78 in β-amyloid-treated cells. This study also showed that a single treatment with GE extracts, gastrodin, or 4HBA induced the expression of GRP78, a marker for enhanced protein folding machinery, suggesting a protective mechanism for GE against β-amyloid. Conclusions: This study reveals the protective effects of GE against β-amyloid-induced cell death, possibly through the enhancement of protein folding machinery of a representative protein, GRP78, and the regulation of CHOP in BV2 mouse microglial cells.