High molecular weight of polysaccharides from Hericium erinaceus against amyloid beta-induced neurotoxicity.
BACKGROUND
Hericium erinaceus (HE) is a well-known mushroom in traditional Chinese food and medicine. HE extracts from the fruiting body and mycelia not only exhibit immunomodulatory, antimutagenic and antitumor activity but also have neuroprotective properties. Here, we purified HE polysaccharides (HEPS), composed of two high molecular weight polysaccharides (1.7 × 10(5) Da and 1.1 × 10(5) Da), and evaluated their protective effects on amyloid beta (Aβ)-induced neurotoxicity in rat pheochromocytoma PC12 cells.


METHODS
HEPS were prepared and purified using a 95 % ethanol extraction method. The components of HEPS were analyzed and the molecular weights of the polysaccharides were determined using high-pressure liquid chromatography (HPLC). The neuroprotective effects of the polysaccharides were evaluated through a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and an MTT assay and by quantifying reactive oxygen species (ROS) and mitochondrial membrane potentials (MMP) of Aβ-induced neurotoxicity in cells.


RESULTS
Our results showed that 250 μg/ml HEPS was harmless and promoted cell viability with 1.2 μM Aβ treatment. We observed that the free radical scavenging rate exceeded 90 % when the concentration of HEPS was higher than 1 mg/mL in cells. The HEPS decreased the production of ROS from 80 to 58 % in a dose-dependent manner. Cell pretreatment with 250 μg/mL HEPS significantly reduced Aβ-induced high MMPs from 74 to 51 % and 94 to 62 % at 24 and 48 h, respectively. Finally, 250 μg/mL of HEPS prevented Aβ-induced cell shrinkage and nuclear degradation of PC12 cells.


CONCLUSIONS
Our results demonstrate that HEPS exhibit antioxidant and neuroprotective effects on Aβ-induced neurotoxicity in neurons.
Department of Medical Research, Center for Shockwave Medicine and Tissue Engineering, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
Jai-Hong
JH
Cheng
Department of Food Science, National Pingtung University of Science and Technology, No. 1, Shuehfu Rd, Neipu, Pingtung, Taiwan.
Chia-Ling
CL
Tsai
Department of Veterinary Medicine, National Pingtung University of Science and Technology, No. 1, Shuehfu Rd, Neipu, Pingtung, Taiwan.
Yi-Yang
YY
Lien
Department of Chinese Pharmaceutical Sciences and Chinese Medicine Resources, China Medical University, Taichung, Taiwan. leemengshiou@mail.cmu.edu.tw.
Meng-Shiou
MS
Lee
Department of Food Science, National Pingtung University of Science and Technology, No. 1, Shuehfu Rd, Neipu, Pingtung, Taiwan. ssheu@mail.npust.edu.tw.
Shyang-Chwen
SC
Sheu
D016229:Amyloid beta-Peptides / Q000633:toxicity; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001487:Basidiomycota / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000494:pharmacology; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008970:Molecular Weight; D009474:Neurons / Q000187:drug effects; D018696:Neuroprotective Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D016716:PC12 Cells; D011134:Polysaccharides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D051381:Rats
D016229:Amyloid beta-Peptides; D016166:Free Radical Scavengers; D018696:Neuroprotective Agents; D011134:Polysaccharides
Amyloid beta; Hericium erinaceus; Neuroprotection; PC12 cell; Polysaccharides