Enhancement of the neuroprotective activity of Hericium erinaceus mycelium co-cultivated with Allium sativum extract

Abstract This study investigated the neuroprotective effects of Hericium erinaceus mycelium enriched with garlic extract (HGE) on rat pheochromocytoma nerve cells (PC12). The survival rates of the PC12 nerve cells and the neurite-bearing cells after the addition of HGE were estimated as 3.5 × 103 viable cells/ml and 2.3 × 103 viable cells/ml, respectively, which were 50% and 30% higher, respectively, compared with the untreated group. For the in vivo ischemia experiments, after treatment with the HGE extract, the hippocampal CA1 region was more strongly stained (>20%) than the control group, and the HGE extract also promoted higher staining levels than HFB, HM and HGEF, and even the garlic extract. This result indicates that HGE must have neuroprotective effects. Furthermore, HGE greatly decreased p21 gene expression to approximately 70% of the control and decreased p21 gene expression to even lower levels compared with HM, HGEF and the garlic extract. This work suggests that a synergistic effect of the H. erinaceus mycelium and the garlic extract (mainly allicin) exist because the amount of allicin in HGE (5.81 µg/ml) was lower than the garlic extract itself (6.89 µg/ml).