Neuroprotective Effects of Polysaccharides and Gallic Acid from Amauroderma rugosum against 6-OHDA-Induced Toxicity in SH-SY5Y Cells

The pharmacological activity and medicinal significance of Amauroderma rugosum (AR) have rarely been documented. We examined the antioxidant and neuroprotective effects of AR on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in an SH-SY5Y human neuroblastoma cell model of Parkinson's disease (PD) and explored the active ingredients responsible for these effects. The results showed that the AR aqueous extract could scavenge reactive oxygen species and reduce SH-SY5Y cell death induced by 6-OHDA. In addition, the AR aqueous extract increased the survival of Caenorhabditis elegans upon juglone-induced toxicity. Among the constituents of AR, only polysaccharides and gallic acid exhibited antioxidant and neuroprotective effects. The AR aqueous extract reduced apoptosis and increased the expression of phospho-Akt, phospho-mTOR, phospho-MEK, phospho-ERK, and superoxide dismutase-1 in 6-OHDA-treated SH-SY5Y cells. The polysaccharide-rich AR extract was slightly more potent than the aqueous AR extract; however, it did not affect the expression of phospho-Akt or phospho-mTOR. In conclusion, the AR aqueous extract possessed antioxidant and neuroprotective properties against 6-OHDA-induced toxicity in SH-SY5Y cells. The mechanism of action involves the upregulation of the Akt/mTOR and MEK/ERK-dependent pathways. These findings indicate the potential utility of AR and its active ingredients in preventing or treating neurodegenerative disorders associated with oxidative stress such as PD.

Protective Effects of Amauroderma rugosum on Doxorubicin-Induced Cardiotoxicity through Suppressing Oxidative Stress, Mitochondrial Dysfunction, Apoptosis, and Activating Akt/mTOR and Nrf2/HO-1 Signaling Pathways

Clinical outcomes for doxorubicin (Dox) are limited by its cardiotoxicity but a combination of Dox and agents with cardioprotective activities is an effective strategy to improve its therapeutic outcome. Natural products provide abundant resources to search for novel cardioprotective agents. Ganoderma lucidum (GL) is the most well-known edible mushroom within the Ganodermataceae family. It is commonly used in traditional Chinese medicine or as a healthcare product. Amauroderma rugosum (AR) is another genus of mushroom from the Ganodermataceae family, but its pharmacological activity and medicinal value have rarely been reported. In the present study, the cardioprotective effects of the AR water extract against Dox-induced cardiotoxicity were studied in vitro and in vivo. Results showed that both the AR and GL extracts could potentiate the anticancer effect of Dox. The AR extract significantly decreased the oxidative stress, mitochondrial dysfunction, and apoptosis seen in Dox-treated H9c2 rat cardiomyocytes. However, knockdown of Nrf2 by siRNA abolished the protective effects of AR in these cells. In addition, Dox upregulated the expression of proapoptotic proteins and downregulated the Akt/mTOR and Nrf2/HO-1 signaling pathways, and these effects could be reversed by the AR extract. Consistently, the AR extract significantly prolonged survival time, reversed weight loss, and reduced cardiac dysfunction in Dox-treated mice. In addition, oxidative stress and apoptosis were suppressed, while Nrf2 and HO-1 expressions were elevated in the heart tissues of Dox-treated mice after treatment with the AR extract. However, the GL extract had less cardioprotective effect against Dox in both the cell and animal models. In conclusion, the AR water extract demonstrated a remarkable cardioprotective effect against Dox-induced cardiotoxicity. One of the possible mechanisms for this effect was the upregulation of the mTOR/Akt and Nrf2/HO-1-dependent pathways, which may reduce oxidative stress, mitochondrial dysfunction, and cardiomyocyte apoptosis. These findings suggested that AR may be beneficial for the heart, especially in patients receiving Dox-based chemotherapy.

A review of the phytochemical and pharmacological properties of Amauroderma rugosum

Amauroderma rugosum (AR) is a basidiomycete in the Ganodermataceae family that has been used traditionally to prevent epileptic attacks and constant crying in babies. However, AR has not been widely studied scientifically. In this review, we summarize the phytochemical components and pharmacological properties of AR that have been reported in the literature. Chemical analyses have revealed that the components of AR include sterols, flavonoids, fatty acids and esters, aromatic acids and esters, phenols, polysaccharides, and triterpenes. Pharmacological properties of AR include antioxidant, anti-inflammatory, neuroprotective, anti-cancer, anti-hyperlipidemic, anti-epileptic, and antibacterial effects. These findings suggest that AR and its bioactive ingredients have potential therapeutic applications, particularly for age-related diseases.