Newly Synthesized Creatine Derivatives as Potential Neuroprotective and Antioxidant Agents on In Vitro Models of Parkinson's Disease

Astaxanthin Inhibits H2O2-Induced Excessive Mitophagy and Apoptosis in SH-SY5Y Cells by Regulation of Akt/mTOR Activation

Oxidative stress, which damages cellular components and causes mitochondrial dysfunction, occurs in a variety of human diseases, including neurological disorders. The clearance of damaged mitochondria via mitophagy maintains the normal function of mitochondria and facilitates cell survival. Astaxanthin is an antioxidant known to have neuroprotective effects, but the underlying mechanisms remain unclear. This study demonstrated that astaxanthin inhibited H2O2-induced apoptosis in SH-SY5Y cells by ameliorating mitochondrial damage and enhancing cell survival. H2O2 treatment significantly reduced the levels of activated Akt and mTOR and induced mitophagy, while pretreatment with astaxanthin prevented H2O2-induced inhibition of Akt and mTOR and attenuated H2O2-induced mitophagy. Moreover, the inhibition of Akt attenuated the protective effect of astaxanthin against H2O2-induced cytotoxicity. Taken together, astaxanthin might inhibit H2O2-induced apoptosis by protecting mitochondrial function and reducing mitophagy. The results also indicate that the Akt/mTOR signaling pathway was critical for the protection of astaxanthin against H2O2-induced cytotoxicity. The results from the present study suggest that astaxanthin can reduce neuronal oxidative injury and may have the potential to be used for preventing neurotoxicity associated with neurodegenerative diseases.

The potential role of creatine supplementation in neurodegenerative diseases

PURPOSE

The maintenance of energy balance in the body, especially in energy-demanding tissues like the muscles and the central nervous system, depends on creatine (Cr). In addition to improving muscle function, Cr is necessary for the bioenergetics of the central nervous system because it replenishes adenosine triphosphate without needing oxygen. Furthermore, Cr possesses anti-oxidant, anti-apoptotic, and anti-excitotoxic properties. Clinical research on neurodegenerative illnesses has shown that Cr supplementation results in less effective outcomes. With a brief update on the possible role of Cr in human, animal, and in vitro experiments, this review seeks to offer insights into the ideal dosage regimen.

METHODS

Using specified search phrases, such as "creatine and neurological disorder," "creatine supplementation and neurodegenerative disorders," and "creatine and brain," we searched articles in the PubMed database and Google Scholar. We investigated the association between creatine supplementation and neurodegenerative illnesses by examining references.

RESULTS

The neuroprotective effects of Cr were observed in in vitro and animal models of certain neurodegenerative diseases, while clinical trials failed to reproduce favorable outcomes.

CONCLUSION

Determining the optimal creatinine regime for increasing brain creatinine levels is essential for maintaining brain health and treating neurodegeneration.

Creatine Activity as a Neuromodulator in the Central Nervous System

Creatine is a nutritional compound that potentially influences cognitive processing and neuroprotection. Recent evidence has demonstrated that similar to neurotransmitters, creatine is released in an excitotoxic and action potential-dependent manner and acts as a neuromodulator. Creatine deficiency syndromes are characterized by severe mental and developmental disorders. Studies have reported that brain creatine content could be enhanced with creatine supplementation. Nevertheless, there is still limited knowledge about the effects of creatine on the central nervous system. However, ample evidence has proved the neuroprotective effects of creatine on various mental aspects, such as cognition, memory skills, and spatial memory. The present review aimed to review available experimental data and clinical observations confirming creatine roles in the central transmission process. A systematic search in the literature was performed in PubMed, Scopus, Embase, Cochrane Library, Web of Science, and Google Scholar database using all available MeSH terms for Creatine, Phosphocreatine, Bioenergetics, Nervous system, Brain, Cognition, and Neuroprotection. Electronic database searches were combined and duplicates were removed. Here, first, creatine and its potential influence on cognitive health and performance were briefly reviewed. Next, the existing experimental and clinical evidence was specifically explored to understand how creatine could interact as a neurotransmitter in the nervous system. Studies have revealed that exogenous creatine supplementation decreases neuronal cell loss in experimental paradigms of neurological diseases. It was observed that creatine could interact with the N-methyl-D-aspartate receptor, Na+-K+-ATPase enzyme, GABAA receptor, serotonin 1A receptors, and presumably α1-adrenoceptor and play critical roles in the central transmission process which implies that creatine can be considered a neuromodulator.