Melastoma dodecandrum lour. Protects against cerebral ischemia-reperfusion injury by ameliorating oxidative stress and endoplasmic reticulum stress.

Ethnopharmacological Relevance: Melastoma dodecandrum Lour. (MD), a traditional Chinese medicine used by the She ethnic group, has been used to treat cerebral ischemia-reperfusion (CIR) injury due to its efficacy in promoting blood circulation and removing blood stasiss; however, the therapeutic effects and mechanisms of MD in treating CIR injury remain unclear.

Aim: To investigate the protective effects of MD on CIR injury, in addition to its impact on oxidative stress, endoplasmic reticulum (ER) stress, and cell apoptosis.

Materials And Methods: The research was conducted using both cell experiments and animal experiments. The CCK-8 method, immunofluorescence staining, and flow cytometry were used to analyze the effects of MD-containing serum on oxygen-glucose deprivation/reperfusion (OGD/R)-induced PC12 cell viability, reactive oxygen species (ROS) clearance, anti-inflammatory, neuroprotection and inhibition of apoptosis. Furthermore, 2,3,5-Triphenyl tetrazolium chloride staining, hematoxylin and eosin staining, Nissl staining, and immunohistochemistry were used to detect infarct size, pathological changes, Nissl corpuscula and neuronal protein expression in middle cerebral artery occlusion (MCAO) rats. Polymerase chain reaction and Western Blotting were conducted in cell and animal experiments to detect the expression levels of ER stress-related genes and proteins.

Results: The MD extract enhanced the viability of PC12 cells under OGD/R modeling, reduced ROS and IL-6 levels, increased MBP levels, and inhibited cell apoptosis. Furthermore, MD improved the infarct area in MCAO rats, increased the number of Nissl bodies, and regulated neuronal protein levels including Microtubule-Associated Protein 2 (MAP-2), Myelin Basic Protein (MBP), Glial Fibrillary Acidic Protein (GFAP), and Neurofilament 200 (NF200). Additionally, MD could regulate the expression levels of oxidative stress proteins malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), and catalase (CAT). Both cell and animal experiments demonstrated that MD could inhibit ER stress-related proteins (GRP78, ATF4, ATF6, CHOP) and reduce cell apoptosis.

Conclusion: This study confirmed that the therapeutic mechanism of the MD extract on CIR injury was via the inhibition of oxidative stress and the ER stress pathway, in addition to the inhibition of apoptosis.