The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) in December 2019 form Wuhan, China leads to coronavirus disease 2019 (COVID-19) pandemic. While the common cold symptoms are observed in mild cases, COVID-19 is accompanied by multiorgan failure in severe patients. The involvement of different organs in severe patients results in lengthening the hospitalization duration and increasing the mortality rate. In this review, we aimed to investigate the involvement of different organs in COVID-19 patients, particularly in severe cases. Also, we tried to define the potential underlying mechanisms of SARS-CoV2 induced multiorgan failure. The multi-organ dysfunction is characterized by acute lung failure, acute liver failure, acute kidney injury, cardiovascular disease, and as well as a wide spectrum of hematological abnormalities and neurological disorders. The most important mechanisms are related to the direct and indirect pathogenic features of SARS-CoV2. Although the presence of angiotensin-converting enzyme 2, a receptor of SARS-CoV2 in the lung, heart, kidney, testis, liver, lymphocytes, and nervous system was confirmed, there are controversial findings to about the observation of SARS-CoV2 RNA in these organs. Moreover, the organ failure may be induced by the cytokine storm, a result of increased levels of inflammatory mediators, endothelial dysfunction, coagulation abnormalities, and infiltration of inflammatory cells into the organs. Therefore, further investigations are needed to detect the exact mechanisms of pathogenesis. Since the involvement of several organs in COVID-19 patients is important for clinicians, increasing their knowledge may help to improve the outcomes and decrease the rate of mortality and morbidity.

Background: Brain ischemia initiates several metabolic events leading to neuronal death. These events mediate large amount of damage that arises after some neurodegenerative disorders as well as transient brain ischemia. Melissa officinalis is considered as a helpful herbal plant in the prevention of various neurological diseases like Alzheimer that is related with oxidative stress. Methods: We examined the effect of Melissa officinalis on hypoxia induced neuronal death in a cortical neuronal culture system as in vitro model and transient hippocampal ischemia as in vivo model. Transient hippocampal ischemia was induced in male rats by tow vessel-occlusion for 20 min. After reperfusion, the histopathological changes and the levels inflammation, oxidative stress status, and caspase-3 activity in hippocampus were measured. Results: Cytotoxicity assays showed a significant protection of a 10 μg/ml dose of Melissa against hypoxia in cultured neurons which was confirmed by a conventional staining (P<0.05). Melissa treatment decrease caspase3 activity (P<0.05) and TUNEL-positive cells significantly (P<0.01). Melissa oil has also inhibited malon dialdehyde level and attenuated decrease of Antioxidant Capacity in the hippocampus. Pro-inflammatory cytokines TNF-α, IL-1β and HIF-1α mRNA levels were highly increased after ischemia and treatment with Melissa significantly suppressed HIF-1α gene expression (P<0.05). Discussion: Results showed that Melissa officinalis could be considered as a protective agent in various neurological diseases associated with ischemic brain injury.

Background: The beneficial effects of curcumin which includes its antioxidant, anti-inflammatory and cancer chemo-preventive properties have been identified. Little information is available regarding the optimal dose and treatment periods of curcumin on the proliferation rate of different sources of stem cells. Methods: In this study, the effect of various concentrations of curcumin on the survival and proliferation of two types of outstanding stem cells which includes bone marrow stem cells (BMSCs) and adult rat neural stem/progenitor cells (NS/PCs) at different time points was investigated. BMSCs were isolated from bilateral femora and tibias of adult Wistar rats. NS/PCs were obtained from subventricular zone of adult Wistar rat brain. The curcumin (0.1, 0.5, 1, 5 and 10 μM/L) was added into a culture medium for 48 or 72 h. Fluorescent density of 5-bromo-2′-deoxyuridine (Brdu)-positive cells was considered as proliferation index. In addition, cell viability was assessed by MTT assay. Results: Treatment of BMSCs with curcumin after 48 h, increased cell survival and proliferation in a dose-dependent manner. However, it had no effect on NSCs proliferation except a toxic effect in the concentration of 10 μM of curcumin. After a 72 h treatment period, BMSCs and NS/PCs survived and proliferated with low doses of curcumin. However, high doses of curcumin administered for 72 h showed toxic effects on both stem cells. Conclusions: These findings suggest that curcumin survival and proliferative effects depend on its concentration, treatment period and the type of stem cells. Appropriate application of these results may be helpful in the outcome of combination therapy of stem cells and curcumin.