Protective Effect of Curcumin on Bone Trauma in a Rat Model via Expansion of Myeloid Derived Suppressor Cells

Targeting mTOR with curcumin: therapeutic implications for complex diseases

The mammalian target of rapamycin (mTOR) is a crucial enzyme in regulating multiple signaling pathways in the body, including autophagy, proliferation and apoptosis. Disruption of these mTOR signaling pathways can lead to an array of abnormalities and trigger disease processes, examples being neurodegenerative conditions, cancer, obesity and diabetes. Under conditions of oxidative stress, mTOR can regulate apoptosis and autophagy, with tissue repair being favored under such circumstances. Moreover, the correlation between mTOR and other signaling pathways could play a pivotal role in the pathophysiology of numerous disorders. mTOR has a tight connection with NF-κB, Akt, PI3K, MAPK, GSK-3β, Nrf2/HO-1, JAK/STAT, CREB/BDNF, and ERK1/2 pathways, which together could play significant roles in the regulation of inflammation, apoptosis, cell survival, and oxidative stress in different body organs. Research suggests that inhibiting mTOR could be beneficial in treating metabolic, neurological and cardiovascular conditions, as well as potentially extending life expectancy. Therefore, identifying new chemicals and agents that can modulate the mTOR signaling pathway holds promise for treating and preventing these disorders. Curcumin is one such agent that has demonstrated regulatory effects on the mTOR pathway, making it an exciting alternative for reducing complications associated with complex diseases by targeting mTOR. This review aims to examine the potential of curcumin in modulating the mTOR signaling pathway and its therapeutic implications.

Myeloid-derived suppressor cells and pulmonary hypertension

Pulmonary hypertension (PH) is a chronic pulmonary vascular disorder characterized by an increase in pulmonary vascular resistance and pulmonary arterial pressure. The detailed molecular mechanisms remain unclear. In recent decades, increasing evidence shows that altered immune microenvironment, comprised of immune cells, mesenchymal cells, extra-cellular matrix and signaling molecules, might induce the development of PH. Myeloid-derived suppressor cells (MDSCs) have been proposed over 30 years, and the functional importance of MDSCs in the immune system is appreciated recently. MDSCs are a heterogeneous group of cells that expand during cancer, chronic inflammation and infection, which have a remarkable ability to suppress T-cell responses and may exacerbate the development of diseases. Thus, targeting MDSCs has become a novel strategy to overcome immune evasion, especially in tumor immunotherapy. Nowadays, severe PH is accepted as a cancer-like disease, and MDSCs are closely related to the development and prognosis of PH. Here, we review the relationship between MDSCs and PH with respect to immune cells, cytokines, chemokines and metabolism, hoping that the key therapeutic targets of MDSCs can be identified in the treatment of PH, especially in severe PH.

Bioperformance Studies of Biphasic Calcium Phosphate Scaffolds Extracted from Fish Bones Impregnated with Free Curcumin and Complexed with β-Cyclodextrin in Bone Regeneration

Fish bones are a natural calcium phosphate (CaP) sources used in biomaterials production for bone regeneration. CaP scaffolds can be enriched with other substances with biological activity to improve bone repair. This study aimed to evaluate the physicochemical properties and bone regeneration potential of biphasic calcium phosphate (BCP) scaffolds impregnated with free curcumin (BCP-CL) or complexed with β-cyclodextrin (BCP-CD) compared to BCP scaffolds. Rietveld’s refinement showed that BCP is composed of 57.2% of HAp and 42.8% of β-TCP and the molar ratio of Ca/P corresponds to 1.59. The scaffolds presented porosity (macro and microporosity) of 57.21%. Apatite formation occurred on the BCP, BCP-CL, and BCP-CD surface, in vitro, in SBF. Micro-Raman technique showed a reduction in the dissolution rate of β-TCP in the curcumin-impregnated scaffolds over time, and in vivo studies on critical-size defects, in rat calvaria, had no additional regenerative effect of BCP-CL and BCP-CD scaffolds, compared to BCP scaffolds. Despite this, the study showed that curcumin impregnation in BCP scaffolds prolongs the release of the β-TCP phase, the BCP- phase with the higher osteoinductive potential, representing an advantage in tissue engineering.