Fig. 2

Figure 2 shows the role of dipeptidyl peptidase-4 (DPP-4) inhibitors, which inhibit the DPP-4 enzymes, which down-regulate the incretin. DPP-4 inhibitors are showing neuroprotective potential in synergistic combination with Vitamin D in COVID-19 patients suffering from neurological disorders. Incretins are a group of metabolic hormones that stimulate insulin and inhibit glucagon, which finally decreases the blood glucose level and pressure and ultimately reduces the chance of cerebral hemorrhagic stroke in COVID-19 patients