Omeprazole

OME is considered to have gastroprotective, antioxidant, anti-inflammatory, antinecrotic, and antiapoptotic effects. The gastroprotective effects of OME are initiated by proton pump inhibition in gastric parietal cells. OME induced heat shock protein (HSP70) and TGF-β stimulated gastroprotective effect that has been observed in clinical cases at a dose of 5–40 mg/kg. The mechanism is also related to the H2 receptor interaction, pH modulation, and CYP2C19 enzyme inhibition.
OME is considered to have antioxidant properties due to its capacity to attenuate lipid peroxidation, block hydroxyl radicals and upregulate the formation of endogenous antioxidants, including superoxide dismutase and glutathione. OME also has an anti-inflammatory effect as a result of inhibition of proinflammatory cytokines, TNF-α, and interleukin-1β. The anti-inflammatory effects of OME lead to a decrease in gastric lesions and an increase in mucosal integrity.
OME has antiapoptotic and antinecrotic effects by reducing the expression of caspase 3 and the mitochondrial calcium level which results in a reduction in gastric lesions and hemorrhages. OME was considered to improve gastric mucosal barrier function and reduce necrotic areas, helping to maintain cellular respiration and lower oxidative stress.

Fig. 1 Pharmacological effects of omeprazole and suggested mechanisms of action. (Paz M F C J, et al. 2020)

Omeprazole (OMP) is a conventional drug to treat gastric ulcers with low solubility and bioavailability. Albalawi M and Khateeb S prepared an omeprazole nanosuspension (OMP-NS), with an average particle size of about 216.1 nm, which is spherical in shape and with an entrapment efficiency of up to 96.97% to greatly increase the drug solubility.
In the experiment of ethanol-induced gastric injury in rats, alcohol-induced gastric injury led to severe oxidative stress (high ROS and MDA and low SOD) and inflammation (increased HMGB1, NF-κB, NLRP3, and pro-inflammatory factors). The data showed that OMP-NS could reduce oxidative indicators better than OMP, and greatly upregulated the protective signaling pathway Nrf2/PPAR-γ/SIRT1 to relieve mucosal damage.

Fig. 2 Therapeutic efficacy of omeprazole nanosuspension in ethanol-induced gastric ulcer. (Albalawi M, Khateeb S. 2025)