NSAID-Induced Gastric Injury: Mitochondrial Dysfunction and Bioenergetic Failure
Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, diclofenac, indomethacin, and ketorolac (Toradol) are among the most commonly used medications worldwide. While effective for pain and inflammation, NSAIDs can damage the stomach lining and increase the risk of erosions, ulcers, and gastrointestinal bleeding. Traditionally, this toxicity was attributed mainly to inhibition of cyclooxygenase (COX) enzymes and the resulting loss of protective prostaglandins. However, modern research demonstrates that mitochondrial dysfunction is an early and critical event in NSAID-induced gastric injury. Toradol has an especially high propensity for gastric injury because it is a non-selective NSAID that strongly inhibits not only COX-2 but also COX-1, an enzyme that is normally continuously active in healthy stomach lining.
Researchers now describe NSAID gastric injury as involving both topical and systemic mechanisms. The first injury occurs when NSAIDs directly contact gastric epithelial cells. Because NSAIDs are weak organic acids, they penetrate cell membranes and disrupt cellular metabolism, leading to cellular stress/injury and even mitochondrial dysfunction. The second injury results from systemic COX inhibition, which reduces protective prostaglandins, especially prostaglandin E₂ (PGE₂), compromising mucosal defense and repair mechanisms including angiogenesis (Takeuchi, 2012, Matsui et al., 2011).
Mitochondria are increasingly recognized as intracellular targets of NSAID toxicity. NSAIDs can uncouple oxidative phosphorylation, impair ATP production, increase reactive oxygen species (ROS), and induce mitochondrial swelling and structural disruption. One of the earliest measurable signs of this damage is loss of mitochondrial membrane potential (MMP), a critical indicator of mitochondrial health. When MMP collapses, cellular energy production declines, oxidative stress rises, and cell death pathways become activated (Ahluwalia et al., 2019). Studies using gastric epithelial cells exposed to diclofenac or indomethacin demonstrated extensive mitochondrial injury, MMP depolarization, and marked reductions in cell survival.
Under normal conditions, PGE₂ helps maintain gastric mucosal integrity by stimulating mucus and bicarbonate secretion, preserving mucosal blood flow, and supporting epithelial restitution after injury. NSAID-induced COX inhibition lowers PGE₂ production, weakening these protective mechanisms. Reduced PGE₂ also contributes to impaired microcirculation, increased mucosal permeability, neutrophil infiltration, and oxidative stress (Takeuchi 2012, Matsui et al., 2011). The gastric microvasculature is particularly important because it delivers oxygen and nutrients needed for tissue repair. When endothelial cells become injured, blood flow decreases and ulcer healing slows. Therefore, preservation of endothelial cell function is a major component of gastric protection.
One intriguing finding from recent studies is that NSAID-induced cellular injury may be partially reversible. Researchers found that post-treatment with NGF, dimethyl-PGE₂ (a stable PGE₂ analog), or AICAR restored mitochondrial membrane potential, improved cell viability, and reduced injury after exposure to diclofenac or indomethacin. These interventions effectively rescued cells from ongoing mitochondrial dysfunction (Ahluwalia et al., 2019).
Although NGF is best known for supporting neurons, research has revealed important protective effects in gastric epithelial and endothelial cells, which both express NGF receptors. Sympathetic and enteric neurons also regulate epithelial cell renewal. Likewise, AICAR, a pharmacological activator of AMPK, has shown significant protective effects against NSAID-induced gastric injury. Studies demonstrated that AICAR both prevented and reversed NSAID-induced reductions in MMP, improved cell survival, and reduced cellular injury. These findings suggest that restoration of cellular energy signaling may help rescue mitochondria damaged by NSAIDs (Ahluwalia et al., 2019). The beneficial effects support the concept that energy failure is a major component of NSAID toxicity.
In summary, NSAIDs are well-known to cause gastric injury—which can occur suddenly and without warning—along with kidney and vascular damage, and also mitochondrial dysfunction. Although I began losing weight rapidly, it was almost overshadowed by the many other debilitating symptoms I was experiencing more acutely. Remarkably, no one connected my decline to the medication I was given immediately prior. To make matters worse, my severe weakness delayed my ability to review my own medical records.
Even without having the pertinent medical information, I knew I was experiencing gastrointestinal injury because of the drastic unintended weight loss and diligently focused on healing my gut. For months, my efforts made little difference. Then, one day, the tide finally began to turn. I knew I was truly recovering when I started regaining weight, sensations returned, my digestion normalized, and my hair began growing back. It felt as if power had finally been restored.
So does disease begin in the gut? To a great extent it can, but it's not in isolation. Gastric blood flow and your nervous system also play a role in gut health, and mitochondrial function underlies it all.
References
Ahluwalia, A., Jones, M. K., Hoa, N., & Tarnawski, A. S. (2019). NSAID-induced injury of gastric epithelial cells is reversible: Roles of mitochondria, AMP kinase, NGF, and PGE₂. American Journal of Physiology-Gastrointestinal and Liver Physiology, 317, G573–G585.
Matsui, H., Shimokawa, O., Kaneko, T., Nagano, Y., Rai, K., & Hyodo, I. (2011). The pathophysiology of NSAID-induced mucosal injuries in stomach and small intestine. Journal of Clinical Biochemistry and Nutrition, 48(2), 107–111.
Takeuchi, K. (2012). Pathogenesis of NSAID-induced gastric damage: Importance of cyclooxygenase inhibition and gastric hypermotility. World Journal of Gastroenterology, 18(18), 2147–2160.
