In vitro and in vivo evidence of the effectiveness of gallic acid on glycerol-induced acute kidney injuries

Because acute kidney injuries (AKI) are one of the critical health problems worldwide, studies on the risk factors, mechanisms, and treatment strategies seem necessary. Glycerol (GLY), known to induce cell necrosis via myoglobin accumulation in renal tubules, is widely used as an AKI model. This study aimed to evaluate the protective effects of gallic acid (GA) against GLY-induced AKI. The study utilized both in vivo and in vitro models. In vivo, healthy rats were divided into six groups: control (normal saline), GLY (10 mg/kg, intramuscularly), GLY + GA10 (10 mg/kg), GLY + GA50 (50 mg/kg), GLY + GA100 (100 mg/kg), and GA (100 mg/kg). GA was administered by gavage for seven consecutive days, followed by a single intramuscular injection of GLY. Kidney biomarkers, lactate dehydrogenase (LDH), oxidative stress markers, inflammatory indices, and histological parameters were assessed 72 h post-injection. In vitro, human embryonic kidney 2 (HK-2) cells were incubated with GLY and GA at different concentrations (30, 60, and 125 mu g/ml) to evaluate cell viability, reactive oxygen species (ROS) production, oxidative stress, and inflammatory cytokines. GLY administration significantly elevated renal dysfunction markers, including blood urea nitrogen and creatinine, alongside oxidative stress and reduced cell viability. GA treatment improved kidney biomarkers, enhanced antioxidant enzyme activity, and reduced inflammatory cytokines. Histological analyses also showed improved kidney structural integrity in GA-treated rats compared to the GLY group. This study confirmed that GLY induces AKI through oxidative stress, inflammation, and structural damage. GA exhibited significant renal protective effects by enhancing antioxidant defenses and reducing inflammation. These findings support GA as a potential natural supplement for preventing or treating renal diseases.