investigation of the protective effects of protocatechuic acid on diazinon-induced liver damage in rats

Pesticides are widely employed to control pests that threaten agricultural productivity by damaging crops and livestock. among them, organophosphate (op) compounds represent one of the most toxic groups used in modern agriculture (kazemi et al., 2012). as a large and heterogeneous class of organophosphorus chemicals, op pesticides exert their toxic effects through biotransformation mediated by cytochrome p450, which promotes oxidative stress and lipid peroxidation, ultimately leading to elevated protein carbonyl (pc) and malondialdehyde (mda) levels (lukaszewicz- hussain, 2010). beyond their well-documented ability to inhibit acetylcholinesterase, op compounds also induce programmed cell death via both intrinsic and extrinsic apoptotic pathways (kaur et al., 2007). within this group, diazinon (dzn) is a broad-spectrum pesticide extensively used as an insecticide, acaricide, and nematicide (aggarwal et al., 2012). dzn has been associated with a wide range of toxic outcomes, including acute biochemical alterations, tissue- and organ-specific damage, cytotoxic and genotoxic effects, reproductive toxicity, and negative ecological consequences (larkin & tjeerdema, 2000). experimental evidence further demonstrates that dzn exposure alters hepatic enzyme activity, disrupts biochemical parameters, and provokes ultrastructural damage in hepatocytes, such as mitochondrial swelling (abdel-daim et al., 2016; kalender et al., 2005). in contrast, natural antioxidant compounds have received increasing attention for their potential protective effects against xenobiotic-induced toxicity. protocatechuic acid (pca), a naturally occurring phenolic acid abundant in fruits, vegetables, cereals, teas, and medicinal plants, exhibits a wide pharmacological profile (song et al., 2020). pca has been reported to exert antioxidant, antiinflammatory, neuroprotective, antitumor, antibacterial, antidiabetic, and antiapoptotic properties (krzysztoforska et al., 2019). its pharmacological effects are largely attributed to its potent in vitro and in vivo antioxidant activity (semaming et al., 2015). in addition, pca protects against hepatotoxicity and nephrotoxicity by modulating enzyme activities, attenuating oxidative stress, and improving biochemical and histopathological alterations (krajka-kuźniak et al., 2004). given these considerations, the present study was designed to investigate the protective potential of pca against dzn-induced hepatotoxicity. specifically, the study aimed to elucidate the effects of pca on inflammation and apoptosis in rat liver tissue. a total of five groups were formed, each consisting of 12 rats. the experimental design was as follows:control group: rats received physiological saline solution daily for 28 days via oral gavage.pca group: rats were administered 100 mg/kg body weight of protocatechuic acid (pca) daily for 28 days via oral gavage.dzn group: to induce liver toxicity, rats were administered 20 mg/kg body weight of diazinon (dzn) daily for 28 days via oral gavage. dzn + pca (50 mg/kg) group: rats were administered 20 mg/kg body weight of dzn daily for 28 days via oral gavage, followed 30 minutes later by 50 mg/kg body weight of pca via oral gavage.dzn + pca (100 mg/kg) group: rats were administered 20 mg/kg body weight of dzn daily for 28 days via oral gavage, followed 30 minutes later by 100 mg/kg body weight of pca via oral gavage.twenty-four hours after the final dzn and pca administrations (day 29), the rats weredecapitated under light sevoflurane anesthesia following adequate sedative induction. for biochemical analyses, blood samples were collected into vacuum tubes without anticoagulant, and subsequently centrifuged at 4000 rpm for 10 minutes at +4 °c to obtain serum samples. alanine aminotransferase (alt) and aspartate aminotransferase (ast) activities in the obtained serum samples were analyzed using an au500 automated biochemistry analyzer (beckman coulter inc., usa). levels of inflammatory and apoptotic markers in liver tissues, including nf-κb, tnf-α, il-1β, caspase-3, bax, bcl-2, and cytochrome c (cyc-c), were determined using the elisa method. all analyses were performed with commercial kitsaccording to the manufacturer’s instructions. an ethical approval for the use of rats was obtained from the atatürk university medical experimental application and research center (atadem) ethics committee (approval no: e 75296309-050.01.04-2300372163, dated 21.11.2023). for the study, a total of 60 mal sprague-dawley rats, weighing 220–250 g and aged 10–12 weeks, were used. this study was supported by the atatürk university scientific research projects coordination unit under project number tdk-2024-13608.the findings of the present study demonstrated that diazinon (dzn) induces hepatic injury primarily by enhancing inflammatory responses and triggering apoptosis in liver tissues. in contrast, protocatechuic acid (pca) exhibited significant anti-inflammatory and anti-apoptotic properties, thereby attenuating the detrimental effects of dzn. these results are in line with previous studies reporting the protective role of pca against oxidative stress, hepatotoxicity, and cellular apoptosis in experimental models (krajka- kuźniak et al., 2004; radhiga et al., 2016; semaming et al., 2015). taken together, the current findings suggest that pca may serve as a promising therapeutic agent for mitigating pesticide-induced hepatotoxicity, particularly through its ability to modulate oxidative stress, inflammatory mediators, and apoptotic pathways. therefore, pca could be considered a potential candidate for the development of novel therapeutic strategies aimed at protecting against dzn-induced liver injury.