Kolaviron Exerts Protection Against Atrazine-evoked Hepatorenal Injury by Targeting Apoptosis, Oxidative Stress, Inflammation Mediated Nf-kb/Cox-2/Il-1β and Beclin-1/Lc3-ii Signaling Cascades in Rats

Technical Summary: Kolaviron Exerts Protection Against Atrazine-Evoked Hepatorenal Injury

Problem Statement
Atrazine (ATZ) is a widely used triazine herbicide effective for weed control but poses significant environmental and health risks due to its persistence and toxicity. It is frequently detected in groundwater and surface water, often exceeding regulatory limits. Previous research has established that ATZ exposure induces oxidative stress, leading to hepatic and renal damage in mammals. Specifically, ATZ has been linked to increased lipid peroxidation, altered expression of apoptotic genes, and mitochondrial dysfunction. While Kolaviron (KV), a natural biflavonoid complex derived from Garcinia kola seeds, is known for its antioxidant and anti-inflammatory properties against various xenobiotics, there is a documented lack of studies evaluating its specific protective efficacy against ATZ-induced hepatorenal damage.

Methodology
The study utilized sixty male Wistar rats (250–300 g) randomly allocated into five groups (n=12) for a 14-day experimental period. The groups included:

1. Control: Administered corn oil (2 mL/kg).
2. KV Only: Administered Kolaviron (200 mg/kg).
3. ATZ Only: Administered Atrazine (100 mg/kg).
4. ATZ + KV1: Co-administered Atrazine (100 mg/kg) and Kolaviron (100 mg/kg).
5. ATZ + KV2: Co-administered Atrazine (100 mg/kg) and Kolaviron (200 mg/kg).

Following the treatment period, liver and kidney tissues were harvested for comprehensive analysis. The study employed:

• Biochemical Assays: Spectrophotometric determination of liver enzymes (ALT, AST) and kidney function markers (urea, creatinine). Antioxidant status was assessed via Superoxide Dismutase (SOD), Catalase, Glutathione Peroxidase (GPx), Reduced Glutathione (GSH), Total Thiols (TSH), and Glutathione-S-Transferase (GST). Oxidative stress markers included Malondialdehyde (MDA), Reactive Oxygen and Nitrogen Species (RONS), Hydrogen Peroxide (H2O2), and Xanthine Oxidase (XO). Inflammatory markers included Nitric Oxide (NO), Myeloperoxidase (MPO), Interleukin-1β (IL-1β), Nuclear Factor Kappa B (NF-κB), and Cyclooxygenase-2 (COX-2).
• Molecular Analysis: ELISA and immunohistochemical techniques were used to quantify protein expressions of apoptotic markers (Bax, Bcl-2, Caspase-3) and autophagy markers (Beclin-1, LC3-II).
• Histopathology: Tissues were fixed, embedded, and stained with Hematoxylin and Eosin (H&E) to examine structural integrity under light microscopy.
• Statistical Analysis: Data were analyzed using One-way ANOVA followed by Tukey's post hoc test (p ≤ 0.05).

Key Results

• Organ Function: ATZ exposure significantly elevated serum ALT, AST, urea, and creatinine levels, indicating severe liver and kidney dysfunction. Co-administration of KV (at both 100 and 200 mg/kg) significantly reduced these markers in a dose-dependent manner, restoring them toward control levels.
• Oxidative Stress and Antioxidant Defense: The ATZ group exhibited a marked depletion of antioxidant enzymes (SOD, CAT, GPx, GSH, TSH) and a significant increase in oxidative stress markers (MDA, RONS, H2O2). KV treatment effectively reversed these alterations, enhancing antioxidant capacity and reducing oxidative damage.
• Inflammation: ATZ triggered a robust inflammatory response characterized by elevated levels of NO, MPO, XO, IL-1β, NF-κB, and COX-2. KV administration significantly suppressed these oxido-inflammatory indices, suggesting the inhibition of the NF-κB signaling pathway.
• Apoptosis and Autophagy: ATZ exposure upregulated pro-apoptotic markers (Bax, Caspase-3) and downregulated the anti-apoptotic marker (Bcl-2), while simultaneously increasing autophagy markers (Beclin-1, LC3-II). KV treatment modulated these pathways, reducing Bax and Caspase-3, restoring Bcl-2 levels, and normalizing Beclin-1 and LC3-II expression, thereby preventing excessive cell death and autophagic flux.
• Histology: Histological examination revealed hepatocyte necrosis and renal tubular degeneration in the ATZ-only group. In contrast, the KV co-treated groups displayed near-normal histoarchitecture, with significant preservation of tissue structure.

Key Contributions and Significance
The study demonstrates that Kolaviron exerts robust hepatorenal protective effects against Atrazine-induced toxicity in rats. The primary contribution of this work is the elucidation of the multi-target mechanism by which KV operates. It does not merely act as a general antioxidant but specifically targets and modulates:

1. Oxidative Stress: By restoring the endogenous antioxidant defense system.
2. Inflammation: By inhibiting the NF-κB/COX-2/IL-1β signaling cascade.
3. Cell Death Pathways: By regulating the balance between apoptosis (Bax/Bcl-2/Caspase-3) and autophagy (Beclin-1/LC3-II).

The authors conclude that KV's ability to simultaneously restore antioxidant status, inhibit oxido-inflammatory responses, and modulate apoptosis and autophagy highlights its pleiotropic pharmacological nature. Consequently, Kolaviron is identified as a promising candidate for the potential treatment or mitigation of herbicide-induced organ injuries, specifically those caused by Atrazine.