Background/Objectives: Gouty arthritis (GA) is a chronic inflammatory condition characterized by hyperuricemia and NLRP3 inflammasome activation, leading to joint damage and systemic inflammation. Although allopurinol (ALP), a xanthine oxidase inhibitor, effectively lowers serum urate levels, it has limited anti-inflammatory effects. This study investigated whether combining disulfiram (DSF), a known NLRP3 inflammasome inhibitor, with ALP enhances therapeutic outcomes in a rat model of gout. Methods: Thirty male Albino Wistar rats (150–200 g) were randomly assigned to five groups (n = 6): control, disease control, ALP-treated, DSF-treated, and ALP + DSF combination. Hyperuricemia was induced using potassium oxonate, followed by MSU crystal injection to trigger acute gout. Treatment lasted 30 days. Efficacy was assessed through clinical scoring, paw swelling, serum uric acid levels, ELISA-based cytokine profiling (IL-1β, TNF-α, IL-6), renal function tests, radiography, and histopathology. Results: Combination therapy with ALP + DSF significantly reduced paw swelling (p < 0.05), inflammation index (p < 0.001), serum uric acid (p < 0.001), and pro-inflammatory cytokines compared to monotherapy. Histopathology revealed preserved synovial architecture and reduced inflammatory infiltration. Radiographic imaging showed attenuated soft tissue swelling and joint erosion. Renal function markers were also improved in the combination group. Conclusions: The combination of ALP and DSF provided superior anti-inflammatory and urate-lowering effects compared to individual treatments. These findings support the potential of disulfiram as an adjunct to conventional ULTs in gout management through dual modulation of urate metabolism and inflammasome-driven inflammation.

Background: d-Limonene (LIM) is a food-derived monoterpenoid phytocompound predominantly found in citrus peels, endowed with potent antioxidant and anti-inflammatory properties, and has been reported to inhibit xanthine oxidase (XO) activity in vitro. This study investigated the dose-sparing efficacy of this dietary bioactive compound in combination with low-dose allopurinol (ALP) using a dual rat model combining potassium oxonate (PO)-induced hyperuricemia and monosodium urate (MSU)-triggered gouty arthritis, thereby capturing both metabolic and inflammatory dimensions of gout. Methods: Female Wistar rats were PO-primed and MSU-challenged, then treated with LIM (50 mg/kg), ALP (5 or 10 mg/kg), or LIM + ALP. Outcomes included paw thickness, dysfunction and inflammation indices, serum uric acid, urea, creatinine, AST/ALT, cytokines (IL-1β, TNF-α, IL-6), oxidative stress markers (MDA, SOD, catalase, GSH), and NLRP3 immunoreactivity, supported by radiographic and histopathological analyses. Data were analyzed by one-way ANOVA with Tukey’s post hoc test. Results: LIM improved clinical and biochemical outcomes versus monotherapies. However, LIM + low-dose ALP exhibited the greatest overall efficacy. On Day 30, paw thickness was significantly lower with LIM + ALP than with LIM alone (3.25 ± 0.31 vs. 3.98 ± 0.72 mm; p < 0.001). Serum uric acid and hepatic transaminases declined most with the combination (p < 0.0001 vs. LIM), accompanied by improved renal indices (p < 0.001). Pro-inflammatory cytokines were markedly reduced, NLRP3 immunostaining was minimal, and oxidative balance shifted toward homeostasis (↓ MDA; ↑ SOD, catalase, GSH). Radiographic and histological evaluations corroborated attenuation of joint inflammation and tissue damage. Conclusions: In the PO + MSU gout model, co-administration of the food-derived compound LIM with low-dose ALP achieved additive, dose-sparing benefits across metabolic, inflammatory, and histological endpoints. While in vivo XO activity was not directly assessed, the findings are consistent with XO-pathway modulation, NLRP3–IL-1β suppression, and redox restoration. These results highlight the potential of dietary bioactives such as d-Limonene to complement standard urate-lowering therapy, warranting further pharmacokinetic and safety validation.