Renoprotective Effects of Hydroxychloroquine and Folinic Acid via ET-1 and NLRP3 Modulation in Reducing Tubular Injury in A Rabbit Model of Methanol-induced Acute Kidney Injury

Prayuda Prayuda (Postgraduate Medical Study Program, Faculty of Medicine, Universitas Udayana, Jl. P.B. Sudirman, Denpasar 80232)
I Gde Raka Widiana (Nephrology and Hypertension Division, Department of Internal Medicine, Universitas Udayana/Prof. dr. I.G.N.G. Ngoerah General Hospital, Jl. P.B. Sudirman, Denpasar 80232)
Ketut Suega (Hematology and Oncology Division, Department of Internal Medicine, Universitas Udayana/Prof. dr. I.G.N.G. Ngoerah General Hospital, Jl. P.B. Sudirman, Denpasar 80232)
Yenny Kandarini (Nephrology and Hypertension Division, Department of Internal Medicine, Universitas Udayana/Prof. dr. I.G.N.G. Ngoerah General Hospital, Jl. P.B. Sudirman, Denpasar 80232)
Ni Wayan Winarti (Department of Pathology Anatomy, Universitas Udayana/Prof. dr. I.G.N.G. Ngoerah General Hospital, Jl. P.B. Sudirman, Denpasar 80232)
Bambang Purwanto (Nephrology and Hypertension Division, Department of Internal Medicine, Universitas Sebelas Maret, Jl. Ir. Sutami 36A, Surakarta 57126)

The Indonesian Biomedical Journal
Vol 17, No 4 (2025)

BACKGROUND: Methanol intoxication is associated with significant morbidity and mortality, particularly when acute kidney injury (AKI) developed. Emerging evidence implicates Endothelin-1 (ET-1) and Nucleotide-binding domain leucine-rich repeat-containing pyrin receptor 3 (NLRP3) inflammasome in renal injury, but their roles in methanol-induced AKI remain unclear. To date, no studies have examined whether hydroxychloroquine or folinic acid, which are known to modulate ET-1 and NLRP3 signaling, could mitigate renal injury in this setting. This study evaluated their therapeutic effects in a rabbit model of methanol-induced AKI.METHODS: The animals subjects were randomly assigned to four groups: control group receiving aquabidest, folinic acid group receiving 2 mg/kg body weight (BW) intraperitoneal folinic acid, hydroxychloroquine group receiving 30 mg/kg BW oral hydroxychloroquine phosphate, and combination group receiving both folinic acid and hydroxychloroquine at the same dosages. Histopathological evaluation of tubular injury scores and immunohistochemical analysis of ET-1 and NLRP3 expression were then conducted.RESULTS: Expressions of ET-1, NLRP3, and tubular injury scores were significantly lower in the hydroxychloroquine, folinic acid, and combination therapy groups compared to the control group (p<0.001). Expression of ET-1 was lowest in folinic acid group (59.38±0.71%), followed by combination group (62.23±1.98%) and hydroxychloroquine group (62.43±1.81%), compared to control group (72.14±1.02%). Expression of NLRP3 was lowest in combination group (58.94±1.05%), followed by folinic acid and hydroxychloroquine group, which showed equal values (60.57±1.38%), compared to control group (72.15±1.02%). Tubular injury scores were also lowest in combination group (27.07±3.16%), followed by hydroxychloroquine group (45.29±1.75%) and folinic acid group (48.38±2.49%), compared to control group (77.15±1.66%).CONCLUSION: Expression of ET-1 and NLRP3, as well as tubular injury scores, are significantly lower in all treatment groups compared to control, suggesting hydroxychloroquine and folinic acid demonstrated renoprotective effects in methanol-induced AKI, likely through modulation of ET-1 and NLRP3 pathways.KEYWORDS: methanol intoxication, acute kidney injury, hydroxychloroquine, folinic acid, endothelin-1, NLRP3 inflammasome, experimental animal models, rabbits