# Anti-Hyperuricemic and Nephroprotective Effects of Hydrolysate Derived from Silkworm Pupae (Bombyx mori): In Vitro and In Vivo Study

## TL;DR

This study shows that a protein hydrolysate from silkworm pupae can lower uric acid and protect the kidneys in hyperuricemia.

## Contribution

The novel contribution is the identification of a silkworm pupae hydrolysate with anti-hyperuricemic and nephroprotective effects through XOD inhibition and transporter modulation.

## Key findings

- SPP reduced serum uric acid, BUN, and creatinine levels in hyperuricemic mice.
- SPP inhibited xanthine oxidase with an IC50 of 7.41 mg/mL.
- SPP upregulated OAT1 and ABCG2, improving uric acid excretion and reducing kidney inflammation.

## Abstract

Background: Hyperuricemia is a prevalent metabolic disorder characterized by elevated serum uric acid (UA) levels. Methods: In this study, hydrolysate (SPP) derived from silkworm pupae protein was isolated and identified, demonstrating anti-hyperuricemic activity. The research aimed to investigate its anti-hyperuricemic and nephroprotective effects, along with potential mechanisms, through in vitro assays and in vivo experiments using potassium oxonate/hypoxanthine-induced hyperuricemic mice. Results: The SPP exhibited significant xanthine oxidase (XOD) inhibitory activity, with an IC50 value of 7.41 mg/mL. Furthermore, SPP administration effectively reduced serum UA, blood urea nitrogen (BUN), creatinine levels, and renal pro-inflammatory cytokines in hyperuricemic mice. Mechanistic studies revealed that the anti-hyperuricemic effects of SPP may involve XOD inhibition and the modulation of renal UA transporters, specifically upregulating organic anion transporter 1 (OAT1) and ATP-binding cassette subfamily G member 2 (ABCG2) expression. Histopathological analysis and inflammatory cytokine profiling further demonstrated that SPP alleviated renal inflammation and pathological damage. Conclusions: These findings suggest that SPP possesses a notable urate-lowering efficacy and renal protective properties, highlighting its potential as a therapeutic agent for the management and prevention of hyperuricemia (HUA).