Melatonin intervention to prevent nanomaterial exposure‐induced damages: A systematic review and meta‐analysis of in vitro and in vivo studies

Abstract

Given its antioxidant, anti‐inflammatory, and antiapoptotic properties, melatonin (MEL), a health‐caring food to improve sleep disorders, is hypothesized to protect against nanomaterial exposure‐induced toxicity. However, the conclusion derived from different studies seemed inconsistent. A meta‐analysis of all available preclinical studies was performed to examine the effects of MEL on nanomaterial‐induced damages. Eighteen relevant studies were retrieved through searching five electronic databases up to December 2023. The meta‐analysis showed that relative to control, MEL treatment significantly increased cell viability (standardized mean difference [SMD = 1.27]) and alleviated liver function (lowered AST [SMD = −3.89] and ALT [SMD = −5.89]), bone formation (enhanced BV/TV [SMD = 4.13] and lessened eroded bone surface [SMD = −5.40]), and brain nerve (inhibition of AChE activity [SMD = −3.60]) damages in animals. The protective mechanisms of MEL against damages caused by nanomaterial exposure were associated with its antiapoptotic (decreased Bax/Bcl‐2 ratio [SMD = −4.50] and caspase‐3 levels [dose <100 μM: SMD = −3.66]), antioxidant (decreased MDA [in vitro: SMD = −2.84; in vivo: SMD = −4.27]), and anti‐inflammatory (downregulated TNF‐α [in vitro: SMD = −5.41; in vivo: SMD = −3.21] and IL‐6 [in vitro: SMD = −5.90; in vivo: SMD = −2.81]) capabilities. In conclusion, our study suggests that MEL should be supplemented to prevent damages in populations exposed to nanomaterials.