# Melatonin as a Potential Dietary Supplement to Counteract Glyphosate-Induced Decline in Honeybee Populations

## TL;DR

Melatonin can protect honeybees from glyphosate harm, improving survival and gut health, which is important for pollination and ecosystems.

## Contribution

Melatonin pretreatment was shown to alleviate glyphosate toxicity in honeybees by restoring gene activity and gut bacteria.

## Key findings

- Melatonin pretreatment increased honeybee survival rates after glyphosate exposure.
- Melatonin restored disrupted gene activity related to immunity, digestion, and metabolism caused by glyphosate.
- Melatonin improved gut bacteria abundance, particularly lactic acid bacteria, in honeybees.

## Abstract

This study addresses the concerning decline of honeybees, vital pollinators for crops and biodiversity, due to exposure to the herbicide glyphosate. We aimed to test whether adding melatonin could protect honeybees from this toxin. Our results show that melatonin significantly improved the survival of honeybees exposed to glyphosate. It helped restore the normal activity of genes related to health, digestion, and development that were disrupted by the herbicide, and it increased beneficial gut bacteria. We conclude that melatonin alleviates glyphosate-induced harm by shielding the bee’s digestive system and restoring internal balance. These findings offer a practical and promising approach to safeguarding honeybee populations, which is crucial for sustainable agriculture and healthy ecosystems.

Due to their role as the main pollinators in agricultural environments, honeybees help improve crop quality and yield and also help maintain global and ecosystem biodiversity. However, pesticide exposure during foraging has resulted in declining honeybee populations, and there are increasing concerns about the potential adverse effects of the herbicide glyphosate (Gly) on honeybees. In this study, we show that exogenous melatonin (Mel) alleviated Gly toxicity in honeybees, and we investigated the mechanisms underlying Mel’s effects using RNA-seq and 16S rRNA sequencing. We show that the survival rate of honeybees exposed to Gly increased significantly after pretreatment with 10 mg/L exogenous Mel in the laboratory. RNA-seq showed that genes involved in immunity, digestion, the nervous system, carbohydrate and amino acid metabolism, and development were altered after Gly treatment; interestingly, pretreatment with Mel had a compensatory effect on transcription in response to Gly. 16S rRNA sequencing revealed that Mel treatment dramatically improved the abundance of lactic acid bacteria in honeybees. These findings reveal how melatonin protects honeybee intestines from glyphosate-induced damage, offering practical strategies for honeybee conservation.