Emodin: Its effects are largely due to hormesis

Area of Science:

• Toxicology
• Pharmacology
• Biomedical Sciences

Background:

• Hormesis, a biphasic dose-response, is increasingly recognized in biological systems.
• Emodin, a natural compound, has demonstrated diverse biological activities.
• Understanding emodin's hormetic effects is crucial for its therapeutic and toxicological evaluation.

Purpose of the Study:

• To conduct the first integrative evaluation of emodin-induced hormetic-biphasic dose responses.
• To analyze study designs, dose-response features, and mechanistic foundations of emodin hormesis.
• To assess the generality of emodin's hormetic effects across biological models and organizational levels.

Main Methods:

• Comprehensive literature review of emodin-induced hormetic responses.
• Analysis of study designs, dose-response data, and mechanistic pathways.
• Evaluation of findings across cellular, organ, and organismal levels, including fish and rodent models.

Main Results:

• Emodin consistently demonstrates hormetic-biphasic dose responses in diverse biological and biomedical literature.
• In vivo studies, particularly in fish models, showed emodin enhanced growth, development, and stress resistance.
• Generalizable adaptive mechanisms involve activation of peroxisome proliferator-activated receptor gamma and the AMPK/Nrf2 pathway.

Conclusions:

• Emodin exhibits significant hormetic effects across various biological systems and models.
• The findings highlight emodin's potential for beneficial effects at low doses and risks at high doses.
• Emodin's hormetic response is mediated by conserved adaptive pathways, suggesting broad biological relevance.