Research Information System
Veterinary Medicine and Science, vol.12, no.3, 2026 (SCI-Expanded, Scopus)
Background and Objectives: This study aimed to assess the effects of grapefruit peel extract on bee health and its anti-nosema activity. Methods: Conventional and microwave-assisted extractions of grapefruit peels were optimized by using the response surface method based on a central composite design approach. HPLC was used to determine the polyphenolic content of the optimal extracts. The effects of optimum extracts on honeybees were evaluated through acute (4%, 2%, 1%, 0.5%, and 0.25%) and chronic (2%, 1%, 0.5%, and 0.25%) toxicity tests, as well as longevity assessments (2%, 1%, 0.5%, and 0.25%). Furthermore, the effects of the extracts on intestinal health were evaluated by histopathological examination, and the anti-nosema activity of the optimum extracts (1%) was assessed. Results: In the toxicity tests, histopathological examinations showed that the extracts had no adverse effects on midgut health. While a 10-day feeding with the optimized extracts did not show a significant difference in overall lifespan, the longevity study showed that bees given 1% of the conventional optimal extract survived longer than the control group. The optimal extracts did not produce high anti-nosema activity at the applied dose. Conclusions: Optimized phenolic-rich extracts have mild health-promoting effects and may offer mild support against Nosema, encouraging further research into bee health and disease management.