Mansoura Veterinary Medical Journal

Pharmacological Safety Profiling of Nigella sativa (NS) and Hibiscus sabdariffa (HS) Extracts in Zebrafish (Danio rerio) Embryos: An Integrative Vet-Pharmacotoxicological Evaluation of LC₅₀, Teratogenicity, and Developmental Outcomes

Ahmed E. A. Mostafa, Department of Preclinical Veterinary Medical Sciences (Pharmacology), Faculty of Veterinary Medicine, Delta University for Science and Technology, Gamasa City, Dakahlia Governorate, EgyptFollow

Corresponding Author

Ahmed E.A. Mostafa

Authors ORCID

0009-0007-7528-4756

Document Type

Original Article

Subject Areas

Pharmacology and toxicology

Keywords

Nigella sativa; Hibiscus sabdariffa; zebrafish embryos; developmental toxicity; LC50; herbal safety

Abstract

Herbal medicines are deeply rooted in Egyptian and Middle Eastern traditions, with Nigella sativa (NS) and Hibiscus sabdariffa (HS) being among the most widely consumed remedies. Despite extensive pharmacological evidence of their therapeutic benefits, systematic safety validation remains limited. Conventional toxicity assessments predominantly rely on rodents and higher vertebrates, which are costly, time-consuming, and ethically challenging. This gap necessitates alternative models that align with the 3R principles (Reduction, Replacement, Refinement). In this study, the zebrafish (Danio rerio) embryo model was employed to evaluate the developmental toxicity and median lethal concentration (LC50) of NS and HS aqueous extracts. Zebrafish embryos at 5 hpf were exposed to increasing concentrations of NS (750–12,000 μg/mL) and HS (10–640 μg/mL) for 96 hours. Mortality, hatchability, and teratogenic abnormalities were systematically recorded. The LC50 for NS at 96 hpf was determined to be 2208 μg/mL, with no evidence of teratogenicity. Conversely, HS exhibited no embryotoxic or teratogenic effects at the tested concentrations, with hatchability remaining at 100%. These findings highlight the wide safety margin of NS and confirm the absence of developmental toxicity for HS. Importantly, this work demonstrates the zebrafish embryo as a reliable and ethically favorable alternative to conventional vertebrate models for preliminary toxicological screening of herbal extracts. By bridging the knowledge gap in the safety validation of widely used Egyptian medicinal plants, this study provides a scientific foundation for their safe integration into complementary and alternative medicine practices.

How to Cite This Article

Mostafa, Ahmed E. A. (2025) "Pharmacological Safety Profiling of Nigella sativa (NS) and Hibiscus sabdariffa (HS) Extracts in Zebrafish (Danio rerio) Embryos: An Integrative Vet-Pharmacotoxicological Evaluation of LC₅₀, Teratogenicity, and Developmental Outcomes," Mansoura Veterinary Medical Journal: Vol. 26: Iss. 2, Article 3.
DOI: https://doi.org/10.35943/2682-2512.1256