Introduction We report, herein, in vitro, and in vivo toxicity evaluation of silver nanoparticles stabilized with gum arabic protein (AgNP-GP) in Daphnia similis, Danio rerio embryos and in Sprague Dawley rats. Purpose The objective of this investigation was to evaluate in vitro and in vivo toxicity of silver nanoparticles stabilized with gum arabic protein (AgNP-GP), in multispecies due to the recognition that toxicity evaluations beyond a single species reflect the environmental realism. In the present study, AgNP-GP was synthesized through the reduction of silver salt using the tri-alanine-phosphine peptide (commonly referred to as “Katti Peptide”) and stabilized using gum arabic protein. Methods In vitro cytotoxicity tests were performed according to ISO 10993–5 protocols to assess cytotoxicity index (IC 50 ) values. Acute ecotoxicity (EC 50 ) studies were performed using Daphnia similis , according to the ABNT NBR 15088 protocols. In vivo toxicity also included evaluation of acute embryotoxicity using Danio rerio (zebrafish) embryos following the OECD No. 236 guidelines. We also used Sprague Dawley rats to assess the toxicity of AgNP-GP in doses from 2.5 to 10.0 mg kg −1 body weight. Results AgNP-GP nanoparticles were characterized through UV (405 nm), core size (20±5 nm through TEM), hydrodynamic size (70–80 nm), Zeta (ζ) potential (- 26 mV) using DLS and Powder X ray diffraction (PXRD) and EDS. PXRD showed pattern consistent with the Ag (1 1 1) peak. EC 50 in Daphnia similis was 4.40 (3.59–5.40) μg L −1 . In the zebrafish species, LC 50 was 177 μg L −1 . Oral administration of AgNP-GP in Sprague Dawley rats for a period of 28 days revealed no adverse effects in doses of up to 10.0 mg kg −1 b.w. in both male and female animals. Conclusion The non-toxicity of AgNP-GP in rats offers a myriad of applications of AgNP-GP in health and hygiene for use as antibiotics, antimicrobial and antifungal agents.

Agradeço a Deus pela minha existência e pela oportunidade de aprender sempre nessa escola que é a vida. Aos meus pais que sempre estiveram ao meu lado, me incentivado, torcendo por mim em todos os momentos, e que se não fosse por eles não teria chegado até aqui. Ao Dr. José Roberto Rogero pela oportunidade, pelo acolhimento, pela orientação, pelos conselhos, pelo apoio, pela confiança, paciência e amizade. Muito obrigada por tudo. À Ms. Sizue Ota Rogero por sempre estar ao meu lado em todos os momentos, principalmente os difíceis, me dando apoio sempre. Obrigada pela sua amizade que quero levar para a vida. À Dra. Mônica Lopes Ferreira, do Laboratório Especial de Toxinologia Aplicada (LETA), do Instituto Butantan, pela amizade, pelo fornecimento dos embriões para o estudo, pelos ensinamentos e pelo incentivo. Ao Dra. Ademar Benévolo Lugão pelo acolhimento, atenção, apoio, conselhos e por proporcionar condições laboratoriais para a conclusão deste trabalho.

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