Acute oral toxicity of zein nanoparticles with encapsulated gamma oryzanol in Sprague Dawley rats

¹ Department of Agro-Industrial, Food and Environmental Technology, Faculty of Applied Science, Food and Agro-Industrial Research Center, King Mongkut’s University of Technology North Bangkok, 1518, Pracharat 1 Road, Bangsue, Bangkok 10800, Thailand
² Expert Center of Innovative Herbal Products (InnoHerb), Thailand Institute of Scientific and Technological Research (TISTR), Khlong Luang, Pathum Thani 12120, Thailand
³ Division of Biochemical Technology, School of Bioresources and Technology, King Mongkut’s University of Technology Thonburi, Bangkhuntian Bangkok 10150, Thailand
⁴ Department of Food Science, The University of Tennessee, 2510 River Drive, Knoxville, TN 37996, United States

^* Corresponding author: vilai.r@sci.kmutnb.sc.th

Abstract

Gamma oryzanol (GO) is well known for its antioxidant activity and health-promoting benefits. The gamma oryzanol-loaded zein nanoparticles (GOZNs) were successfully prepared in our previous study. In the present work, the acute oral toxicity of GOZNs was evaluated based on OECD guideline 420. GOZNs were fabricated by the liquid-liquid dispersion and lyophilized. The samples displayed a mean diameter of 311.20±3.01 nm and high loading capacity of 311.22±7.97 to 322.69±5.67 mg-GO/g-powder after 42-day storage at -18^oC. Healthy female Sprague Dawley rats (8 weeks of age) were used for the experiments. Five female rats were administered a single dose of 2,000 mg GO/kg body weight via the oral route. Observations of toxicity signs were recorded for the first 24 hours, and the changes in the general physical conditions were monitored for 14 days before the gross necropsy on day 15. The results show that Sprague Dawley rats exhibited normal growth, and neither mortality nor acute toxicity signs were observed throughout the study period. The findings revealed that GOZNs did not have acute toxicity and were safe when administered orally in Sprague Dawley rats for short periods with LD50 > 2,000 mg/kg.