Subacute and subchronic toxicity of microencapsulated pomegranate juice in rats and mice

Pomegranate (Punica granatum L.) is a fruit used extensively in traditional medicine by ancient and modern cultures. Different parts of the tree and fruit, such as leaf, peel, pericarp, aril, seed, and juice contain considerable amounts of phenolic compounds with high antioxidant activities. To improve its storability, pomegranate juice was microencapsulated by spray drying. The present study evaluated microencapsulated pomegranate juice (MPJ) for toxic effects in Wistar rats and CD-1 mice to determine if MPJ can be considered safe for human consumption and used as a nutraceutical. No deaths or deleterious effects occurred when high doses of 5000 mg/kg were orally administered in rats for 14 days, indicating an absence of subacute toxicity. Similarly, 3000 mg/kg MPJ administered to CD-1 mice for 90 days did not show subchronic toxicity. In fact, MPJ resulted in lowered weight gain in both rats and mice. Cytotoxic and microbiological analyses of MPJ were also performed. MPJ did not cause any cytotoxicity in epithelial cell culture as tested using the Alamar blue assay. Additionally, histopathological analysis of kidney and liver corroborated the absence of toxicity in CD-1 mice. The microbial load of the MPJ was low, and no pathogenic bacteria were present. In conclusion, the results reported here show that high doses of MPJ are apparently innocuous in rats and mice for the 14 and 90 days investigated, respectively. Although preliminary, our results suggest that MPJ may be safe to ingest and may even have beneficial effects in reducing weight gain.