Biological safety of Syagrus coronata (Mart.) Becc. Fixed oil: Cytotoxicity, acute oral toxicity, and genotoxicity studies

Ethnopharmacological relevance: Syagrus coronata, popularly known as licuri, is a palm native to caatingas. The fixed oil extract of licuri nuts is used by the population of Northeast Brazil for therapeutic purposes, including as an antifungal, anti-inflammatory, and a cicatrizant agent. However, there is no scientific information on the possible harmful health effects of the oil and hence its medicinal usability is unknown.

Aim of the study: We aimed to analyze the biological safety and possible antioxidant activity of fixed S. Coronata oil.

Materials and methods: Chemical analysis of the oil was performed using gas chromatography with flame ionization detection (CG-FID). The cytotoxicity of varying concentrations of the oil (12.5, 25, 50, 100, and 200 μg/mL) was evaluated using the tetrazolium reduction assay in three cell lines: HEK-293 kidney embryonic cells, J774.A1 macrophages, and the tumor line Sarcoma-180 (S-180). Oral toxicity, genotoxicity, and mutagenicity tests were performed in mice which were administered a single dose of 2000 mg/kg of fixed licuri oil, by gavage. For acute toxicity tests, changes in blood and biochemical parameters, behavior, and weight were analyzed; histomorphometric analyses of the liver, kidney, and spleen were also performed. The comet assay and micronucleus (MN) test were performed to analyze genotoxicity. The antioxidant potential was assessed by the total antioxidant capacity (AAT) and DPPH elimination activity.

Results: Licuri oil consists predominantly of saturated fatty acids, and lauric acid is the major compound. The highest concentrations of the oil showed low levels of cytotoxicity; however, LC50 was not reached in any of the tests. The acute toxicity study did not reveal any evidence of adverse effects in animals treated with oil; biochemical investigation of blood showed a decrease in blood concentration of total proteins and uric acid. The kidneys, spleen, and liver showed no morphological changes indicative of a pathological process. Genotoxic or mutagenic activity was not detected through both the comet assay and MN test. In addition, the oil showed low antioxidant activity in both methods.

Conclusion: Licuri oil from the stem of S. coronata did not present significant toxic effects as well as absence of genetic damage when administered orally. Future studies are needed to investigate its pharmacological potential.