Chemical Composition, Edible Safety, and Antioxidant Activity Evaluation of Flowers in a Medicinal Plant Dendrobium chrysotoxum.

Dendrobium chrysotoxum stem is a famous traditional ethnic medicinal, and its flowers have the potential to be used as new food or traditional Chinese medicine resources. However, the chemical composition, edible safety, and antioxidant capacity of D. chrysotoxum flowers are insufficient. In this study, we collected 49 samples of D. chrysotoxum flowers from 49 cultivation sites across five southern provinces in China. The heavy metals and pesticide residues in D. chrysotoxum flowers were determined. Furthermore, this experiment conducted a systematic toxicological safety assessment, analyzed the chemical composition, and evaluated the antioxidant capacity of D. chrysotoxum flowers. The results showed that none of the 49 samples of D. chrysotoxum flowers posed safety risks regarding the five heavy metals and 33 banned pesticide residues. The toxicological safety assessment confirmed that there was no observed toxicity in mice at an acute oral dose of 30.0 g kg(-1). The D. chrysotoxum flower extract showed no mutagenic effects on mice. Within the dosage range of 6.67 g kg(-1), the D. chrysotoxum flower extract did not induce micronuclei in mouse bone marrow erythrocytes or cause chromosomal aberrations in mouse spermatocytes. Additionally, within the dosage range of 10 g kg(-1), the D. chrysotoxum flower extract exhibited no subchronic toxicity in mice. A total of 2,047 metabolites were identified in D. chrysotoxum flowers and classified into 15 superclasses using a widely targeted metabolomics method. Sixteen amino acids were measured using high-performance liquid chromatography. This study demonstrates that D. chrysotoxum flowers are safe for human consumption at recommended dosages. Furthermore, D. chrysotoxum flowers contain a variety of functional compounds with antioxidant properties, making them suitable for development and use as edible flowers.