Anxiolytic effect of hydroethanolic extract of sour orange peel (Citrus aurantium) in zebrafish (Danio rerio).

Sour orange (Citrus aurantium) is a plant species rich in polyphenolic compounds to which various biological properties such as antimicrobial and antioxidant are attributed; however, its peel is generally considered a waste product and is not used despite being also rich in secondary metabolites. The objective of this research was to determine the effect of the hydroethanolic extract of C. aurantium on the anxiety of zebrafish (Danio rerio) using the light/dark tank test. The results obtained show that the hydroethanolic extract of the peel of C. aurantium increased the residence time (125 s) of D. rerio in the clear compartment of the test tank compared to the negative control group (27 s); this is interpreted as a promising anxiolytic action when compared to the values obtained in the group treated with diazepam (140 s). Likewise, it was observed that the hydroethanolic extract of the C. aurantium peel increased the latency time of first entry into the dark compartment (20 s), similarly to diazepam (24 s) and differentiated from the negative control group (4 s).