The effects of the aqueous extract (AE) from Hyptis pectinata leaves was studied on rodent central nervous system (CNS). Pharmacological screening, open field, forced swimming, apomorphine-induced hypothermia, elevated plus maze and thiopental-induced sleep tests were used in male and female Swiss mice and Wistar rats. The AE was admnistered orally in single doses 30 minutes before each test. In the screening test the AE (400 mg/kg, p.o., n =3) decreased the frequency of grooming behavior. In the open field test it decreased the amount of time rats spent grooming (AE400: 51.3 ± 8.8, q = 5.513, P < 0.01, n = 10), similarly to diazepam (control: 107.3 ± 14.2; diazepam: 15.4 ± 4.3, q = 9.049, P < 0.001, n = 10). In the forced swimming test the AE (400 mg/kg) decreased the immobility time (con: 181.3 ± 7.2 s; imip: 91.6 ± 8.9 s, q = 7.958, P < 0.001; AE400: 111.6 ± 14.5 s, q = 6.193, P < 0.001, n = 9), indicating a possible antidepressive effect. This was confirmed in the apomorphine-induced hypothermia model where the extract (200 mg/kg) antagonized the apomorphine effect (AE200: -0.27 ºC, q = 5.588, P < 0.001, n = 10), similarly to imipramine (imipramine: 5 mg/kg) (control: -1.08 ºC; imipramine: 0.02 ºC, q = 7.589, P < 0.001, n = 10). No effect of the AE was detected in the elevated plus maze and in the sleeping time induced by thiopental models. Our results suggest a possible antidepressive effect of the aqueous extract obtained from the leaves of Hyptis pectinata.
Hyptis pectinata; Lamiaceae; medicinal plants; depression
