Phytochemical and pharmacological studies of Lycium schweinfurthii methanolic leaves extract (Solanaceae) in mice

Abstract

Lycium schweinfurthii is found in stony and sandy places belonging to the Solanaceae family which is widely distributed in North Africa and Mediterranean area. The leaves and fruits of this plant have traditionally been used for gastrointestinal diseases. This study was aimed to evaluate the neuropharmacological activity of the methanolic extract of Lycium schweinfurthii in experimental animals. The methanolic extract of the leaves was prepared by the fractionation technique. Male Albino mice of 22.2 ± 2.1 gm were used to evaluate the activity of the extract by Irwin primary screening test, diazepam and thiopental -induced sleep and open field apparatus for general locomotor activity as well as analgesic activity was evaluated by acetic acid-induced writhing and hot-plate. The phytochemical screening was performed by qualitative and quantitative analysis. Diazepam at 2 and 20 mg/kg, flumazenil at 2 mg/kg, thiopental at 40 mg/kg, diclofenac at 25 and 50 mg/kg and indomethacin at 20 mg/kg were all used as references. The selected dose of 400 mg/kg of the methanolic extract was selected after the Irwin screening test. Lycium schweinfurthii extract significantly prolonged the duration of diazepam-induced sleep without significant difference in the onset of sleep. Pretreatment with flumazenil completely blocked the hypnotic effects of the plant extract and diazepam. The plant extract with thiopental did not produce any significant change in the onset and duration time of sleep. In an open-field test, a combination of the plant extract with diazepam produced a significant reduction in both exploratory and general locomotor activity which was observed in four min and 30 min, respectively. The plant extract significantly induced a profound central and peripheral analgesic action. While, the phytochemical screening showed presences of flavonoids, tannins, saponins, phenols, cardiac glycoside, alkaloids and carbohydrates in the extract. The total flavonoids were the most content compounds in the extract. Thus, these findings indicate that Lycium schweinfurthii has depression, sedative and analgesic like activities.