Pharmacological evaluation of the anxiolytic-like effects of an aqueous extract of the Raphanus sativus L. sprouts in mice.

Raphanus sativus L. (Brassicaceae), commonly known as radish, is consumed worldwide as a vegetable. However, its benefits on mental health are unknown. The aim of this study was to evaluate its anxiolytic-like effects and safety using different experimental models. An aqueous extract of R. sativus sprouts (AERSS) was pharmacologically evaluated by intraperitoneal route (i.p.) at 10, 30, and 100 mg/kg and orally (p.o.) at 500 mg/kg on behavior by using open-field and plus-maze tests. In addition, its acute toxicity (LD50) was determined by the Lorke's method. Diazepam (1 mg/kg, i.p.) and buspirone (4 mg/kg, i.p.) were the reference drugs. A significant and anxiolytic-like dosage of AERSS (30 mg/kg, i.p.) resembling the effects of reference drugs was chosen to explore the involvement of GABAA/BDZs site (flumazenil, 5 mg/kg, i.p.) and serotonin 5-HT1A receptors (WAY100635, 1 mg/kg, i.p.) as a possible mechanism of action. A 500 mg/kg, p.o. dosage of AERSS produced an anxiolytic-like response equivalent to 100 mg/kg, i.p. No acute toxicity was observed since a LD50 > 2000 mg/kg, i.p. The phytochemical analysis allowed the identification and quantification of major presence of sulforaphene (2500 µM), sulforaphane (15 µM), iberin (0.75 µM), and indol-3-carbinol (0.75 µM), as major constituents. Both the GABAA/BDZs site and serotonin 5-HT1A receptors were involved in the anxiolytic-like activity of AERSS, depending on the pharmacological parameter or the experimental assay tested. Our results demonstrate that the anxiolytic activity of R. sativus sprouts involves GABAA/BDZs site and serotonin 5-HT1A receptors supporting its health benefits in the treatment of anxiety beyond the satisfaction of basic nutritional needs.

Acetylcholinesterase inhibition and antioxidant activity properties of Petiveria alliacea L.

ETHNOPHARMACOLOGICAL RELEVANCE: Petiveria alliacea L. is traditionally used as a folk medical herb in different regions of the world to treat different ailments including those related to the central nervous system. Previous studies have proved that extracts from P. alliacea show improvement in memory and learning process. AIM OF THE STUDY: To study extracts, fractions, subfractions and isolated compounds from P. alliacea on acetylcholinesterase inhibition and antioxidant activity. MATERIAL AND METHODS: Extracts obtained with different polarity solvents and fractions from P. alliacea were evaluated for their inhibitory activity on acetylcholinesterase by Ellman method. This screening allowed the selection of the methanol fraction as the most active and continued a bio-guided study. The compounds identified in methanol fraction were analyzed by high performance liquid chromatography-mass spectrometry (HPLC-MS). Identification of (E)-Tagetone was performed by 1H and 13C NMR spectra. Moreover, the antioxidant activity was evaluated by DPPH and ABTS methods, and the cell viability was assessed by WST-1 method. RESULTS: Two extracts of different polarity were obtained from P. alliacea. The methanol extract and its fraction showed an inhibitory activity on acetylcholinesterase; however, methanol fraction was found to be most potent with 86.5 % AChE inhibition. The methanol fraction also showed antioxidant activity and was not toxic on SH-SY5Y cells. Different compounds including capreoside, narcissin, indane, (-)-isocaryophyllene, (-)-ß-pinene, (E)-tagetone and peonidin 3-O-sambubioside 5-O-glucoside were identified. CONCLUSION: This is the first report indicating that P. alliacea methanol fraction and its subfractions bear acetylcholinesterase inhibition and antioxidant activity properties. This work establishes the basis for further studies in the development of new therapies for neurodegenerative disorders such as Alzheimer 's disease.

Antinociceptive and anxiolytic-like effects of a neo-clerodane diterpene from Salvia semiatrata aerial parts.

CONTEXT: Salvia semiatrata Zucc. (Lamiaceae) is a species used as a tranquilizer and to relieve pain in folk medicine in Santiago Huauclilla, Oaxaca, Mexico. OBJECTIVE: To evaluate the antinociceptive and anxiolytic-like effects of S. semiatrata extracts and identify a bioactive metabolite. MATERIALS AND METHODS: The extracts were obtained by maceration of S. semiatrata aerial parts using solvents in increasing polarity (hexane, ethyl acetate and methanol). A neo-clerodane diterpene was extracted from the ethyl acetate fraction using open column chromatography. Identification of this metabolite was performed by crystallography, 1H NMR, 13C NMR, ATR-IR, ECD, MS and elemental analysis. The antinociceptive activity was explored using the writhing and formalin tests. Whereas, the anxiolytic-like responses were analysed in the open-field, hole-board and plus-maze tests. All the treatments were administered using oral gavage in male CD1 mice and explored 30 min after administration of the individual extracts (300 mg/kg) or the compound 1 (0.1, 1 or 10 mg/kg). RESULTS: All the extracts produced significant reduction in the nociceptive and anxiety-like behaviour compared to mice treated with the vehicle (0.5% tween 80 in saline solution). The spectroscopic analysis corroborated the presence of the neo-clerodane diterpene 7-keto-neoclerodan-3,13-dien-18,19:15,16-diolide (1), as partial responsible of the antinociceptive and anxiolytic-like effects, which produced a dose-dependent response in the writhing test with an ED50=4.15 mg/kg. Discussion and conclusions: These results reinforce the medicinal properties of S. semiatrata in folk medicine, where participation of a neo-clerodane diterpene was evidenced in the inhibitory central nervous system activity of this species.

Pharmacological evaluation of the anxiolytic-like effects of Lippia graveolens and bioactive compounds.

CONTEXT: Lippia species (Verbenaceae) are widely used in Latin America and Africa as folk medicine for their tranquilizing properties. OBJECTIVE: To evaluate the anxiolytic-like effects and safety of Lippia graveolens Kunth. by exploring its aqueous and organic leaf extracts and identifying the responsible chemical constituents. MATERIAL AND METHODS: Aqueous and organic extracts (hexane, ethyl acetate and methanol) were pharmacologically evaluated at several doses. Chemical constituents were identified using MS, NMR and GC-MS analysis. The isolated compounds (3 mg/kg, i.p.), extracts (1, 3, 10 and 30 mg/kg, i.p.), and the reference drug diazepam (0.1 mg/kg, i.p.) were assessed in CD-1 mice using experimental behavioural models: open-field, cylinder, hole-board, plus-maze and sodium pentobarbital-induced hypnosis, as well as their acute toxicity (LD50). RESULTS: After administration of the extracts and bioactive compounds, a significant anxiolytic-like response from 1 mg/kg, i.p. was observed, resembling the effect of diazepam. Major presence of thymol (33.40%) was observed in the hexane extract; whereas for the first time in this species a p-cymene + thymol mixture (9.78%), naringenin (0.18%) and cirsimaritin (1.16%) were obtained as bioactive constituents of the ethyl acetate crude extract. Acute toxicity was calculated to be LD50 = 1000 mg/kg for the crude hexane extract, lower in comparison to the other extracts analyzed (LD50 > 2000 mg/kg). DISCUSSION AND CONCLUSION: Our results suggest that L. graveolens exerts anxiolytic-like activity involving many kinds of constituents, mainly of the terpenoid and flavonoid nature. These results reinforce the potential use of this species in the therapy of anxiety.