Background and Aim: Sedative drugs mostly cause dose-dependent depression of the central nervous system which results in hypnosis and anesthesia possibly; however, these agents are associated with some side effects ranging respiratory, digestive, immune system dysfunctions, tolerance, cognitive function deterioration, and physical dependence; hence, investigations of newer and safer agents are, therefore, imperative. The current study was aimed at investigating the sedative-hypnotic (S-H) effects of the methanol leaf extract of Ficus exasperata in mice.

Materials and Methods: Phytochemical screening of the leaf extract was conducted, and S-H activity of the plant extract was evaluated. Twenty Swiss Albino mice were randomly divided into four groups of five mice each. The mice in Groups A and B were injected with the extract intraperitoneally (IP) at the dose rate of 100 and 200 mg/kg, respectively, those in Group C were injected with xylazine at the dose rate of 10 mg/kg, while Group D mice received distilled water at the dose rate of 2 ml/kg. All the four experimental groups were injected with ketamine (IP) at the dose rate of 100 mg/kg after 30 min.

Results: Phytochemical analysis of the extract revealed the presence of carbohydrates, cardiac glycosides, reducing sugars, steroids and triterpenes, saponins, tannins, condensed tannins, and flavonoids, while anthraquinones, anthracene derivatives, and alkaloids were absent. Results from the S-H evaluation show no significant difference (p≥0.05) on the onset of sleep time between the four experimental groups; however, statistically significant difference (p≤0.05) was recorded in the sleep duration time between the groups treated with only ketamine and the other experimental groups pre-treated with either the extract or xylazine before ketamine administration. The group pre-treated with a high dose of the plant extract (200 mg/kg) and the treated with ketamine after 30 min exhibited longer sleeping duration time. The plant extract, xylazine and ketamine, sedated the mice for some period of time after arousal from sleep.

Conclusion: Our finding suggests that methanol leaf extract of F. exasperata possesses S-H potential that may require further scientific investigations.

Keywords: Ficus exasperata, methanol leaf extract, mice, sedative-hypnotic activity.

1. Kerecsen, L. and Kirishna, B.R. (2019) CNS drugs: Sedatives-hypnotics-anxiolytic drugs. In: Davis, C. and Harris, S.R., editors. USMLE step 1 Pharmacology Lecture Notes. Kaplan Medical, a Division of Kaplan, Inc., New York.

2. Dhawan, K., Dhawan, S. and Chhabra, S. (2003) Attenuation of benzodiazepine dependence in mice by a tri-substituted benzoflavone moiety of Passiflora incarnata Linneaus: A non-habit forming anxiolytic. J. Pharm. Pharm. Sci., 6(2): 215-222.

3. Lawal, I.O., Borokini, T.I., Oyeleye, A., Williams, O.A. and Olayemi, J.O. (2012) Evaluation of extract of Ficus exasperata Vahl root bark for antimicrobial activities against some strains of clinical isolates of bacterial and fungi. Int. J. Mod. Bot., 2(1): 6-12. [Crossref]

4. Berg, C.C. (1989) Classification and distribution of Ficus. Experientia, 45(7): 605-611. [Crossref]

5. Ahmed, A., Mueen-Ahmed, K.K., Zainul-Abedin, M.D., Alias, A. and Karim, A.A. (2012) Traditional uses and pharmacological potential of Ficus exasperata Vahl. Syst. Rev. Pharm., 3(1): 15-23.

6. Posner, L.P. (2017) Injectable anesthetics. In: Papich, M.G. and Riviere, J.E., editors. Veterinary Pharmacology and Therapeutics. 10th ed. Wiley-Blackwell, Iowa, USA. p247-280.

7. Pandey, A. and Tripathi, S. (2014) Concept of standardization, extraction and pre phytochemical screening strategies for herbal drug. J. Pharmacogn. Phytochem., 2(5): 115-119.

8. Evans, W.C. (2009) Trease and Evans Pharmacognosy. 16th ed. Saunders Publishers, Elsevier, Edinburgh, UK. p196, 227, 228, 246, 304, 324, 327, 358.

9. Silva, G.L., Lee, I. and Kinghorn, A.D. (1998) Special problems with the extraction of plants. In: Cannell, R.J.P., editor. Natural Products Isolate. Human Press, New Jersey, United States. p343-363. [Crossref]

10. Harborne, J.B. (1973) Phytochemical Methods: A Guide to Modern Techniques of Plant Analysis. Vol. 119. Chapman and Hall Ltd., London, England. p212-231.

11. Sofowora, A. (1993) Medicinal Plants and Traditional Medicine in Africa. Spectrum Book Ltd., Ibadan, Nigeria. p150-153.

12. Jiang, J.G., Huang, X.J., Chen, J. and Lin, Q.S. (2007) Comparison of the sedative and hypnotic effect of flavonoid, saponins and polysaccharides extracted from Semen Ziziphus jujube. Nat. Prod. Res., 21(4): 310-320. [Crossref] [PubMed]

13. Pitychoutis, P.M., Pallis, E.G., Mikail, H.G. and Papadopoulou-Daifoti, Z. (2011) Individual differences in novelty-seeking predict differential responses to chronic antidepressant treatment through sex-and phenotype-dependent neurochemical signatures. Behav. Brain Res., 223(1): 154-168. [Crossref] [PubMed]

14. Adebayo, E.A., Ishola, O.R., Taiwo, O.S., Majolagbe, O.N. and Adekeye, B.T. (2009) Evaluations of the methanol extract of Ficus exasperate stem bark, leaf and root for phytochemical analysis and antimicrobial activities. Afr. J. Plant Sci., 3(12): 283-287.

15. Aguirre-Hernandez, E., Gonzalez-Trujano, E., Terrazas, T., Santoyo, J.H. and Guevara-Fefer, P. (2016) Anxiolytic and sedative-like effects of flavonoids from Tilia americana var. mexicana: GABAergic and serotonergic participation. Salud Ment., 39(1): 37-46. [Crossref]

16. Moniruzzaman, M., Atikur-Rahman, M. and Ferdous, A. (2015) Evaluation of sedative and hypnotic activity of ethanolic extract of Scoparia dulcis Linn. Evid. Based Complement. Alternat. Med., March 2015: 1-6. [Crossref] [PubMed] [PMC]

17. Khan, I.N., Sarker, M.I. and Ajrin, M. (2014) Sedative and anxiolytic effects of ethanolic extract of Calotropis gigantea (Asclepiadaceae) leaves. Asian Pac. J. Trop. Biomed., 4(1): 400-404. [Crossref] [PubMed] [PMC]