Title:Phytochemical Investigation, Acute Toxicity, Central Analgesic and Antioxidant Activities of Extracts and Essential Oil of Cotula cinerea Del (Asteraceae)
VOLUME: 16 ISSUE: 2
Author(s):Fatima E. Guaouguaou*, Mohamed A.A. Bebaha, Khalid Taghzouti and Nour E. Es-Safi*
Affiliation:Mohammed V University in Rabat, LPCMIO, Materials Science Center (MSC), Ecole Normale Superieure, Rabat, Mohammed V University in Rabat, LPCMIO, Materials Science Center (MSC), Ecole Normale Superieure, Rabat, Laboratory of Animal Physiology, Faculty of Sciences, Rabat, Mohammed V University in Rabat, LPCMIO, Materials Science Center (MSC), Ecole Normale Superieure, Rabat
Keywords:Cotula cinerea, essential oil, polyphenols, acute toxicity, analgesic, antioxidant.
Abstract:
Background: Cotula cinerea belongs to the Asteraceae family and grows in desert areas such
as Moroccan Sahara. The use of this plant in Moroccan traditional medicine prompted us to investigate
its chemical composition, its acute oral toxicity, its analgesic and antioxidative activities.
Methods: Extraction was conducted by steam distillation for essential oil and by maceration using
solvents (hexane, ethyl acetate, n-butanol) for other non-volatile compounds. Quantitative analysis of
total polyphenols, procyanidins and flavonoids was conducted through spectrophotometric assays.
Qualitative phytochemical composition of the essential oil was investigated by GC/MS analysis. Acute
oral toxicity was tested at a dose of 2000 mg/kg in mice. Central analgesic effect was assessed in rat
using tail flick and hot plate models and the obtained results were compared to morphine. Antioxidant
activity of the essential oil and the obtained extracts was evaluated through 2,2-diphenyl-1-
picrylhydrazyl (DPPH°) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays and
the obtained results were compared to TROLOX.
Results: The obtained results showed that the studied extracts contained significant amounts of total
polyphenols, flavonoids and condensed tannins. The phytochemical composition of the essential oil was
predominated by thujone, eucalyptol and santolinatriene. The results of the acute oral toxicity showed
that the tested essential oil and extracts were not toxic even at the highest dose of 2000 mg/kg. Experiments
on analgesic activity showed that the administered extracts have a central analgesic effect. The
highest effect was observed with the n-butanol and ethyl acetate extracts for both tail-flick and hot plate
tests. The antioxidant activity of the explored extracts showed higher scavenging activities of the
studied samples compared to TROLOX.
Conclusion: Our results indicate thus that C. cinerea could be considered as a source of various secondary
metabolites including terpenoids and polyphenols. Exploration of its biological activities showed
that the plant essential oil and extracts possessed antioxidant and analgesic effects. Based on the results
of this study, it is likely that extracts of C. cinerea could open perspectives for its use for pain relief.