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Conyza canadensis is a plant widely used in traditional medicine in Morocco for the treatment of varied health challenges. However, to the best of our knowledge, there is no scientific study justifying the traditional use of Conyza extract as an anxiolytic and antidepressant agent. Moreover, data regarding the polyphenolic fraction is limited. Therefore, the present study was conducted to investigate the chemical composition of an aqueous extract obtained from the aerial parts of Conyza, its antioxidant potential, and the anxiolytic and antidepressant-like effects of the sample (100 and 200 mg/kg body weight (bw)) in the scopolamine (Sco) (0.7 mg/kg bw) rat model. To achieve this purpose, a variety of antioxidant tests (including free radical-scavenging activity and lipoxygenase-inhibitory potential assays) and behavioral procedures, such as the elevated plus-maze and forced swimming tests, were performed. The results demonstrated that the aqueous extract of Conyza canadensis is rich in catechins and flavonoids which possess good antioxidant activity. Additionally, concentrations of 100 and 200 mg/kg of the extract exhibited significant anxiolytic and antidepressant-like profiles following scopolamine treatment. Therefore, we propose that the use of Conyza canadensis could be a new pharmacological target for the amelioration of major depression.

Mentha suaveolens (MS), Conyza canadensis (CC), Teucrium polium (TP) and Salvia verbenaca (SV) are used in Morocco to treat hypertension. Our aim was to characterize the composition and vasoreactivity of extracts of MS, CC, TP and SV. The chemical compositions of aqueous extracts of MS, SV and TP, and of a hydromethanolic extract of CC, were identified by HPLC-DAD. The vasoreactive effect was tested in rings of the thoracic aorta of female Wistar rats (8–14 weeks-old) pre-contracted with 10 µM noradrenaline, in the absence or presence of L-NAME 100 µM, indomethacin 10 µM or atropine 6 µM, to inhibit nitric oxide synthase, cyclooxygenase or muscarinic receptors, respectively. L-NAME and atropine decreased the vasorelaxant effect caused by low concentrations of MS. Atropine and indomethacin decreased the vasorelaxant effect of low concentrations of SV. High concentrations of MS or SV and the effect of SV and TP were not altered by any antagonist. The activation of muscarinic receptors and NO or the cyclooxygenase pathway underlie the vasorelaxant effect of MS and SV, respectively. Neither of those mechanisms underlines the vasorelaxant effect of CC and TP. These vasorelaxant effect might support the use of herbal teas from these plants as anti-hypertensives in folk medicine.

Objective: The aim of this present study is to investigate the antidiarrheal, spasmolytic and antioxidant activities of aqueous extract of Mentha suaveolens Ehrh (AEMS), to study their underlying mechanisms in animal models and to reveal its main functional groups using Fourier Transform Infra-Red Spectroscopy (FTIR). Methods: Mentha suaveolens Ehrh was studied for antidiarrheal activity on Wistar rats of both sexes at the doses of 200 and 800 mg/kg body weight using castor oil-induced diarrhea, castor oil-induced enteropooling and small intestinal transit models. The extract was studied for antispasmodic property in isolated rabbit jejunum using various spasmogenic agents including Ach (10-5M), KCl (100 mM) and in the absence and in the presence of L-NAME (10-4 M) and the methylene blue (10-5 M).The antioxidant capacity of AEMS was carried out using DPPH radical scavenging activity and the ferric reducing antioxidant potential (FRAP). Ascorbic acid and Butylated HydroxyToluene (BHT) were used as references. The functional chemical groups were determined by FTIR. Results: The great antidiarrheal potential of AEMS seems to be mediated through calcium antagonism. The marked and concentration-dependent induced spasmolytic effect of AEMS appears to involve Ca2+ voltage channel blockade and the NO/cGMP pathway activation. AEMS possessed strong and concentration-dependent antioxidant potency using DPPH and FRAP. Polyphenols, carboxyl and carbohydrates were found to be the main functional groups in the AEMS analyzed by FTIR. Conclusion: Overall, our current findings provide scientific proves in animal models for the traditional use of AEMS in folk medicine for the prevention or the treatment of gastrointestinal diseases in Morocco.