This work aims to investigate the acute toxicity of methanolic extract (MeOHE) from Marrubium deserti leaves and evaluate their in vivo anti-inflammatory and analgesic properties. Quantitative determinations of total polyphenols and flavonoïds revealed that MeOHE is rich in polyphenols (184 ± 0.78 mg GAE/mg of extract) and flavonoïds (28.48 ± 0.40 μg QE/mg of extract). In addition, the dosage of condensed tannins showed that MeOHE contains an amount of 5.75 ± 0.42 mg E-Catechin/mg of extract. The study of acute toxicity in Wister albino rats, at a dose of 2000 mg/kg and the dose of 5000 mg/kg shows that MeOHE did not produce any toxic signs or deaths in rats for all parameters studied. Assessment of anti-inflammatory activity in vivo by the paw edema assay induced by carrageenan showed that oral administration of MeOHE at a dose of 200 mg/kg in rats treated with carrageenan causes a significant decrease (86.4%) of inflammation compared with the control group and which is slightly greater than the effect of diclofenac (85.52%) that was used as a positive control. The analysis of C-reactive protein shows the absence of this protein in the plasma of rats treated with MeOHE of the plant. As regards the analgesic activity of the MeOHE has a very significant reduction in numbers of abdominal writhes (5.14 ± 0.23) at a dose of 400 mg/kg bw, these results are very similar to those obtained in the group treated with paracetamol (5 ± 1.58) at a dose of 400 mg / kg bw.
