Equisetum arvense, a medicinal plant belonging to the family of Equisetaceae, is used in the fight against infectious or inflammatory diseases. The aim of this research was to assess the acute oral toxicity, to identify some phenolic acids and flavonoids by HPLC analysis, and to evaluate the antioxidant and the anti-inflammatory activities of E. arvense methanol extract (EAME) and aqueous (EAQE) extracts. The acute toxicity study was carried out using Swiss albino mice. Animals were observed during 14 days and signs of toxicity were controlled, afterwards, mice were sacrificed for biochemical studies. HPLC method was used to analyze E. arvense extracts. Antioxidant activity was determined using DPPH, reducing power, free hydroxyl radicals assays and antihemolytic activity. Xylene-induced ear edema in mice and carrageenan-induced paw edema in rat were used to evaluate anti-inflammatory activity. Formaldehyde-induced paw edema was used to assess anti-arthritic effect of extracts. In the acute toxicity study, both extracts did not engender any mortality or changes in general behaviors of tested animals. The LD50 was found to be superior to 5000 mg/kg DW. Extracts, rich in polyphenols and/or flavonoids, showed high antioxidant activity. Both extracts showed significant anti-inflammatory and anti-arthritic effects on animal models. These results revealed that E. arvense extracts can be a valuable source of phenolic compounds and flavonoids with powerful antioxidant and anti-inflammatory properties.

Capparis spinosa L. is a Mediterranean shrub widely used in traditional herbal medicine. This medicinal plant possesses several biological activities such as antioxidant, hepatoprotective and immunomodulatory effects. The present study aims to assess antioxidant and anti-inflammatory effects of Algerian C. spinosa methanolic extracts from leaves (LME), stems (SME) and fruits (FME). Determination of total polyphenols, flavonoids and tannins was carried out using colorimetric methods. Antioxidant properties were evaluated using free radical scavenging activity against DPPH and ABTS, reducing power and β-carotene/linoleic acid tests. The Anti-inflammatory activity was assessed using carrageenan induced paw edema (CIPE), xylene (XIEE) and croton oil-induced ear edema (CIEE) models. The results showed that LME contains the highest concentrations of polyphenols, flavonoids and tannins. This extract also showed the highest reducing power (EC50= 32.83 ± 0.57 μg/ml), and scavenging activity against DPPH and ABTS radicals (IC50 = 30.51 ± 1.86 μg/ml and 11.93± 0.08 μg/ml, respectively), whilst the preventing of β-carotene bleaching was strong and similar for the three studied extracts. Unlike stem, both leaf and fruit exerted anti-edematous effect on all studied models. In conclusion, these results confirmed that C. spinosa parts possess different antioxidant and anti-inflammatory effects related to their content in polyphenol and/or flavonoid contents, and justify the wide traditional use of this plant. Extracts of C. spinosa can serve as a good source of phytoconstituents used as drugs to treat inflammatory illness.