HPLC Analysis, Acute toxicity and Assessment of Antioxidant and Anti-inflammatory Capacity of different Extracts of Equisetum arvense

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.