In vivo acute toxicity, analgesic and anti-inflammatory activities of phenolic extract of Matricaria pubescens

Abstract

Purpose: To evaluate the in vivo acute toxicity, analgesic and anti-inflammatory proprieties of the phenolic extract of Matricaria  pubescens (Desf.) Schultz (Asteraceae).

Methods: Acute toxicity assessment was carried out on 18 mice that were divided equally into three groups and treated orally with saline,  2500 and 5000 mg/kg of M. pubescens extract, respectively. The evaluation of peripheral analgesic activity was done by applying  acetic acid-induced contortion test on 40 mice. The mice were divided into 5 equal groups of 8 mice each. Negative and positive control groups were treated orally with saline (1 %) and acetylsalicylic acid (200 mg/kg), respectively. Other groups were treated with 50, 100 and  200 mg/kg of M. pubescens extract. Study groups were administered saline, diclofenac potassium (10 mg/kg) and M. pubescens extract  orally at 50, 100, and 200 mg/kg. Central analgesic activity was carried out using the tail immersion test. The distribution and treatment of  the mice was similar to the analgesic model. Anti-inflammatory effect was evaluated by carrageenan-induced mice paw edema.  

Results: Acute toxicity results showed that the LD50 of M. pubescens phenolic extract is above 5000 mg/kg, which means that this extract  is safe. Peripheral and central analgesic data revealed that different doses of extract significantly inhibited abdominal  contractions and reduced pain caused by heat compared to control (p ˂ 0.05). Anti-inflammatory activity data indicate significant  inhibition of inflammatory edema at various doses compared to diclofenac potassium (p ˂ 0.05).

Conclusion: The phenolic extract of M.  pubescens exerts significant peripheral, central analgesic and anti-inflammatory activities in mice. However, further investigations are  required to ascertain the potentials of the extract for its clinical development.