Effect of Silymarin on paclytaxol-induced hyperalgesia in male mice

Abstract

Background. Paclitaxel increases the tubulin polymerisation and causes complications for mitotic ducts and is used to treat various cancers, including lung, ovaries, esophagus and head and neck. Paclitaxel has been shown to be an autonomic effect and interference with the microtubule system, causing environmental toxicity (neuropathy) in the use of this drug, which is considered as one of the side effects of this drug. Silymarin, an antioxidant flavonolignans complex derived from the herb milk thistle (Silybum marianum), is frequently used in the treatment of liver diseases which it capable of protecting liver cells directly by stabilizing the membrane permeability throug inhibiting lipid peroxidation and scavenging free radicals. Objectives: The aim of this study was to investigate the effect of silymarin on paclitaxel induced pain in mice by using the tail-flick test. Moreover, we compared the analgesic effect of silymarin and morphine (as a standard analgesic drug) on pain induced by paclitaxel. Materials and Methods: The study was performed using 56 adult male mice, weighing 25-30 g. Neuropathic pain was induced by intraperitoneal (IP) administration of paclitaxel (2mg/kg). The required dose of silymarin was dissolved in 1ml of propylene glycol and the effect of silymarin (25, 50,100 mg/kg, IP) on paclitaxel induced pain was assessed using the Tail-flick test. Results: IP administration of paclitaxel (2 mg/kg) produced significant (P < 0.01) alodynia on day 15. Silymarin (100 mg/kg, IP) caused significant (P < 0.01) increase in tail-flick latency time, in comparison with control group. The analgesic effect of morphine (5 mg/kg, IP) was greater than silymarin. Conclusion: Our result showed that silymarin reduced paclitaxel-induced pain. We suggest that silymarin can be used clinically for improving paclitaxel-induced pain in cancer patients.