title: Effects of luteolin and luteolin-morphine co-administration on acute and chronic pain and sciatic nerve ligated-induced neuropathy in mice.
abstract: Background Neuropathic pain (NP) is a common condition accompanied by nerve injury. To date, there is no definite treatment approved for this disorder. In addition, many drugs that are used for NP cause adverse reactions. Luteolin is a naturally occurring flavonoid with diverse pharmacological properties such as anti-inflammatory, antioxidant and anticancer. We sought to investigate luteolin effects on chronic, acute and neuropathic pain as well as its potential to increase morphine anti-nociceptive effects in mice. Methods Albino mice (20-25 g) were randomly divided into 14 groups (n=7) including morphine 1 mg/kg body weight +luteolin (5 mg/kg body weight), morphine (9 mg/kg body weight, i.p.), luteolin (2.5, 5 and 10 mg/kg body weight), imipramine 40 mg/kg body weight and normal saline (NS) (0.9 %) as vehicle and subjected to hot plate test. Formalin test was done in the following groups: NS, diclofenac sodium (10 mg/kg body weight, i.p.), morphine (9 mg/kg body weight, i.p.) and luteolin (2.5, 5 and 10 mg/kg body weight). Results Administration of luteolin single dose (5 and 10 mg/kg body weight) significantly reduced neuropathic pain ( p<0.05$\rm{p}<0.05$) in comparison to negative control. Anti-nociceptive effects of luteolin were comparable to imipramine as the standard positive control ( p<0.001$\rm{p}<0.001$). Co-administration of luteolin and morphine potentiated morphine 1 mg/kg body weight painkilling effects ( p<0.001$\rm{p}<0.001$). Conclusions Our results showed that luteolin alone reduces neuropathic pain. Furthermore, when co-administered with morphine 1 mg/kg body weight, luteolin potentiates morphine effects. Therefore, luteolin-morphine co-administration might be a valuable alternative for the conventional treatment.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Hashemzaei
authors.forename: Mina
authors.initials: M
authors.lastname: Abdollahzadeh
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Iranshahi
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Golmakani
authors.forename: Ramin
authors.initials: R
authors.lastname: Rezaee
authors.forename: Kaveh
authors.initials: K
authors.lastname: Tabrizian
mesh_terms: D000208:Acute Disease; D000700:Analgesics / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D059350:Chronic Pain / Q000188:drug therapy*; D004195:Disease Models, Animal; D004359:Drug Therapy, Combination; D005557:Formaldehyde; D041743:Herb-Drug Interactions; D006358:Hot Temperature; D047311:Luteolin / Q000494:pharmacology / Q000627:therapeutic use*; D051379:Mice; D009020:Morphine / Q000494:pharmacology / Q000627:therapeutic use*; D059226:Nociceptive Pain / Q000188:drug therapy*; D010146:Pain / Q000188:drug therapy; D059408:Pain Management; D059348:Peripheral Nerve Injuries / Q000150:complications; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*; D012584:Sciatic Nerve; D020426:Sciatic Neuropathy / Q000188:drug therapy*; D012585:Sciatica / Q000188:drug therapy
chemical_list: D000700:Analgesics; D010936:Plant Extracts; D005557:Formaldehyde; D009020:Morphine; D047311:Luteolin