title: Neuroprotective effect of a triterpenoid saponin isolated from Momordica cymbalaria Fenzl in diabetic peripheral neuropathy.
abstract: OBJECTIVE
  To investigate the neuroprotective potential of a saponin isolated from the roots of Momordica cymbalaria against peripheral neuropathy in streptozotocin-induced diabetic rats.
  
  
  METHODS
  A steroidal saponin (SMC) was isolated from M. cymbalaria Fenzl and purified by preparative high-performance liquid chromatography. Diabetes was induced in male Wister rats by injecting streptozotocin 45 mg/kg. Diabetic rats were divided into six groups for neuroprotective effect--three each for preventive and curative groups. Neuropathic analgesia was assessed by tail-flick and hot-plate methods. Dorsal root ganglion (DRG) neurons and sciatic nerves were isolated, and histopathological analysis was performed. Antioxidant activity (superoxide dismutase, catalase, and inhibition of lipid peroxidation) of the saponin was also carried out on the isolated DRG neurons and sciatic nerves to assess total oxidative stress.
  
  
  RESULTS
  In both preventive and curative protocols, rats administered with SMC showed significant decrease in tail immersion latency time and increase in pain sensitivity when compared to diabetic control group. There was improvement in the myelination and degenerative changes of the nerve fiber in both the groups, and an obvious delay in the progression of neuropathy was evident. SMC treatment showed significant decrease in superoxide dismutase, catalase activity, and lipid peroxidation in the nerves.
  
  
  CONCLUSIONS
  The steroidal saponin of M. cymbalaria (SMC) possesses potential neuroprotective effect in diabetic peripheral neuropathy with respect to neuropathic analgesia, improvement in neuronal degenerative changes, and significant antioxidant activity.
authors.affiliation: Department of Pharmacology, Karnataka College of Pharmacy, Bangalore, Karnataka, India.
authors.forename: Raju B
authors.initials: RB
authors.lastname: Koneri
authors.affiliation: Department of Pharmacology, Karnataka College of Pharmacy, Bangalore, Karnataka, India.
authors.forename: Suman
authors.initials: S
authors.lastname: Samaddar
authors.affiliation: Department of Pharmacology, Karnataka College of Pharmacy, Bangalore, Karnataka, India.
authors.forename: S M
authors.initials: SM
authors.lastname: Simi
authors.affiliation: Department of Pharmacology, Karnataka College of Pharmacy, Bangalore, Karnataka, India.
authors.forename: Srinivas T
authors.initials: ST
authors.lastname: Rao
mesh_terms: D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000150:complications*; D005727:Ganglia, Spinal / Q000187:drug effects / Q000473:pathology; D008297:Male; D029775:Momordica / Q000737:chemistry*; D018696:Neuroprotective Agents / Q000302:isolation & purification / Q000494:pharmacology*; D018384:Oxidative Stress; D010523:Peripheral Nervous System Diseases / Q000150:complications / Q000517:prevention & control*; D051381:Rats; D017208:Rats, Wistar; D012584:Sciatic Nerve / Q000187:drug effects / Q000473:pathology; D013311:Streptozocin / Q000008:administration & dosage; D023382:Toxicity Tests, Acute; D014315:Triterpenes / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity
chemical_list: D018696:Neuroprotective Agents; D014315:Triterpenes; D013311:Streptozocin
keywords: Antioxidant; diabetic peripheral neuropathy; neuroprotection; saponin of Momordica cymbalaria