title: Antioxidant and radioprotective effect of the active fraction of Pilea microphylla (L.) ethanolic extract.
abstract: The ethanolic extract of Pilea microphylla (L.) was defatted, successively fractionated with acetone and the residue so obtained was found to be most potent when subjected to detailed free radical scavenging and in vivo radioprotection studies. The most active fraction reacts with free radicals, such as DPPH (50 microM), ABTS(.)(-) (100 microM) and (.)OH (generated by Fenton reaction) with IC(50) value of 23.15 microg/ml, 3.0 microg/ml and 310 microg/ml, respectively. The most active fraction inhibited iron-induced lipid peroxidation in phosphatidyl choline liposomes with an IC(50) of 13.74 microg/ml. The kinetics of scavenging of DPPH and ABTS(.)(-) radicals were followed at different concentrations of the fraction by employing stopped-flow studies. The observed first order decay rate constants at 200 microg/ml and 50 microg/ml of fraction with DPPH (50 microM) and ABTS(.)(-) (50 microM) were found to be 0.4s(-1) and 2.1s(-1), respectively. The fraction when screened for in vivo radioprotection in Swiss albino mice showed 80% protection at a dose of 900 mg/kg and with a DRF of about 1.12. The fraction was also found to protect livers of irradiated mice from depletion of endogenous antioxidant enzymes like glutathione, GST, SOD, catalase and thiols. The fraction also protected the villi height, increased the number of crypt cells while offering general protection to the intestine from acute radiation effects. The fraction also protected the hematopoietic system as assessed by endogenous spleen colony assay, contributing to the overall radioprotective ability.
authors.affiliation: Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal 576104, Karnataka, India.
authors.forename: K R
authors.initials: KR
authors.lastname: Prabhakar
authors.forename: V P
authors.initials: VP
authors.lastname: Veerapur
authors.forename: Punit
authors.initials: P
authors.lastname: Bansal
authors.forename: Vipan Kumar
authors.initials: VK
authors.lastname: Parihar
authors.forename: Machendar
authors.initials: M
authors.lastname: Reddy Kandadi
authors.forename: P
authors.initials: P
authors.lastname: Bhagath Kumar
authors.forename: K I
authors.initials: KI
authors.lastname: Priyadarsini
authors.forename: M K
authors.initials: MK
authors.lastname: Unnikrishnan
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D052160:Benzothiazoles / Q000494:pharmacology; D001713:Biphenyl Compounds; D002374:Catalase / Q000378:metabolism; D003114:Colony-Forming Units Assay; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D000431:Ethanol / Q000737:chemistry; D016166:Free Radical Scavengers / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism; D020128:Inhibitory Concentration 50; D007422:Intestines / Q000166:cytology / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects; D007700:Kinetics; D015227:Lipid Peroxidation / Q000187:drug effects* / Q000528:radiation effects; D051379:Mice; D008871:Microvilli / Q000187:drug effects / Q000473:pathology / Q000528:radiation effects; D010713:Phosphatidylcholines / Q000378:metabolism; D010851:Picrates / Q000494:pharmacology; D010936:Plant Extracts / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D013154:Spleen / Q000166:cytology / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects; D013347:Subcellular Fractions / Q000737:chemistry; D013451:Sulfonic Acids / Q000494:pharmacology; D027003:Urticaceae / Q000737:chemistry*; D014916:Whole-Body Irradiation / Q000379:methods
chemical_list: D000975:Antioxidants; D052160:Benzothiazoles; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010713:Phosphatidylcholines; D010851:Picrates; D010936:Plant Extracts; D011837:Radiation-Protective Agents; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D000431:Ethanol; C004931:1,1-diphenyl-2-picrylhydrazyl; D002374:Catalase; D005978:Glutathione