title: Antioxidant and antibacterial activity of different parts of Leucas aspera.
abstract: OBJECTIVE
  To evaluate antioxidant, antimicrobial and cytotoxic activity of different parts (root, flower, leaf and stem) of Leucas aspera (L. aspera) (Labiatae).
  
  
  METHODS
  Different parts of L. aspera were extracted with 80% (v/v) methanol. The methanol extracts were subjected to antioxidant, antimicrobial and brine shrimp lethality assay.
  
  
  RESULTS
  All the extracts showed moderate to potent antioxidant activity, among which the root extract demonstrated the strongest antioxidant activity with the IC50 value of 6.552 µg/mL. Methanol extract of root possessed antioxidant activity near the range of vitamin E and thus could be a potential rich source of natural antioxidant. In case of antimicrobial screening, crude extracts of root, flower, leaf and stem showed notable antibacterial activity against tested microorganisms. The root extract showed the highest mean zone of inhibition ranging from 9.0-11.0 mm against tested microorganisms, at a concentration of 100 mg/mL. In the brine shrimp lethality bioassay, it was evident that the methanol root extract did not show significant toxicity. The LC50 value for 12 h and 24 h observation was 2.890 mg/mL and 1.417 mg/mL, respectively.
  
  
  CONCLUSIONS
  The present finding suggests that the methanol root extract of L. aspera could be developed as pharmaceutical products.
authors.affiliation: Institute for Research in Molecular Medicine, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia.
authors.forename: Ai Lan
authors.initials: AL
authors.lastname: Chew
authors.forename: Jeyanthi James Antony
authors.initials: JJ
authors.lastname: Jessica
authors.forename: Sreenivasan
authors.initials: S
authors.lastname: Sasidharan
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D001156:Artemia / Q000187:drug effects; D001419:Bacteria / Q000187:drug effects; D001713:Biphenyl Compounds / Q000378:metabolism; D019686:Lamiaceae / Q000737:chemistry*; D000432:Methanol; D050296:Microbial Viability / Q000187:drug effects; D010851:Picrates / Q000378:metabolism; D035261:Plant Components, Aerial / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D018517:Plant Roots / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D001713:Biphenyl Compounds; D010851:Picrates; D010936:Plant Extracts; C004931:1,1-diphenyl-2-picrylhydrazyl; D000432:Methanol
keywords: Antimicrobial activity; Antioxidant activity; Cytotoxic activity; Inhibition of zone; Labiatae; Leucas aspera; Natural antioxidant