title: Evaluation of antioxidant and antibacterial activities of aqueous, methanolic and alkaloid extracts from Mitragyna speciosa (Rubiaceae family) leaves.
abstract: Studies on the antioxidant and antimicrobial activities of Mitragyna speciosa leaf extracts are lacking. In this study the antioxidant properties of water, methanolic and alkaloid M. speciosa leaf extracts were evaluated using the DPPH (2,2-diphenyl-1- picrylhydrazyl) radical scavenging method. The amount of total phenolics and flavanoid contents were also estimated. The DPPH IC(50) values of the aqueous, alkaloid and methanolic extracts were 213.4, 104.81 and 37.08 microg/mL, respectively. The total phenolic content of the aqueous, alkaloid and methanolic extracts were 66.0 mg, 88.4, 105.6 mg GAE/g, respectively, while the total flavanoid were 28.2, 20.0 and 91.1 mg CAE/g respectively. The antioxidant activities were correlated with the total phenolic content. This result suggests that the relatively high antioxidant activity of the methanolic extract compared to aqueous and alkaloid extract could be possibly be due to its high phenolic content. The aqueous, alkaloid and methanolic extracts were screened for antimicrobial activity. The extracts showed antimicrobial activity against Salmonella typhi and Bacillus subtilis. The minimum inhibitory concentrations (MICs) of extracts determined by the broth dilution method ranged from 3.12 to 6.25 mg/mL. The alkaloid extract was found to be most effective against all of the tested organisms.
authors.affiliation: Centre for Drug Research, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia.
authors.forename: Suhanya
authors.initials: S
authors.lastname: Parthasarathy
authors.forename: Juzaili
authors.initials: J
authors.lastname: Bin Azizi
authors.forename: Surash
authors.initials: S
authors.lastname: Ramanathan
authors.forename: Sabariah
authors.initials: S
authors.lastname: Ismail
authors.forename: Sreenivasan
authors.initials: S
authors.lastname: Sasidharan
authors.forename: Mohd I Mohd
authors.initials: MI
authors.lastname: Said
authors.forename: Sharif Mahsufi
authors.initials: SM
authors.lastname: Mansor
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D000432:Methanol / Q000737:chemistry; D032065:Mitragyna / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D000470:Alkaloids; D000900:Anti-Bacterial Agents; D000975:Antioxidants; D010936:Plant Extracts; D014867:Water; D000432:Methanol