BIO-GUIDED STUDY ON <i>MELASTOMA MALABATHRICUM</i> LINN LEAVES AND ELUCIDATION OF ITS BIOLOGICAL ACTIVITIES

Abstract

The present study aimed to isolate and identify constituents with antibacterial activity from the Methanol extract of <i>Melastoma malabathricum</i> leaves (MMML) through bioassay guided fractionation. Furthermore, the study scoped to evaluate the cytotoxic effects of <i>M. malabathricum</i> leaves fractions for possible protective effect of antoxidative constituents present in the fractions. The MMML extract was fractionated by Vacuum Liquid Chromatography (VLC) to afford <i>M. malabathricum</i> leaves fractions (ML1-ML6) of increasing polarities. Antibacterial activity of plant extract, six fractions and two bioactive constituents against <i>Staphylococcus aureus</i> reference strain, methicillin-resistant <i>Staphylococcus aureus</i> reference strain (MRSA), eleven clinical MRSA isolates, three clinical <i>Pseudomonas aeruginosa</i> isolates and <i>P. aeruginosa</i> reference strain was evaluated using Minimum Inhibitory Concentration (MIC). The bioactive constituents responsible for antibacterial activity of MMML, fractions were detected by direct TLC-bioautography. The data obtained from MIC assay showed that ML5 effectively inhibited growth of all test bacterial pathogens. Direct TLC-bioautography revealed that ML5 had the highest number of antibacterial compounds. Following bioassay-guided fractionation, Kaempferol-3-<i>O</i>-(2”, 6”-di-<i>O-p-trans</i>-coumaroyl)-<i>β</i>-glucopyranoside and Kaempferol were isolated from ML5. The structures of bioactive compounds were elucidated using Nuclear Magnetic Resonance (NMR) spectroscopy from ¹HNMR and ¹³CNMR. In addition, the cytotoxic effect of <i>M. malabathricum</i> leaves fractions (ML1-ML6) revealed that ML5 had the highest Cytotoxicity Concentration (CC₅₀) at 0.75 mg mL^-1, an observation traceable to the presence of flavonoids constituents with antioxidant properties. Therefore, the results clearly indicate that MMML, fractions and bioactive constituents have profound antibacterial activity. Furthermore, antioxidative compounds from ML5 fraction exert their effects by enhancing the level of CC₅₀

RETRACTED ARTICLE: Melastoma malabathricum Linn attenuates complete freund’s adjuvant-induced chronic inflammation in Wistar rats via inflammation response

“…MM plant has been utilized in the treatment of inflammation and rheumatism by the local people in Dibrugarh district, Assam. The plant is rich source of different chemical constituents such as α-amyrin, patriscabatine and auranamide [13], kaempferol-3-O-(2”,6”-di-O-p-trans-coumaroyl)glucoside, quercitrin, Mefloquine, (+) 3,4-Dehydroproline amide, 2-(3,5-Diphenyl-pyrazol-1-yl) benzothiazole, Kaempferol, Kaempferol-3-O-(2”, 6”-di-O-p-trans-coumaroyl)-β-glucopyranoside [14, 52]. …”

Transcriptomic Response inPseudomonas aeruginosatowards Treatment with a Kaempferol Isolated fromMelastoma malabathricumLinn Leaves

“…Previous studies have elucidated that K F can inhibit P. aeruginosa growth [6,7]. In regard to this inhibitory effect, the approach of transcriptomic analysis is useful to identify the differentially expressed genes in this bacterium.…”

“…Strains of P. aeruginosa are aeruginosa infections are increasingly required and gaining more and more attention [4]. Previous studies by our research group demonstrated that K F can induce P. aeruginosa cell wall damage [6,7]. us, we decided to investigate the gene expression profile of P. aeruginosa growing in kaempferol-3-O-(2′,6′-di-O-trans-p-coumaroyl)-β-D glucopyranoside isolated from Melastoma malabathricum known to locals in Malaysia as "senduduk."…”

Natural product (Abutilon hirtum extracts) in treating environment - related infections (Salmonellosis and Typhoid fever)

“…The extract of A.hirtum was fractionated by column chromatography process as reported by Dawang et al [20] using the following mobile phase; n-hexane: Methanol(MeOH) as (10:0, 15:1,9:4,8:2,7: 3,6:4,5:5,4:6,3:7,2:8) and MeOH:Ethanol (EtoAC) (10:0,9:1,8:2, 7:3,6:4,5:5) and the effluent was collected in a small fraction (150cm3) in a beaker. Fractions from crude plant extract were pooled together based on similar profile on Thin Layer Chromatography (TLC, AlugramXtra SIL G/uv 254, MAC HERY-NAGEL GmbH and Co. Kg, Germany) to yield 11 A.hirtum leaf fractions of AF1-AF11 due to variance in polarity and types of constituents extracted [21].However only 1 most effective fraction obtained after preliminary bioassay of the 11 fractions was tested against the isolates.…”