Microcalorimetry coupled with principal component analysis for investigating the anti-Staphylococcus aureus effects of different extracted fractions from Dracontomelon dao

Abstract

With the prevalence resistance of Staphylococcus aureus to antibacterial agents, developing novel antibacterial agents is urgent. Recently, plant extracts have got more focus. In this study, the power-time curves produced by S. aureus under the action of the four extracted fractions (PE, CHCl 3 , EtOAc, and n-BuOH fractions) from the leaves of Dracontomelon dao were determined by microcalorimetry, and then some quantitative parameters, such as growth rate constant k, total heat output Q t , maximum heat-output power P m , and the appearance time t m were obtained. By analyzing the parameters using principal component analysis, the anti-S. aureus effects of the four fractions were systematically evaluated and compared. Meanwhile, the total flavonoid contents in these fractions were analyzed. The results have evidenced that different fractions using various extraction solvents expressed various anti-S. aureus effects, and the inhibitory effects were presented in a flavonoid content-dependent manner. The EtOAc fraction with the highest total flavonoid content (41.86 %) expressed the strongest anti-S. aureus effect with halfinhibitory concentration (IC 50 ) of 83.93 lg mL -1 , which might be applied as a novel antibacterial agent in practice for some infectious diseases. In addition, the microcalorimetric method should be strongly suggested in screening for novel antibacterial agents for fighting against pathogenic bacteria.

Antibacterial Activity of Dracontomelon Dao Extracts on Methicillin-Resistant S. Aureus (Mrsa) and E. Coli Multiple Drug Resistance (Mdr)

“…The results for S. aureus similar to study using the ethyl acetate extracted fraction of D. dao leaves. Ethyl acetate fraction had the highest total flavonoid content (41.86%), expressed the strongest anti-S. aureus effect with half-inhibitory concentration (IC 50 ) of 83.93 µg/mL (Zhao et al, 2015). The results for E. coli similar to study using the ethyl acetate extracted fraction of D. dao leaves.…”

Dracontomelon dao (Blanco) Merr. & Rolfe Anacardiaceae

“…The stem bark extracts were also reported to exhibit antibacterial potential against methicillin-resistant Staphylococcus aureus and Escherichia coli multidrug-resistant strain (Yuniati et al 2018). Ethyl acetate extracts of leaves also demonstrated an antibacterial effect on E. coli (Liu et al 2014) and S. aureus (Zhao et al 2015). The flavonoids, including cianidanol, L-epicatechin, quercetin, and luteolin, were reported as central components in leaf ethyl acetate extract of D. dao (Li et al 2017).…”

“…Also, the ethanolic extract from the sapwood of D. dao exhibited antimicrobial activity against gramnegative bacteria: Salmonella typhimurium and Klebsiella pneumoniae; grampositive bacteria: S. aureus and Bacillus subtilis; and fungi: Candida albicans and Aspergillus niger (Dela Peña et al 2019). Several systematic solvent extractions of D. dao like petroleum ether, chloroform, ethyl acetate, n-butanol, and water exhibited significant anti-E. coli and anti-S. aureus (Liu et al 2013;Zhao et al 2015), and anti-Pseudomonas aeruginosa activities (Wu et al 2015). Moreover, essential oil of D. dao has been reported to have antitumor activity (Su et al 2008).…”

Evaluation of the Antibacterial Effects of Flavonoid Combination from the Leaves of Dracontomelon dao by Microcalorimetry and the Quadratic Rotary Combination Design

“…Previous studies have showed that the ethanol extracts of the leaves of D. dao demonstrate anti- Staphylococcus aureus and anti- Bacillus subtitles activities (Khan and Omoloso, 2002 ). The subsequent studies from our research team have also indicated that the different extracts from the leaves of D. dao by means of systematic solvent extraction (including petroleum ether, chloroform, ethyl acetate, n-butanol, and water) show anti- Escherichia coli (the greatest IC 50 value is 83.93 μg·ml −1) and anti- Staphylococcus aureus (the greatest IC 0 value is 98.5 μg·ml −1 ) activities, especially the ethyl acetate fraction, the main components of which were flavonoids, including Cianidanol, L-Epicatechin, Quercetin, and Luteolin (Liu T. et al, 2013 ; Zhao et al, 2015 ), exhibit significant anti- Pseudomonas aeruginosa (IC 50 = 18.06 μg·ml −1 ) activity (Wu et al, 2015 ). The metabolic power-time ( P-t ) curves were established (Kong et al, 2009b ; Braissant et al, 2010 ; Ren et al, 2010 ; Kabanova et al, 2012 ).…”