Phytochemical Extracts of Leucas aspera and Dahlia pinnata Exhibit Antimicrobial Properties in Escherichia coli and Enterococcus faecalis

Abstract

Background:: Phytochemicals such as tannins, alkaloids, flavonoids, and peptides been found to have antimicrobial activity against a variety of bacterial strains. Objective:: However, optimal extraction procedures for these phytochemicals and their efficacy evaluation against certain pathogenic bacterial strains remain unclear. Method:: Therefore, in this study phytochemicals from Leucas aspera (L. aspera) and Dahlia pinnata (D. pinnata) were extracted by hot and cold extraction methods using water and methanol as solvents. In addition, antimicrobial activity of L. aspera and D. pinnata extracts against bacterial strains such as the gram-negative Escherichia coli (E. coli) and the gram-positive Enterococcus faecalis (E. faecalis) were performed by Minimal Inhibitory Concentration (MIC) and CFU quantification assays. Results:: The majority of the phytochemicals such as protein, carbohydrate, tannins, flavonoids, phenols, and saponins were present in our extracts but steroids were absent in the extract. Protein, tannins, flavonoids, phenols, and saponins were present in both L. aspera and D. pinnata. The yield of proteins was high (1.990 ± 0.091 mg/ml) in methanol extracts of L. aspera and low (0.199 mg/ml) in aqueous extracts. However, the yield of tannins was high (1.713 ± 0.079 mg/ml) in methanol extracts of D. pinnata and low (0.528 ± 0.136 mg/ml) aqueous extracts. The MIC of D. pinnata extracts were found to be 200 mg/ml for both E. coli and E. faecalis. However the L. aspera extracts had a MIC of 100 mg/ml and 200 mg/ml on E. coli and E. faecalis, respectively. Conclusion:: This article demonstrated the potential use of phytochemicals as novel antimicrobial compounds against bacterial infections.

Phytochemical profile of petals from black Dahlia pinnata by flow injection analysis–electrospray ionization–Fourier transform ion cyclotron resonance mass spectrometry

“…20,21 There is little information on the phytochemical profile of Dahlia; however, a study conducted on D. pinnata, whose extraction was performed using water and methanol (polar solvents), revealed the presence of flavonoids, saponins, and tannins and the absence of reducing sugars and steroids. 22 The results of the quantitative phytochemical study are presented in Table 2. The phenol, flavonoid, tannin, and total sugar contents in the M extract are higher than in the DM and H extracts.…”

Enterococcus faecalis thrives in dual-species biofilm models under iron-rich conditions

“…Colony Forming Units (CFU) assay was performed for both the single and dual-species bacterial cultures [13]. One ml of bacterial culture at 0.5 OD 588 was chosen and serially diluted from 10 − 1 to 10 − 8 in LB broth.…”

“…Once the plates were solidi ed, 5 µL of Kanamycin with various concentrations (1000, 500, 100, and 50µg/ml) was pipetted over the agar surface and allowed to incubate overnight at 37°C. The culture plates were then observed for the zone of inhibition [13]. All the experiments were done in triplicates.…”

Image analysis reveals cellular fragmentation of Spirulina platensis upon treatment with heavy metal ions

“…Studies have demonstrated the possibility of using MATLAB-based techniques to quantify the changes in E. faecalis protein localization pattern upon treatment with antimicrobial peptides (Kandaswamy et al, 2013). Although earlier studies have reported that compounds such as phytochemicals from tropical plants and nanoparticles (Govindarajan, Selvaraj, et al, 2022;Saravanan et al, 2020;Sivaramakrishnan et al, 2019) can target or kill bacterial cells but those studies were limited to few (1-10) compounds due to lack of fully automated high-throughput image analysis methods. Apart from screening, one can also take advantage of image analysis tools to perform phenotypic analysis that would result in the identification of bacterial pathotypes Govindarajan et al, 2020;Shanmugasundarasamy et al, 2022), which will be immensely helpful in the identification of water-borne pathogens for environmental water quality monitoring.…”