GC-MS based metabolomic profiling of Aporosa cardiosperma (Gaertn.) Merr. leaf extracts and evaluating its therapeutic potential

Abstract

Aporosa cardiosperma is a plant species majorly found in the Indian Western Ghats that belongs to the phyllanthaceae family with ethnobotanical importance. Using a Fourier Transform-Infrared Spectrometer (FT-IR) and Gas Chromatography-Mass Spectrometry (GC-MS) for evaluating leaf extracts of A. cardiosperma, significant functional groups and metabolite constituents were determined, and its total flavonoid, phenol, and tannin content were quantified. Further, its antibacterial efficacy was investigated against microorganisms that cause fish and human disease and are resistant to common antibiotics, including Staphylococcus aureus, Bacillus subtilis, Mycobacterium tuberculosis, Klebsiella pneumoniae, Aeromonas hydrophila, and Pseudomonas aeruginosa. Regarding the outcomes of GC-MS analysis, the primary metabolites in the A. cardiosperma leaf extracts were heneicosane (57.06%), silane (13.60%), 1-heptadecene (10.09%), 3-hexadecene (9.99%), and pentadecane (9.54%). In comparison to other solvents, methanolic extract of A. cardiosperma leaves had increased phenolic, flavonoid, and tannin content; these findings are consistent with in vitro antioxidant potential and obtained that the methanolic extract (100 µg/mL) exhibited the higher percentage of inhibition in DPPH (82.35%), FRAP (86.20%), metal chelating (72.32%), and ABTS (86.06%) antioxidant assays respectively. Similar findings were found regarding the antibacterial efficacy against pathogenic bacteria. Comparatively, to other extracts, methanolic extracts showed more significant antibacterial activity at a lower minimum inhibitory concentration (MIC) value (250 µg/mL), whilst ethyl acetate and hexane solvent extracts of A. cardiosperma leaves had higher MIC values 500 µg/mL and 1000 µg/mL respectively. The antimicrobial potential was validated by investigating bacterial growth through the extracts acquired MICs and sub-MICs range. Bacterial growth was completely inhibited at the determined MIC range. In conclusion, A. cardiosperma leaf extract's phytochemical fingerprint has been determined, and its potent antibacterial and antioxidant activities were discovered. These findings of the current study will pave the way for developing herbal treatments from A. cardiosperma for various fish and human diseases.

Figure 1

Standard graph of Gallic acid equivalents (a), Quantitative analysis of the total phenolic content (b), Standard graph of Tannic acid equivalents (c) and Quantitative analysis of the total tannin content (d), Standard graph of Quercetin equivalents (e), Quantitative analysis of the total flavonoid content (f) present in the various extracts of A. cardiosperma leaf.

Figure 2

FT-IR spectrum of A. cardiosperma leaf extracts.

Figure 3

GC–MS chromatogram of the various A. cardiosperma leaf extract.

Figure 4

DPPH radical scavenging activity of different extracts of A. cardiosperma leaf (a). FRAP activity of different extracts of A. cardiosperma leaf (b). The metal chelating activity of various extracts of A. cardiosperma leaf (c). ABTS radical scavenging activity of different extracts of A. cardiosperma leaf (d). Data are the means ± standard error of the mean of three replicates. Different superscript asterisk indicates a significant difference between treatments, and “ns” indicates no significance (P < 0.05, Tukey’s multiple comparisons test).

Figure 5

Growth curves of S. aureus (a) under the influence of various extracts of A. cardiosperma leaf Methanol (i), Ethyl acetate (ii), and Hexane (iii). Growth curves of B. subtilis (b) under the influence of various extracts of A. cardiosperma leaf Methanol (i), Ethyl acetate (ii), and Hexane (iii). Growth curves of M. tuberculosis (c) under the influence of various extracts of A. cardiosperma leaf Methanol (i), Ethyl acetate (ii), and Hexane (iii). All the experiments were compared with positive control: Streptomycin (25 µg/mL).

Figure 6

Growth curves of A. hydrophila (a) under the influence of various extracts of A. cardiosperma leaf Methanol (i), Ethyl acetate (ii), and Hexane (iii). Growth curves of K. pneumoniae (b) under the influence of various extracts of A. cardiosperma leaf Methanol (i), Ethyl acetate (ii), and Hexane (iii). Growth curves of P. aeruginosa (c) under the influence of various extracts of A. cardiosperma leaf Methanol (i), Ethyl acetate (ii), and Hexane (iii). All the experiments were compared with positive control: Streptomycin (25 µg/mL).