Marine seagrasses serve as an important source of secondary metabolites with diverse pharmacological properties. This study comprehensively evaluated the phytochemical profile, functional group composition, antioxidant capacity, antimicrobial potential of Halophila decipiens extracts obtained using solvents of different polarity and qualitative phytochemical screening revealed that methanolic, ethanolic and aqueous extracts were rich in terpenoids, phenols, flavonoids, alkaloids, saponins and carbohydrates, whereas nonpolar solvents (dichloromethane, hexane, petroleum ether) were predominantly enriched with phytosterols and steroids. Quantitative estimation elucidated that the ethanolic extract contained the highest TPC (78.42 ± 1.36 mg GAE/g), while the aqueous extract exhibited the maximum TFC (77.08 ± 1.18 mg QE/g). FTIR spectral elucidation identified diverse functional entities like aromatic rings ( 690-900 cm⁻¹) C-H out of plane bending vibrations, alkenes (1600-1680 cm⁻¹) C = C stretching vibrations, ethers (1087–1220 cm⁻¹) C-O stretching vibrations, carboxylic acids (1709 cm⁻¹) C = O stretching vibrations, hydroxyls (3340–3517 cm⁻¹) O-H stretching vibrations and amines (3326–3349 cm⁻¹) N-H stretching vibrations, validating the presence of bioactive constituents responsible for the observed activities. Antioxidant capacity was evaluated through the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, the 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation decolorization assay and phosphomolybdenum assay. In the DPPH radical assay, the ethanolic extract exhibited the most pronounced activity (68.42 ± 0.41% at 100 µg/mL; IC₅₀ = 23 µg/mL), followed by the methanolic and aqueous extracts, approaching the potency of ascorbic acid (IC₅₀ = 15.5 µg/mL). Similarly, the ABTS assay revealed maximal inhibition for the aqueous extract (72.3 ± 0.30% at 100 µg/mL), while the ethanolic extract manifested superior activity at lower concentrations. The total antioxidant capacity (31.94 ± 0.60 µg ascorbic acid equivalent (AAE)/g) further substantiated the contribution of polyphenolic and flavonoid constituents. Antimicrobial evaluation demonstrated distinct inhibitory zones against Staphylococcus aureus (13.0 ± 0.06 mm), Listeria monocytogenes (20.0 ± 0.63 mm) and Pseudomonas aeruginosa (14.0 ± 0.07 mm) confirming the bactericidal efficacy of polar solvent extracts particularly, acetone, ethanol and methanol extracts. Collectively these findings affirm H.decipiens as a promising marine botanical with substantial antioxidant and antibacterial potential for natural therapeutic development.

Exploration of Halophila Decipiens Extracts for their Phytoconstituents, Radical Scavenging Capacity and Antibacterial Properties

期刊论文
发表日期：

2026年3月6日

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T. Radhamani,
A. Nirmala

摘要

Marine seagrasses serve as an important source of secondary metabolites with diverse pharmacological properties. This study comprehensively evaluated the phytochemical profile, functional group composition, antioxidant capacity, antimicrobial potential of Halophila decipiens extracts obtained using solvents of different polarity and qualitative phytochemical screening revealed that methanolic, ethanolic and aqueous extracts were rich in terpenoids, phenols, flavonoids, alkaloids, saponins and carbohydrates, whereas nonpolar solvents (dichloromethane, hexane, petroleum ether) were predominantly enriched with phytosterols and steroids. Quantitative estimation elucidated that the ethanolic extract contained the highest TPC (78.42 ± 1.36 mg GAE/g), while the aqueous extract exhibited the maximum TFC (77.08 ± 1.18 mg QE/g). FTIR spectral elucidation identified diverse functional entities like aromatic rings ( 690-900 cm⁻¹) C-H out of plane bending vibrations, alkenes (1600-1680 cm⁻¹) C = C stretching vibrations, ethers (1087–1220 cm⁻¹) C-O stretching vibrations, carboxylic acids (1709 cm⁻¹) C = O stretching vibrations, hydroxyls (3340–3517 cm⁻¹) O-H stretching vibrations and amines (3326–3349 cm⁻¹) N-H stretching vibrations, validating the presence of bioactive constituents responsible for the observed activities. Antioxidant capacity was evaluated through the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, the 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation decolorization assay and phosphomolybdenum assay. In the DPPH radical assay, the ethanolic extract exhibited the most pronounced activity (68.42 ± 0.41% at 100 µg/mL; IC₅₀ = 23 µg/mL), followed by the methanolic and aqueous extracts, approaching the potency of ascorbic acid (IC₅₀ = 15.5 µg/mL). Similarly, the ABTS assay revealed maximal inhibition for the aqueous extract (72.3 ± 0.30% at 100 µg/mL), while the ethanolic extract manifested superior activity at lower concentrations. The total antioxidant capacity (31.94 ± 0.60 µg ascorbic acid equivalent (AAE)/g) further substantiated the contribution of polyphenolic and flavonoid constituents. Antimicrobial evaluation demonstrated distinct inhibitory zones against Staphylococcus aureus (13.0 ± 0.06 mm), Listeria monocytogenes (20.0 ± 0.63 mm) and Pseudomonas aeruginosa (14.0 ± 0.07 mm) confirming the bactericidal efficacy of polar solvent extracts particularly, acetone, ethanol and methanol extracts. Collectively these findings affirm H.decipiens as a promising marine botanical with substantial antioxidant and antibacterial potential for natural therapeutic development.