From Phytochemicals to Molecular Targets: Integrated Antioxidant, Antimicrobial and In Silico Characterization of Ocimum americanum L.

Ocimum americanum leaves showed abundant flavonoids, phenolics, and tannins overall.
Aqueous extracts demonstrated strongest antioxidant activity across multiple validated assays.
Aqueous extracts exhibited bactericidal activity against Proteus vulgaris with MIC.
Dehydrodieugenol showed favorable binding toward bacterial DNA gyrase B protein.
Computational findings support bioactive potential, requiring further experimental validation studies.

KEYWORDS

antioxidant potential

phytochemical composition

TOPICS

ABSTRACT

Cancer is still among the major causes of death in the world and the rates are on the rise especially in the developing nations like India. The weakness of traditional medicines and the increasing disease burden have necessitated the need to investigate plant based bioactive compounds as an alternative form of medicine. The current research paper explores the phytochemical constituents, antioxidant properties, and antimicrobial property of Ocimum americanum leaf extracts grown in Tamil Nadu, India. Qualitative phytochemical screening has identified the availability of bioactive constituents such as flavonoids, alkaloids, tannins, phenols, saponins and terpenoids in the different solvent extracts. Significant total flavonoids (178 mg/g), phenols (68.41 mg/g), tannin (58.47 mg/g), and carotenoid were found in the quantitative analysis, showing a high level of phytochemicals. Antioxidant activity evaluated using both the DPPH and ABTS assays displayed concentration-dependent radical scavenging activity with the extract having 30-65% and 41-63% inhibitory activity as compared to the standard ascorbic acid, respectively. Besides, antimicrobial activity assessed through disc diffusion technique showed good inhibitory activity against bacterial pathogens, where the aqueous and methanol extracts were significantly active especially against Proteus vulgaris. The findings demonstrate the great pharmacological potential of O. americanum as a natural source of antioxidant and antimicrobial agents. Comprehensively, this research article confirms the therapeutic interest of O. americanum and indicates its possible use in the design of plant-based medication to treat diseases associated with oxidative stress and microbial infections, including cancer induced complications.

ABBREVIATIONS

ROS – Reactive Oxygen Species
ADMET – Absorption, Distribution, Metabolism, Excretion, and Toxicity
DPPH – 2,2-Diphenyl-1-picrylhydrazyl
ABTS – 2,2′-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)
FRAP – Ferric-Reducing Antioxidant Power
TAC – Total Antioxidant Capacity
MIC – Minimum Inhibitory Concentration
MBC – Minimum Bactericidal Concentration
ANOVA – Analysis of Variance
HSD – Honestly Significant Difference
SD – Standard Deviation
CI – Confidence Interval
GI – Gastrointestinal
BBB – Blood–Brain Barrier
CYP – Cytochrome P450
AMES – Ames Mutagenicity Test
PAINS – Pan-Assay Interference Structures
PDB – Protein Data Bank
ATP – Adenosine Triphosphate
DNA – Deoxyribonucleic Acid
CFU – Colony-Forming Units
TPTZ – 2,4,6-Tris(2-pyridyl)-s-triazine
AAE – Ascorbic Acid Equivalent
ESOL – Estimated Solubility
MW – Molecular Weight
TPSA – Topological Polar Surface Area
Log P – Partition Coefficient
UV – Ultraviolet
C20H22O4 – Dehydrodieugenol Molecular Formula
C10H16O2 – Limonene Dioxide 1 Molecular Formula
E. coli – Escherichia coli
S. aureus – Staphylococcus aureus
P. vulgaris – Proteus vulgaris
A. niger – Aspergillus niger

ACKNOWLEDGEMENTS

The authors gratefully acknowledge the Department of Biotechnology, St Joseph’s College (Autonomous), Trichy, Tamil Nadu, India, for providing the laboratory infrastructure, research facilities, and technical support required for conducting the phytochemical, antioxidant, and antimicrobial analyses. The authors also sincerely acknowledge Rapinat Herbarium, St Joseph’s College, Tiruchirappalli, for the botanical authentication of the Ocimum americanum specimen. The authors further thank the respective institutional authorities for their support and encouragement throughout the study.

FUNDING

This research received no external funding. All work was conducted using institutional resources without dedicated grant support.

CONFLICT OF INTEREST

The authors declare that they have no known financial, personal, academic, or other relationships that could inappropriately influence, or be perceived to influence, the work reported in this manuscript. All authors confirm that there are no competing interests to declare.

PEER REVIEW INFORMATION

Article has been screened for originality

REFERENCES (58)

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