Siddha Herbal Extracts as Natural Antimicrobial Agents Against Multidrug-Resistant Bacteria
Keywords:
Siddha medicine, Multidrug-resistant bacteria, Antimicrobial resistance, Herbal extracts, Medicinal plants, MRSA, Anti-biofilm activity, Natural antimicrobial agents, Phytochemicals, Drug discovery.Abstract
Background: Antimicrobial resistance (AMR) has emerged as one of the most critical global public health challenges of the twenty-first century. The rapid spread of multidrug-resistant (MDR) bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, carbapenem-resistant Pseudomonas aeruginosa, and Acinetobacter baumannii, has significantly reduced the effectiveness of conventional antibiotics. Consequently, there is an urgent need to identify novel antimicrobial agents from natural sources. The Siddha system of medicine, a traditional healthcare system practiced in South India, possesses a rich repository of medicinal plants with documented antimicrobial properties. Increasing scientific evidence suggests that Siddha herbal extracts contain bioactive phytochemicals capable of inhibiting the growth of multidrug-resistant bacterial pathogens.
Objective: To review the antimicrobial potential of Siddha herbal extracts against multidrug-resistant bacteria, summarize the current scientific evidence regarding their antibacterial mechanisms, and evaluate their future prospects as alternative or complementary antimicrobial agents.
Methods: A comprehensive literature review was conducted using electronic databases including PubMed, Scopus, Web of Science, ScienceDirect, Google Scholar, SpringerLink, and the AYUSH Research Portal. Relevant studies published between 2000 and 2025 were screened and analyzed. Classical Siddha texts, experimental investigations, phytochemical studies, molecular docking analyses, anti-biofilm studies, clinical reports, and review articles related to Siddha herbal extracts and antimicrobial resistance were included in the review.
Results: The review identified several Siddha medicinal plants with significant antibacterial activity against multidrug-resistant bacteria, including Andrographis paniculata (Nilavembu), Azadirachta indica (Veppam), Tinospora cordifolia (Seenthil), Ocimum tenuiflorum (Tulsi), Phyllanthus emblica (Nellikai), Piper longum (Thippili), Syzygium aromaticum (Kirambu), and Terminalia chebula (Kadukkai). These plants contain diverse phytochemicals such as andrographolide, azadirachtin, berberine, eugenol, gallic acid, piperine, flavonoids, and tannins that exhibit antibacterial effects through multiple mechanisms, including disruption of bacterial cell walls and membranes, inhibition of protein and nucleic acid synthesis, suppression of quorum sensing pathways, and prevention of biofilm formation. Several studies also reported synergistic interactions between Siddha herbal extracts and conventional antibiotics, suggesting their potential role in overcoming antimicrobial resistance.
Conclusion: Siddha herbal extracts represent a promising source of natural antimicrobial agents against multidrug-resistant bacteria. Their broad-spectrum antibacterial activity, anti-biofilm effects, immunomodulatory properties, and multitarget mechanisms provide a strong scientific basis for further investigation.
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