A Review: Study of Tulsi as Immune Booster

Abstract

Tulsi (Ocimum sanctum), revered in Ayurveda as the \"Queen of Herbs,\" has been extensively studied for its remarkable immunomodulatory properties, positioning it as a potent natural immune booster. This review consolidates contemporary scientific research and traditional wisdom to evaluate Tulsi’s multifaceted role in enhancing immune function. Rich in bioactive compounds such as eugenol, ursolic acid, rosmarinic acid, and ?-caryophyllene, Tulsi exerts its immune-enhancing effects through antioxidant, anti-inflammatory, antimicrobial, and adaptogenic mechanisms. Preclinical and clinical studies demonstrate that Tulsi augments innate and adaptive immunity by modulating key immune cells, including macrophages, neutrophils, T-cells, and natural killer (NK) cells, while also enhancing antibody production. Its ability to mitigate oxidative stress and suppress pro-inflammatory cytokines (e.g., TNF-?, IL-6) further supports its role in maintaining immune homeostasis. Additionally, Tulsi’s adaptogenic properties help counteract stress-induced immunosuppression by regulating the hypothalamic-pituitary-adrenal (HPA) axis, thereby bolstering overall immune resilience. Emerging evidence suggests its efficacy against viral and bacterial infections, making it particularly relevant in the post-pandemic era. Despite promising findings, further well-designed clinical trials are needed to standardize dosage and optimize therapeutic protocols. This review underscores Tulsi’s potential as a safe, holistic, and evidence-based immune booster, bridging the gap between traditional medicine and modern scientific validation

Introduction

The immune system protects the body against infections, toxins, and chronic diseases. Interest in natural immunomodulators has grown, especially after COVID-19 highlighted the need for safe immunity boosters. Ocimum sanctum (Tulsi or Holy Basil), a traditional Ayurvedic herb, is recognized for its immune-enhancing properties due to its bioactive compounds like eugenol, ursolic acid, and rosmarinic acid. These compounds exhibit antioxidant, anti-inflammatory, antimicrobial, and adaptogenic effects, which collectively improve immune function by boosting immune cell activity, reducing harmful inflammation, and mitigating stress-related immune suppression.

Phytochemicals in Tulsi support both innate and adaptive immunity by increasing macrophage and natural killer cell activity, promoting T- and B-cell responses, and modulating cytokines to maintain immune balance. Tulsi also counters oxidative stress and enhances antibody production, helping the body combat infections and inflammatory conditions.

Traditionally used for respiratory illnesses, fever, and stress, Tulsi’s effectiveness is supported by modern studies showing improved immune markers and reduced incidence of infections. Clinical trials, though limited, demonstrate its potential in enhancing immune responses and lowering inflammation, while being generally safe at recommended doses.

This review consolidates traditional knowledge with scientific evidence, highlighting Tulsi as a promising natural immune booster and adaptogen, while calling for more standardized clinical research to confirm optimal dosing and long-term safety.

Conclusion

Tulsi (Ocimum sanctum) emerges as a scientifically validated and traditionally revered natural immune booster, with multifaceted mechanisms that enhance both innate and adaptive immunity. Its rich phytochemical profile—including eugenol, ursolic acid, and rosmarinic acid—confers potent antioxidant, anti-inflammatory, antimicrobial, and adaptogenic properties, making it effective in combating infections, reducing oxidative stress, and modulating immune responses. Preclinical and clinical studies demonstrate that Tulsi enhances macrophage activity, T-cell proliferation, antibody production, and NK cell function, while also mitigating stress-induced immunosuppression by regulating cortisol levels. Traditional Ayurvedic applications further support its role in respiratory health, fever management, and overall immune resilience. However, while existing evidence is compelling, more large-scale, randomized controlled trials (RCTs) are needed to standardize dosage, evaluate long-term safety, and compare efficacy with conventional immune-modulating agents. Given its safety, accessibility, and holistic benefits, Tulsi stands as a promising adjunct therapy in preventive healthcare, particularly in an era where natural immunity enhancers are in high demand. Future research should focus on bioavailability optimization, synergistic formulations (e.g., with turmeric or ashwagandha), and mechanistic studies in human trials to fully harness its therapeutic potential.

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Copyright © 2025 Mr. Prem Jadhav, Mrs. Aqsa Z. Shaikh, Mr. Rishikesh S. Bachhav, Mr. Dev Rawal, Mr. Siddharth Lohar. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.