Review - Phytomedicine (Neem)

Abstract

Neem (Azadirachta indica A. Juss) is a renowned tree in Asian and African countries, known for its extensive medicinal and industrial applications due to a rich array of bioactive compounds, particularly nutraceuticals and triterpenoids like azadirachtin, nimbin, and salannin. This review compiles recent research on the extraction, characterisation, and encapsulation of neem oil and its extracts into advanced delivery systems such as hydrogels, liposomes, and nanocapsules, alongside their biological evaluations and toxicity profiles. Various extraction methods, including hot (Soxhlet) and cold (maceration) solvent extraction, and hydro-distillation, have been employed to optimise yield, with methanol showing optimal results for oil extraction in some studies (7.68 ± 0.11% by weight). Characterisation techniques like FTIR, H-NMR, and LCMS have confirmed the presence of diverse functional groups and specific compounds. To overcome challenges such as photosensitivity and rapid degradation, and to enhance targeted delivery and efficacy, neem extracts have been successfully incorporated into hydrogels, liposomes, and polymeric nanocapsules. Liposomal formulations prepared with soya lecithin and cholesterol (4:1 ratio) showed 69.52 ± 1.9% entrapment efficiency and sustained drug diffusion (62.178% ± 0.91 over 24 hours), proving stable for three months at 2–8°C. This comprehensive review underscores neem\'s potential as a source of valuable bioactive compounds and the critical role of nanotechnology in developing efficient and safer delivery systems for its application in food, pharmaceuticals, agriculture, and cosmetics

Introduction

Phytomedicine refers to herbal medicines derived from plants that possess therapeutic and healing properties. The use of herbs in healthcare dates back to ancient civilizations, with early documentation such as Sheng Nong’s Herbal Book (around 3000 BC) describing hundreds of medicinal plants. Although Earth has nearly 420,000 plant species, only a limited portion is fully understood for medicinal, nutritional, and research use. Ancient people learned the medicinal value of herbs through observation and trial, forming the basis of traditional systems like Chinese Herbal Medicine (CHM) and Indian herbal medicine. Today, 3.5–4 billion people rely on herbal medicine for primary healthcare, and 70–95% of people in developing countries still depend on plant-based treatments. Plants survive using diverse secondary metabolites that act as natural defenses and many of these bioactive compounds are useful in treating human diseases.

Neem (Azadirachta indica)

Neem is a medicinal tree native to the Indian subcontinent and widely grown in tropical regions. It contains a rich variety of phytochemicals such as azadirachtin, nimbin, nimbidin, salannin, quercetin, and many polyphenols and triterpenes. Neem is an evergreen tree reaching 15–20 meters in height, producing olive-like fruits with fibrous pulp and seeds rich in medicinal oil.

Neem's leaves, seeds, fruits, bark, and oil contain antibacterial, antifungal, antiviral, antioxidant, and insecticidal compounds. Quercetin and β-sitosterol contribute to its strong antimicrobial activity. Neem oil contains limonoids, glycerides, and polyphenols and has a distinctive bitter and garlic-like odor.

Uses of Neem

• Widely used in Ayurveda for over 2,000 years.

• Has antifungal, antibacterial, antiviral, antidiabetic, contraceptive, and sedative properties.

• Called the “village pharmacy” because all parts of the tree are medicinal.

• Neem compounds can act as spermicides.

• Neem oil is used in soaps, shampoos, cosmetics, and for treating acne and skin infections.

• Effective as a natural pesticide against 500+ insects by disrupting their growth.

• Safe, eco-friendly, and non-poisonous to beneficial animals and insects.

• Used for fungal infections due to compounds like nimbidol and gedunin that inhibit fungal growth.

Conclusion

Neem is an extraordinarily versatile and ecologically beneficial plant, serving as a natural resource with widespread applications in agriculture, medicine, and the environment. Its rich composition of bioactive compounds, such as azadirachtin, provides antimicrobial, anti-inflammatory, anti-diabetic, and anti-carcinogenic properties. This makes neem invaluable as a sustainable and environmentally friendly alternative to synthetic pesticides and medicines. Continued research into neem\'s complex chemical interactions and mechanisms will likely unlock even more applications and insights for future human welfare and global ecological health.

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Copyright

Copyright © 2025 Maneesh Kumar Pandey, Sujeet Pratap Singh, Pramod Mishra, Tarkeshwar Prasad Shukla. 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.