Neem (Azadirachta indica A. Juss): a multifaceted tree & an elixir in the traditional system of Indian medicine

Neem, called ‘Arista’ in Sanskrit, meaning ‘reliever of sickness’, often referred to as ‘the bitter gem’, is one of the most celebrated plants in the Indian Traditional Healthcare system for its diverse medicinal properties. Scientifically, Azadirachta indica, is classified in the Mahogany (Meliaceae) family. Neem stands out as a beacon of promise for the twenty-first century. Each part of the Neem tree, i.e., its flowers, leaves, fruits, seed, seed oil, Neem cake, and gum, has therapeutic properties. Researchers have identified nearly 300 distinct phytochemicals within the Neem tree, having diverse pharmacological effects like antimicrobial, antiviral, antifungal, anti-inflammatory, anti-plasmodial, antiseptic, antipyretic, anti-diabetic, and anti-ulcer activities thereby justifying the symbolic term ‘elixir’ written in the title of this review. Neem is mentioned in ancient Ayurvedic treatises like Charaka Samhita, Susruta Samhita, Ashtanga Hridaya (a book authored by Vaghbata) and in nighantus (medical lexicon) written over the ages. In Ayurveda, plenty of formulations contain Neem as an ingredient. This review sheds light on Azadirachta indica A. Juss (Neem plant) from the standpoint of the traditional system of Indian medicine vis-à-vis its taxonomical position, macroscopic and organoleptic characteristics, bio-activities, use as bio-pesticide and bio-fertilizer, active phytoconstituents, and pharmacological studies. Additionally, it presents a compilation of folklore recipes and Ayurvedic, Homeopathic, Siddha and Unani formulations (ASU & H) that contain Neem as an ingredient.