Planta Med 2020; 86(13/14): 906-940
DOI: 10.1055/a-1107-9370
Biological and Pharmacological Activity
Reviews

Harnessing the Phytotherapeutic Treasure Troves of the Ancient Medicinal Plant Azadirachta indica (Neem) and Associated Endophytic Microorganisms

Ravindra N. Kharwar
1   Mycopathology and Microbial Technology Laboratory, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, India
,
Vijay K. Sharma
1   Mycopathology and Microbial Technology Laboratory, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, India
2   Medical School of Kunming University of Science and Technology, Kunming, P. R. China
,
Ashish Mishra
1   Mycopathology and Microbial Technology Laboratory, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, India
,
Jitendra Kumar
1   Mycopathology and Microbial Technology Laboratory, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, India
2   Medical School of Kunming University of Science and Technology, Kunming, P. R. China
,
Dheeraj K. Singh#
1   Mycopathology and Microbial Technology Laboratory, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, India
,
Satish K. Verma
1   Mycopathology and Microbial Technology Laboratory, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, India
,
Surendra K. Gond##
3   Department of Botany, Visva-Bharati, Shantiniketan, India
,
Anuj Kumar
4   Department of Botany, Buddha PG College, Kushinagar, India
,
Nutan Kaushik
5   Amity Food and Agriculture Foundation, Amity University, Noida, India
,
Bharadwaj Revuru
6   Institute of Environmental Research (INFU), Department of Chemistry and Chemical Biology, Technische Universität Dortmund, Dortmund, Germany
,
Souvik Kusari
6   Institute of Environmental Research (INFU), Department of Chemistry and Chemical Biology, Technische Universität Dortmund, Dortmund, Germany
› Author Affiliations
Supported by: DST, New Delhi, India SB/EMEQ-121/2014
Supported by: Bundesministerium für Bildung und Forschung 031B0512E


Abstract

Azadirachta indica, commonly known as neem, is an evergreen tree of the tropics and sub-tropics native to the Indian subcontinent with demonstrated ethnomedicinal value and importance in agriculture as well as in the pharmaceutical industry. This ancient medicinal tree, often called the “wonder tree”, is regarded as a chemical factory of diverse and complex compounds with a plethora of structural scaffolds that is very difficult to mimic by chemical synthesis. Such multifaceted chemical diversity leads to a fantastic repertoire of functional traits, encompassing a wide variety of biological activity and unique modes of action against specific and generalist pathogens and pests. Until now, more than 400 compounds have been isolated from different parts of neem including important bioactive secondary metabolites such as azadirachtin, nimbidin, nimbin, nimbolide, gedunin, and many more. In addition to its insecticidal property, the plant is also known for antimicrobial, antimalarial, antiviral, anti-inflammatory, analgesic, antipyretic, hypoglycaemic, antiulcer, antifertility, anticarcinogenic, hepatoprotective, antioxidant, anxiolytic, molluscicidal, acaricidal, and antifilarial properties. Notwithstanding the chemical and biological virtuosity of neem, it has also been extensively explored for associated microorganisms, especially a class of mutualists called endophytic microorganisms (or endophytes). More than 30 compounds, including neem “mimetic” compounds, have been reported from endophytes harbored in the neem trees in different ecological niches. In this review, we provide an informative and in-depth overview of the topic that can serve as a point of reference for an understanding of the functions and applications of a medicinal plant such as neem, including associated endophytes, within the overall theme of phytopathology. Our review further exemplifies the already-noted current surge of interest in plant and microbial natural products for implications both within the ecological and clinical settings, for a more secure and sustainable future.

# Present Address: Department of Botany, Harish Chandra PG College, Varanasi, India


## Present address: Department of Botany, MMV, Banaras Hindu University, Varanasi, India




Publication History

Received: 26 October 2019

Accepted after revision: 27 January 2020

Article published online:
03 March 2020

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