The World Health Organization recognizes the existence of some 20,000 medicinal plants on this planet today, all having a wide range of therapeutic properties.
The isolation, characterization and standardization of the bioactive principles in these plants is an active area of research. Scientists expect to find new drug leads as they investigate more and more plants.
For example, antimalaria drugs were developed from the extract of the plant known as Artemisia Annua. Knowledge about the healing properties of this plant existed in China for thousands of years.
Now a new book series on Medicinal Plants published by the Daya Publication House, New Delhi, will provide comprehensive information about current developments in this area.
The book will feature two chapters by Dr. Zeena Pillai of the Amrita Department of Chemistry at Amritapuri in collaboration with Dr. Beena Joy, Principle Technical Officer, Agroprocessing and Natural Products Division, NIIST, Trivandrum.
The first chapter titled Embelin: A Lead Molecule for the Future? focuses on the antibacterial properties of the derivatives of Embelin.
“Embelia Ribes, the plant seeds containing Embelin, are naturally available in Kerala. They are used in various Ayurvedic formulations and in the medicinal soup known as marunnu kanji in Malayalam, which is prepared during the rainy month of Karkitaka,” Dr. Zeena explained.
“Embelin is receiving much attention in recent years due to its biological and physiological properties such as antihelmintic, antifertility, antitumour, analgesic, amtimicrobial, anti-inflammatory. Ceratin derivatives of Embelin give better results than even the widely-used antibiotic drug, Streptomycin,” she pointed out.
In the chapter, the process of isolation, characterization and standardization was explained. Usually the dried berries are crushed into powder and subjected to solvent extraction, using a mixture of various organic solvents like hexane and ethyl acetate. The crude product is recrystallized from cold hexane yielding orange flakes of embelin. The characterization is carried out by spectroscopy. Various derivatives can be prepared by simple chemical reactions. Elaborating on the challenge of synthesizing natural compounds, Dr. Zeena added, “The medicinal properties of bioactive compounds can be enhanced by properly derivatising (transforming) them with simple chemical reactions but usually they are obtained in very small amounts only.”
The second chapter contributed by the duo was titled Chemoprofiling and Antioxidant Activity Studies of Shilajit – A Herbal Composition. Shilajit is a mineral commonly found in the Himalayan region, formed in those specific climatic conditions over many centuries, from remains of plant life. Ancient Indian scriptures ascribe many wonderful powers to Shilajit for tackling many ailments of the body and mind. As a powerful antioxidant helping delay ageing, it is an essential ingredient of popular ayurvedic preparations such as Chandraprabha Vati or Chavanprash.
“Antioxidant studies have shown that Shilajit is useful for diabetics not only because of α -amylase inhibition, but because its liquid extract is strongly active. The chemoprofiling of these active extracts has shown the presence of different organic compounds,” Dr Zeena shared.
January 31, 2013
School of Arts and Sciences, Amritapuri