Pharmacognosy is the study of drugs derived from natural sources. It forms an important part of pharmaceutical research and development.
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Pharmacognosy involves the identification, physicochemical characterization, cultivation, extraction, preparation, quality control, and biological assessment of drugs. A plant leaf, flower, root, animal or plant extract may be used to isolate the bioactive chemical.
Any plant preparation used for health purposes, rather than simply for nutritional supplementation or to add flavor to food, is called a medicinal preparation. Some examples of such compounds include caffeine, salicylic acid, and some chemotherapeutic, inotropic, and anti-gout agents.
The term "pharmacognosy" was coined by Anotheus Seydler, a German botanist, from the two Greek words "pharmakon", meaning drug or medicine, and "gnosis", meaning knowledge. Even today, about a quarter of all prescription drugs in the United States have one or more bioactive compounds derived from plants.
Pharmacognosy in drug development
According to the American Society of Pharmacognosy, the definition of pharmacognosy is "the study of the physical, chemical, biochemical, and biological properties of drugs, drug substances or potential drugs or drug substances of natural origin, as well as the search for new drugs from natural sources."
Pharmacognosy is used by pharmaceutical companies to screen, characterize and produce new drugs for the treatment of human disease. Often, naturally occurring drugs cannot be mass produced, so they must be studied in order to develop synthetic biosimilars.
Producing these compounds synthetically allows modifications to be made, such as increases in their bioavailability, altered pharmacokinetics and improved efficacy. These modifications can transform a crude inactive plant extract into a powerful drug, as has been observed in certain anticancer drugs. Thus, natural compounds can provide excellent models to produce novel drugs.
Pharmacognosy involves botanical knowledge to classify and name the plant and understand its genetic pattern and its cultivation. Chemical knowledge is also important in this field for isolating, identifying, and quantitatively assessing the bioactive compounds in the plant sources. Finally, pharmacology plays a role in pharmacognosy, as it allows for researchers to detect and evaluate the biological properties of plants and and determine their effects on living systems.
A working knowledge of quality control is also needed wihtin pharmagnosy, as it ensures correct identification and purity of the drug, as well as accurate testing of its efficacy and safety.
Importance of pharmacognosy
Traditionally, pharmacognosy was recognized as a vital part of drug development processes and pharmacy education; however, the advent of new miracle drugs that can be synthesized in the laboratory led to a decline in its practice.
Recently, many scientists are now recognizing that indigenous knowledge about the medicinal virtue of many plants should never be lost, as it offers great insight into the development of new drugs. For example, artemisinin from the Artemisia annua or ginghaosu tree, is recognized as an ancient Chinese drug for malaria.
The respect for ancient wisdom is reflected in the form of phytotherapy and phytopharmaceuticals. The use of plant products to treat illnesses is well known in South American nations, China and India, where billions of dollars are spent on pharmacognosy research to identify and market natural medicinal drugs.
The importance of medicinal plants should also be studied in other countries in order to fight currently untreatable and/or life-threatening diseases such as Alzheimer’s, HIV, chronic pain, and malaria. Several natural drugs are currently under investigation in clinical trials.