Human culture has always depended heavily on medicinal plants. Medicinal plants have always been at the forefront of the culture of almost every civilization as a source of medicine. It is believed that traditional medicines contain medicinal plants in abundance, which are also the source of many modern medicines. For thousands of years, medicinal plants have been used to treat diseases, preserve food, add flavor, and prevent disease epidemics. The biological properties of plant species used throughout the world are generally the result of secondary metabolites produced by the plants. Products obtained from plants control the growth of microorganisms in various conditions. We have given a general overview of medicinal plants in this review.
History Of Use Of Medicinal Herbs
It is very difficult to tell when plants were used as medicines. Around 600,000 years ago, there is evidence that plants were cultivated for their medicinal properties. Medicinal plants were written about 5000 years ago in India, China and Egypt, and at least 2500 years ago in Greece and Central Asia. Since ancient times, people have been trying to cure their ailments by using nature. Plants were used in the same way as animals were used, initially by instinct.
Everything was based on empirical evidence because at that time there was insufficient information about the causes of disease, the plants useful for its treatment, and how they were used. Over time, it became clear why certain medicinal plants were used to treat certain diseases; As a result, the use of medicinal plants began to be limited to facts and gradually rejected the empirical framework. The earliest written evidence of the use of medicinal plants in making medicines comes from an approximately 5000-year-old Sumerian clay slab from Nagpur. Some records claim that the people of Egypt and China were among the earliest people to use plants as medicine, dating back as far as 27 centuries BC. Hippocrates, the founder of Greek medicine, and Aristotle, Hippocrates' student, used medicinal plants to treat diseases. The ancient Greeks were also familiar with the medicinal properties of some medicinal plants. The Greek scientist Theophrastus then founded the school of medicinal plants. Pedanius Dioscorides, a physician and surgeon who lived between 75 and 45 BC, then wrote an encyclopedia called De Materia Medica, describing 600 medicinal medicinal plants through a series of scientific studies on medicinal plants.
History of medicinal plants in Iran
According to the findings of Iranian historical studies, the use of medicinal herbs in Iran dates back to the time of the Aryan civilization, around 6500 to 7000 BC, when Zarathustra mentioned the properties of medicinal plants in his writings. A plant called haoma or ephedra (Ephedra major hosta) was considered a sacred plant in the Zoroastrian religion of Iran. The integration of prehistoric beliefs and practices from the early inhabitants of Iran, including the Mesopotamians, Babylonians, Assyrians, Elamites, and other ancient civilizations, led to the development of the traditional sciences of medicine and pharmacy. Iranians have long benefited from extensive knowledge of the properties of medicinal plants. This argument is best illustrated by the sacred Zoroastrian book Avesta. The Dorandidu, one of the five books of the Avesta, contains several sections on phytotherapy, medicinal plants and their applications. However, sadly, the famous Library of Alexandria was deliberately destroyed in a fire during Alexander the Macedonian campaign. As a result, there is no established evidence for the botanical history of Iran. The remaining books collected by this sect on medicinal plants were also later destroyed by the Mongol ruler Hulagu Khan, who also destroyed the palaces of the Ismailis and burned their libraries. Then, in the eighth and ninth centuries, great works such as Avicenna's Canon and Razi's Al Hawi show that Iranian doctors, including Avicenna and Razi, made significant advances in Persian medicine. Ibn al-Baitar wrote a book in the 13th century describing the properties of over 1400 plants of which he was personally aware.
Medicinal herbs and traditional medicine
The World Health Organization (WHO) defines traditional medicinal plants as natural plant materials used for the treatment of diseases at a local or regional level in the absence of minimal industrial processing. Because it is natural and causes comparatively few complications, traditional herbal medicine has been used for thousands of years in both developed and developing countries. The history of herbal medicine is analogous to the history of early medicine. The texts of the Ebers Papyrus, which were written around 1500 BC and contain many plant names, were the first books written about plants. These books were also the first books written about medicine. In Asia, Africa, and Latin America, many traditional medicines are used to meet basic health needs. In industrialized countries, this practice, often referred to as complementary or alternative medicine, is spreading rapidly. The term "complementary and alternative medicine" (CAM) is used by the National Institutes of Health (NIH) in the United States to cover health systems, practices, and products that are not currently considered part of conventional medicine. Traditional Chinese medicine (TCM) is currently the most widely practiced system of traditional medicine throughout the world, followed by Indian medicine. While "Asian medicine" often includes TCM, India (Ayurveda), and Tibetan medicine, "Oriental medicine" refers to Chinese, Japanese, and Korean medicines chosen by Korean immigrants. The most common treatment in traditional medicine is the use of medicinal plants.
Medicinal plants and conventional medicine
The World Health Organization (WHO) states that medicinal plants and traditional medicine are now used as a primary source of healthcare by more than 80% of the world's population. This number includes many people from China, India, and all the developing countries of the world, as well as many people from many advanced countries. Although drugs of synthetic origin and specially developed in laboratories are currently being used to treat most diseases, taking some drugs can cause some harm to the body. However, their apparent effects in treating diseases have contributed to the growth of their use. As a result, public confidence in the efficacy of medicinal plants and the products produced by them is continuously increasing.
Aspirin, which is obtained from willow bark, digoxin, which is obtained from foxglove, morphine, which is obtained from opium poppy, quinine, which is obtained from cinchona skin, and pilocarpine, which is obtained from Maranham Jaborandi. are among the earliest drugs based on current clinical, pharmacological and chemical studies. More than fifty percent of the medicines available in the market today are obtained from medicinal plants in some way or the other. Phytotherapy is becoming increasingly popular all over the world. As a result, herbal medicines have replaced synthetic compounds globally, in what we can describe as a return to nature to reduce pain and disease. Herbs used in medicine are obtained from nature.
Drug discovery of natural compounds
Traditional processes
Natural compounds used in drug discovery Traditional methods Plant materials are tested for medicinal purposes using traditional methods. If any evidence of agitation is observed, the concentrate is fractionated, and the mobile compound is quantified and identified. Bioassay-guided separation refers to the process of dissolution and separation in which each step is usually guided by biological tests. Regardless of bioactivity, direct product isolation methods are sometimes used to isolate many natural compounds that are suitable for measuring any biological activity. However, this process can be inefficient and slow, and does not guarantee that key compounds isolated through screening will be chemically successful or even recordable.
Modern processes of discovering natural drugs
High-throughput screening (HTS) is one of the modern methods for natural drug discovery. With full and robotic automation, hundreds of molecules can be screened through multiple tests with small amounts of compounds in a short period of time. To include natural products in contemporary HTS programs, a library of natural compounds should be established. Laying the foundation of such a library used to be difficult, time-consuming and complex; However, with the development of state-of-the-art techniques for separation and identification of natural products, the situation has improved significantly. A library of completely natural products from which scientists can quickly isolate the key compound gives the best results, for faster development of new drug formulations such as full or partial synthesis, in vivo experiments and clinical trials.
Medicinal herbs in the future
The future of medicinal herbs There are approximately half a million plants in the world, most of which have not yet been studied in medical practice, and current and future studies on medicinal activities may be effective in the treatment of diseases. As a result, the future of medicinal herbs is bright. The use of medicinal plants is very old; However, there are several disadvantages to using the whole plant or raw material for treatment or experimentation, such as changes in plant compounds in different climates, simultaneous development of synergistic compounds that have adverse effects on antagonists or other unexpected changes in bioactivity. and changes or loss of bioactivity due to raw material variability, storage, storage and preparation; As a result, moving away from plant benefits to the isolation of compounds and the use of pure substances with bioactivity has some advantages, such as making it easier to detect toxic doses, to test therapeutic effects, and to control the quality of therapeutic formulations. goes. The development of chemistry and the process of isolating, purifying, and determining plant compounds coincided with the beginning of the development of herbal medicines.
In the past, the process of identifying the structures of active compounds from extracts was difficult and could take weeks, months, or even years depending on the complexity of the compounds. Drug discovery of organic compounds from plant materials was also difficult. An important recent advance in the classification of compounds is the creation of magnetic field and precision instruments such as nuclear magnetic resonance (NMR) as well as high performance liquid chromatography (HPLC/MS) and liquid chromatography mass spectrometry (LC/MS).Their native organisms are extremely limited in quantity. As a result, the rate of bioassay-guided calibration has recently improved significantly. Even though research into medicinal plant production has been successful in the last few decades, there are many obstacles in the way. The quality of the herbal product has been checked. The issue of standardization of raw materials is important for the plant industry.
During their growth, processing and collection, herbaceous plants are susceptible to infection. Heavy metal pollution and contamination are two main issues with herbal medicines. Therefore to produce herbal medicines, it is necessary to increase the quantity and quality of bioactive compounds, as well as make efforts to discover additional herbal medicines. Traditional and millennial beliefs about the quality and safety of medicines derived from plants cannot be trusted, as the use of natural substances is increasing around the world. As a result, the quality and safety of these drugs must be studied thoroughly and accurately; Therefore, to obtain reliable information about the use of medicinal plants in health care, scientific and illuminating studies are necessary.
On the other hand, unprincipled use of these resources has led to the loss of medicinal plant species, which is one of the challenges faced by medicinal plants. The International Union for Conservation of Nature estimates that 50 000 to 80 000 species of flowering plants are used for medicinal purposes worldwide. Of these, approximately 15,000 species are at risk of extinction as a result of over-harvesting and habitat destruction, and 20% of their wildlife resources are being depleted as a result of growing human populations and excessive plant consumption. As a result, environmental ethics must be taken into account when exploiting natural resources for the discovery of natural medicines. The goal of Good Agricultural Practice (GAP) for medicinal plants is to make it easier to control production, guarantee quality, and standardize herbal medicines. GAP is a method that uses high quality, safe and uncontaminated (raw medicine) herbal medicines to solve problems. Quality aspects of environmental ecology, production location, germplasm, cultivation, collection, and pesticide detection, as well as macroscopic or microscopic verification, chemical identification of active compounds, and metal element screening, are all included in the GAP (46). GAP has been seriously implemented and promoted in many countries. For example, in China, GAP has helped traditional medicinal plants grow in areas where they are traditionally grown.
Although many people now use herbal medicines as part of their primary care, there are still many questions about how safe and effective the plants are. Although herbal medicines have the potential to advance healthcare, there are several significant barriers that must be overcome before they can be effectively integrated with conventional medicine. One of the main obstacles in this field is that scientists around the world cannot accurately translate and interpret texts and research results on plants. In fact, researchers and practitioners must receive training in the application of plant compounds from both modern and traditional medicine to successfully incorporate plants into medical systems. Additionally, empirical arguments should be transformed into evidence-based arguments to increase the credibility of the use of plants in traditional medicine. Finally, standardization of herbal medicines and natural products as well as numerous inquiries regarding safety, precise dosage, treatment duration, side effects, acute and chronic toxicity must be answered. If these issues are resolved then it is possible to use medicinal plants as a cost effective, safe and effective healthcare.
Conclusion and future outlook
There is no doubt that interest in plant-based products has increased around the world. More than 85% of people in the Middle East, Latin America, Africa and Asia rely primarily on traditional medicine, especially herbal medicines, for their health care needs. About 100 million people in the EU still use traditional, complementary and herbal medicines, and in some countries, they account for up to 90% of the population. The market of herbal medicines is growing. Chinese herbal medicine sales totaled more than US$83 billion in 2012, representing a 20% increase compared to the 2011 market. By 2020, it is estimated that the global market for herbal supplements will exceed US$115 billion. The fastest growing markets are Asia-Pacific and Europe. Concerns about the negative effects of synthetic drugs are becoming increasingly prominent, and female subjects are predominantly putting forward these demands. As a result, moving from production to crop production may require major research development investment in human resource training. The importance of research on medicinal plants has never been appreciated before. To treat, prevent diseases, and maintain health, some medicinal plants are used as a source of adjuvant therapy in global healthcare systems. Even though medicinal plants have long been used in traditional medicine, scientific research on active plant compounds and how they work may lead to new therapeutic benefits and nature-based products in the future. To accomplish this, it is fundamentally necessary to conduct extensive research to control the quality of raw drugs and their manufacturing to justify their use in the modern medical system; To harness the benefits of these plants, animal studies and clinical trials are needed. A practical strategy should also be developed to conserve these resources while developing medicines from medicinal plants.
