Phytotherapy

Herbal medicine (also Herbalism) is the study of the botany and use of medicinal plants. Plants have been the basis for medical treatments through much of human history, and such traditional medicine is still widely practiced today. Modern medicine makes use of many plant-derived compounds as the basis for evidence-based pharmaceutical drugs. Although herbalism may apply modern standards of effectiveness testing to herbs and medicines derived from natural sources, few high-quality clinical trials and standards for purity or dosage exist. The scope of herbal medicine is sometimes extended to include fungal and bee products, as well as minerals, shells and certain animal parts. Herbal medicine (also Herbalism) is the study of the botany and use of medicinal plants. Plants have been the basis for medical treatments through much of human history, and such traditional medicine is still widely practiced today. Modern medicine makes use of many plant-derived compounds as the basis for evidence-based pharmaceutical drugs. Although herbalism may apply modern standards of effectiveness testing to herbs and medicines derived from natural sources, few high-quality clinical trials and standards for purity or dosage exist. The scope of herbal medicine is sometimes extended to include fungal and bee products, as well as minerals, shells and certain animal parts. Herbal medicine is also called phytomedicine or phytotherapy. Paraherbalism describes alternative and pseudoscientific practices of using unrefined plant or animal extracts as unproven medicines or health-promoting agents. Paraherbalism differs from plant-derived medicines in standard pharmacology because it does not isolate or standardize biologically active compounds, but rather relies on the belief that preserving various substances from a given source with less processing is safer or more effective – for which there is no evidence. Herbal dietary supplements most often fall under the phytotherapy category. Archaeological evidence indicates that the use of medicinal plants dates back to the Paleolithic age, approximately 60,000 years ago. Written evidence of herbal remedies dates back over 5,000 years to the Sumerians, who compiled lists of plants. Some ancient cultures wrote about plants and their medical uses in books called herbals. In ancient Egypt, herbs are mentioned in Egyptian medical papyri, depicted in tomb illustrations, or on rare occasions found in medical jars containing trace amounts of herbs. Among the oldest, lengthiest, and most important medical papyri of ancient Egypt, the Ebers Papyrus dates from about 1550 BC, and covers more than 700 compounds, mainly of plant origin. The earliest known Greek herbals came from Theophrastus of Eresos who, in the 4th century BC, wrote in Greek Historia Plantarum, from Diocles of Carystus who wrote during the 3rd century BC, and from Krateuas who wrote in the 1st century BC. Only a few fragments of these works have survived intact, but from what remains, scholars noted overlap with the Egyptian herbals. Seeds likely used for herbalism were found in archaeological sites of Bronze Age China dating from the Shang Dynasty (c. 1600–1046 BC). Over a hundred of the 224 compounds mentioned in the Huangdi Neijing, an early Chinese medical text, are herbs. Herbs also commonly featured in the traditional medicine of ancient India, where the principal treatment for diseases was diet. De Materia Medica, originally written in Greek by Pedanius Dioscorides (c. 40–90 AD) of Anazarbus, Cilicia, a Greek physician, pharmacologist and botanist, is one example of herbal writing which was used for 1500 years until the 1600s. The World Health Organization (WHO) estimates that 80 percent of the population of some Asian and African countries presently use herbal medicine for some aspect of primary health care. Pharmaceuticals are prohibitively expensive for most of the world's population, half of whom lived on less than $2 U.S. per day in 2002. In comparison, herbal medicines can be grown from seed or gathered from nature for little or no cost. Many of the pharmaceuticals currently available to physicians have a long history of use as herbal remedies, including opium, aspirin, digitalis, and quinine. According to the World Health Organization, approximately 25% of modern drugs used in the United States have been derived from plants. At least 7,000 medical compounds in the modern pharmacopoeia are derived from plants. Among the 120 active compounds currently isolated from the higher plants and widely used in modern medicine today, 80% show a positive correlation between their modern therapeutic use and the traditional use of the plants from which they are derived. In a 2010 global survey of the most common 1000 plant-derived compounds, 156 had clinical trials published. Preclinical studies (cell culture and animal studies) were reported for about one-half of the plant products, while 120 (12%) of the plants evaluated – although available in the Western market – had no rigorous studies of their properties, and five were toxic or allergenic, a finding that led the authors to conclude 'their use ought to be discouraged or forbidden.' Nine plants evaluated in human clinical research included Althaea officinalis (marshmallow), Calendula officinalis (marigold), Centella asiatica (centella), Echinacea purpurea (echinacea), Passiflora incarnata (passionflower), Punica granatum (pomegranate), Vaccinium macrocarpon (cranberry), Vaccinium myrtillus (bilberry), and Valeriana officinalis (valerian), although generally there were inconsistent, often negative results, and the studies were of low quality. In 2015, the Australian Government's Department of Health published the results of a review of alternative therapies that sought to determine if any were suitable for being covered by health insurance; Herbalism was one of 17 topics evaluated for which no clear evidence of effectiveness was found. Establishing guidelines to assess safety and efficacy of herbal products, the European Medicines Agency provides criteria for evaluating and grading the quality of clinical research in preparing monographs about herbal products. In the United States, the National Center for Complementary and Integrative Health of the National Institutes of Health funds clinical trials on herbal compounds, provides fact sheets evaluating the safety, potential effectiveness and side effects of many plant sources, and maintains a registry of clinical research conducted on herbal products. According to Cancer Research UK as of 2015, 'there is currently no strong evidence from studies in people that herbal remedies can treat, prevent or cure cancer'. The use of herbal remedies is more prevalent in patients with chronic diseases such as cancer, diabetes, asthma and end-stage renal disease. Multiple factors such as gender, age, ethnicity, education and social class are also shown to have association with prevalence of herbal remedies use.