For most of human history herbal medicines were the number one remedy used by people worldwide. All that gradually changed with the advent of chemistry and pharmacology. Instead of using herbal teas or pastes people started to use standardized drugs produced by pharmaceutical companies, prescribed by medical professionals, and dispensed by pharmacies. Many of these drugs were naturally occurring substances or derivates that had been used as part of herbal medicines for a long time. Aspirin or acetylsalicylic acid (ASA), for example, is a derivative of salicylate, which can be found in such plants as willow tree and myrtle. It was first mentioned as a remedy for pain, fever, and inflammation in an Egyptian papyrus more than 3500 years ago.
Scientists, especially ethnobotanists, went all over the planet in search of other substances from plants, fungi, and lichen that could be tested for their medicinal properties. Over time, however, chemists took over and more and more pharmaceuticals were created in the lab. That made the process more controlled and made it easier for companies to claim patents on newly synthesized drugs. Yet, approximately 95% of tested components fail in clinical trials and for those few that pass the whole process from start to finish takes about 12 years and costs up to $800 million or more.
That kind of investment is a lot of money for developed countries, but almost too much for most developing countries, which explains why there are no new drugs coming out of developing countries. It also explains why there are only few and often no recently introduced drugs for rare disorders or disorders that mainly occur in poorer countries. Malaria is a typical example for that. Although there are an estimated 200 million cases of malaria every year and about half a million deaths related to malaria, there hasn’t been a new drug to treat malaria since artemisinin-based combination therapy (ACT) was introduced in the 1990s. One of the reasons for companies not investing into the development of new antimalarial drugs is that about 85% of all cases occur in Africa, where people can only afford to get the drug if governments or international non-governmental organizations (NGOs) subsidize the costs of treatment.
Starting in the mid-1990s a new approach developed that looked into traditional herbal medicines and their efficacy in treating certain diseases. For example, researchers in India conducted a nationwide survey of Ayurvedic physicians to take inventory of herbs used to treat conditions such as arthritis, diabetes, and hepatitis. After they had identified certain herbs for treatment of arthritis they started observational studies in a clinical setting as well as animal studies. Because this approach reverses the order in which traditional pharmacology works it is usually called reverse pharmacology.
In the case of malaria reverse pharmacology pointed to the benefits of Mexican prickly poppy (Argemone Mexicana) for the treatment of milder cases of malaria. Although the poppy was native to Mexico, it somehow made its way to Africa sometime in the 1800s and soon became a part of herbal remedies. When researchers talked to traditional healers in Mali in West Africa they learned about the beneficial effect of Argemone tea on patients with mild malaria. That led to a first prospective study that compared using Argemone tea for half of the patients and a standard artemisinin-based combination therapy (ACT) for the other half. Surprisingly Argemone tea did almost as well as ACT therapy in patients with non-life threatening malaria, although it hadn’t been refined and patients just drank as much tea as they liked.
But, there are still a lot of scientists, especially in pharmacology, that are skeptical or outright opposed to this approach. They prefer to use well defined compounds and point to the fact that herbal remedies often contain a mix of many active substances that may cancel each other out or cause uncontrollable side effects. Teas and infusions are almost impossible to standardize, which makes it difficult to give exact doses of active ingredients to the patients. They also point to unknown toxicities of plants or parts of plants. When we look at Mexican poppy, for example, then we find that the poppy seeds contain the poison sanguinarine, which was implicated in a mass poisoning of 3000 people in India in 1998 that lead to the death of 65 people. The leaves, however, are nonpoisonous and tea is safe to consume.
Another success story for reverse pharmacology and herbal remedies is happening in the western Pacific. Palau is an island nation of more than 500 islands that is a paradise for scuba diving and snorkeling. However, Palau also has the seventh highest obesity rate on the planet and may inhabitants suffer from high blood pressure (hypertension) and diabetes. Instead of trying the tried and tested methods that failed to stop the obesity epidemic in western developed countries, doctors tried to find herbal remedies to help treat hypertension and diabetes. After analyzing traditional herbal medicines they were able to draw up a list of herbs that showed potential. In the end two plants, Morinda citrifolica (a tree from the coffee family), and Phaleria nisidai, were associated with weight loss (M. citrifolica) and lowering of high blood pressure (P. nisidai).
Finding scientific proof that traditional herbal remedies are almost as good for the treatment of a variety of diseases as modern drugs while often having far fewer side effects is a boost to many who look for a more holistic approach to medicine. Many people in developed and developing countries are trying to live a more healthy life by eating local and often organic produce, by cutting down on animal protein, and by using traditional remedies when possible and available. The more their number grows the more companies will try to cater to their needs and demands, and the more herbal remedies will be used to treat physical and mental health disorders.
© Peter Reuter 2015