Tag Archives: ethnobotany

Will herbal medicine provide a cure for COVID-19?


COVID Organics, the miracle ‘cure’ for COVID19. Original source of photo unknown.

As the pandemic spread around the world, the President of Madagascar, Andry Rajoelina, made a startling announcement. He launched a new drink, COVID-Organics,  developed by Malagasy scientists, which was purported to cure the new disease. The evidence of its efficacy was slight, but the basis behind it was linked to a history of local herbal lore and an existing treatment for malaria*, combined with an association with a modern-style research institute.

Already several African states, including Tanzania, Guinea-Bissau and Congo-Brazzaville, have invested scarce resources on importing the new treatment, and it’s being rolled out across Madagascar, some of which is at national expense. It’s easy to understand why. Western medicines are often unaffordable at the best of times, and in the international scramble for resources they are now simply out of reach. COVID Organics is available on the doorstep. Moreover, there is a strong desire to support native expertise, despite most international scientists advising caution in the absence of any reliable evidence. Every society looks to its own authority figures for hope and guidance. We shouldn’t criticise desperate people for trying whatever remedy is actually available.

The claim of a wonder treatment was however met with scepticism from medical experts. President Rajoelina has hit out at critics from the Global North, accusing them of a condescending attitude towards African expertise. At the same time there is a reluctance by many to openly dismiss a treatment that has been promoted as an indigenous African solution drawn from a respected tradition. Even the WHO did so only obliquely.

I am on record as being strongly in favour of recognising and valuing alternative approaches to the development of knowledge beyond the frequently colonial attitudes we are responsible for perpetuating. In this case, however, I’m not inclined to mince my words. COVID-Organics on its own will probably do no harm, but there’s very little chance that it will do any good. By all means test it like any other potential drug, but its provenance doesn’t make it any more plausible as a candidate treatment. And if it takes the place of known, genuinely effective interventions (social distancing, hand washing etc.), or wastes money that could be spent on proven medical care, then it will become positively dangerous to health.

Why am I so sceptical? Those who advocate herbal medicine as an alternative to conventional treatment usually follow one of two lines of argument in support. The first is that it is an ancient practice, based on thousands of years of development, and that this long duration has ensured the transmission of only the most effective cures.

It’s easy to pick this apart. Firstly, the foundations of herbal medicine were derived from theoretical grounds which we now know to have been fundamentally flawed. In its Western form these include the Doctrine of Signatures, which states that God indicated the medical uses of plants through their physical characteristics, or treating symptoms as manifestations of the four humours. Such methods of identifying possible plants and matching them to conditions is little better than random. We shouldn’t expect paradigms that predate germ theory to stumble on insights into a novel threat.

Second, herbalists will often advocate their art by picking out those remedies which have gone on to be important medical drugs. It’s a classic case of the prosecutor’s dilemma; a number of effective treatments have come from plants, but not all medical plants are effective. One which is usually rolled out is the Madagascar periwinkle, which gave rise to a lucrative pharmaceutical used to treat a common form of childhood leukemia. This is however completely unrelated to its traditional usage as a largely ineffective treatment for diabetes. That it yielded such a valuable modern drug owes as much to serendipity as herbal medicine.

Finally, the legend that tropical forests contain a fabled pharmacopeia whose secrets are held by traditional healers has been comprehensively demolished by prolonged enquiry. The story remains persistent because of its connection to a number of beloved folk images rather than any basis in evidence. We have probably taken all the low-hanging medical fruit from the plant kingdom already. A forest-dwelling shaman won’t solve our new problem, not least because remote tribal people live at such low densities that they tend not to suffer from contagious viruses.

Should we instead be scouring the plant kingdom for potential COVID cures? To do so would almost certainly be a waste of time and resources. Not that I’m sure some unscrupulous or naive researchers are putting in grant applications to do exactly that right now. Note that most major pharmaceutical companies gave up on this approach to drug research many years ago after wasting spectacular sums in the process. If it worked then Big Pharma would be doing it already for the diseases we already have.

OK, you might ask, but what if one of these herbal cures turned out to actually work? Medical plants contain a vast number of chemicals. Identifying, purifying and testing the active ingredients is a long process. Sometimes physiological effects rely on complex interactions with other constituents which mean that the individual chemicals don’t act quite the same in isolation. Controlled dosages of herbal medicines are almost impossible to achieve. And there is a high risk that one or other component will be allergenic or otherwise harmful. Demonstrating efficacy and comprehensive safety of a botanical treatment is therefore much harder than for any single component drug.

To summarise, it is possible that herbal medicine might eventually lead to a cure for COVID-19, but it is much less likely to do so than conventional scientific approaches. Even if a cure does eventually arrive through the herbal route, it will take much longer, likely many years, and the lack of any precedents in the modern era is not encouraging. We haven’t found a herbal cure for any other virus yet, and not for want of trying. Maybe Madagascar really has stumbled on the solution to the world’s greatest current problem. Until we have some solid evidence, however, I wouldn’t bet on it. We are all desperate for a cure to appear but wasting time and scarce resources on dead ends will ultimately cost lives.



* Is it coincidence that both the presidents of Madagascar and the United States have promoted the use of treatments for malaria, a fever caused by parasitic infection, as supposed cures for an entirely unrelated virus?



The bitter tree

Like many ecologists I have a fascination with the scientific names that attach themselves to species. Sometimes these celebrate the person who discovered or described the species*, or a benefactor, or are made as a tribute to a notable person. One that I recently stumbled across is the South American tree Quassia amara, a common understorey species of disturbed lowland forests. Until I encountered the backstory to its name while reading The Ethnobotany of Eden (which I strongly recommend) I had no idea where its name came from. The story is complex and revealing.

The tree is one of a relatively small proportion of tropical species which owes their name to Linnaeus, indicating that its significance was recognised early in the development of modern taxonomy. That a Swedish botanist came to hold a sample is due to its potential as a remedy for fevers, a serious concern of the European powers whose hold over tropical lands was still tenuous while their colonists struggled with malaria and other unfamiliar afflictions.

The tree’s Latin name celebrates the man who introduced the plant to Europeans as a medicine, the freed slave Graman Quassi (c.1690–1787), originally of the Akan people of West Africa from modern-day Ghana, hence his Kwa name Kwasimukámba which I will use in preference here. He arrived in Suriname as a child slave of the Dutch empire. So successful was Kwasimukámba that he not only lived an unusually long and ultimately comfortable life but was also celebrated internationally. He even travelled to The Hague and received an audience with Willem V, the Prince of Orange, who bestowed a number of extravagant gifts on him in recognition of his service to the empire.

If we ended the story here then it would be almost heart-warming. But let’s delve deeper. How did Kwasimukámba come to be a freed slave?

Many other slaves escaped from servitude in South America and formed independent communities, known as the maroons, often deep into colonised territories. Some of these became well-established enough to effectively become trade partners of the European powers and were tolerated. Others, such as the Saramaka, fought lengthy insurgencies before eventually winning this recognition. It was in this struggle that Kwasimukámba first demonstrated his worth to the Dutch, acting as a negotiator and tracker on behalf of the white colonists. Later he led a corps of African conscripts known as the Black Rangers, even losing one of his ears in the fighting against the rebels. For his efforts he was gifted a gold breastplate on which was inscribed ‘Quassie, faithful to the whites’. The Saramaka remember him as a traitor.

What then of the tree that bears his name? It was Kwasimukámba who introduced it to Europeans as a local remedy for fever in his other noted capacity as a herbalist and sorceror**. It was soon overtaken as a cure for malaria by Cinchona, another South American tree and the source of quinine. Nevertheless, Quassia amara is still used as an effective treatment for intestinal parasites, an insecticide, and a bittering agent in foods and drinks. The second part of the species name, amara, comes from the Spanish word meaning ‘bitter’. Even here Kwasimukámba is memorialised because the most bitter of the tree’s chemical constituents is now known as quassin, one of a family of chemicals called the quassinoids. These are amongst the most bitter-tasting chemicals in nature and form ingredients of Angostura bitters***.


Flowers of Quassia amara. All parts of the plant can be used for their extracts.

Without wishing to be unfair to Kwasimukámba, whose reputation as a healer cannot be entirely unfounded, it is highly unlikely that he personally discovered the medicinal benefits of Quassia. More likely is that he learnt of its efficacy through his interactions with the Saramaka or other maroons. They, in turn, are likely to have acquired the knowledge from the indigenous peoples they encountered in the forests. My scepticism about who deserves the credit is simply based on a matter of probability. Native healers had been using the tree for many generations before the African slaves and their European masters arrived, and continue to do so.

We will never know who first named the bitter tree and divined its useful medicinal properties. In a fair accounting of history they would receive the credit for Quassia, although Kwasimukámba deserves his recognition too. He can hardly be blamed for the accolade of being immortalised in science as the tree was named for, not by, him. Then again, in his later years he styled himself ‘Professor of Herbology’, so he was not averse to personal aggrandisement.

So who was Kwasimukámba: a manumitted slave who achieved fame in his lifetime? An imperial collaborator? A talented herbalist? Or a charlatan who took credit for the insights of others? The truth must be all of those things, and no single story is complete without the rest. We should beware making moral judgements on our forebears, as I’ve argued before, because these were complex people making personal decisions in very different times. The name Quassia links a bitter-flavoured tree to a bitter history, one that invokes slavery, oppression, forgotten indigenous peoples and the legacies of colonialism. The struggles of the Saramaka for recognition of their rights continue to the present day. Perhaps we shouldn’t resent Kwasimukámba his place in the annals of science though. At least this once an oppressed slave managed to make a decent life for himself. I can raise a glass to that.



* Which usually means the first person from the Global North to place the species in the context of a largely imperial system of classification. That a species was long known to local people in its place of origin is usually overlooked, although taxonomists are getting better at this.

** Not all of his concoctions were as widely approved of.

*** Amusingly Angostura bitters do not contain the bitter-tasting bark of Angostura trifoliata, but are instead named after the town in Venezuela from where the recipe originated. I should write another blog post about that.

Kratom: when ethnobotany goes wrong


Mitragyna speciosa (Korth.) Havil., otherwise known as kratom. Image credit: Uomo vitruviano

Efforts to control the trade and usage of recreational drugs* struggle against human ingenuity, driven by our boundless determination to get loaded. The search for new legal highs has led in two directions. One is the generation of new synthetic drugs which are sufficiently chemically distinct to avoid the regulations but which remain pharmacologically effective. These are often more dangerous than the illegal drugs they replace. The other is to mine the accumulated cultural and medical repositories of herbal lore from around the world to find psychoactive plants which haven’t yet been banned. Species are suddenly raised from obscurity to become the latest rush.

Over recent years a variety of plants have gone through a process of initial global popularity followed by a clamp-down, usually once a death has been associated with their use or abuse (even indirectly). A wave of media attention, hysteria and misinformation typically leads to regulatory action long before the formal medical evidence begins to emerge. One of the most recent episodes was over Salvia divinorum which enjoyed brief popularity as the legal hallucinogen of choice among students, despite being inconsistent in its effects and often quite unpleasant. Wherever you’re reading this, it’s probably already been banned.

Most of these plants have a long history of safe and moderate intake by indigenous populations in the regions where they grow naturally, either for ritual or medical purposes. The same can be said of many of the more common drugs we all know of: opium, coca and cannabis have many traditional uses stretching back for thousands of years. The problems arise when they are taken out of their cultural contexts and used for purely recreational purposes. This is often combined with plant breeding to increase the content of their psychoactive ingredients or chemical treatments that enhance their potency or synthesise their active components (such as in the production of heroin). A relatively benign drug is transformed from its original form into something much more problematic.

The latest plant to emerge as a potential drug in Europe, though already banned in many places, is Mitragyna speciosa, more commonly known as kratom, and native to several countries in Southeast Asia. Here in Ireland its active ingredient has been designated a Schedule 1 drug** since 2017. Pre-emptive legislation in other countries is quickly catching up.

I will confess to not having heard of kratom before it became a Western health concern. This is probably true of most people outside Asia, but more surprising to me given a long-standing interest in ethnobotany in Southeast Asia and having lived in Malaysia. I had previously subscribed to the view expressed in most textbooks that natural painkillers were absent from the regional flora, an opinion confirmed through my own discussions with orang asal shamen***. This may be because kratom grows in drier areas than I’ve worked in; I’ve certainly never come across it in any surveys of traditional agricultural systems in Malaysia. Pain relief is one of the scarcest and most sought-after forms of medicine, so if kratom is effective then I’m now puzzled that it isn’t more widespread.

In its normal range kratom is used as a mild painkiller, stimulant and appetite suppressant in the same way as coca leaves have been used for thousands of years in South America. The dosage obtained from chewing leaves, or even from extracts prepared by traditional methods, is likely to be low. This is very different from its recent use in Western countries where higher dosages and combinations with other drugs (including alcohol and caffeine) are likely to both enhance its effects and increase its toxicity. It is also more commonly sold over the internet as a powder.

Nevertheless, a parallel increase in recreational use within its native range has also been reported, although as of 2016 with no deaths associated. Recreational use also has a long history in Thailand, and habitual use in Malaysia has been known of since at least 1836. It is now thought to be the most popular illegal drug in south Thailand, though arguments continue over whether it ought to be regulated, despite the acknowledged risk of addiction. In this it mirrors the discussion over khat, a botanical stimulant widely used across Arabia and East Africa****. Where cultural associations are long-standing it is seen as less threatening than drugs from overseas.

Along with its long use as a drug in its own right, kratom has also been used as a substitute for opium (when unavailable) or treatment for addiction. It also has a folk usage in treating hypertension. This points towards the potential for beneficial medical uses which would be delayed or unrealised if knee-jerk regulation prevents the necessary research from being conducted. Compare the situation with cannabis: its medical use in China goes back thousands of years, but the stigma associated with its use in the West (which we can partly blame on Marco Polo) delayed its decriminalisation. Cannabis remains illegal in many countries despite steadily accumulating evidence of its medical value.

I’m a firm believer that we should recognise, respect and learn from the botanical knowledge of other cultures. Banning traditional medicines (and even socially important recreational drugs) in their home countries on the basis of their abuse by people in the Global North is morally wrong. Excessive regulation also deprives us of many of the potential benefits which might come from a better understanding of these plants.

All this is not to diminish the real physical and mental damage caused by addiction, and the need to protect people from abuse and the associated social costs. But the urge to get high is nothing new, and the cultures that have formed alongside psychoactive plant chemicals, from morphine to mescaline, usually incorporated ways of controlling their use and appreciating them in safe moderation. In Tibetan regions where I’ve worked cannabis is a frequent garden plant, and teenagers enjoy a quiet rebellious smoke with little stigma attached, while adults eventually grow out of the phase. Our own immature explorations of ethnobotany need to learn that there’s much more to a plant than the titillation provided by its active ingredients.



UPDATE: after posting, @liana_chua pointed out this fascinating blog post by @PaulThung about the market-driven boom in kratom production in West Kalimantan, where it is known as puri. It’s a great reminder that what’s seen as a growing problem in the Global North can simultaneously be a development opportunity for people in deprived regions.



* I dislike the term ‘war on drugs’ because I don’t like the tendency to militarise the vocabulary surrounding complex and nuanced issues (see also ‘terror’). Also, as others have pointed out, war is dangerous enough without being on drugs as well.

** Schedule 1 covers drugs which have no accepted medicinal or scientific value. The classification in Ireland is therefore based on uses rather than the potential for harm or addiction. This can become a bit circular. For example, nicotine isn’t on the list, but its only medical usage is in treating nicotine addiction. Cannabis, however, is on the list.

*** Of course I hadn’t considered before now that this is something they might not want to talk about, given that kratom is regulated in Malaysia, where it is known as ketum,  although attempts to ban it outright have not yet come to fruition. Still I would have expected to spot a large shrub in the Rubiaceae if they were growing it deliberately.

**** I’ve often chewed khat in countries where its use is tolerated, and it’s a great way to boost your mood and energy level during fieldwork. It is also addictive, of course.