Samuel Mariko Ndwiga pounds dried tree bark in a mortar. From the powder, the 86-year-old herbalist who plies his trade in Embu, Kenya, concocts medicine to treat a myriad diseases.
Samuel Mariko Ndwiga pounds dried tree bark in a mortar. From the powder, the 86-year-old herbalist who plies his trade in Embu, Kenya, concocts medicine to treat a myriad diseases.
From stomach ache to epilepsy to erectile dysfunction to skin diseases and malaria, this tree, the Greenheart, known scientifically as warburgia ugandensis has been proven by laboratory tests to be a wonder drug of sorts — not just for humans but livestock, too. The tree grows all over East Africa.
“It has been scientifically proven to have anti-microbial activities against protozoan, bacterial and fungal ailments,” explains Dr Alice Muchugi, a lecturer at Kenyatta University’s Department of Biochemistry and an expert in tree genetics.
Mr Ndwiga, who is registered as a herbalist at the Ministry of Culture, has the tree, locally known as muthiga, growing behind his house in Kiangima village in Kenya’s Eastern Province. The homestead is dotted with medicinal plants, including the skincare herb, aloe vera.
He says that over the years, the tree has been one of his most trusted arsenals against disease, right from the Independence struggle in Kenya.
“I used it to treat Mau Mau fighters in the bush,” he says proudly.
However, he warns, the tree is a powerful drug and can be dangerous if used wrongly. It should be mixed with other herbs, he says. Dr Muchigu concurs.
Nonetheless, the tree remains popular in herbal medicine in the region. Besides Mr Ndwiga’s clients, who are largely the rural populace, extracts from the tree are making their way into urban centres and enjoying pride of place in supermarket shelves across East Africa.
Shrewd entrepreneurs are setting up processing units in the region to manufacture syrups, powders, dietary supplements and tablets from parts of the tree. One such factory is located in Kampala and the products are distributed across the region.
Though Kenya is yet to set up its own factory to manufacture the herb, parts of Mount Elgon are said to provide raw material for processors in nearby Uganda.
In Kenya, there is a growing interest in commercial exploitation of this tree.
Jonah Muguna, a retired civil servant, is leading a group of residents of Meru, also in Eastern Province, in processing parts of the tree into herbal teabags.
Without a factory, the group hires grinders and transports the powder to Nairobi, 200km away, for packaging and labelling.
They hope to make money from the growing interest in herbal medicine.
Currently, even those who used to consider herbal medicine primitive and preferred conventional medicine are giving it a try.
With such growing attention, experts are sounding the alarm, saying the tree could become extinct soon unless measures are taken to stem over-exploitation.
In addition to threats from those stripping its bark — the most potent part of the tree — for sale to herbalists and processors, it is a source of firewood and charcoal. This has put pressure on tree populations in the wild.
Preserving the tree
Already, the World Agroforestry Centre, has launched a project to preserve the tree.
Jonathan Muriuki, a research scientist at the International Centre for Research in Agroforestry, says they are assisting farmers to grow an improved strain of warburgia ugandensis.
“Science can produce better species but even these need proper raising in nurseries,” Mr Muriuki says.
A survey conducted in Mount Kenya, he adds, found that the trees are getting scarce, with only one tree being counted over a distance of five kilometres.
Dr Muchugi, who is working with ICRAF on the project, says there is a need for policy makers to prioritise conservation of the tree species.
In East Africa, she adds, Uganda and Tanzania lead in the rate at which the tree is being exploited, while Kenya is catching up fast.
She says the tree can be converted into a cash crop if taken up by farmers and processors.
This would see it being tended like tea bushes and its leaves plucked periodically for delivery to processors.
The tree has more than just medicinal use. Dr Muchugi says the leaves are used as spices in parts of Tanzania and the tree is a common ornamental plant, used in many towns in the region due to the fact that it is evergreen.
In Nairobi, the tree is believed to have lent one of Nairobi’s suburbs, Muthaiga, its name. It is known as Muthiga in the local dialect and is said to have been common in the area.
With these multiple uses, scientists and herbalists alike are in agreement that warburgia ugandensis should be protected and conserved for future generations.