A man tends to vegetables and medicinal plants used to make soaps, oils, ointments and mosquito-repellent jelly, among others. (Photo: Jeffrey Abrahams)

Kenyan scientists have confirmed that more than 20 local plant species are effective against many of the top killer cancers today.

During a three-day annual scientific conference of the Kenya Medical Research Institute (Kemri), more than 30 researchers left no doubt that the country had immense capacity to deal with cancer from its plant resources.

The scientists from various local universities collaborating with Kemri described how they located and studied plant species and confirmed in laboratories that plant extracts hold effective treatments to even the most deadly cancers, the Standard newspaper reports. The evidence presented at a conference in Nairobi suggested that every Kenyan dying of cancer lives near a possible cancer treatment or cure.

Between the researchers, 16 projects were presented involving about 20 plants, some including pearl millet and the sijambok pod. Most of the plants the scientists reported are widely used locally for medicinal purposes and many specifically for treating cancer.

“More than 60 percent of currently used anti-cancer agents are derived from natural sources,” explained Sabina Wangui Wachira of the Centre for Traditional Medicine and Drug Research at Kemri. “Our work was to provide scientific evidence to support claims that some Kenyan medicinal plants are active against cancer.”

Together with Jomo Kenyatta University of Agriculture and Technology Wachira investigated the effectiveness of three local plants against cancers. These included the well-known red stinkwood (Prunus africana), which has been exploited internationally for the treatment of prostate cancer. This time the focus was on effectiveness of the tree’s bark against breast cancer, a major killer of women.

“We found extracts from the bark highly effective against breast cancer cell lines, explaining why many communities use it as a medicine,” Wachira told the conference. She told of their drawback in trials with the local confetti and pepper-wood trees, the latter known as mkaa in Kiswahili. The researchers reported the two trees had shown little activity against breast cancer but were very effective against the cell lines of colon cancer.

Crispus M Ngule of the same department at Kemri told of their experiments with tamarind fruit (mkwanju) and pearl millet. They tested extracts from these plants against prostate, cervical and breast cancers and found them to be highly effective. During the conference such heart-warming stories were told more than a dozen times, explaining how different plant species and parts had passed crucial laboratory tests on their effectiveness in stopping the proliferation of cancerous cells.

A combination of the highly popular and already domesticated Moringa oleifera with leaf extracts of the African Indigo called sargellat by the Marakwet of the Rift Valley had also been investigated. Researcher Jecinta Wanjiru Ndungu of Rongo University said the two trees were seen to stop the proliferation of cervical, breast and prostate cancer cell lines in the laboratory. Even when tested against the breast cancer drug Tamoxifen the local herbs were found to stand their ground well.

This was not the first time Kenyan researchers were presenting evidence that local plants have provable ability to treat cancer. But never before had Kenya’s premier research institute brought such an impressive arsenal against the deadly disease under one roof. “We are happy that scientists are now confirming what we have always known and practised. It is time to convert the knowledge into products and service,” said Dr Shadrack Moimett of Koibatek Herbal Clinic in Eldoret.

Such an assurance though, was conspicuously lacking from the Kemri conference. Without exception all presenters recommended further research in their work before any drugs can be developed. “Further studies are recommended to isolate the bioactive compounds from the crude extracts and determine their mechanisms of action against cancerous cells,” said Regina Mwangangi of Kenyatta University.

Mwangangi had presented victories against breast cancer from the extracts of the black wattle tree and the bitter leaf vegetable called lisabakhwa by the Luhya ethnic group.

This prescribed route to product development, Dr Moimett and other experts say, could be painfully long and prohibitively expensive, a cost that would be reflected in the final product. Julius Wanjohi Mwangi, director of Intellectual Property Rights at University of Nairobi, estimates that it takes ten to 17 years and between $200 million to more than $2 billion to develop a new conventional drug.

Mwangi, a professor of pharmacognosy (the study of medicine derived from natural sources), broke new ground two years ago when he presented the first public defence of herbal medicine at the University of Nairobi. Mwangi and a team from the university had collected data at a herbal medicine clinic in Nakuru for five years. During this period, about 55 000 people had been treated at the clinic. Some 6 000 of the patients had gone to the clinic with heart conditions while another 2 000 had cancer.

Mwangi demonstrated that herbal medicines actually work against many diseases, including cancer. Mwangi, Moimett and like-minded experts suggest that Kenya goes the Chinese way to quickly develop safe and affordable natural health products. “We could learn from the Chinese, who are doing a lot of clinical and other scientific work on their herbal medicines while concurrently using them in their hospitals,” said Mwangi.

The Health Bill 2016, now in its final stages in Kenya's Parliament, proposes the formation of a legal body to oversee the management of alternative medicine in Kenya. Such a body will set standards for all herbal products and, importantly, formulate policies to facilitate the referral of patients between herbalists and conventional hospitals. The proposed Traditional Herbal Medicine and Medicinal Plants Bill 2014 could be a game changer. 

A recent study revealed that among 115 children with cancer at Moi Teaching and Referral hospital in Eldoret, 95 percent were given complementary medicines such as herbs by their parents. A 2011 World Bank survey estimated Kenya has 40 000 herbalists compared to about 4 500 Western-style doctors.