Why finding potent antioxidants in natural products makes good health revenue

Janice Limson

How long you live is a cocktail of diet, stress levels, exercise, luck and genes. In each of these areas, scientists are hard at work unraveling the mechanisms, finding new clues to help explain how and why we age and, importantly, how to extend quality of life. Antioxidants in medicinal plants remains an active area of research with untapped potential.

Many disease processes in our bodies are linked to free radicals. Free radicals are molecules with an unpaired electron and since electrons prefer to be paired, they tend to take electrons from elsewhere. The elsewhere becomes a problem if this is from a protein or from DNA or a cell membrane and it is a problem simply because this can alter the functioning of the protein, unravel the cell membrane or damage DNA. The repercussions of that are perhaps not as great if the damage can be contained by the body’s natural defense systems, which can neutralize free radicals normally generated in our bodies. The reality is that the build-up of this damage leads to ageing. At its worst it can lead to diseases that can cause life-threatening illness which shorten lives. While ageing is inevitable, the question is not whether we can stop the clock, but can we slow it down? Can illness linked to free radicals be curbed or slowed?

Some may argue that the best shot we have is our body’s innate ability to protect itself – through a suite of weaponry made up of, amongst others, enzymes, proteins and hormones. Much of this is determined by our genetic make-up and the key to future interventions lies in understanding and unraveling genes that can help to explain why people age differently, why some live to a century or more, and why some are predisposed to certain illness. Therein is a key to future drug or gene therapies that might one day radically solve some of the riddles of ageing.

While socio-economic factors cannot be discounted, some of the riddles might be a little simpler, like food. Here, looking to certain nations with their reported longevities or reported lowered incidence of neurodegenerative diseases can shed some light. Many scientists have focused on identifying antioxidants in certain foods or medicinal plants used traditionally in certain cultures. If free radicals are associated with certain diseases and ageing, then identifying antioxidants in certain food sources can help pinpoint future supplements.

Indeed, the antioxidant supplement market appears inexhaustable. Around the world, red wine in particular is known to be rich in antioxidants such as the molecule resveratrol. Identifying this molecule as a potent antioxidant to fight free radicals is now well under way and most health food stores stock supplements containing this molecule. Fucoxanthin, another antioxidant molecule studied for, amongst others, its possible anti-diabetic and anti-cancer properties is a component of a certain macroalga that makes its way daily into Far Eastern cuisine, in Japan in a country enjoying one of the highest average lifespans with diets rich in fresh vegetables, fish and seaweed.

In India, with its reported lower incidence of neurodegenerative disease, research into dietary spices like turmeric and chillies has indeed yielded potent antioxidants such as curcumin and capsaicin. On the back of this traditional knowhow, and supported by certain scientific studies, many of these antioxidants have strong commercial markets globally.

But what of South Africa and southern Africa? Compared to Europe, only a handful of medicinal plants have been cultivated and exploited for commercial potential in southern Africa, despite some intense research activity. Sustainable cultivation of well-established medicinal plants represents viable potential for job creation.

Success stories in South Africa include Rooibos. Supported by scientists, the tea and its health properties are legendary, forming part of the South African story. Sutherlandia frutescens tinctures and extracts also backed by scientific research have made their way into health food stores and the story of Buchu is well known.

The publication of an African Herbal Pharmacopeia in 2010 represents a promising first step in turning the oral tradition into a written one. But the concerns to the public are manifold, from fly-by-night industries making scientifically unverified claims, to poor understanding of the toxicity of certain plants and their potential to cause harm in humans. Unsubstantiated claims or inadequate toxicity testing may have other consequences with loss of market confidence in traditional plant remedies limiting the scope to reach larger markets. Measured, scientific approaches with adequate testing are key to the success of these and to responsible usage. The field remains wide open for scientific studies to develop SA’s traditional plants sector and further expand these for social and economic benefit for the country.

 

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Several universities and science councils in South Africa host programmes examining plants for medicinal properties. Here we take a brief snapshot.

Professor Kobus Eloff, one of SA’s leading scientists in the area of phytomedicine heads the University of Pretoria’s Phytomedicine Programme. A team of scientists, postgraduates and students have cut their teeth on a wide range of plants for possible human use and in recent years on the lucrative veterinary market. With several patents and two products in the market, this programme has successfully made the transition from the laboratory to the market.

The Medical Research Council of South Africa’s Indigenous Knowledge Systems (or IKS) programme has built a solid reputation for research and engagement in this area. A traditional medicines database developed by the South African Traditional Medicines Research Unit at the University of Cape Town: http://databases.mrc.ac.za/Tramed3/ catalogues a wide variety of plants, their reported benefits, their toxicology, available pharmacological information and chemical information. Funded by the MRC, the University of the Western Cape’s South African Traditional Medicines Research Group has published a series of monographs on traditional medicines at http://www.sahealthinfo.org/traditionalmeds/monographs.htm.

Professor Roy Jobson, based at Rhodes University in Grahamstown, provides some guidance to the public on examining the medicinal claims of complementary medicines http://www.ru.ac.za/medicinespromotioninsouthafrica/. Anthropologists at the Biocultural Diversity Conservation cluster of the Institute for Social and Economic Research http://www.ru.ac.za/iser/research/bioculturaldiversity/ at Rhodes University examine the link between cultural and biological diversity, having studied the use and trade of medicinal plants within the Eastern Cape for well over a decade. A natural products research group in the Faculty of Pharmacy (Dr Denzil Beukes and his colleagues) examine medicinal plants and quality of herbal medicines, working alongside scientists in Biotechnology to develop new tools for rapid identification of plants with antioxidant properties.

Professor Nceba Gqaleni, a South African Research Chair in Indigenous Health Care Systems at the University of KwaZulu Natal, heads a Traditional Medicines programme which “contributes to developing scientifically proven African traditional medicines”. http://tradmed.ukzn.ac.za/Home.aspx.

Prof Afolayan heads several scientists engaged in medicinal plants research in the Centre for Phytomedicines Research at the University of Fort Hare in the Eastern Cape.

Nelson Mandela Metropolitan University also runs an active medicinal plants programme within its Department of Biochemistry and Microbiology. http://biomicro.nmmu.ac.za/Activities/Research.