Abstract: Ethno-science is a term used to encompass studies describe local people’s interaction with the natural surroundings. This including ethnoecology and ethnobotany among others. Ethnobotany has been constructed not to be limited only to plant but also to include studies of algae, lichens and fungi. It is strongly linked with taxonomy, pharmacognosy, phytochemistry, ecology and conservation biology. Ethnobotany with no doubt remains the main revenue contributing to both orthodox and traditional medicine. A number of useful drugs have been developed based on ethnobotanical approaches. However, for most of the investigated plant-derived molecules the mechanism of actions are unknown or merely assumed and specific structure activity relationships have rarely been determined. This situation suggest a focus on a new trend of studies to implement polypharmacological approaches on complex herbal mixtures and extracts. This imply that medicinal plant study should be deviated from targeting a single molecule policy in order to produce useful healthcare products. Issues regarding protection and biopiracy have emerged recently as a results of the growing economic focus of biological prospecting based on traditional knowledge. This including concerns about indigenous rights, cultural knowledge and traditional resources. End users of these information are often third parties who have no direct link with the indigenous communities. This situation fuel the need for socio-ethnobotany, a new sub discipline of ethnobotany that deals with the question of how indigenous people can be compensated for sharing their ethnobotanical knowledge. This article aims to highlight issues related to ethnobotany, current challenges and future perspectives.
INTRODUCTION
The term ethnoscience originated from a combination of ethnology and science. It has been used in different disciplines related to local community based knowledge and practices including ethnoastronomy, ethnoecology, ethnobotany, ethnomedicine, ethnopharmacology, ethnozoology, ethnoagronomy and other related disciplines1,2.
Ethnobotany as a term1 was first used by John Harshberger in 1895. He defined the term as the use of plants by aboriginal peoples. Since then, several definitions were utilized to refer to ethnobotany such as: Folk botany, the description of the various methods by which local people utilize plants, the study of direct interrelations between humans and plants and recently the term was defined as the science of people’s interaction with plants3.
Ethnobotany is without a doubt, a multi disciplinary subject. The growing interest in ethnobotany can be observed through the increased number of journals such as Journal of Ethnobiology, Journal of Ethnopharmacology, Ethnobotany, Ethnobotany Research and Applications and the range of university courses that contain modules associated with different aspects of ethnobotany, especially the medicinal uses of plants4.
Ethnobotanical-based selection of plants has gained in popularity as a means to identify which plants contain relevant compounds for exploitation. This economic focus of biological prospecting, including the use of patents and other intellectual property mechanisms has highlighted important issues concerning indigenous rights, cultural knowledge and traditional resources4. This situation led to the emerge of what the so called socio-ethnobotany, a new sub discipline of ethnobotany that deals with the question of how indigenous people can be compensated for sharing their ethnobotanical knowledge5. This article aims to highlight issues related to ethnobotany, contributions, challenges and future perspectives.
ETHNOBOTANY AND ALTERNATIVE MEDICINE
During an opening remarks at the International Forum on Traditional Medicine in China, (Macao 19 August, 2015), Dr. Margaret Chan, Director-General of the World Health Organization stated that modern medicine and traditional medicine make unique contributions to health but both also have their limits and short comings.
Traditional medicine based on the WHO strategy6 was defined as the sum total of the knowledge, skill and practices based on the theories, beliefs and experiences indigenous to different cultures, whether explicable or not, used in the maintenance of health as well as in the prevention, diagnosis, improvement or treatment of physical and mental illness (http://www.who.int/medicines/areas/traditional/definitions/en/). Whereas the term Complementary Medicine (CM) according to the WHO strategy referred to a broad set of health care practices that are not part of that country’s own tradition or conventional medicine and are not fully integrated into the dominant health-care system. However, both terms are used interchangeably for traditional medicine in some countries (http://www.who.int/medicines/areas/traditional/definitions/en/)6. Based on these definition, ethnobotany should be categorized under alternative and complementary medicine, since the claimed properties are subjected to scientific validations and therefore deem to be explicable.
Ethnobotanist were previously more ecological oriented discipline, focusing on interrelationships and interactions between components of a limited ecological zone. This view has been shifted to a wider angle when researchers started considering plants as integral parts of the ecosystem in which they are found from socio-economic and cultural perspectives. This current framework of study in ethnobotany emphasizes different skills and disciplines to be enrolled in a team work mission including botanists, anthropologists, pharmacologists, molecular biologists and medical practitioners7. Ethnobotany as a discipline is currently oriented towards the exploration of new plant resources, collecting of genetic materials, drug discovery and products development8. In recent years, the discipline of ethnobotany has become increasingly associated with the search for medicines. This search for herbal medicines and phytonutrients continues to expand rapidly across the world with many people now resorting to these products for treatment of various health challenges in both developing and developed countries. It worth mentioning that these herbal remedies become available not only in drug stores but also in food stores and supermarkets9-11. As a result, many herbal products are undergoing a transition from classic herbal teas to standardized extracts in Europe, North America and Australia12-14. In these developed countries, the most important among many other reasons for seeking herbal therapy is the belief that it will promote healthier living. Herbal medicines are therefore, often viewed as a balanced and moderate approach to healing and recently represents a substantial proportion of the global drug market9,10. Pan et al.15 provided another proof for the growing interest in herbal medicine industry, the researchers stated that: Chinese traditional medicine has been a novel basis of drug development in China. Up to 2007, China has collected 3563 extracts, 64715 compositions and 5000 single compounds from 3000 Chinese herbs together with about 130 kinds of chemical drugs obtained.
As the global use of herbal medicinal products continues to grow and many more new products are introduced into the market, public health issues and concerns surrounding their safety are also increasingly recognized. Although some herbal medicines have promising potential and are widely used, many of their pharmacological properties remain unverified. This makes knowledge of their potential toxicity and adverse effects very limited16. It has become essential, therefore to furnish the general public including healthcare professionals with adequate information based on scientific findings to facilitate better understanding of the risks associated with the use of these products and to ensure their safety, efficacy and suitable quality17.
ETHNOBOTANICAL LEADS AND POTENTIAL FOR BIOPROSPECTING
Plants produce economically important organic compounds such as oils, resins, tannins, rubber, gums, waxes, dyes, flavors and fragrances, pesticides and pharmaceuticals5. As indicated earlier, many of the medicines used and/or currently in use such as: Aspirin, codeine, ipeacac, pilocarpine, pseudoephedrine, quinine, reserpine, scopolamine, theophylline and vinblastine. etc., have been derived from medicinal plants based on ethnobotanical research programs8. It is estimated that among the total flowering plants occur in the tropical regions of the world, only few in percentages were studied for their pharmaceutical potentials. Following this direction, Subramoniam18 stated that all chlorophyll-a bearing plants have pharmaceutical potential. This statement was made based on the recently reported anti-inflammatory activity in chlorophyll-a and its related products. Recently, many of the reputed pharmaceutical companies have produced a number of herbal preparations based on ethnobotanical leads for different purposes. Few examples of these products and their botanical sources are given in Table 1.
CHALLENGES AND FUTURE PERSPECTIVES OF ETHNOBOTANY AND HERBAL MEDICINE
Issues regarding safety and quality control: The increasing interest on plants and their ethnobotanical bioperspecting were in general based on the perception that herbal remedies or drugs are always safe. This infact is a false assumption. Herbs have been shown to be capable of producing a wide range of undesirable or adverse reactions some of which are capable of causing serious injuries, life-threatening conditions and even death. In many countries, herbal medicines and related products are introduced into the market without any mandatory safety or toxicological evaluation10. Ekor17 reported that over the past decade, the use of herbal medicines represents approximately 40% of all healthcare services delivered in China. And the percentage of people who have used herbal medicines at least once in Australia, Canada, USA, Belgium and France is estimated to be between 48-75%. This rapid increase of interest towards herbal medicine raise major concerns about the need for effective scientific evaluation of safety and toxicity of these crude materials. Although, some products, such as certain standardized herbal extracts have undergone extensive clinical investigation and subjected to systematic review/meta-analysis, however, that still does not help much when it comes to large scale due to the complex nature of the herbal products and the variation between manufacturers methods. Efficacy and safety measures should be extract specific for preparations of the same herb with a very similar profile of constituents32. A number of cases have been reported on adverse effects and toxicity caused by herbal products. One of these cases was an incidents reported by Ekor17 during investigation on Yoyo "Cleanser" bitters, a herbal remedies that is widely used in Nigeria. The known herbal product has gained so much public acceptance over time and continues to enjoy increased patronage among consumers. The study revealed that this herbal formula was capable of elevating plasma levels of liver enzymes and inducing hypokalemia after 30 days of administration in rats17. More efforts and attentions are seriously needed to validate safety and efficacy of herbal products and to provide a guidelines on proper utilizations.
Intellectual property rights and biopiracy: Information about the uses of specific species of plants in a community is usually obtained via interviews of individuals or groups of people and the scope of this information may vary based on the methods used. The economic focus of biological prospecting based on these indigenous knowledge, including the use of patents and other intellectual property mechanisms has highlighted important issues concerning indigenous rights, cultural knowledge and traditional resources. This situation raises important questions about the contribution of ethnobotanical research to the local communities as being the primary sources of these knowledge4. Invasion of unprotected indigenous resources including traditional knowledge which has been termed biopiracy, represents major challenges facing efforts to integrate modern and alternative medicine approaches.
| Table 1: | Botanical name, family, ethnobotanical leads, verified biological activities and herbal products produced from some medicinal plants |
Researchers have sometimes sought patents for compounds that had already been used for centuries. A recent clear example for this conflict of interest may be observed with the discovery of a promising anticancer agents isolated from Guiera senegalensis, a plant common in the Sahel and widely used by Mali’s Dogon people33. Therefore, establishment of a guideline for protection of cultural knowledge and intellectual property rights could provide a significant control on ethical utilization and dissemination of cultural knowledge for both academic researchers and industrial applications.
Lack of information on mechanism of actions of herbal drugs and disease-gene network: Other challenges face study on ethnobotany and herbal medicine are lack of scientific and technological approaches to indicate pharmacodynamic properties and mechanism of actions of ethnobotanical based-herbal drugs. This may due in part to the complexity of herbal ingredients, unknown targets in human body and the mechanism of action underlying the herbal medicine efficiencies34. This situation support the movement towards implementation of polypharmacology approach as an emerging paradigm for drug discovery based on the new philosophy of drug design which has been transformed from "One drug one target" to "One drug multiple targets". This phenomena includes either a single drug acting on multiple targets of a unique disease pathway or a single drug acting on multiple targets pertaining to multiple disease pathways35. Mapping the polypharmacology network onto the human disease-gene network would reveal the drug targets and the related diseases. This may justify some of the recorded effects of botanical drugs against different diseases36. Liu et al.34 reported their findings on implementation of polypharmacological approach on licorice, a reputable Chinese herbal drugs. The researchers constructed a system pharmacology approach combining the oral bioavailability screening, drug-likeness evaluation, blood-brain barrier permeation, target identification and network pharmacology. Applying this method to herbal drugs used in alternative medicine may open up the possibility to understand the explicit targets of active ingredients and their interactions in the context of molecular networks.
CONCLUSION
Indigenous knowledge and ethnoscience need to be integrated with biotechnological approaches to provide scientific validation of the end products and to achieve sustainable management of natural resources. Modern and traditional health care often exist side by side but seldom cooperate. Pharmacological screening including implementation of polypharmacological approaches are necessary to provide better understanding and justification of mechanism of actions based on the new philosophy of multiple molecules-multiple targets-multiple diseases. The economic focus of biological prospecting, including the use of patents and other intellectual property mechanisms raise issues of biopiracy concerning indigenous rights, cultural knowledge and traditional resources. There is an urgent need for both global and local legal frameworks to regulate bioprospecting activities and to eliminate biopiracy. Socio-ethnobotany is one of the new developments in ethnobotany deals with the question of how indigenous people can be compensated for sharing their ethnobotanical knowledge with the industrialized world. Bioprospecting based on ethnobotanical approach for medicinal plant research could lead to the production and development of useful healthcare products such as phytomedicines, nutraceuticals and food supplements.
ACKNOWLEDGMENT
This study was funded by the Fundamental Research Grants (FRGS grant vot:59321) managed by Research and Innovation Affairs and Research Management Centre (RMC), University Malaysia Terengganu.