|ISSN No. 1606-7754 Vol.14 No.1 April 2006|
Medicinal plants with potential antidiabetic activity - A review of ten years of herbal medicine research (1990-2000)
Mohamed Bnouham*, Abderrahim Ziyyat, Hassane Mekhfi, Abdelhafid Tahri, Abdelkhaleq Legssyer
Laboratory of Cellular Physiology and Pharmacology, Department of Biology, University of Mohamed the First, Faculty of Sciences, BP. 524, 60000 Oujda, Morocco
Medical plants play an important role in the management of diabetes mellitus especially in developing countries where resources are meager. This review presents the profiles of plants with hypoglycaemic properties, reported in the literature from 1990 to 2000. The profiles presented include information about the scientific name, family, methodology used, the degree of hypoglycaemic activity and the active agents. The large number of plants described in this review (176 species belonging to 84 families) clearly demonstrated the importance of herbal plants in the treatment of diabetes. It also shows the effort to isolate new potential antidiabetic agents. The plant families, including the species (sp), most studied for their, confirmed hypoglycaemic effects include: Leguminoseae (11 sp), Lamiaceae (7 sp), Liliaceae (8 sp), Cucurbitaceae (7 sp), Asteraceae (6 sp), Moraceae (6 sp), Rosaceae (6 sp), Euphorbiaceae (5 sp) and Araliaceae (5 sp). The most studied species are: Citrullus colocynthis (Opuntia streptacantha Lem. (Cactaceae), Trigonella foenum greacum L. (Leguminosea), Momordica charantia L. (Cucurbitaceae), Ficus bengalensis L. (Moraceae), Polygala senega L. (Polygalaceae), and Gymnema sylvestre R. (Asclepiadaceae). Many studies have confirmed the benefits of medicinal plants with hypoglycaemic effects in the management of diabetes mellitus. The effects of these plants may delay the development of diabetic complications and correct the metabolic abnormalities. Moreover, during the past few years some of the new bioactive drugs isolated from hypoglycaemic plants showed antidiabetic activity with more efficacy than oral hypoglycaemic agents used in clinical therapy. (Int J Diabetes Metab 14: 1-25, 2006)
Key words: Diabetes, nephropathy, microalbuminuria, proteinuria, cardiovascular risk
The aim of this review is to collate all available data on plants with hypoglycaemic effects reported in the Medline (PubMed) during the 1990-2000 period. This review and those of Ivorra et al.1 and Atta-Ur-Rahman2 show the importance and the interest placed on medicinal plants in the drive to demonstrate their antidiabetic effects and to isolate the bioactive agents.
Many ethnobotanical surveys on medicinal plants used by the local population have been performed in different parts of the world including Morroco, Saudi Arabia, Taiwan, and Trinidad andTobogo.2-5,-8-9 Several plant species have been described as hypoglycaemic. These inclde Opuntia streptacantha Lem, Trigonella foenum graecum L, Momordica charantia L, Ficus bengalensis L, Polygala senega L., Gymnema sylvestre R., Allium sativum, Citrullus colocynthis, myrrh, black seeds, helteet, fenugreek, aloe and Artemisia.2-5 Other species are less well known.
In the present review, interest is focused on experimental studies performed on hypoglycaemic plants and their bioactive components. Studies which did not use experimental procedures, such as casual surveys or folk medicine4,6-9 are not reported. Moreover, studies based on preparations of mixtures of plants with unknown origin were not considered in the present review.
Several medicinal plants have been used as dietary adjunct and in the treatment of numerous diseases without proper knowledge of their function. Although phytotherapy continues to be used in several countries, few plants have received scientific or medical scrutinity. Moreover, a large number of medicinal plants possess some degree of toxicity. For example, it was reported that about one third of medicinal plants used in the treatment of diabetes are considered to be toxic.11
We believe that the list of medicinal plants presented in this review is useful to researchers, as well as practitioners. This list is best used only as a preliminary screening of potential antidiabetic plants, not as a definitive or complete list of hypoglycaemic plants.
The list of potential hypoglycaemic plants is presented in the following paragraphs. The scientific name of the plant, the family and the name of the country in which they are available are indicated. The description of methods used in the experiments, model animals, and the degree of hypoglycaemia, doses, toxicity and active ingredients are also included. Plants which did not show any significant hypoglycaemic effect were not included.