Use of Antidiabetic Plants in Morocco and Québec

In the western world, we are witnessing a vastly growing and renewed interest in complementary and alternative medicines. In particular, the herbal medicine market has exploded, evolving from an esoterical and marginal phenomenon (herbal shops and health food stores) to a mass consumer market (pharmacies and department stores). With this increasing interest in phytomedicines, more individuals will explore the possibility of using herbal medicines to complement conventional antidiabetic therapy, as is already the case in certain minority cultures (1,2). Therefore, we carried out an ethnopharmacological survey of the antidiabetic plants most frequently recommended by herbalists, naturopaths, and other traditional practitioners. We compared results obtained in Morocco, where phytotherapy is commonly used in traditional medicine, and in Québec, where the use of medicinal plants is still marginal but follows the North American explosive trend. To obtain the most precise information on the frequency of use of antidiabetic medicinal plants, we asked individuals to list, in decreasing order of importance, the four to five plants most often recommended or sold for the treatment of diabetes. We found profound differences between Québec and Morocco.

Indeed, only Trigonella foenum graecum (fenugreek) was among the top ten most recommended antidiabetic plants in both surveys, appearing first in Morocco and second in Québec. Fenugreek is well known for its traditional use as an antidiabetic plant (3–5). It contains several hypoglycemic and hypolipidemic constituents and has been the object of clinical trials confirming its beneficial action in diabetes (3,4).

In Québec, Vaccinium spp. (blueberry) received first place. The European bilberry Vaccinium myrtillus improves the microvascular and lipid perturbations associated with diabetes (3,6). However, its cousin, Vaccinium angustifolia, the Canadian blueberry, has not received such scientific attention and may be an interesting candidate antidiabetic plant to study. Several of the other top ten most common antidiabetic plants in Québec are already known for their hypoglycemic activity, including Taraxacum officinale (dandelion), Gymnema sylvester (gymnema), Glycyrrhiza glabra (licorice), Syzygium cumini (jambul), Opuntia streptacantha (prickly pear), and Panax ginseng/P. quinquefolium (ginseng) (3–5).

In contrast, the most commonly recommended antidiabetic plants of the Morocco survey are less often the objects of published scientific study, despite their long history of traditional medicinal use. Aside from fenugreek and Lupinus albus (white lupin), which are known antidiabetic plants, Globularia alypum (globularia) (7) and Nigella sativa (nigella) (8) have recently been shown to exert interesting hypoglycemic effects in animal models of diabetes. Other commonly used plants were Artemisia herba alba (artemisia), Origanum compactum (oregano), and Vitis vinifera (red vine).

In conclusion, our ethnopharmacological survey has revealed several interesting candidate antidiabetic plants, particularly the Canadian blueberry and certain plants of Mediterranean origin commonly used in Morocco, such as globularia and nigella. However, it remains important to determine the safety and efficacy of these claimed antidiabetic plants and to understand their mode(s) of action. In that context, it is crucial for government and other granting agencies to support collaborative research efforts aimed at establishing the clinical efficacy of candidate antidiabetic plants and elucidating their mode(s) of action.