Background: The increasing incidence of diabetes worldwide has urged researchers
to explore novel antidiabetic agents from natural products. Ethnomedicinal
field studies on diabetes have expanded across the globe, documenting large numbers of
folk medicinal plants against diabetes. Nonetheless, a systematic review of these surveys
has not been conducted so far. This study documents the medicinal plants traditionally
used globally for managing diabetes.
Methods: Key databases including Sciencedirect, Medline/PubMed, and Google Scholar
were scrutinized. The Plant List and The International Plant Names Index (IPNI) were
used to validate the scientific plant names.
Results: 2004 traditionally used plants belonging to 1112 genera and 197 families were
reported across 92 countries for the management of diabetes. Leguminosae (105 genera
and 193 species), Compositae (97 genera and 188 species), and Lamiaceae (47 genera
and 121 species) were the main plant families reported. Momordica charantia L., Syzygium
cumini (L.) Skeels, Allium sativum L., Azadirachta indica A.Juss., Catharanthus
roseus (L.) G.Don, Olea europaea L., Trigonella foenum-graecum L., Gymnema
sylvestre (Retz.) R.Br. ex Sm., Aloe vera (L.) Burm.f., and Allium cepa L were the species
mostly reported. Indeed, the antidiabetic properties of these main species have been
evidenced by experimental studies. Several antidiabetic compounds acting via different
mechanisms have been identified, including momordicoside, karaviloside, cucurbitacin,
charantin, and charantoside from M. charantia, cuminoside from S. cumini, S-allyl cysteine
sulfoxide from A. sativum, limonoids from A. indica, alkaloids including vindoline,
vindolidine, vindolicine and vindolinine from C. roseus, oleuropein and oleanolic acid
from O. europaea, flavone C-glycosides such as vicenin-1, isoschaftoside, and schaftoside
from T. foenum-graecum seeds, gymnemosides, gymnemagenin, and pregnane glycosides
from G. sylvestre, chysalodin from A. vera, and quercetin from A. cepa.
Conclusion: This review is the first to provide a compiled list of traditional medicinal
plants used worldwide against diabetes.