Table 2.

Natural inhibitors with antidiabetic effects.

S.N.	Natural inhibitor	Plant source	Effect	Mode of action	Reference
1	Bark and wood extract	Illicium religiosum	Antiglycating	Antioxidant	88
2	Ethyl extract of dried leaves	Allium cepa	Antihyperglycaemic and antiglycating	Antioxidant	88, 89
3	Hull extract	Fagopyrum esculentum	Antiglycating	Antioxidant	88
4	Leaf extract	Origanum officinalis	Antiglycating	Antioxidant	88
5	Ethyl ether extract	Allium sativum	Hypoglycaemic	Stimulation of insulin secretion	90
6	Allicin	Allium sativum	Antidiabetic	Hypoglycemic	91
7	Leaf gel extract	Aloe vera	Hypoglycaemic	Reduction in blood sugar, improvement in plasma insulin	93
8	Extract of seeds	Acacia arabica	Hypoglycaemic	Stimulation of insulin secretion from beta cells	94
9	Beta vulgarocides	Beta vulgaris	Antiglycating	Antihyperglycaemic, Enhanced glucose tolerance	97
10	Methanolic extract	Phallanthus amarus	Reduce blood sugar level	Antioxidant	101
11	Dried leaf powder	Gymnema sylvestris	Antihyperglycaemic	Decrease in the activity of gluconeogenic enzymes	110, 111
12	Caffeic acid	Ilex paraguariensis	Antiglycating	AGEs inhibition by acting on Methylglyoxal	119
13	Extract	Empetrum nigrum L.	Antiglycating	Radical scavenger	121
14	Chlorogenic acids	Chrysanthemum sp.	Interfere with glucose absorption and alter gene expression of antioxidant enzymes	Free radical and metal scavenging activity	126
15	Cinnamic acid derivatives such as ferulic acid	Cimicifuga heracleifolia	Antiglycating	AGEs inhibitor	127, 128, 129
16	Ellagic acid	Numerous fruits and vegetables	Antiglycating	Inhibition of CML through a dicarbonyl trap	130
17	Quercetin	Many plants	Antidiabetic and Antiglycating	Antioxidant, traps MG and Glyoxal	131, 132, 133
18	Thymoquinone	Nigella sativa	Antiglycating	Antioxidant	136, 137