Antioxidant Effects and Mechanisms of Medicinal Plants and Their Bioactive Compounds for the Prevention and Treatment of Type 2 Diabetes: An Updated Review

Table 2

Plant sources, structures, and antidiabetic mechanisms of some potential antidiabetic phytochemicals on different cell lines.

Number	Plant	Phytochemical isolated	Assay used	Antidiabetic mechanism	Structure	Reference
1	Black beans	Cyanidin; 3-Glucoside	Adipocyte 3T3-L1	Upsurge in adipocyte glucose uptake, improvement in GLUT 4 expression and translocation, elevation in nuclear PPARγ activity, improvement in insulin resistance		[351, 352]
2	Camellia sinensis (green tea), Acacia karroo, Harungana madagascariensis, and Prunus africana	(–)-Epicatechin (EP)	3T3-L1 adipocytes	Promote the translocation of GLUT 4 through the activation of PI3K and elevation in the phosphorylation of PKCλ/ζ		[353]
		(-)-Epigallocatechin (EGC)	3T3-L1 adipocytes	Upgrade the translocation of GLUT 4 by way of stimulation of PI3K and elevation in the phosphorylation of PKCλ/ζ		[353]
3		(–)-Epigallocatechin-3-gallate (EGCG)	3T3-L1 adipocytes	Weakens JNK phosphorylation and elevates GLUT 4 translocation		[354–359]
			H4IIE cells	Accelerates the PI3K/aPKCλ, AMPK, and NF-κB pathways
			Insulin-resistant L6 myotubes	Quickens glucose uptake and accelerates translocation of GLUT 4 to plasma membrane in skeletal muscle
			HepG2	Mitigates insulin signalling blockade by reducing IRS-1 Ser307 phosphorylation through the AMPK activation pathway
			L6 cells	Enhances glucose uptake by expanding GLUT 4 translocation to plasma membrane
			L6E9 myotubes and 3T3-L1 adipocytes	Accelerates glucose uptake as well as GLUT 4 expression and translocation
4	Catharanthus roseus, Acalypha wilkesiana, and Elaeodendron croceum	Naringenin	L6 myotubes	Accelerated glucose uptake and enhanced AMPK activation		[360]
5	Drynaria fortunei (Kunze) J. Sm., Citrus aurantium L., and Citrus medica L.	Naringin	L6 myotubes	Accelerated glucose uptake and enhanced AMPK activation		[360]
6	Averrhoa carambola L	Apigenin-6-C-β-L-fucopyranoside	Rat soleus muscle	Acceleration of insulin secretion and glycogen synthesis and cutting down blood glucose level		[361]
7	Citrus tangerine, Citrus reticulata, and Citrus depressa	Tangeritin	C2C12 myotubes	Phosphorylated AMPK and AS160 and enhanced glucose uptake and GLUT 4 translocation		[362, 363]
			3T3-F442A adipocytes	Accelerated glucose uptake
8	Justicia spicigera	Kaempferitrin	Rat soleus muscle	Acceleration of glucose uptake, GLUT 4 translocation, and glucose homeostasis		[364]
9	Euonymus alatus	Kaempferol	3T3-L1 adipocytes	Enhanced glucose uptake and mitigated hyperglycemia and PPARγ agonist activity		[365]
10	Beaumontia grandiflora	Kaempferol 3-neohesperidoside	Rat soleus muscle	Enhances glycogen synthesis		[366]
11	Maclura pomifera, Maclura tinctoria, and Psidium guajava	Morin	HepG2	Enhances the phosphorylation of the insulin receptor, Akt, and FOXO1, hinders gluconeogenesis, and enhances glycogen synthesis		[367]
12	Black ginger (Kaempferia parviflora Wall.)	Pentamethyl quercetin	3T3-L1 cell	Elevation of GLUT 4 and PPAR levels in mRNA		[368]
13	Curcuma domestica valeton, Cuscuta reflexa, and Daucus carota	Quercetin	3T3-L1 adipocytes	Enhanced glucose uptake and mitigated hyperglycemia and PPARγ agonist activity		[365]
14	Solanum crinitum Lam	Tetramethylkaempferol	3T3-L1 cell	Elevation of GLUT 4 and PPAR levels in mRNA		[368]
15	Tetracera scandens	Genistein	INS-1 rat insulinoma cells	Stimulated insulin secretion via activation of Ca^2+/CaMK II		[369]