Table 2.

Overview of studies reporting on the ameliorative effect of gallic acid derived compounds against obesity-associated complications.

Author, Year	Experimental Model, Dose Used, and Intervention Period	Comparative/Combination Therapy	Experimental Outcome and Proposed Mechanism
Ong et al., 1995 [113]	Adipocytes from epididymal fat pads from male Wistar rats treated with gallic acid at 1–1000 µM for various times from 20 min to 2 h	Tannic acid was used at 1–1000 µM for various times from 20 min to 2 h	Tannic acid inhibited insulin stimulated lipogenesis through promoting activation of insulin-receptor-associated tyrosine kinase phosphorylation. Whereas, gallic acid showed no effect
Ren et al., 2006 [114]	3T3-L1 pre-adipocytes incubated with 6-deoxytetra-O-galloyl-α-d-glucopyranose, tetra-O-galloyl-α-d-xylopyranose and 6-chloro-6-deoxy-1,2,3,4-tetra-O-galloyl-α-d-glucopyranose at 30 µM for 15 min	None	Improved glucose uptake
Hsu and Yen, 2007 [96]	3T3-L1 adipocytes were treated with gallic acid at 1–250 μM for 72 h	o-coumaric acid and rutin were used at with 1–250 μM for 72 h	o-coumaric acid and rutin demonstrated better effect in inhibiting glycerol-3-phosphate dehydrogenase activity, and the expression of peroxisome proliferator activated receptor (PPAR)γ, CAAT/enhancer-binding proteins (C/EBPR) and leptin. While also upregulating adiponectin levels
Hsieh et al., 2010 [97]	3T3-L1 and C3H10T1/2 adipocytes treated with gallic acid at 5–10 μM for 2 h	Compound C, n-acetyl-l-cysteine, epigallocatechin gallate and other catechins, such as epicatechin, epigallocatechin, and epicatechin 3-gallate were used at 5–10 μM for 2 h	Epigallocatechin gallate performed better than other compounds in inhibiting insulin stimulated glucose uptake, with mechanistic involvement of 5’ adenosine monophosphate -activated protein kinase (AMPK) pathways
Totani et al., 2011 [22]	High fat diet fed male Wistar rats treated with gallic acid at 90 ppm in diet for 12 weeks	(z)-3-(3,4,5-trihydroxybenzoyloxy) propane-1,2-diyl dioleate (DOGGA) and octyl gallate (OG) were both used at 90 ppm in diet for 12 weeks	DOGGA showed pronounced effect than OG in reducing the body weight in rats. Gallic acid showed no effect
Sergent et al., 2012 [115]	In vitro bioassays testing epigallocatechin-3-gallate at 0.8 µM	Kaempferol and quercetin were effective at 13.4 and 21.5 µM, respectively	Epigallocatechin-3-gallate presented pronounced pancreatic lipase inhibitory effect than both kaempferol and quercetin
Park et al., 2014 [116]	3T3-L1 adipocytes treated with gallic acid at 30, 60 and 90 µM during differentiation period	KMU-3, a derivative of gallic acid, was used at 1, 5 and 10 µM during differentiation period	KMU-3 outperformed gallic acid in suppressing lipid accumulation in cells. Mechanistically, it inhibited expressions of C/EBP-A, PPARγ, and Fas, as well as some pro-inflammatory markers
Yang et al., 2015 [117]	3T3-L1 pre-adipocyte treated with epigallocatechin 3-O-(3-O-methyl) gallate and epicatechin-3-gallate at 20, 40 and 80 μg/mL for 48 h	None	Epigallocatechin 3-O-(3-O-methyl) gallate presented higher activity than epicatechin-3-gallate in inhibiting adipogenesis and proliferation
Jeon et al., 2016 [118]	3T3-L1 adipocytes treated with methyl gallate at 25, 50 and 75 µM for 48 h	None	Inhibited adipogenesis through stabilizing β-catenin suppression of PPARγ expression. Further stimulated canonical Wnt/β-catenin signaling
Ediriweera et al., 2017 [14]	MCF-7 cells treated with gallic acid at 90 µM for 48 h	Ascorbic acid (6.5 µM), catechin (583 µM), curcumin (3.5), epigallocatechin gallate (7.5 µM), and quercetin (70 µM) for 48 h	Only quercetin, curcumin and epigallocatechin gallate showed significant protective effects against leptin-induced proliferation
Zengin et al., 2017 [101]	In vitro docking experiments assessing lipase inhibitory effect of gallic acid	p-OH-benzoic acid, catechin, epigallocatechin gallate, epicatechin, and rosmarinic acid	Epigallogatechin gallate and rosmarinic acid displayed best docking scores for the inhibition of α-glucosidase, α-glucosidase and lipase activities