Table 2.

Summary of uses of quercetin as antioxidant, antimicrobial, antidiabetic and anticancer agent

Uses of quercetin	Therapeutic agent	Activity performed	Outcomes	Reference
Antioxidant	Quercetin with Hesperidin	DPPH, nitric oxide, hydroxyl radical, hydrogen peroxide radical, superoxide and reducing power assay	Increased activity of both compounds against DPPH	[3]
	Quercetin alone	Ovarian aging	Increase in genes of oxidative stress level	[18]
	Quercetin alone	H2O2	Reduced cytotoxicity of H2O2 by quercetin along with neuroprotective effects	[19]
	Six quercetin derivatives and onion extract	DPPH	quercetin, tamarixetin, isorhamnetin and quercetin-3-O-glucuronide showed increased antioxidant activity	[20]
	quercetin and its glucosides	Role of hydroxyl groups by DFT	OH, groups in B-ring and C-ring contribute primarily to the antioxidative exercises	[21]
Antibacterial	Quercetin extracted from C. officinalis	S.aureus	Growth inhibition of S. aureus	[22]
	Quercetin	Resistant S. aureus and S. saprophyticus	Antibacterial effects against MRSA, MSSA, VRSA and VISA	[23]
	13 flavonoids and 6 organic acids	E. faecalis, S. aureus, E. coli and P. aeruginosa	All compounds showed activity against gram –ve bacteria	[24]
	Catechin, quercetin nanoparticles with chitosan	S. aureus, B. subtilis and E. coli	Enhanced antibacterial effect of nanoparticles	[25]
	Conversion of rutin to quercetin by Aspergillus niger	S. aureus, E. coli and P. aeruginosa	Increased activity against S. aureus was reported	[26]
Antifungal	Quercetin with fluconazole	vulvovaginal candidiasis	Synergistic antifungal effect of quercetin and fluconazole	[27]
	Quercetin with kaempferol	C. orthopsilosis, C. metapsilosis and C. parapsilosis	Greater effect of quercetin than kaempferol as antifungal agent	[28]
	Quercetin alone	Aspergillus flavus	Quercetin showed antifungal activity against Aspergillus flavus	[29]
	Quercetin/rutin and amphotericin B	Cryptococcus neoformans and Candida species	Synergistic antifungal activity was reported	[30]
	Quercetin gold nanoparticles	Aspergillus fumigatus	Strong antifungal activity of nanoparticles against Aspergillus fumigatus	[31]
Antiviral	Quercetin	Dengue virus	Quercetin kills dengue virus	[32]
	Quercetin	HCV	Reduction in viral load	[33]
	Quercetin glucoside	Zeka virus	Cytopathic effects of quercetin glucoside against Zeka virus	[34]
	Lecithin quercetin phytosome	Corona virus	Cytopathic effects of quercetin against COVID-19	[35]
	Quercetin	Influenza A virus	Inhibition of viral cell fusion by quercetin	[36]
Antidiabetic	Quercetin SEDDS	Streptozotocin-induced diabetic	Increased antihyperglycemic effects of quercetin	[37]
	Plant extract of Prunus persica	Streptozotocin-induced diabetic	Reduction in hyperglycemic levels	[10]
	Quercetin	Streptozotocin-induced diabetic Wistar rats	Reduction in blood glucose levels	[38]
	Quercetin loaded soluplus micelles	In vivo rat model	Increased bioavailability of quercetin resulted in decrease in blood glucose levels	[39]
	Quercetin	osteopenia induced by diabetes	Normal blood glucose levels and bone structure in quercetin treated group	[40]
Anticancer	Quercetin and irinotecan	Gastric cancer cell lines	Enhanced anticancer effects by combination therapy	[41]
	Quercetin and 5-FU	13 HCC liver cancer cell line	Synergistic anticancer effects of both compounds	[11]
	Quercetin and cisplatin	EMT6 breast cancer cell line	Synergistic anticancer effects in combined form	[42]
	Quercetin thermosensitive hydrogel	Ovarian cancer mouse model	Enhanced apoptosis shown by hydrogel of quercetin	[43]
	Quercetin and gefitinib nanoparticles	Lung cancer	Enhanced antitumor effect in nanoparticles form	[44]
Anti-inflammatoty	Lecithin-quercetin nanoparticles in gel form	Osteoarthritis on white male Spargue-Dawley rats	Significant reduction in inflammation and edema	[45]
	Quercetin and galangin	Atopic dermatitis in mouse model	Reduction in nitric oxide, interlukin-6 and NF-kB which reduced inflammation	[46]
	Quercetin and six derivatives with onion extract	Human platelets	Inhibition of COX-1 and 12-LOX resulted in anti-inflammatory effect	[20]
	Quercetin	Inflammasome NLRP3	Suppression of NLRP3 lead to reduction in inflammation	[47]
	Quercetin	Endothelial cell function	Inhibition of inflammation by alteration of HUVAC	[48]