Intracellular ROS protection efficiency and free radical-scavenging activity of quercetin and quercetin-encapsulated liposomes

Figures & data

Figure 1. Chemical structure of 3,5,7,3’,4’-pentahydroxyflavone.

Figure 2. Electron Micrograph of Liposomes Prepared using the Bangham method.

Figure 3. Nano-encapsulation renders quercetin completely dispersible in aqueous media. Free quercetin is poorly soluble in aqueous media. In contrast the equivalent quantity of quercetin encapsulated in liposomes is fully dispersible in aqueous media.

Table I. Physicochemical characteristics measured for Liposomal quercetin prepared.

	Liposome type	Encapsulation efficiency	z-potential (mV) Mean ± SD	Size (nm) Mean ± SD
liposome-Q	SUV	40.7 ± 3.1%	− 4.47 ± 1.3	100.974 ± 0.3

Figure 4. Dose-dependent inhibition of proliferation of MCF-7 cells treated with Q-L (♦), free quercetin (■), and L (▲). A, MCF-7 cells were treated with various doses of Q-L, free quercetin, or L for 48 hours. During the anti-proliferative assays, the liposome concentration in the Q-L was always the same as liposome. Cell viability was detected using MTT assays. The experiment was repeated thrice and the average number of cell is shown with error bars.

Table II. Effect of free quercetin and encapsulated quercetin on viability of MCF-7 cells exposed to cumene hydroperoxide (CHP).

freeQ (μM)	encapQ	CHP (μL)	Viable cells (%) freeQ	Viable cells (%) encapQ
0	0	0	100 (± 3)	100 (± 3)
0	0	5	21 (± 4)	21 (± 4)
1	1	5	31 (± 3)	32 (± 4)
5	5	5	45 (± 4)	48 (± 5)
10	10	5	67 (± 5)	70 (± 3)
50	50	5	81 (± 4)	90 (± 4)

Figure 5. Ability of quercetin and liposomal quercetin to reduce ferric iron in comparison with a known hydrophilic antioxidant.

Figure 6. Comparison of free radical-scavenging activity of quercetin, BHA, and liposomal quercetin on 2,2-diphenyl-1-picrylhydrazyl radical (BHA: butylatedhydroxyanisole).