Table 1.
Percent composition (weight/weight) of formulation F1, F2, and F3.
Fig 1.
In vitro antioxidant activity of NGN.
NGN was added at indicated concentration and assayed for scavenging the radical ABTS (Panel A), •OH (Panel B), iron-independent lipid peroxidation (Panel C) and iron-induced lipid peroxidation (Panel D). Results (percentage of inhibition comparing to control) represent means ± SEM of triplicate values representative of two separate experiments.
Fig 2.
Naringenin (NGN) containing formulations functional stability.
F1, F2, and F3 containing NGN storage was at 4°C (A) and 40°C (B) /75% RH for 6 months. The functional stability of NGN containing formulations was determined by the ABTS radical scavenging activity. Results are mean ± SEM.
Fig 3.
Naringenin (NGN) containing formulation reduces skin edema induced by UVB irradiation.
Samples of dorsal skin were collected 12 h after the end of irradiation and used to measure the edema. Bars represent means ± SEM of 5 mice per group per experiment and are representative of two separate experiments. *p<0.05 compared to the non-irradiated control groups (white bars); #p<0.05 compared to the irradiated control groups (black bars).
Fig 4.
Naringenin (NGN) containing formulation inhibits UVB irradiation-induced cytokine production.
The levels of TNF-α (A), IL-1β (B), IL-6 (C) and IL-10 (D) were determined in samples collected 4 h after the end of irradiation. Bars represent means ± SEM of 5 mice per group per experiment and are representative of two separate experiments. *p<0.05 compared to the non-irradiated control groups (white bars); #p<0.05 compared to the irradiated control groups (black bars).
Fig 5.
Effect of naringenin (NGN) containing formulation on antioxidant capacity of skin after UVB irradiation.
The antioxidant capacity was measured using FRAP (A) and ABTS (B) assays in samples collected 12 h after the end of irradiation. (C) Catalase activity was determined in samples collected 2 h after the end of irradiation. Bars represent means ± SEM of 5 mice per group per experiment and are representative of two separate experiments. *p<0.05 compared to the non-irradiated control groups (white bars); #p<0.05 compared to the irradiated control groups (black bars).
Fig 6.
Naringenin (NGN) containing formulation inhibits superoxide anion generation and lipid peroxidation induced by UVB irradiation.
(A) Superoxide anion production was measured by nitroblue tetrazolium (NBT) reduction assay in samples collected 2 h after the end of irradiation. (B) Lipid peroxidation was measured by tert-butyl hydroperoxide-(LOOH) initiated chemiluminescence (QL) assay in samples collected 4 h after the end of irradiation. Bars represent means ± SEM of 5 mice per group per experiment and are representative of two separate experiments. *p<0.05 compared to the non-irradiated control groups (white bars); #p<0.05 compared to the irradiated control groups (black bars).
Fig 7.
Naringenin (NGN) containing formulation inhibits UVB irradiation-induced down-regulation of glutathione system components.
(A) Reduced glutathione (GSH) levels were measured in samples collected 12 h after the end of irradiation. Expression of (B) glutathione peroxidase 1 (Gpx1) and (C) glutathione reductase (Gr) in the skin was measured 4 h after the end of irradiation by qPCR. Bars represent means ± SEM of 5 mice per group per experiment and are representative of two separate experiments. *p<0.05 compared to the non-irradiated control groups (white bars); #p<0.05 compared to the irradiated control groups (black bars).
Fig 8.
Naringenin (NGN) containing formulation inhibits UVB irradiation-induced Nrf2 down-regulation and improves HO-1 expression in the skin.
Expression of (A) Nrf2 and (B) heme oxygenase-1 (HO-1) in the skin was measured 4 h after the end of irradiation by qPCR. Bars represent means ± SEM of 5 mice per group per experiment and are representative of two separate experiments. *p<0.05 compared to the non-irradiated control groups (white bars); #p<0.05 compared to the irradiated control groups (black bars).