Table 2.
List of studies that have evaluated F. lycii and age-related macular degeneration.
| SNo | Authors (year) | Study Subjects | Administration of F. lycii | Impact on Variables | Conclusion |
|---|---|---|---|---|---|
| A | STUDIES IN ANIMAL MODELS/CELL LINES | ||||
| 1 | Dong et al. (2013) [47] | Human RPE cells (blue light) | Pretreatment with F. lycii in 3 concentrations (0.01 mg/mL, 0.1 mg/mL, 1 mg/mL) | Decreased levels of ROS and apoptotic cells | F. lycii pre-treatment can protect RPE cells against blue light induced damage via inhibiting ROS over generation and subsequent apoptosis in RPE cells. |
| 2 | Du et al. (2013) [48] | Human RPE cells and porcine photoreceptor outer segments | F. lycii in culture medium in 3 concentrations (0.01 mg/mL, 0.1 mg/mL, 1 mg/mL) | (1) RPE cells—increased proliferation and ability to phagocytose photoreceptor outer segments (2) decreased photoreceptor outer segment-induced lipofuscin accumulation in RPE cells | F. lycii treatment enhanced the ability of RPE cells to phagocytose photoreceptor outer segments along with proliferation and removal of lipofuscin. |
| 3 | Liu et al. (2015) [49] | Human RPE cell line (exposed to H2O2) | Pretreatment with different concentrations of F. lycii (0, 10, 50, 100, 500, 1000, 5000 ug/mL) | (1) Prevented loss of cell viability with maximal effect at 500 ug/mL (2) Reduced cell apoptosis (3) Inhibited up-regulation of Bcl-2 and down-regulation of Bax gene | F. lycii protected RPE cells against H2O2-induced acute oxidative stress injury (apoptotic cell death). This is probably attributable to increase in Bcl-2/Bax due to up-regulation of Bcl-2 and down-regulation of Bax expression. |
| 4 | Hsieh et al. (2018) [50] | Human RPE cell line (exposed to UVB) | Pretreatment with aqueous and ethanol extracts of F. lycii (from 0–200 ug/mL for 2 h) | (1) Prevented loss of cell viability (2) Reduced endogenous ROS levels (3) Reduced cell apoptosis (4) Attenuated loss of mitochondrial membrane potential (5) Dose dependent protection against DNA damage as measured by γH2AX levels (6) Prevented G2/M-arrest | F. lycii demonstrated protective effect on oxidative-induced apoptosis of RPE cells exerted via antioxidant property and protective activity on growth arrest as well as DNA damage. Ethanol extract showed stronger antioxidant effect when compared to aqueous extract. |
| 5 | Cheng et al. (2018) [41] | Rats, Male Sprague-Dawley (exposed to white light) | Diet supplemented with F. lycii 250 mg/kg for 54 days, submicron (particle size = 100 ± 70 nm) or blended (particle size = 3.58 ± 3.8 µm) type | (1) Maintained outer nuclear layer thickness (2) Preserved a and b waves on ERG, decreased MDA levels, higher total glutathione levels | F. lycii has protective effect on light induced retinal degeneration via its antioxidant property as evident by lower MDA and higher total glutathione levels. Submicron type provided better protection than blended type probably due to improvement in pharmacokinetics. |
| 6 | Tang et al. (2018) [51] | Mice, BALB/cJ (exposed to white light) | F. lycii (150 mg/kg, low dose, 300 mg/kg, high dose) once per day for 7 days | (1) Attenuated cell nuclei loss in outer nuclear layer (2) Ameliorated light induced damage in the form of decrease ROS production and increased rhodopsin (3) Prevented decrease in a- and b- wave amplitudes (6) Increased mRNA levels of TrxR1 and Nrf2 and decreased mRNA levels of PARP14 | F. lycii protected photoreceptor cells against light-induced retinal damage probably due to decrease ROS production and up-regulation of anti-oxidative genes (Nrf2 and TrxR1). The resultant decrease in oxidative stress leads to reduction in mitochondrial damage and in apoptosis of photoreceptors. |
| B | STUDIES IN HUMAN SUBJECTS | ||||
| 7 | Bucheli et al. (2011) [20] | 150 healthy subjects (65–70 years) | F. lycii (milk based formulation, 13.7 g/d) for 90 days, Placebo-controlled, double-masked, randomized | Subjects with F. lycii supplementation demonstrated: (1) Decreased hypopigmentation and soft drusen accumulation in macula (2) Increased plasma Z levels by 26% (3) Increased antioxidant capacity by 57% | F. lycii supplementation was associated with prevention of early AMD features, such as macular hypopigmentation and soft drusen accumulation, due to its antioxidant activity. |
| 8 | Vidal et al. (2014) [52] | 150 healthy subjects (65–70 years) | F. lycii (milk based formulation, 13.7 g/d) for 90 days, Placebo-controlled, double-masked, randomized | Subjects with F. lycii supplementation demonstrated: (1) Increased plasma anti-oxidant capacity (2) Higher IgG antibody response, sero-conversion and protection rates following influenza vaccine (3) Improved syndrome of Yin deficiency | F. lycii supplementation reinforced immune defenses in elderly subjects, probably attributable to its antioxidant property, thus decreasing the likelihood of developing AMD. |
| 9 | Li et al. (2018) [53] | 114 subjects with AMD (51 to 92 years) | F. lycii supplementation (25 g/day for 90 days) Prospective, randomized controlled trial | AMD subjects with F. lycii supplementation demonstrated (1) Three-fold increased serum Z but not lutein (2) Increased macular pigment optical density (3) significant increased best corrected visual acuity | F. lycii supplementation increased serum Z, macular pigment as well as visual function (visual acuity) in patients with early AMD without causing any detectable adverse effects. |
RPE: Retinal pigment epithelium; ROS: Reactive oxygen species; POS: photoreceptor outer segment; ARPE-19: Arising retinal pigment epithelial cell line-19; H2O2: Hydrogen peroxide; Bcl-2: B-cell lymphoma 2; UVB: ultraviolet B-rays; MDA: Malondialdehyde; ERG: Electroretinogram; TrxR1: Thioredoxin reductase 1; Nrf2: Nuclear factor (erythroid-derived 2)-like 2; PARP 14: Poly (adp-ribose) polymerase member 14: mRNA: messenger RNA.