METHODS: ARPE-19 cells were cultured in Dulbecco's Modified Eagle Medium-F-12 supplemented with 10% foetal bovine serum and 1% penicillin-streptomycin in a humidified 5% CO2 incubator maintained at 37°C. Cells were treated with 247 µmol/L lutein, 49 µmol/L zeaxanthin and 1% (v/v) of either coconut oil, corn oil, peanut oil, olive oil, sunflower oil, soybean oil, castor oil, or linseed oil for 48h. Lutein and zeaxanthin concentration in the cells were quantified by high performance liquid chromatography.
RESULTS: Among the oils tested, the highest lutein and zeaxanthin uptake was observed with coconut oil while the lowest was observed with linseed oil.
CONCLUSION: ARPE-19 uptake of lutein and zeaxanthin are found to be dependent on the type of oils.
MATERIALS AND METHODS: ARPE-19 cells were pre-treated with LUT, ZEA, or both for 24 h before 200 μM H2O2 challenge. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. DICER1 and Alu RNA were quantified by western blotting and real-time polymerase chain reaction, respectively.
RESULTS: H2O2 increased cell Alu RNA expression and decreased cell viability of ARPE-19, but had no significant impact on the DICER1 protein level. LUT, alone and in combination with ZEA pre-treatment, prior to H2O2 challenge significantly improved cell viability of ARPE-19 and reduced the level of Alu RNA compared to the negative control.
CONCLUSIONS: These results support the use of LUT alone, and in combination with ZEA, in AMD prevention and treatment. This study is also the first to report LUT modulating effects on Alu RNA.
METHODS: Skin phototype was determined using Fitzpatrick phototype quiz, DSMII ColorMeter measured skin colours, sun exposure quantified using an index (SEI) and phototest performed with MEDlight-Multitester.
RESULTS: A total of 167 healthy volunteers participated. There were 110 (66%) females and 56 (34%) males; 124 (74.7%) were Malay, 27 (16.3%) Chinese and 14 (8.4%) Indians. One hundred and nine (65.7%) skin phototype IV, 30 (18.1%) phototype III and 27 (16.3%) phototype V. IPDDA ranges from 6 ± 1.5-5.7 ± 1.4 J/cm2 . MED-UVB were 96.9 ± 17.6, 124 ± 29.3 and 118.6 ± 27.4 mJ/cm2 for phototype III, IV and V, respectively. All MED-UVA were outside the tested dose range of 3.6-11 J/cm2 . MMD-UVB were 106 ± 18.2, 134 ± 25.6 and 136 ± 31.1 mJ/cm2 while MMD-UVA were 4.1 ± 4.1, 4.9 ± 3.8 and 5.7 ± 3.7 J/cm2 respectively for phototypes III, IV and V. MED-UVB, MMD-UVB and MMD-UVA did not depend on skin phototype. Facultative skin whiteness (L*), erythema (E) and melanin content (M) correlated significantly with MED-UVB while constitutive skin colours were significant for L*, yellowness (b*), E and M. Sun exposure did not significantly correlate with MED-UVB and MMDs, however, an inverse relationship with MED-UVB was demonstrated.
CONCLUSION: Minimal erythema doses in our cohort were slightly different from other regional countries. Constitutive and facultative skin whiteness, erythema and melanin content correlated with MED. There was no association between skin phototype and sun exposure with MED or MMD.