The equation for calculating Miller Units (MU) is as follows: where A420 represents absorbance of o-nitrophenol, OD600 represents optical density of the culture, t is the time of the reaction, and V is the culture volume.
The inhibition efficiency was expressed as follows: (1−[A]test/[A]control) × 100, where [A]test and [A]control represent the optical density at 490 nm for the test and control experiments, respectively.
We then estimated the absorption rate spectra of each pigment at the cornea (Scornea) by the formula, Sconea = 10−[Lens+Macular]×Sretina, where Lens and Macular represent the optical density spectra of lens and macular pigment, respectively, measured in humans [65].
HSAF content was expressed as a 'peak area/OD600' index as described previously (Wang et al. 2014), where the 'peak area' is the area under the peak corresponding to HSAF in the HPLC analysis, while the OD600 represents the optical density of the culture at the time point used for HSAF extraction.
For each experimental condition, worm growth was assessed by measuring the parameter "Extinction" (EXT; represents the optical density of the worms, which measures the decrease in laser light intensity when an object passes through the laser beam).
†EIA score represents test/cutoff optical density ratios.
The percentage inhibition was calculated: (ODwithout inhibitor - ODwith inhibitor)/ODwithout inhibitor × 100, where OD represents the optical density.
Each experiment was performed in triplicate and the values are represented as optical density (OD) or percentages.
Relative Growth was calculated as follows: when ODtreated - ODzero > 0; Cell death occurred if ODtreated - ODcontrol < 0, where ODtreated represents the optical density of treated cells at the day of the assay, ODcontrol the optical density of the untreated control cells and ODzero the optical density at the moment of drug addition.
With the first formula [ 21], BFI = AB-CW, where AB represents the optical density at 595 nm (OD595nm) of a well containing stained attached bacteria and CW, the OD595nm of the stained control wells containing bacteria-free medium only, here supplemented with BHI.
