Methods
Acquisition and extraction of plants
All plant materials were acquired from Neal's Yard Remedies
Ltd (Table 1). Dried herbs were ground in a pestle
and mortar, extracted in boiling water at a ratio of 500 mg
herb to 10 mL of boiling water and cooled prior to sonication
for 15 minutes to extract maximum components
from within the cells. The following day the debris was
removed via filtration with Whatman no. 1 filter paper
and the filtrate was passed through a 0.2 μm membrane
into clean, pre-weighed glass vials. The resulting filtrates
were fan dried and weighed. The dried material was stored
at -20°C and re-suspended in water at 10 mg/mL for use
in the assays. White tea powder was extracted in a similar
manner except it was extracted in cold water and used
without further processing. Pomegranate fruit and green
tea leaf extracts were supplied as used in formulations in
glycerine. These were dissolved in water at 10% weight by
volume for use in the assays. Two tinctures (rose and
mahonia in 90% ethanol) were filtered before evaporation
and re-suspension in water for the assays.