NC	negative control; no extract.
PC	Positive control with 0.2% BHT (butylated hydroxyl toluene).
CC	Treatment with Cymbopogon citratus water extract (0.2% w/w).
CL	Treatment with Curcuma longa L. water extract (0.2% w/w).
MF	Treatment with Myristica fragrans water extract (0.2% w/w).
ZO	Treatment with Zingiber officinale water extract (0.2% w/w).
TV	Treatment with Thymus vulgaris water extract (0.2% w/w).
Mixture	Treatment with an equal amount of the previous five (CC, CL, MF, ZO and TV) aqueous extracts (0.2% w/w).