Fig. 1

In vitro screening results on the expression of Nrf2 activity of methanol crude and sub-fractions from five medicinal plants on HaCaT cells, including crude extract and sub-fractions from (A) Helicteres hirsuta leaves (LHH); (B) Piper sarmentosum roots (RPS); (C) Zingiber zerumbet rhizomes (RZZ), (D) Oroxylum indicum stems (SOI) and (E) Phyllanthus amarus stems (SPA). Negative control: DMSO; positive control: tBHQ.