Upon induction by thermal stress, the GFP fluorescence is visible at the head of the worm, including the pharynx and the anterior nerve ring in the transgenic worm but not in the wild-type controls. The expression of
hsp-16-2 induced by heat shock was significantly suppressed by 33% in CL2070 worms fed with EGb761. Exposure of the transgenic worms to 40 M juglone, an oxidative stressor, for 24 h generated higher
hsp-16-2 expression than that induced by heat shock. Shorter exposure time to juglone also induced
hsp-16-2 expression but to a lesser degree: an 11% and 30% induction were observed in worms exposed to juglone for 6 h and 12 h, respectively (24 h exposure set as 100%). The juglone-induced expression of
hsp-16-2 was remarkably attenuated by 86% in worms pretreated with 100 g/ml EGb 761, compared with untreated controls (EGb761, GFP mean pixel density 180 vs. control GFP mean pixel density 25, n=120 worms, P<0.001). Similar results were obtained in worms exposed to a higher concentration of juglone (60 M).