Figure 5.

PPARγ is involved in cannabinoid-induced cell death. (a) HepG2 or HuH7 cells were incubated with different doses of THC or JWH-015 for 48 h in the presence or absence of 3 μM GW9662 (GW) and cell viability was assayed by MTT. Results are shown as the mean±S.D. of three different experiments, each performed in triplicate. *P<0.05 and **P<0.01 as compared with cannabinoid-treated cells by Student's t-test. (b and c) HepG2 cells transfected either with control siRNA or PPARγ-selective siRNA (siPPARγ) were incubated with 8 μM THC or 8 μM JWH-015 (JWH) for 48 h and cell viability was assayed by MTT. Results are shown as the mean±S.D. of five different experiments (**P<0.01 as compared with control cells and ^##P<0.01 as compared with siControl cannabinoid-treated cells by Student's t-test). (c) HepG2 cells were incubated with different doses of Troglitazone for 48 h and cell viability was assayed by MTT. (d) HepG2 cells were incubated with THC (2 μM), JWH (2 μM), Troglitazone (20 μM) or THC plus Troglitazone for 48 h and cell viability was assayed by MTT