Figure 3: Effect of Hibiscus syriacus ethanolic extract (HSEE) on collagen contraction. (a–c) 2 × 105 HDF cells were seeded in 24-well plates mixed with 2 mg/ml of collagen solution. The plates were incubated at 37°C for 30′ to induce collagen gel formation. TGFβ at concentration of 2.5 ng/ml was used as positive control. At the end of incubation the medium with treatment was added and the plates were incubated overnight. The day after the gel was released from the bottom of the well to induce collagen gel contraction. 24 h later, pictures were taken and gel area was estimated. Each column value of the plot represents the average of four experiments and error bars indicate standard deviations. value < 0.05 is represented by . P value < 0.001 is represented by . (b) Representative image of collagen floating gel after 24 hours of HSEE treatment. HDF cells treated with HSEE showed higher contractibility than untreated HDF cells.