*3.6. Collagen Synthesis Rate*

GLSE, at a concentration of 0.5–5 μg/mL, showed a higher collagen synthesis effect than the other extract types (Figure 7). The results indicate that the GLFE methanolic extract had phytochemicals that inhibited the collagen synthesis effect. As Figure 1 shows, GLFE extracts showed lower collagen synthesis effects at concentrations ranging from 1 to 20 μg/mL, which decreased in a concentration-dependent manner. GLFE extract concentrations higher than 2 μg/mL did not affect collagen synthesis. However, no significant difference was observed between GLAE and GLRE extracts in collagen synthesis at any of the concentrations used in the experiment.

**Figure 6.** ALP activity of extracts from each part of *G. littoralis* in osteoblastic MC3T3-E1 cell line. Each value is the mean ± standard deviation of nine replicate tests. Mean values followed by the same letter are not significantly different based on the DMRT (*p* < 0.05). P.C.: Positive control (ascorbic acid (50 μg/mL), β-glycerophosphate (100 mM). GLSE: *G. littoralis* leaf, stem extracts, GLFE: *G. littoralis* fruit extracts, GLAE: *G. littoralis* all extracts, GLRE: *G. littoralis* root extracts.

**Figure 7.** Collagen synthesis effects of extracts from each part of *G. littoralis* in osteoblastic MC3T3-E1 cell line. Each value is mean ± standard deviation of nine replicate tests. Mean values followed by the same letter are not significantly different based on the DMRT (*p* < 0.05). P.C.: Positive control (ascorbic acid (50 μg/mL), β-glycerophosphate (100 mM). GLSE: *G. littoralis* leaf, stem extracts, GLFE: *G. littoralis* fruit extracts, GLAE: *G. littoralis* all extracts, GLRE: *G. littoralis* root extracts.
