Effects of xyloglucans from Tamarindus indica seed on human skin cells

Two xyloglucans were gained from Tamarindus indica, L., Fabaceae, seed using cold water extraction (TSw) and copper complex precipitation (TSc) respectively. TSw and TSc were investigated on human skin fibroblasts (NHDF) and keratinocytes (NHEK, HaCaT) concerning their effects on necrotic cytotoxicity, cell proliferation, cell cycle and migration. Furthermore internalization of TSw and TSc and enzymatic degradation of TSw and TSc using xyloglucanase were carried out.

TSw and TSc exerted no necrotic cytotoxicity. Both were completely internalized after 12h of incubation and significantly enhanced the cellular proliferation and migration of keratinocytes and fibroblasts. The effect on keratinocyte proliferation was shown to be independent of the used concentration. On the other hand 0.1µg/mL and 1µg/mL TSc significantly increased the proliferation rate of NHDF compared to 0.01µg/mL and the effect of 10µg/mL which were significantly different to 100µg/mL. Both xyloglucans triggered the skin cells to move from G0/G1-phase into S and G2-phase already after 3h incubation. Enzymatic hydrolysis revealed enhancement in activity on NHDF in comparison with those two xyloglucans but on HaCaT keratinocytes, the enzymatic hydrolyzed TSc lost its activity. On the other hand TSw maintained the cell proliferation promoting effect after enzymatic hydrolysis.