Alternative Utilization of Vegetable Crop: Pumpkin Polysaccharide Extract and Their Efficacy on Skin Hydration

Abstract

Traditional pumpkin (Cucurbita moschata) and Japanese pumpkin (C. maxima) consist of natural polysaccharides. From a scientific basis, natural polysaccharides could be applied to improve hydration in the cosmetic field. The purified polysaccharide was extracted and deproteinized with the CaCl2 method. Japanese pumpkin showed the higher value of physicochemical properties including yield (12.96 ± 0.60%), total polysaccharide content (0.89 ± 0.04 mg/mL), swelling capacity (4.00 ± 0.00%), swelling index (1.04 ± 0.00%), solubility (126.67 ± 5.77%), viscosity (1.25 ± 0.00 cps), water capacity (0.93 ± 0.15 g/g) and oil absorption capacity (5.93 ± 0.06 g/g) than traditional pumpkin. Additionally, Japanese pumpkin (IC50 9.30 ± 0.58 µg/mL) provided higher antioxidant activity by DPPH assay than traditional pumpkin (IC50 9.98 ± 0.25 µg/mL). The evaluation of efficacy on skin hydration in fifteen Thai volunteers indicated that Japanese pumpkin showed non-skin irritation. An extract concentration of 0.05–0.1% showed a significantly increased effect in moisturizing ability according to concentration (p < 0.05). This result supported that it was safe and effective to use as a moisturizer for cosmetic products.