RESUMEN
Objective: Dendrobium spp., the major globally commercializing tropical orchid, has been continuously used in Chinese medicine. However, preparation and standardization of this therapeutic orchid including its clinical evidence for topical application are sparely to be exploited. Methods: Maceration of the white orchid (Dendrobium cv. Khao Sanan) in water was varied on the extraction time. The extraction yields and total polysaccharide content of the extracts were compared. The best extract condition was selected, standardized, and evaluated on safety and skin hydrating efficacy in human volunteers. Results: The extraction for 3 h gave the extract with polysaccharide content that significantly (P < 0.001) greater than the other extraction times with the following specification: yield [(35.60 ± 2.51)%], moisture content [(7.65 ± 0.21)%], total polysaccharide, sugar, reducing sugar and ash content [(72.95 ± 2.37)%, (34.38 ± 0.00)%, (16.28 ± 0.00)%, and (0.12 ± 0.00)%], pH (4.42 ± 0.01), viscosity [(15.07 ± 0.12) cps] swelling and water absorption capacities [(10.00 ± 0.00)%, (1.19 ± 0.24) g/g]. This antioxidative polysaccharide caused no skin irritation with a better skin hydrating efficacy than the untreated skin and the benchmark as examined in 22 Thai volunteers. Conclusion: White Dendrobium is ready to be supplied as a specialty ingredient with a safe and efficient profile for skin dryness therapy. This innovative application of the identified traditional Chinese medicinal herb flows in the main stream of the consumers’ preferences and demand upon natural derived products.