title: Effect of Alpinia zerumbet components on antioxidant and skin diseases-related enzymes.
abstract: BACKGROUND
  The skin is chronically exposed to endogenous and environmental pro-oxidant agents, leading to the harmful generation of reactive oxygen species. Antioxidant is vital substances which possess the ability to protect the body from damage cause by free radicals induce oxidative stress. Alpinia zerumbet, a traditionally important economic plant in Okinawa, contains several interesting bioactive constituents and possesses health promoting properties. In this regard, we carried out to test the inhibitory effect of crude extracts and isolated compounds from A. zerumbet on antioxidant and skin diseases-related enzymes.
  
  
  METHODS
  The antioxidant activities were examined by DPPH, ABTS and PMS-NADH radical scavenging. Collagenase, elastase, hyaluronidase and tyrosinase were designed for enzymatic activities to investigate the inhibitory properties of test samples using a continuous spectrophotometric assay. The inhibitory capacity of test samples was presented at half maximal inhibitory concentration (IC50).
  
  
  RESULTS
  The results showed that aqueous extract of the rhizome was found to have greater inhibitory effects than the others on both of antioxidant and skin diseases-related enzymes. Furthermore, 5,6-dehydrokawain (DK), dihydro-5,6-dehydrokawain (DDK) and 8(17),12-labdadiene-15,16-dial (labdadiene), isolated from rhizome, were tested for antioxidant and enzyme inhibitions. We found that DK showed higher inhibitory activities on DPPH, ABTS and PMS-NADH scavenging (IC50 = 122.14 ± 1.40, 110.08 ± 3.34 and 127.78 ± 4.75 μg/ml, respectively). It also had stronger inhibitory activities against collagenase, elastase, hyaluronidase and tyrosinase (IC50 = 24.93 ± 0.97, 19.41 ± 0.61, 19.48 ± 0.24 and 76.67 ± 0.50 μg/ml, respectively) than DDK and labdadiene.
  
  
  CONCLUSIONS
  Our results indicate that the rhizome aqueous extract proved to be the source of bioactive compounds against enzymes responsible for causing skin diseases. Moreover, DK could be used as a potent inhibitor and be further exploited to be used in anti-skin disease formulations.
authors: Department of Bioscience and Biotechnology, The United Graduate School of Agricultural Science, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan.
authors: Jamnian
authors: J
authors: Chompoo
authors: Atul
authors: A
authors: Upadhyay
authors: Masakazu
authors: M
authors: Fukuta
authors: Shinkichi
authors: S
authors: Tawata
mesh_terms: D032429:Alpinia / Q000737:chemistry*; D000975:Antioxidants / Q000494:pharmacology* / Q000627:therapeutic use; D017364:Collagenases / Q000378:metabolism; D003879:Dermatologic Agents / Q000494:pharmacology / Q000627:therapeutic use; D004791:Enzyme Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D016166:Free Radical Scavengers / Q000494:pharmacology; D006801:Humans; D006821:Hyaluronoglucosaminidase / Q000037:antagonists & inhibitors; D020128:Inhibitory Concentration 50; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors; D018384:Oxidative Stress; D010196:Pancreatic Elastase / Q000037:antagonists & inhibitors; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D027343:Rhizome; D012867:Skin / Q000187:drug effects / Q000201:enzymology*; D012871:Skin Diseases / Q000188:drug therapy / Q000201:enzymology*
chemical_list: D000975:Antioxidants; D003879:Dermatologic Agents; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D010936:Plant Extracts; D014442:Monophenol Monooxygenase; D006821:Hyaluronoglucosaminidase; D010196:Pancreatic Elastase; D017364:Collagenases