title: Hepatoprotective effects of kombucha tea: identification of functional strains and quantification of functional components.
abstract: BACKGROUND
  Kombucha tea (KT), a traditional health beverage containing potential hepatoprotective agents, is fermented from sugared tea by a symbiotic culture of yeast and bacteria for 8 days. However, the functional strains that produce components for the hepatoprotective property of KT remain unclear. Multiple strains are involved in traditional KT production. Therefore, KT has not been standardized or produced commercially. This study aimed to identify the functional strains and quantify the functional components with hepatoprotective effects in kombucha tea.
  
  
  RESULTS
  Gluconacetobacter sp. A4 was one of the microorganisms in KT in which the D-saccharic acid-1,4-lactone (DSL) produced by G. sp. A4 was significantly higher than that produced by original tea fungus at 8 days of fermentation. Traditional KT (TKT, tea broth fermented by mixed tea fungus), modified KT (MKT, fermented by single G. sp. A4), and DSL significantly inhibited the acetaminophen-induced increase of alanine aminotransferase, alkaline phosphatase, triglyceride and malondialdehyde, as well as facilitating the reduction of total antioxidant capacity in mice. Furthermore, MKT and TKT are both similar to DSL in terms of protection against acetaminophen-induced liver injury in mice. These results suggested a positive relationship between DSL content and the hepatoprotective effect of TKT, MKT and DSL groups.
  
  
  CONCLUSIONS
  G. sp. A4 was concluded to be a potential functional strain and DSL might be the key functional component for the hepatoprotective property in KT. The stronger capability of G. sp. A4 in producing DSL makes it a better choice for the commercial production of KT.
authors.affiliation: College of Engineering, China Agricultural University, Beijing, 100083, People's Republic of China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.forename: Baoping
authors.initials: B
authors.lastname: Ji
authors.forename: Wei
authors.initials: W
authors.lastname: Wu
authors.forename: Ruojun
authors.initials: R
authors.lastname: Wang
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Yang
authors.forename: Di
authors.initials: D
authors.lastname: Zhang
authors.forename: Wenli
authors.initials: W
authors.lastname: Tian
mesh_terms: D000082:Acetaminophen; D000410:Alanine Transaminase / Q000097:blood; D000469:Alkaline Phosphatase / Q000097:blood; D000818:Animals; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology / Q000627:therapeutic use; D001628:Beverages; D028241:Camellia sinensis / Q000737:chemistry* / Q000382:microbiology; D056486:Chemical and Drug Induced Liver Injury / Q000097:blood / Q000201:enzymology / Q000517:prevention & control*; D005285:Fermentation; D005937:Glucaric Acid / Q000494:pharmacology / Q000627:therapeutic use*; D041821:Gluconacetobacter; D007783:Lactones / Q000494:pharmacology / Q000627:therapeutic use*; D008099:Liver / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D051379:Mice; D008813:Mice, Inbred ICR; D010936:Plant Extracts / Q000378:metabolism / Q000494:pharmacology / Q000627:therapeutic use*; D013662:Tea / Q000382:microbiology*; D014280:Triglycerides / Q000097:blood; D015003:Yeasts
chemical_list: D000975:Antioxidants; C571832:D-Glucaric acid, 1,4-lactone; D007783:Lactones; D010936:Plant Extracts; D013662:Tea; D014280:Triglycerides; D000082:Acetaminophen; D008315:Malondialdehyde; D000410:Alanine Transaminase; D000469:Alkaline Phosphatase; D005937:Glucaric Acid
keywords: Gluconacetobacter sp; acetaminophen-induced liver injury; commercial production; d-saccharic acid-1,4-lactone; modified kombucha tea