title: Flavonoids in Scutellaria immaculata and S. ramosissima (Lamiaceae) and their biological activity.
abstract: OBJECTIVE
  The aim of this study was to investigate the flavonoid composition of Scutellaria immaculata and S. ramosissima (Lamiaceae) and the in-vitro biological activity of their extracts and flavonoids.
  
  
  METHODS
  The flavonoid composition of S. immaculata (Si) and S. ramosissima (Sr) were analysed using LC-MS. Antimicrobial activity was studied in vitro against a range of bacteria and fungi using diffusion and microdilution methods. Anti-trypanosomal and cell proliferation inhibitory activity of the extracts and flavonoids was assessed using MTT. The antioxidant activity of the flavonoids and extracts were evaluated using DPPH* test.
  
  
  RESULTS
  LC-MS investigation of Si and Sr plants allowed the identification, for the first time, of an additional 9 and 16 flavonoids, respectively. The methanol, chloroform and water extracts from these plants and six flavonoids (scutellarin, chrysin, apigenin, apigenin-7-O-glucoside, cynaroside and pinocembrine) exhibited significant inhibition of cell growth against HeLa, HepG-2 and MCF-7 cells. The chloroform extract of Sr showed potent cytotoxic effects with IC50 (drug concentration which resulted in a 50% reduction in cell viability) values of 9.25 ± 1.07 µg/ml, 12.83 ± 1.49 µg/ml and 17.29 ± 1.27 µg/ml, respectively. The highest anti-trypanosomal effect against T. b. brucei was shown by the chloroform extract of Sr with an IC50 (drug concentration which resulted in a 50% inhibition of the biological activity) of 61 µg/ml. The pure flavonoids showed an IC50 range between 3 and 29 µm, with cynaroside as the most active compound with an IC50 value of 3.961 ± 0.133 µm. The chloroform extract of Sr has potent antimicrobial activity against Streptococcus pyogenes (minimum inhibitory concentration, MIC = 0.03 mg/ml). Pinocembrine exhibited a strong activity against the all bacteria except Escherichia coli and yeasts. Water extracts of Sr and Si exhibited potent antioxidant activity with IC50 values of 5.62 ± 0.51 µg/ml and 3.48 ± 0.02 µg/ml, respectively. Scutellarin exerted stronger antioxidant activity than other flavonoids.
  
  
  CONCLUSIONS
  This is the first study reporting an in-vitro biological investigation for Si and Sr. Especially the chloroform extract of Sr showed potent anticancer and antimicrobial activity. Cynaroside had a highly selective and strong cytotoxicity against T. b. brucei while showing only mild effects against cancer cells.
authors: Institute of the Chemistry of Plant Substances AS RUz, Tashkent, Uzbekistan.
authors: Nilufar Z
authors: NZ
authors: Mamadalieva
authors: Florian
authors: F
authors: Herrmann
authors: Mahmoud Z
authors: MZ
authors: El-Readi
authors: Ahmad
authors: A
authors: Tahrani
authors: Razan
authors: R
authors: Hamoud
authors: Dilfuza R
authors: DR
authors: Egamberdieva
authors: Shahnoz S
authors: SS
authors: Azimova
authors: Michael
authors: M
authors: Wink
mesh_terms: D000890:Anti-Infective Agents / Q000032:analysis / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000032:analysis / Q000494:pharmacology / Q000627:therapeutic use*; D000975:Antioxidants / Q000494:pharmacology*; D047310:Apigenin / Q000032:analysis / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D001713:Biphenyl Compounds / Q000378:metabolism; D005419:Flavonoids / Q000032:analysis / Q000494:pharmacology*; D005960:Glucosides / Q000032:analysis / Q000494:pharmacology / Q000627:therapeutic use; D005965:Glucuronates / Q000032:analysis / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D047311:Luteolin / Q000032:analysis / Q000494:pharmacology / Q000627:therapeutic use; D009369:Neoplasms / Q000188:drug therapy; D008517:Phytotherapy; D010851:Picrates / Q000378:metabolism; D035261:Plant Components, Aerial; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018517:Plant Roots; D031363:Scutellaria / Q000737:chemistry*; D014344:Trypanocidal Agents / Q000032:analysis / Q000494:pharmacology*; D014346:Trypanosoma brucei brucei / Q000187:drug effects; D015003:Yeasts / Q000187:drug effects
chemical_list: D000890:Anti-Infective Agents; D000972:Antineoplastic Agents, Phytogenic; D000975:Antioxidants; D001713:Biphenyl Compounds; D005419:Flavonoids; D005960:Glucosides; D005965:Glucuronates; D010851:Picrates; D010936:Plant Extracts; D014344:Trypanocidal Agents; C484876:scutellarin; D047310:Apigenin; C066408:luteolin-7-glucoside; C004931:1,1-diphenyl-2-picrylhydrazyl; D047311:Luteolin