title: Phytochemical constituents and biological activities of different extracts of Strobilanthes crispus (L.) Bremek leaves grown in different locations of Malaysia.
abstract: BACKGROUND
  Strobilanthes crispus is a well-known herb in Malaysia with various pharmaceutical properties. S. crispus is known to contain several biologically active chemical constituents which are responsible for its pharmaceutical quality.
  
  
  METHODS
  Strobilanthes crispus leaves grown in three different locations in Malaysia [Kelantan (North-east), Selangor (Central), and Penang (North)], were investigated for differences in the content of secondary metabolites [total phenolics content (TPC), total flavonoids content (TFC), and total saponins content (TSC)] as well as for their antioxidant and anticancer properties. Phenolic acids and flavonoids were identified using ultra-high performance liquid chromatography (UHPLC). Ferric reducing antioxidant potential (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays were used to evaluate the antioxidant activities. The anticancer activity of extracts against HeLa cancer cell line was evaluated using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay.
  
  
  RESULTS
  Samples from the three different locations when extracted with two solvents (aqueous and ethanol extracts) yielded significantly different results for TPC, TFC, and TSC as well as for antioxidant activity. Aqueous extract of S. crispus leaves collected from Kelantan exhibited the highest values: TPC [12.62 mg gallic acid equivalents (GAE)/g dry matter (DM)], TFC (7.44 mg quercetin equivalents (QE)/g DM), TSC (44.7 mg diosgenin equivalents (DE)/g DM), DPPH (73.8 %), and FRAP (267.5 μM of Fe (II)/g) activity with a half-maximal inhibitory concentration (IC50) of 44.1 μg/mL compared to the extracts of leaves collected from the other two locations. The most important secondary metabolites identified in this study, based on concentration, were phenolics classified as followed: caffeic acid>ferulic acid>gallic acid>chlorogenic acid>trans-cinnamic acid; flavonoids: quercetin>rutin>catechin>apigenin>naringenin>kaempferol. Extracts of leaves collected from Kelantan exhibited better anticancer activity against HeLa cancer cell line with an IC50 of 182.5 μg/mL compared to the extracts of leaves from Selangor (IC50 = 266.4 μg/mL) and Penang (IC50 = 331.5 μg/mL) and to tamoxifen (IC50 = 63.4 μg/mL). S. crispus leaves with the highest content of secondary metabolites exhibited the most potent antioxidant and anticancer activity.
  
  
  CONCLUSIONS
  Therefore, based on the potent antioxidant and anticancer activity of leaves extracts, it appears that S. crispus grown in the North-east of Malaysia (Kelantan) is a potential source of anticarcinogenic therapeutic compounds.
authors.affiliation: Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia. alighasemzadeh@upm.edu.my.
authors.forename: Ali
authors.initials: A
authors.lastname: Ghasemzadeh
authors.affiliation: Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia. hawazej@upm.edu.my.
authors.forename: Hawa Z E
authors.initials: HZ
authors.lastname: Jaafar
authors.affiliation: Department of Nutrition & Dietetics, Faculty of Medicine & Health Sciences, Universiti Putra Malaysia, 43400, UPM, Serdang, Selangor, Malaysia. asmah@upm.edu.my.
authors.forename: Asmah
authors.initials: A
authors.lastname: Rahmat
mesh_terms: D027901:Acanthaceae / Q000737:chemistry; D000146:Acids, Carbocyclic / Q000032:analysis / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000032:analysis / Q000494:pharmacology*; D000975:Antioxidants / Q000032:analysis / Q000494:pharmacology*; D002460:Cell Line / Q000187:drug effects; D005419:Flavonoids / Q000032:analysis / Q000494:pharmacology; D006367:HeLa Cells / Q000187:drug effects; D006801:Humans; D008296:Malaysia; D064209:Phytochemicals / Q000032:analysis / Q000494:pharmacology*; D010936:Plant Extracts / Q000032:analysis / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*; D012503:Saponins / Q000032:analysis / Q000494:pharmacology
chemical_list: D000146:Acids, Carbocyclic; D000970:Antineoplastic Agents; D000975:Antioxidants; D005419:Flavonoids; D064209:Phytochemicals; D010936:Plant Extracts; D012503:Saponins