Antioxidant Properties of Fractions for Unripe Fruits of Capsicum annuum L. var. Conoides

Anticancer Agents Med Chem. 2018 Feb 7;17(14):1971-1977. doi: 10.2174/1871520617666170419142728.

Abstract

Background: Capsicum plant, especially for C. annuum, is an abundant resource for bioactive antioxidants, but few studies have examined the unripe fruit part of the Capsicum plant.

Objective: MeOH extract of unripe fruits of C. annuum L. var. conoides (UFCA) was chromatographed over a silica gel column using a gradient of CH2Cl2/MeOH as eluent to produce 9 fractions. Antioxidant activities are evaluated along with cell viabilities of 9 fractions of UFCA.

Method: The antioxidant properties were analyzed in terms of total phenol content (TPC), total flavonoid content (TFC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, 2,2-azinobis (3-ethyl-benzothiazoline-6- sulfonic acid) (ABTS) radical scavenging, ferric reducing, and ferrous ion-chelating ability. The cell viability of human oral cancer cells (Ca9-22) was measured by 3-(4,5-dimethylthiazol-2-yl)-(3-carboxymethoxyphenyl)-2- (4-sulphophenyl)-2H-tetrazolium (MTS) assay.

Results: Except for TFC, fractions (Frs.) 1 and 2 showed the lowest level of these antioxidant properties. Frs. 3 to 9 showed dose-responsive induction for antioxidant effects. Fr. 8 and Fr. 5 respectively showed the highest levels of TPC and TFC for 1162 ± 11 gallic acid equivalents (GAE) (mg)/UFCA (g) and 1295 ± 32 quercetin equivalents (QCE) (mg)/UFCA (g). The cell viability of Fr. 3 was moderately decreased (78.2%) while those of Frs. 4, 5, and 9 were dramatically decreased (55.6, 57.8, and 46.8%, respectively) in oral cancer Ca9-22 cells. UFCA-derived 14 compounds/mixtures derived from Frs. 1, 2, 3, 4, and 8 displayed differential antioxidant performance for these analyses.

Conclusion: Taken together, fractions of UFCA displayed diverse antioxidant and anticancer effects for oral cancer cells. Some fractions of UFCA may be potent natural antioxidant supplements for antioral cancer cell treatment.

Keywords: Antioxidant; Capsicum annuum; fractions; oral cancer; oral cancer cells.; unripe fruits.

MeSH terms

  • Antioxidants / chemistry
  • Antioxidants / isolation & purification
  • Antioxidants / pharmacology*
  • Capsicum / chemistry*
  • Cell Survival / drug effects
  • Dose-Response Relationship, Drug
  • Drug Discovery
  • Flavonoids / chemistry
  • Flavonoids / isolation & purification
  • Flavonoids / pharmacology*
  • Fruit / chemistry*
  • Humans
  • Mouth Neoplasms / drug therapy*
  • Mouth Neoplasms / pathology
  • Structure-Activity Relationship
  • Tumor Cells, Cultured

Substances

  • Antioxidants
  • Flavonoids