Correlation among antioxidant, antimicrobial, hemolytic, and antiproliferative properties of Leiothrix spiralis leaves extract

Abstract

The biological activities of a plant extract depend on a complex sum of individual properties including the antioxidant activity. Several biological activities protect against the harmful action of reactive oxygen species (ROS), and here we focused our attention on the relationship between the biological activities tested and the antioxidant properties. In this study, the total flavonoid content as well as the antioxidant, antimicrobial, hemolytic and cytotoxicity activities of the methanolic extract of Leitothrix spiralis leaves were evaluated. The extract showed a total flavonoid content of 19.26% and the chemical characterization by HPLC-PAD confirmed the presence of flavonoids as the major secondary metabolite compounds. Significant antioxidant activity (IC(50) = 1.743 μg/mL ± 0.063) was demonstrated and was effective against Gram-negative organisms and all Candida strains tested, and showed an ability to inhibit hyphal formation. Non-hemolytic and antiproliferative activity could be demonstrated.

Keywords: Leiothrix spiralis; antimicrobial; antioxidant; citotoxicity; hemolytic; luteolin.

Figure 1

HPLC-PAD (Photodiodo Array Detector) chromatogram recorded at 254 nm of the methanolic extract of leaves from L. spiralis. For chromatographic conditions see Experimental section.

Figure 2

UV spectra of the chromatographic (HPLC) data of the methanolic extract of leaves from L. spiralis (peaks 1–7). Conditions: Phenomenex Synergi Hydro RP18 (250 × 4.6 mm i.d.; 4 μm) equipped with a Phenomenex security guard column (4.0 × 2.0 mm i.d.). The mobile phase composition was methanol. The gradient program was as follows: 5%–100% MeOH in 60 min. The flow rate was 1.0 mL/min and the total run time was 60 min.

Figure 2

UV spectra of the chromatographic (HPLC) data of the methanolic extract of leaves from L. spiralis (peaks 1–7). Conditions: Phenomenex Synergi Hydro RP18 (250 × 4.6 mm i.d.; 4 μm) equipped with a Phenomenex security guard column (4.0 × 2.0 mm i.d.). The mobile phase composition was methanol. The gradient program was as follows: 5%–100% MeOH in 60 min. The flow rate was 1.0 mL/min and the total run time was 60 min.

Figure 2

UV spectra of the chromatographic (HPLC) data of the methanolic extract of leaves from L. spiralis (peaks 1–7). Conditions: Phenomenex Synergi Hydro RP18 (250 × 4.6 mm i.d.; 4 μm) equipped with a Phenomenex security guard column (4.0 × 2.0 mm i.d.). The mobile phase composition was methanol. The gradient program was as follows: 5%–100% MeOH in 60 min. The flow rate was 1.0 mL/min and the total run time was 60 min.

Figure 3

Hyphal formation of C. albicans NCPF 3153 cells. (A) 12 h normal growth; (B) 24 h normal growth; (C) C. albicans cells treated with 0.005 mg/mL anphotericin B (ANF) as the positive control; Hyphal formation of C. albicans cells was obviously inhibited by the extract at (D) 1 mg/mL; (E) 0.5 mg/mL; (F) 0.25 mg/mL at 12 h; and (G) 1 mg/mL; (H) 0.5 mg/mL; (I) 0.25 mg/mL at 24 h. Luteolin did not inhibit the hyphal formation (J) 0.25 mg/mL; (K) 0.125 mg/mL; (L) 0.062 mg/mL at 12 h; (M) 0.25 mg/mL; (N) 0.125 mg/mL; (O) 0.062 mg/mL at 24 h, compared with (A) and (B). The black bar represents a length of 50 μm.

Figure 3

Hyphal formation of C. albicans NCPF 3153 cells. (A) 12 h normal growth; (B) 24 h normal growth; (C) C. albicans cells treated with 0.005 mg/mL anphotericin B (ANF) as the positive control; Hyphal formation of C. albicans cells was obviously inhibited by the extract at (D) 1 mg/mL; (E) 0.5 mg/mL; (F) 0.25 mg/mL at 12 h; and (G) 1 mg/mL; (H) 0.5 mg/mL; (I) 0.25 mg/mL at 24 h. Luteolin did not inhibit the hyphal formation (J) 0.25 mg/mL; (K) 0.125 mg/mL; (L) 0.062 mg/mL at 12 h; (M) 0.25 mg/mL; (N) 0.125 mg/mL; (O) 0.062 mg/mL at 24 h, compared with (A) and (B). The black bar represents a length of 50 μm.

Figure 4

Effect of extract on cell viability and LDH release in cultured HeLa cells. Cells were treated with different concentrations of extract, and luteolin (31 mg/L) was used as positive control.* Significantly different from the basal conditions.

Figure 5

Hemolytic activity of extract of leaves of L. spiralis. Extract (filled circle) and positive control Triton X-100 (open circle).

Figure 6

Hemolytic activity of luteolin. Luteolin (filled circle) and positive control Triton X-100 (open circle).