Cosmos caudatus extract/fractions reduce smooth muscle cells migration and invasion in vitro : A potential benefit of suppressing atherosclerosis

Abstract

Highlights: Cosmos caudatus Ethanolic extract fractionation by n-butanol produced a phenolics-saponin rich fraction.Cosmos caudatus butanol fraction was the most potent in all antioxidant and MTT assays.High concentrations of all fractions increased cells migration and invasion in vitro.Butanol fraction intermediate concentration maximally inhibited VSMC migration and invasion.Mild concentrations of crude and butanol fractions showed the best invasion inhibition index.

Background: Cosmos caudatus Kunth is a medicinal herb used traditionally in Latin America and South East Asia to retard aging, rigidify bones and for several cardiovascular uses.

Objective: Is to assess C. caudatus extract/fractions' antioxidant and vascular smooth muscle cells (VSMC) migration and invasion inhibition capacity in vitro.

Methods: Cosmos caudatus shoots were extracted by cold maceration in 50% ethanol to produce crude (CEE), and then the extract was fractionated to butanol (Bu.F), and aqueous fractions (Aq.f). Phenolics and saponins were quantified in extract and fractions by colorimetric methods and their antioxidant capacity was assayed in four different tests. Cytotoxic effect and safety level concentrations were determined for the fractions by using MTT assay. Migration and invasion inhibitory potential were measured in vitro at three different concentrations equivalent to (IC₁₀, IC₂₅, and IC₅₀). Finally, invasion inhibitory index was calculated to obtain the best fraction(s) that show(s) the highest ratio of cell invasion inhibition to the total cell migration inhibition.

Results: Butanol fraction yield was the lowest; nevertheless, its phytochemical contents, antioxidant activities as well as its potency were the highest. Unlike other fractions, Bu.F was strongly correlated with all antioxidant assays experimented. In addition, it has the highest inhibitory effect at IC₂₅ against VSMCs migration and invasion that accounts for 53.93% and 59.94% respectively. Unexpectedly, Bu.F and CEE at IC₁₀ displayed the highest invasion inhibitory index (approx. 68%).

Conclusion: Butanol fraction of C. caudatus offers a potentiality for the discovery of new leads for preventing atherosclerosis.

Keywords: Antioxidant; Atherosclerosis; Cosmos caudatus; Invasion; Migration.

Fig. 1.

Boyden Chamber Kit, where cells migrate from the upper insert to the lower chamber and invade the ECM membrane following a concentration gradient. In the case of migration kit, there is no ECM layer.

Fig. 2.

(A) Total phenolic contents (TPC), total saponin contents (TSC) and total steroidal saponin contents (TSSC) for C. caudatus fractions. (B) The extraction yield for crude (CEE), butanol (Bu.f) and aqueous (Aq.f) fractions. Data were presented as a mean ± standard deviation, n = 3. a-c Different letters within the same group indicate significant difference (p < 0.05) according to ANOVA and post hoc with Tukey tests. *Significant difference between groups at (p < 0.05).

Fig. 3.

Antioxidant activities for crude, butanol, and aqueous fractions derived from Cosmos caudatus. Data were presented as a mean ± standard deviation, n = 3. a-c Different letters within the same row indicate significant difference (p < 0.05) according to ANOVA and post hoc with Tukey tests.

Fig. 4.

Cytotoxic effect of C. caudatus extract and fractions on the proliferation of A-10 cell line. Each data point represents the mean of three independent experiments ± SD with four replicates at each dosage. Control group represented 100%.

Fig. 5.

Migration inhibition capacity for C. caudatus CEE, Bu.F, and Aq.F. Different letters within the same fraction indicate significant differences (p < 0.05).

Fig. 6.

Invasion inhibition capacity for C. caudatus CEE, Bu.F, and Aq.F. Different letters within the same fraction indicate significant differences (p < 0.05).

Fig. 7.

Invasion inhibition index for the aqueous, crude and butanol extract/fractions of C. caudatus at different doses.