Inhibitory effect on human platelet aggregation, antioxidant activity, and phytochemicals of Canna warszewiczii (A. Dietr) Nb. tanaka

Abstract

Background: Canna warszewiczii (A. Dietr) Nb. Tanaka has been traditionally used to treat heart diseases in Vietnam, but there is a lack of scientific evidence. Objectives: This study investigated the inhibitory effect on human platelet aggregation, antioxidant activity, and main phytochemicals of fractions from the aerial and rhizome parts of the plant. Materials and Methods: Human platelets were prepared and incubated with different fraction doses (0.33, 0.75, and 1.5 mg/mL). Platelet aggregation was triggered by different agonists (adenosine diphosphate [ADP], collagen, and ristocetin). 2,2-diphenyl-1-pycrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays were done to test the free-radical scavenging activities. Spectrophotometry assays using Folin–Ciocalteu and aluminum chloride were used to determine total flavonoid content (TFC) and total polyphenol content (TPC). The phytochemical screening was also implemented. Results: The n-hexane, dichloromethane, and ethyl acetate (EA) fractions from both the rhizome and aerial parts significantly inhibited ADP-, collagen-, and ristocetin-platelet aggregations and decreased significantly the area under the platelet aggregation curve and aggregation velocity in a concentration-dependent manner, but the water fractions did not. The EA fractions showed the strongest DPPH and ABTS scavenging activity and highest TPC and TFC. Organic fractions contained variable bioactive compounds: flavonoids, polyphenols, glycosides, cardiac glycosides, coumarins, steroids, emodols, tannins, and cholesterols. Conclusion: The plant extracts or fractions could be used in the preparation of functional foods or supplements with antioxidant and antiplatelet activity. It is also a good candidate for searching novel bioactive compounds used in pharmaceutical industries for the development of antiplatelet and antioxidant agents to prevent and/or treat heart and oxidative stress-related diseases.