Comparative conventional extraction methods of ethanolic extracts of Clinacanthus nutans leaves on antioxidant activity and toxicity
ISSN: 0007-070X
Article publication date: 7 July 2020
Issue publication date: 5 October 2020
Abstract
Purpose
The purpose of this paper is to evaluate the antioxidant activity and toxicity of Clinacanthus nutans leaves from three conventional extraction methods, i.e. maceration, Soxhlet and magnetic stirring.
Design/methodology/approach
Total flavonoid content (TFC) and phenolic content (TPC) were determined using colorimetric method of aluminum chloride and Folin-Ciocalteu (FC) assay, respectively. Antioxidant property of C. nutans was evaluated using 2,2'-diphenyl-1-pierylhydrazyl (DPPH) free radical scavenging assay. Cytotoxic activity of C. nutans against brine shrimp was evaluated based on LC50 (lethality concentration) after 24 h exposure to the plant extract.
Findings
The highest TPC of C. nutans was observed with Soxhlet extraction method (98.87 ± 10.43 mg of gallic acid equivalents (GAE/g) followed by maceration (68.77 ± 2.45 mg of GAE/g) and magnetic stirring (46.75 ± 2.45 mg of GAE/g). Interestingly, remarkable highest TFC was observed with magnetic stirring (568.90 ± 4.85 mg of rutin equivalent (RE)/g) followed by maceration (249.60 ± 2.79 mg of RE/g) and Soxhlet (174.8 ± 1.74 mg of RE/g). On the other hands, the extract obtained using maceration method showed the highest antioxidant activity (IC50: 14.18 mg/mL compared to ascorbic acid 144.36 µg/mL). Cytotoxicity of C. nutans from all extraction methods showed similar LC50 values with maceration (3.81 mg/mL), Soxhlet (2.61 mg/mL) and magnetic stirring (4.56 mg/mL), respectively.
Originality/value
Both phenolic and flavonoids are responsible for the antioxidant activity, of C. nutans extracts. Based on Meyer's toxicity index, all extracts were nontoxic (LC50>1 mg/mL).
Keywords
Acknowledgements
This study was funded by (removed for peer-reviewed purpose). The author was grateful toward (removed from peer-reviewed purpose) for providing plant sample for this study.This study was funded by Management & Science University's seed grant (SG-444-0518-SPH). The author was grateful towards Taman Pertanian Universiti (TPU), UPM for providing plant sample for this study.
Citation
Chuah, P.N., Nyanasegaram, D., Yu, K.-X., Mohamed Razik, R., Al-Dhalli, S., Kue, C.S., Shaari, K. and Ng, C.H. (2020), "Comparative conventional extraction methods of ethanolic extracts of
Publisher
:Emerald Publishing Limited
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