Impact of extraction techniques and process optimization on antioxidant and antibacterial potential of Kalanchoe pinnata leaf extract

Abstract

Kalanchoe pinnata (Lam.) Pers. is an ethnomedicinal plant known for its antioxidant, antibacterial, and therapeutic potential. The current study was an effort to explore the impact of extraction technique on the phytochemical, antioxidant, and antibacterial profile of the plant extracts. K. pinnata leaf extracts were prepared using conventional solvent extraction (100% methanol; 50% methanol: 50% water; 100% water), microwave-assisted extraction at 700-W power (3 min; 6 min; 9 min), and supercritical fluid extraction (SFE) (3500 psi; 4500 psi; 5500 psi). Best results were attained from SFE in terms of total phenolic content (240 ± 3 mg GAE/g), total flavonoid content (165.2 ± 0.4 mg QE/g), 2,2-diphenyl-1-picrylhydrazyl radical scavenging potential (91.9 ± 0.4%), 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid assay value (8.04 ± 0.03 mMol TE/g) and ferric reducing antioxidant power assay value (471.7 ± 0.8 µg/mL). K. pinnata leaf extracts have been found to be most effective against Yersinia pseudotuberculosis (22.20 ± 0.95 mm) and least effective againstProteus vulgaris (0 ± 0 mm). High-performance liquid chromatography analysis of K. pinnata extract showed that it contains flavanol quercetin (2.0 ± 0.1 mg/g). It is evident from the findings of current study that K. pinnata extract can effectively treat bacterial infections and can cure metabolic disorders by reducing oxidative stress. Application of advance extraction techniques enhances the biological activity of plant extracts.

Keywords

• Kalanchoe pinnata
• supercritical fluid extraction (SFE)
• microwave-assisted extraction (MAE)
• conventional solvent extraction (CSE)
• high-performance liquid chromatography (HPLC)