Kanuka bush leaves for Alzheimer’s disease: Improved inhibition of -secretase enzyme, antioxidant capacity and yield of extracts by ultrasound assisted extraction

• Main Authors: Hafiz Majid, Filipa V.M. Silva
• Format: Article
• Language: English; English
• Published: Elsevier 2021
• Subjects: QK710-899 Plant physiology; SB1-1110 Plant culture
• Online Access: https://eprints.ums.edu.my/id/eprint/36518/1/ABSTRACT.pdf; https://eprints.ums.edu.my/id/eprint/36518/2/FULL%20TEXT.pdf; https://eprints.ums.edu.my/id/eprint/36518/; https://doi.org/10.1016/j.fbp.2021.04.018
• Institution: Universiti Malaysia Sabah

Alzheimer’s disease (AD) is a neurodegenerative disease leading to irreversible neuronal damage. Kanuka or Kunzea ericoides (A. Richard) revealed a remarkable inhibition of - secretase activity, an important enzyme for AD. This study presents optimization of the ultrasound assisted extraction (UAE) of inhibitors of -secretase and antioxidants from K. ericoides leaves, and yield by response surface methodology (RSM). Experimental validation of optimized conditions and 50% inhibitory extract concentrations (IC50) determinations were performed. The extraction time and temperature were significant for enzyme inhibition, RSA (DPPH radical scavenging activity) and yield, while acoustic power density had less effect on the 3 responses. The optimum conditions were 15.6 min extraction time, 69 ◦C and 0.43 W/mL. The ultrasound extraction produced better extracts in term of enzyme inhibition and RSA (lower IC50: 14.25 g/mL enzyme, 3.17 g/mL RSA), in comparison to Soxhlet and maceration combined with heat, and a more rapid extraction with increased yield of extraction. Ultrasound kanuka extracts can potentially complement existing AD treatment