Nano Milling Application of Mutamba (West Indian Elm) Leaves Extract to Enhance its In Vitro Bioactivity

Guazuma ulmifolia or mutamba has been traditionally used for many years as a slimming agent. Various studies reported the antihyperlipidemic activity of mutamba leaves extract due to its flavonoid content.

This research was conducted to improve the bioactivity of mutamba leaves extract by applying ball-milling technology.

Unground dried mutamba leaves were extracted in ethanol 40%. The resulting extract (ME) was nano-milled and characterized for its physicochemical parameters. The ball milling process was optimized by performing in various durations, ball and powder ratios, and rotation speed.

The optimized process of ball milling produced nano-extract (NanoME) with a particle size of 492,57±55,96 nm confirmed with particle size and SEM. Compared with ME, the crystallinity and thermal behavior of NanoME did not change by particle size reduction. The reduction of particle size also did not improve the HMG-CoA reductase inhibitor activity. ME and NanoME showed a comparable activity compared to Pravastatin. However, the bioactivities of NanoME including DPPH antioxidant activities improved 8-fold compared to ME. These findings showed that the inhibition of HMG-CoA reductase activity was not inherently correlated to its antioxidant activity.

The improvement of these activities was attributed to the increase in their flavonoid content. This study emphasizes the role of particle size reduction or nano-extract preparation in increasing the biological activity of plant extracts.