Natural products encapsulated alginate nanoformulations for diabetes mellitus: Preparation, characterisation, properties, and biological activities

The rising global prevalence of diabetes brings severe complications driven by inflammation and oxidative stress. Alginate is a naturally derived biopolymer revealing good biocompatibility and biodegradability. Alginate has been extensively utilised in pharmaceutical applications. The inclusion of natural products into an alginate/alginate-based matrix is identified as a promising strategy for the development of new effective therapies against diabetes mellitus. This review attempts to summarise the studies reported on the development of natural product-based alginate nanoformulations for the management of diabetes, focusing on its main pathophysiological features such as hyperglycemia, inflammation, and oxidative stress. The electronic databases “Science Direct”, “PubMed”, and “Google Scholar” were searched to retrieve articles published over the past five years (2019-2024). Herbal extracts and compounds encapsulated alginate-based nanoformulations were documented for their antidiabetic, antioxidant, and anti-inflammatory potentials through either in vivo studies or in vitro assays. Natural products encapsulated alginate-based nanoformulations have been formulated using various methods and characterised mainly via dynamic light scattering, zeta potential, polydispersity index, scanning electron microscopy, and Fourier transform infrared spectroscopy. Abundantly, inhibitory potentials of α-amylase and α-glucosidase enzymes and inflammatory cytokines have been assessed to evaluate antidiabetic and anti-inflammatory activities of natural product-based nanoformulations, respectively. Most of the studies reported 2,2-diphenyl-1-picrylhydrazyl assay in vitro and estimation of malonaldehyde and antioxidant enzymes in vivo in the assessment of antioxidant activity of natural products-based alginate nanoformulations. To date, clinical trials have not been reported for natural products-based alginate formulations. The present review frames an overview of natural products encapsulated alginate-based nanoformulations, and their evaluation of antidiabetic, anti-inflammatory, and antioxidant activities.