To investigate the use of chitosan nanoparticles (CS-TPP-NPs) as carriers for α- and β-arbutin. In this study, CS-TPP-NPs containing α- and β-arbutin were prepared via the ionic cross-linking of CS and TPP and characterized for particle size, zeta potential, and dispersity index. The entrapment efficiency and loading capacity of various β-arbutin concentrations (0.1, 0.2, 0.4, 0.5, and 0.6%) were also investigated. SEM, TEM FTIR, DSC and TGA analyses of the nanoparticles were performed to further characterize the nanoparticles. Finally, stability and release studies were undertaken to ascertain further the suitability of the nanoparticles as a carrier system for α- and β-arbutin. Data obtained clearly indicates the potential for use of CS-TPP-NPs as a carrier for the delivery of α- and β-arbutin. The size obtained for the alpha nanoparticles (α-arbutin CSNPs) ranges from 147 to 274 d.nm, with an increase in size with increasing alpha arbutin concentration. β-arbutin nanoparticles (β-arbutin CSNPs) size range was from 211.1 to 284 dn.m. PdI for all nanoparticles remained between 0.2-0.3 while the zeta potential was between 41.6-52.1 mV. The optimum encapsulation efficiency and loading capacity for 0.4% α-arbutin CSNPs were 71 and 77%, respectively. As for β-arbutin, CSNP optimum encapsulation efficiency and loading capacity for 0.4% concentration were 68 and 74%, respectively. Scanning electron microscopy for α-arbutin CSNPs showed a more spherical shape compared to β-arbutin CSNPs where rod-shaped particles were observed. However, under transmission electron microscopy, the shapes of both α- and β-arbutin CSNP nanoparticles were spherical. The crystal phase identification of the studied samples was carried out using X-ray diffraction (XRD), and the XRD of both α and β-arbutin CSNPs showed to be more crystalline in comparison to their free form. FTIR spectra showed intense characteristic peaks of chitosan appearing at 3438.3 cm-1 (-OH stretching), 2912 cm-1 (-CH stretching), represented 1598.01 cm-1 (-NH2) for both nanoparticles. Stability studies conducted for 90 days revealed that both α- and β-arbutin CSNPs were stable in solution. Finally, release studies of both α- and β-arbutin CSNPs showed a significantly higher percentage release in comparison to α- and β-arbutin in their free form. Chitosan nanoparticles demonstrate considerable promise as a carrier system for α- and β-arbutin, the use of which is anticipated to improve delivery of arbutin through the skin, in order to improve its efficacy as a whitening agent.
This research investigated a UPLC-QTOF/ESI-MS-based phytochemical profiling of Combretum indicum leaf extract (CILEx), and explored its in vitro antioxidant and in vivo antidiabetic effects in a Long-Evans rat model. After a one-week intervention, the animals' blood glucose, lipid profile, and pancreatic architectures were evaluated. UPLC-QTOF/ESI-MS fragmentation of CILEx and its eight docking-guided compounds were further dissected to evaluate their roles using bioinformatics-based network pharmacological tools. Results showed a very promising antioxidative effect of CILEx. Both doses of CILEx were found to significantly (p < 0.05) reduce blood glucose, low-density lipoprotein (LDL), and total cholesterol (TC), and increase high-density lipoprotein (HDL). Pancreatic tissue architectures were much improved compared to the diabetic control group. A computational approach revealed that schizonepetoside E, melianol, leucodelphinidin, and arbutin were highly suitable for further therapeutic assessment. Arbutin, in a Gene Ontology and PPI network study, evolved as the most prospective constituent for 203 target proteins of 48 KEGG pathways regulating immune modulation and insulin secretion to control diabetes. The fragmentation mechanisms of the compounds are consistent with the obtained effects for CILEx. Results show that the natural compounds from CILEx could exert potential antidiabetic effects through in vivo and computational study.