Development and characterization of Cassia fistula plant extract-loaded chitosan/PVA composites for broad-spectrum antimicrobial applications

With the increase in the rate of AMR, efforts to determine broad spectrum alternatives have grown in intensity. This research used the phytochemical extracts obtained from Cassia fistula plant sources in combination with CS/PVA composite matrix to prepare broad spectrum antimicrobial composites that would provide added benefits such as increased stability and release rates. Phytochemical screening was done using leaf, flower, and seed extracts. Antimicrobial potential was tested using antimicrobial testing methods, MIC determinations, phytochemical tests, and GC/MS techniques. The phytochemical screening indicated that all the extracts contained flavonoids, alkaloids, glycosides, saponins, terpenoids, and phenols, with flower extracts exhibiting the greatest number of phytochemicals. The antimicrobial study conducted on E. coli, Pseudomonas aeruginosa, MRSA, and Proteus mirabilis exhibited concentration dependent inhibitory effect, where multiple extract formulations provided better performance than a single extract formulation. Among all formulations, Sample G had exhibited the most potent antimicrobial efficacy with the lowest MIC values due to the enhanced combined effects of phytoconstituents and polymer delivery system. The GC-MS profiling of the formulations had exhibited major bioactive constituents such as Myo-Inositol derivatives, fatty acids, phytosterols, tocopherols, terpenoids, and phenolic compounds having antimicrobial and antioxidant potentials. The semi-interpenetrating nature of the CS/PVA polymer matrix provided good phytoconstituents stability and improved sustained drug release characteristics.