Development of Luteolin-Loaded Calcium Alginate and Gum Tragacanth Blend Microbeads for Oral Delivery: In Vitro Characterization, Antioxidant, Antimicrobial, and Anticancer Activity Against Colon Cancer Cell Line (HT-29).

Abstract

The utilization of herbal bioactive compounds for health maintenance is now increasing the interest of consumers because it has therapeutic benefits. Luteolin (LLN) is a natural bioactive compound and is found in various plant sources. It has many pharmacological activities, i.e., anticancer, antidiabetic, antioxidant, anti-inflammatory, and antimicrobial. It has poor water solubility, leading to low dissolution, low bioavailability, and low therapeutic efficacy. The present research work was to develop the LLN-loaded gel microbeads using a combination of sodium alginate (SA) and gum tragacanth polymers to strengthen microbeads (BD) and enhance the therapeutic efficacy. The microbeads were prepared by using the ionotropic gelation method and evaluated by various physicochemical parameters, i.e., particle size, encapsulation efficiency, swelling index, FITR, and X-ray diffraction study. The optimized microbeads (LLNBD3) showed a 97.63 ± 3.12% yield, 845 ± 6.21 μm in size, and 78.54 ± 3.65% drug entrapment efficiency. The microbeads exhibited excellent swelling in intestinal pH (6.8) compared with an acidic medium (pH 1.2). The LLNBD3 exhibited a sustained release profile (89.23 ± 2.51% in 12 h) with first-order release kinetics (R² = 0.9752) with the Fickian diffusion mechanism of drug release. The Fourier transform infrared spectra and X-ray diffractograms did not show any distinct peaks of LLN, revealing that the LLN was encapsulated into a microbeads matrix. The LLNBD3 showed significant antioxidant activity compared with pure LLN, confirmed by the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) method. In addition, it also showed remarkable in vitro anticancer activity against the colorectal cell line (HT-29) and antimicrobial activity against Staphylococcus aureus and Escherichia coli. The stability study demonstrated no significant change in swelling and release behavior. The finding concluded that tragacanth gum and SA microbeads could be promising drug carriers to improve the dissolution and oral delivery of herbal bioactive compounds and synthetic drugs.