Synergistic effect of peppermint oil and black seed oil loaded into alginate beads for treating irritable bowel syndrome in animal model

Abstract

Black seed oil (BSO) have traditional claims and scientific evidences for therapeutic and pharmacological values. Similarly, peppermint oil (PO) has been used for a long time as a therapeutic agent for stomach related diseases. In conjunction with their therapeutic benefit, they have become an interest in utilization in pharmaceutical use. The key objective and major challenge of this study was to develop a pH sensitive BSO and PO loaded alginate bead as an intestinal release matrix system designed to release in the intestine without releasing the drug in the gastric fluid. To overcome these challenges, organic-solvent-free, green, and environmentally friendly electrohydrodynamic atomization (EHDA) technique was employed to prepare BSO and PO loaded alginate beads. This process enabled the formulation of small size and uniform beads with suitable diffusion, and swelling characteristic resulting in process performance enhancement. The current study deals with the development, optimization, and in vitro characterization of BSO and PO beads in different aspects like emulsion stability (ES), particle size distribution, zeta potential, yield percentage (Y%), physical appearance i.e. scanning electron microscopy (SEM), encapsulation efficiency (EE%), quantification of thymoquinone and menthol, shape, weight uniformity, ex vivo mucoadhesive properties, in vitro drug release profile, and gastrointestinal tract (GIT) beads distribution. Prior to that, the compatibility was tested using attenuated total reflectance-Fourier-transform infrared spectroscopy (ATR-FTIR) and differential scanning calorimetry (DSC). Then the optimized formulation was administered to evaluate the therapeutic efficacy as an anti-inflammatory effect of BSO and PO loaded beads in irritable bowel syndrome (IBS) in mustard oil (MO)-induced Sprague-Dawley rats. The results indicate that the voltage and flow rate have significant influenced on beads size and sphericity factor as well as on encapsulation efficiency. All prepared formulations (F1-F9) exhibited low release rate in simulated gastric fluid (SGF) (pH 1.2) within 2 h. However, all these beads (F1-F9) showed better drug release profile in simulated intestinal fluid (SIF) (pH 6.8) at the next 2 h. The optimized formulation (F8) has shown excellent ex-vivo mucoadhesive properties, well distributed in various parts of the intestine, well swelling behaviour and release in the SIF. BSO and PO-loaded alginate beads exhibited potential improvement of IBS on MO-induced rat compare to non-treatment group. These formulations were significantly suppressed proinflammatory cytokines like interleukin- IL-1β, IL-6, and TNF-α expression upregulated of anti-inflammatory cytokine (IL-10) expression in MO-induced intestinal inflammation. However, within the treatment groups, BSO-loaded alginate beads potentially upregulated the anti-inflammatory cytokine (IL-10) expression compared to other treatment groups. The combination of BSO (75 mg) and PO (25 mg) treatment group showed synergistic therapeutic effect by improving disease symptoms and suppressing IL-1β, IL-6, and TNF-α expression. The technique for the preparation of beads was found to be simple, reproducible, easily controllable, economical, and appeared to be a promising approach to control the bead’s nature and to ensure release into targeted site after oral administration. This formulation is considered as an anti-inflammatory drug candidate with possible synergistic effect for IBS treatment. Keywords: black seed oil, Peppermint oil, electrohydrodynamic technique, microencapsulation, inflammation, IBS.