MATERIALS AND METHODS: Floating tablets were prepared by direct compression using HPMC K100M, sodium-bicarbonate and microcrystalline-cellulose. A 23 factorial-design (RStudio-v4.3.3) was used to optimize microenvironmental pH, floating lag time (FLT) and drug release. Optimized tablets were characterized for micromeritic properties, XRD, SEM, in vitro buoyancy, swelling, drug release, in vitro anti-H. pylori activity and in vivo gastric retention in Sprague-Dawley rats.

RESULTS: The optimized formulation achieved a microenvironmental pH of 7.20 ± 0.26, FLT of 15.84 ± 0.50 s, and total floating time of approximately 12 h. Cumulative AMX release reached 98.49 ± 1.69% over 12 h with non-Fickian kinetics, and XRD/SEM analysis indicated reduced crystallinity and increased amorphous character of AMX within the hydrated matrix. The formulation showed significant in vitro anti-H. pylori activity and prolonged in vivo gastric retention.

AIM OF THE STUDY: Phytochemical investigation and assessment of pharmacological mechanism(s) involved in anti-ulcer effect of methanolic extract of the seeds of E. conferta.

MATERIALS AND METHODS: Bioactive phytoconstituents were isolated by column chromatography. These were identified by spectroscopic techniques including infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) and mass spectrometry. Methanolic extract (MEC) of the seeds was prepared by cold maceration and its anti-ulcerogenic potential was evaluated using indomethacin (50 mg/kg) and water immersion stress models in male rats. The animals were pre-treated with different doses of MEC (400 and 800 mg/kg) and the therapeutic effect was compared with standard drug i.e. ranitidine (RANT; 50 mg/kg). The ameliorative effects of MEC were investigated on gastric juice pH, total acidity, free acidity and ulcer index. The assays of malionaldehyde (MDA), catalase (CAT), superoxide dismutase (SOD), glutathione (GSH) and pro-inflammatory cytokines i.e. interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were carried out to find out the possible mechanism(s) of protection. Further, histopathological changes were also studied.

RESULTS: Chromatography studies and further confirmation by spectroscopic techniques revealed the presence of four different compounds in MEC i.e oleic acid (1), stearic acid (2), ascorbic acid (3) and quercetin (4). MEC exhibited anti-ulcerogenic effect in dose dependent manner which may be attributed to suppression of pro-inflammatory cytokines (IL-6, TNF-α) and MDA (112.7%), and up-regulation of protective factors such as CAT (90.48%), SOD (92.77%) and GSH (90.01%). Ulcer inhibition, reduction in total and free acidity and increase in gastric juice pH were observed in MEC treated rats as compared to disease control animals. Histopathological findings confirmed decreased cell infiltration, less epithelial cell damage and regeneration of gastric mucosa in dose dependent manner.

METHODOLOGY/PRINCIPAL FINDINGS: Sprague Dawley rats were separated into 7 groups. Groups 1-2 were orally challenged with carboxymethylcellulose (CMC); group 3 received 20 mg/kg omeprazole and groups 4-7 received 50, 100, 200 and 400 mg/kg of ethanolic leaf extract, respectively. After 1 h, CMC or absolute ethanol was given orally to groups 2-7. The rats were sacrificed after 1 h. Then, the injuries to the gastric mucosa were estimated through assessment of the gastric wall mucus, the gross appearance of ulcer areas, histology, immunohistochemistry and enzymatic assays. Group 2 exhibited significant mucosal injuries, with reduced gastric wall mucus and severe damage to the gastric mucosa, whereas reductions in mucosal injury were observed for groups 4-7. Groups 3-7 demonstrated a reversal in the decrease in Periodic acid-Schiff (PAS) staining induced by ethanol. No symptoms of toxicity or death were observed during the acute toxicity tests.