Development and evaluation of a gastro-retentive delivery system for improved antiulcer activity of ginger extract (Zingiber officinale)

Aim was to develop and optimize multiunit gastro-retentive floating beads (FBs) intended for localized and prolonged release of ginger for treating gastric ulcers. Protective effect of ginger extract (GE) against ulcer is well documented, but therapeutic use is compromised due to poor bioavailability and physicochemical properties. GE was only slightly soluble (3.19?±?0.38?mg/ml) in simulated gastric fluid (SGF; pH 1.2). The solubility decreased in water to 0.69?±?0.03?mg/ml and further by 26% in the presence of calcium carbonate (0.5% w/v). We prepared FBs of GE using calcium carbonate and sodium alginate in different proportions. Beads were evaluated for diameter, buoyancy, entrapment, and porosity. In vitro dissolution showed a Fickian release with a cumulative release of >80% at 24?h. Preclinical evaluation was done in cold-restraint stress induced gastric ulcers, in albino rats, in terms of (i) ulcer index, hemorrhagic streaks (l), mucus content, (ii) oxido-nitrosative stress, and (iii) histopathology. GE loaded FBs (200?mg/kg) were significantly better than free GE and better/equivalent to cimetidine (10?mg/kg). The system was evaluated for therapeutic effect (curative), i.e. after the induction of ulcers. Most of the natural phytochemical or antioxidants show pretreatment effectiveness. We, however, developed and established GE FBs for sustained curative effect.     

Antioxidant activity and controlled release analysis of red ginger oleoresin (Zingiber officinale var rubrum) encapsulated in chitosan cross-linked by glutaraldehyde saturated toluene

The aim of this study was to determine encapsulation efficiency, particle size, and characterization of red ginger oleoresin microcapsules such as controlled release, morphology microcapsule and also determine the antioxidant activity of red ginger oleoresin microcapsules. The red ginger oleoresin was dispersed in chitosan and stirred to form an emulsion, then added to corn oil and stirred again to form a second emulsion. Glutaraldehyde saturated toluene (GST) as a crosslinking agent was added dropwise into the emulsion and continues to be stirred for the solidification process. Chitosan microspheres filled with red ginger oleoresin were washed using petroleum ether followed by hexane and then dried in the oven. Controlled release analysis was carried out in a phosphate buffer medium at pH 7.4. Red ginger oleoresin microcapsules produced the highest encapsulation efficiency was 82.54 ± 3.5 with a mean diameter ranging from 110.12 ± 12.2 to 161.42 ± 40.1 µm. Cumulative release of red ginger oleoresin from microcapsules reached the highest level was 61.69 ± 1.3% from 2% chitosan concentration and 5 ml GST, and the lowest level was 50.01 ± 1.8% from 4% chitosan concentration and 20 ml GST after they were immersed in phosphate buffer for 72 h. The value of antioxidant activity was between 38.28 ± 0.07% and 61.99 ± 0.33%. The release mechanism based on the Korsmeyer-Peppas model was Fickian diffusion with a diffusion coefficient value of 1.332 × 10^?11–4.576 × 10^?13 cm²/s.     

Anticonvulsant effect of <Emphasis Type="Italic">Sclerocarya birrea</Emphasis> (A. Rich.) Hochst. subsp. <Emphasis Type="Italic">caffra</Emphasis> (Sond.) Kokwaro (Anacardiaceae) stem-bark aqueous extract in mice

Sclerocarya birrea (A.Rich.) Hochst. subsp. caffra (Sond.) Kokwaro (family: Anacardiaceae) is traditionally used in South African folk medicine for the treatment, management and control of a variety of human ailments, including childhood convulsions and epilepsy. In the present study, we have investigated the anticonvulsant activity of the plant’s stem-bark aqueous extract (SBE) against pentylenetetrazole (PTZ)-, picrotoxin (PCT)-, and bicuculline (BCL)-induced seizures in mice. Phenobarbital and diazepam were used as reference anticonvulsant drugs for comparison. Like the reference anticonvulsant agents used, S. birrea SBE (100–800 mg/kg p.o.) significantly (P<0.05–0.001) delayed the onset of, and inhibited, PTZ-induced seizures. The plant extract (SBE, 100–800 mg/kg p.o.) also markedly inhibited PCT-induced seizures, but only weakly inhibited BCL-induced seizures. In general, the average onset of convulsion was delayed or inhibited, while the average duration of convulsion was not significantly altered (P>0.05). The plant extract also depressed the central nervous system. In conclusion, the findings of the present experimental animal study indicate that S. birrea SBE possesses anticonvulsant activity, thus lending pharmacological support to the suggested folkloric, ethnomedical uses of the plant extract in the management, control, and treatment of childhood convulsions and epilepsy in some rural communities of South Africa.