Isolation and characterization of components responsible for neuroprotective effects of Allium cepa outer scale extract against ischemia reperfusion induced cerebral injury in mice.

The antioxidant-mediated neuroprotective effect of Allium cepa outer scale extract (ACE) in mice with cerebral ischemia-reperfusion (I-R) injury was demonstrated in our earlier work. The current investigation aimed at establishing the bioactive component(s) responsible for this activity. Thus ACE was fractionated into ethyl acetate (EF) and aqueous (AF) fractions. These fractions were evaluated against cerebral I-R injury in mice. I-R injury in mice was induced by bilateral common carotid artery occlusion followed by 24 hr reperfusion. Memory, sensorimotor functions, cerebral infarct size, and oxidative stress were measured to address the neuroprotective mechanism of test substances. EF showed marked improvement of memory and sensorimotor functions by reducing brain oxidative stress and infarct size in mice after I-R injury. The bioactive EF was subjected to chromatographic (HPLC-PDA, HPLC-MS, preparative HPLC) and spectroscopic studies to isolate and identify the neuroprotective compounds. This lead to separation of three components, namely quercetin, quercetin 4'-O-glucoside, and the remaining fraction, from EF. The separated components were biologically evaluated. These components showed improvement in mice with I-R injury. But, EF displayed more marked neuroprotective effects as compared to the isolated components. The distinct neuroprotective outcome of EF may be credited to the synergistic action of compounds present in EF. Further studies such as evaluation of neurotoxic effects and other possible neuroprotective mechanisms are required to develop EF as a neuroprotective drug.

Development of Biodegradable Injectable In situ Forming Implants for Sustained Release of Lornoxicam.

OBJECTIVE: The focus of this study was to develop in situ injectable implants of Lornoxicam which could provide sustained drug release. METHODS: Biodegradable in situ injectable implants were prepared by polymer precipitation method using polylactide-co-glycolide (PLGA). An optimized formulation was obtained on the basis of drug entrapment efficiency, gelling behavior and in vitro drug release. The compatibility of the formulation ingredients were tested by Fourier transform infrared (FT-IR) spectroscopy, and differential scanning colorimetry (DSC). SEM study was performed to characterize in vivo behavior of in situ implant. Pharmacokinetic study and in vivo gelling study of the optimized formulation were performed on Sprague-Dawley rats. Stability testing of optimized formulation was also performed. RESULTS: The drug entrapment efficiency increased and burst release decreased with an increase in the polymer concentration. Sustained drug release was obtained up to five days. SEM photomicrographs indicated uniform gel formation. Chemical interaction between the components of the formulation was not observed by FT-IR and DSC study. Pharmacokinetic studies of the optimized formulation revealed that the maximum plasma concentration (Cmax), time to achieve Cmax (Tmax) and area under plasma concentration curve (AUC) were significantly higher than the marketed intramuscular injection of lornoxicam. Stability study of optimized batch showed no change in physical and chemical characteristics. CONCLUSION: Lornoxicam can be successfully formulated as in situ injectable implant that provides long-term management of inflammatory disorders with improved patient compliance.