Effect of various formulation variables on the encapsulation and stability of dibucaine base in multilamellar vesicles

Formulation of local anesthetics in liposomal topical drug delivery system could provide a sustained and localized anesthesia. The aim of this study was to develop a liposomal dibucaine base (DB) local anesthetic delivery system. DB-loaded multilamellar vesicles (MLVs) were prepared through varying lipid composition, induced charge and pH of the hydration medium. Liposomes were characterized for morphology, size, entrapment efficiency (EE), in vitro drug release and stability including leakage stability. The percentage of drug entrapped in liposomes was found to be hydration medium pH dependent and charge dependent and more pronounced for negatively charged liposomes prepared using hydration medium of pH 9. In vitro release studies of liposomes have shown a sustained release of entrapped dibucaine compared to control solution. Results revealed that adjusting the various formulation variables of dibucaine base MLVs could yield stable and effective topical liposomal local anesthetic formulations.     

Inula Viscosa Extracts Induces Telomere Shortening and Apoptosis in Cancer Cells and Overcome Drug Resistance

Telomerase is activated in human papillomavirus (HPV) positive cervical cancer and targeting telomeres offers a novel anticancer therapeutic strategy. In this study, the telomere targeting properties, the cytotoxic as well as the pro-apoptotic effects of hexane (IV-HE) and dichloromethane (IV-DF) fractions from Inula viscosa L. extracts were investigated on human cervical HeLa and SiHa cancer cells. Our data demonstrate that IV-HE and IV-DF extracts were able to inhibit cell growth in HeLa and SiHa cells in a dose-dependent manner and studied resistant cell lines exhibited a resistance factor less than 2 when treated with the extracts. IV-HE and IV-DF extracts were able to inhibit telomerase activity and to induce telomere shortening as shown by telomeric repeat amplification protocol and TTAGGG telomere length assay, respectively. The sensitivity of fibroblasts to the extracts was increased when telomerase was expressed. Finally, IV-HE and IV-DF were able to induce apoptosis as evidenced by an increase in annexin-V labeling and caspase-3 activity. This study provides the first evidence that the IV-HE and IV-DF extracts from Inula viscosa L. target telomeres induce apoptosis and overcome drug resistance in tumor cells. Future studies will focus on the identification of the molecules involved in the anticancer activity.     

Neuroprotective effect of carnosine and cyclosporine-A against inflammation,apoptosis, and oxidative brain damage after closed head injury in immature rats

Context: Traumatic brain injury in the pediatric population can have a great economic and emotional impact on both the child's family and society.

Objective: The present study aimed to compare the effects of carnosine (CAR) and/or cyclosporine A (CyA) on oxidative brain damage after closed head injury (CHI) in immature rats.

Materials and methods: Thirty-day-old rat pups were divided into five groups: non-traumatic control group, trauma group underwent CHI, trauma group injected with CAR (200?mg/kg, i.p.) following CHI for 7?d, trauma group injected with CyA (20?mg/kg, i.p.) given 15?min and 24?h after CHI, and trauma group treated with CAR and CyA. At the end of the treatment, rats were sacrificed; blood and brains were collected for assessing different biochemical parameters.

Results: Trauma significantly increased brain level of malondialdehyde, nitric oxide, glucose, calcium, inflammatory mediators. Brain DNA damage was confirmed by comet assay and the significant increase in brain caspase-3 activity. Moreover, the serum level of Fas ligand in traumatized animals was significantly elevated. Concomitant decrease in brain-reduced glutathione (GSH) and calcium-adenosine triphosphatase activity was observed in the traumatized-untreated group. Treatment of traumatized animals with CAR and/or CyA ameliorated all the biochemical changes induced by CHI with marked protective effect in the combination group.

Discussion and conclusion: CAR and CyA exerted a synergistic neuroprotective effect against CHI through blocking the induction of lipid peroxidation, reducing inflammatory, and oxidative stress biomarkers, preserving brain GSH content, and reducing the alterations in brain apoptotic biomarkers in traumatized animals.     

Protective effects of combined therapy of gliclazide with curcumin in experimental diabetic neuropathy in rats

Diabetic neuropathy is the most common chronic complication of diabetes. The aim of the present study was to evaluate the protective effects of curcumin against neuropathy in gliclazide-treated diabetic rats. Diabetes was induced by an intraperitoneal injection of streptozotocin (45 mg/kg). Diabetic animals were given gliclazide (10 mg/kg, orally) alone or combined with curcumin (100 mg/kg, orally) or gabapentin (30 mg/kg, intraperitoneally as a positive control). Behavioral responses to thermal (hot plate and tail flick) and mechanical (tail pinch) pain, and some biochemical tests (serum glucose, C-peptide, peroxynitrite, lipid peroxides, and tumor necrosis factor-α) were assessed after 5 consecutive weeks of daily treatment. Combined treatment of curcumin with gliclazide significantly increased hot-plate and tail-flick latencies in comparison with that of the diabetic control group. The threshold of mechanical hyperalgesia was also significantly elevated. Serum glucose and C-peptide levels were significantly increased in the combined treatment compared with the diabetic control group, whereas serum levels of peroxynitrite, lipid peroxide, and tumor necrosis factor-α production were significantly decreased. The data suggest that the combination of curcumin with gliclazide may protect against the development of diabetic neuropathy, with favorable effects with respect to the gliclazide/gabapentin combination.     

Melatonin improves the therapeutic role of mesenchymal stem cells in diabetic rats

The present study aimed to investigate the role of bone marrow mesenchymal stem cells (MSCs) and/or melatonin (MT) for improvement of β-cell functions in STZ diabetic rats. Male albino rats (130–150?g) were divided into six groups. Control group: received phosphate-buffered saline (PBS); melatonin group received melatonin (10?mg/kg b.wt./day for 2 months by oral gavage); diabetic untreated group; diabetic group treated with melatonin; diabetic group treated with MSCs (a single intravenous injection of 3?×?10⁶ cell in PBS); and diabetic group co-treated with stem cells and melatonin. The results showed significant improvement in glucose, insulin, total antioxidant, and malondialdehyde level in diabetic rats treated with either MSCs alone or in combination with melatonin. The imumuno-histochemical analysis showed that MSCs and/or melatonin treatment reduced the rate of inflammation and apoptosis of the islet cells as well as increased the rate of pancreatic cell division. Such results were indicated by a significant improvement in the level of TNF-α, IL-10, PCNA, and caspase-3 to levels very close to the control. Co-treatment of MSCs and MT resulted in an improvement in the tissue of the pancreas and reduced number of damaged β-cells. It can be concluded that co-treatment of stem cells and melatonin has a significant role in restoring the structural and functional efficiency of β-cells in the pancreas more than stem cells alone. Such results may be due to the role of melatonin as an antioxidant in increasing the efficiency and vitality of stem cells.