Preparation of Atorvastatin Loaded Chitosan Nanoparticles: In Vitro and In Vivo Evaluations

This study is aimed at the preparation and evaluation of atorvastatin (AN)-loaded chitosan (CS) nanoparticles to achieve improved bioavailability of atorvastatin as its bioavailability is very poor. Chitosan is a popular choice in the application as a drug delivery carrier due to its biocompatibility, chemical versatility, aqueous solubility and low cost. Hence, a total of nine formulations (AN1–AN9) were prepared to study the effects of CS:tripolyphosphate (TPP) ratio and the amount of drug. The best formulation was selected by calculating the overall desirability (OD) factor. Among all, AN9 was found to possess the maximum percentage yield, loading efficiency and percentage (%) drug release compared to other formulations due to the incorporation of more amount of polymer compared to other formulations. SEM microphotographs and zeta-sizer reports indicated that atorvastatin-loaded chitosan nanoparticles were in the nanometric range and were spherical, discrete and uniform in size. The selected polymer chitosan was found to possess good compatibility with atorvastatin, without any mutual interaction, based on the results of DSC and FTIR analyses. The nanoparticles were found to have good flow properties. The in vivo results proved that the best formulation has shown significant difference in the reduction of triglycerides (TG), total cholesterol (TC) and no significant change in high density lipids (HDL) cholesterol levels in blood when compared with the marketed formulation. Better regenerative changes were observed during histopathological evaluation of liver in a group treated with atorvastatin nanoparticles than those of other groups, that confirmed the improved hypolipidemic action. Thus, from all the above observations, it was concluded that AN9 formulation has shown the highest in vitro drug release and loading efficiency than other formulations, which might be due to increased entrapment of drug and the surface area through decreased particle size which further confirmed the improved in vitro bioavailability and in vivo performance than those of marketed atorvastatin tablet. This study strongly suggests the use of chitosan nanoparticles as drug delivery system to improve the bioavailability of atorvastatin.

The Evaluation of the virulence factors of clinical Candida isolates and the anti-biofilm activity of Elettaria cardamomum against multi-drug resistant Candida albicans

Background and Purpose:

Today, treatment of life-threatening fungal infections, caused by Candida species, has become a major problem. In the present study, we aimed to evaluate the antifungal susceptibility patterns of different clinical Candida isolates, determine the virulence factors in multi-drug resistant (MDR) Candida species, and assess the anti-biofilm activity of Elettaria cardamomum against MDR Candida species.

Materials and Methods:

A total of 202 isolates from different Candida species were obtained from three governmental hospitals in Senthamangalam, Tiruchengode, and Namakkal, Tamil Nadu, India. The isolates were identified, using conventional methods. Candida species were tested for virulence factors such as biofilm, protease, and phospholipase activity. The minimum inhibitory concentration (MIC) of Elettaria cardamomum against MDR biofilm-forming C. albicans was determined, using plate and tube methods.

Results:

The identified Candida isolates (n=202) were C. albicans (74/202), C. glabrata (53/202), C. parapsilosis (44/202), C. tropicalis (15/202), and C. dubliniensis (16/202). The isolates were subjected to antifungal susceptibility testing and the virulence factors were determined. In terms of biofilm production, non-C. albicans species such as C. dubliniensis showed 75% activity. Also, regarding protease activity, C. parapsilosis (75%) showed the highest percentage of protease production. In addition, Candida species showed strong positivity for phospholipase activity (62.87%). In the MIC method, the acetonic extract completely inhibited biofilm production at a concentration of 125 µl (56.25 µg). In comparison with the ethanolic extract, the acetonic extract showed major activity against biofilm production.

Conclusion:

Based on the findings, pathogenic C. albicans species were inhibited by the ethanolic and acetonic extracts of E. cardamomum. In recent years, MDR and biofilm-forming pathogenic Candida species have been increasingly detected in clinical settings. Therefore, herbal derivatives might contribute to the treatment of infections without causing any side-effects and prevent the associated mortality.

Ameliorative potential of Coccinia grandis extract on serum and liver marker enzymes and lipid profile in streptozotocin induced diabetic rats

Diabetes mellitus is the most severe metabolic pandemic of the 21(st) century, affecting essential biochemical activities in almost every cell in the body. Indian literatures have already mentioned herbal remediation for a number of human ailments. The present study was undertaken to evaluate the potential of Coccinia grandis extract on serum and liver marker enzymes (ALP, AST, ALT and LDH) and lipid profile (total cholesterol, phospholipids, triglycerides and free fatty acids in serum and liver) in streptozotocin induced diabetic animals. The experimental animals were treated with methanolic extract of Coccinia grandis and the levels of marker enzymes and lipid profile were estimated. The ALP, AST, ALT and LDH levels were increased in diabetic rats and restored to near normal levels after administration of plant extract. The lipid profile increased in diabetic group and after the treatment with the plant extract the levels were reverted to near normal. Thus the methanolic extract of Coccinia grandis has a potent ability to restore the marker enzymes and the lipid profile was reverted to near normal levels.

Glucose induces lipid peroxidation and inactivation of membrane-associated ion-transport enzymes in human erythrocytes in vivo and in vitro

Erythrocytes of diabetic subjects (non-insulin dependent) were found to have eight- to ten-fold higher levels of endogenously formed thiobarbituric acid reactive malonyldialdehyde (MDA), thirteen-fold higher levels of phospholipid-MDA adduct, 15-20% reduced Na(+)-K(+)-ATPase activity with unchanged Ca+2-ATPase activity, as compared with the erythrocytes from normal healthy individuals. Incubation of normal erythrocytes with elevated concentrations (15-35 mM) of glucose, similar to that present in diabetic plasma, led to the increased lipid peroxidation, phospholipid-MDA adduct formation, reduction of Na(+)-K(+)-ATPase (25-50%) and Ca+2-ATPase (50%) activities. 2-doxy-glucose was 80% as effective as glucose in the lipid peroxidation and lipid adduct formation. However, other sugars, such as fructose, galactose, mannose, fucose, glucosamine and 3-O-methylmannoside, and sucrose, tested at a concentration of 35 mM, resulted in reduced (20-30%) lipid peroxidation without the formation of lipid-MDA adduct. Kinetic studies show that reductions in Na(+)-K(+)-ATPase and Ca+2-ATPase activities precede the lipid peroxidation as the enzyme inactivation occur within 30 min of incubation of erythrocytes with high concentration (15-35 mM) of glucose, while lipid peroxidation product, MDA appears at 4 hr and lipid-MDA adducts at 8 hr. The lipoxygenase pathway inhibitors, 5,8,11-eicosatriynoic acid and Baicalein (5,6,7-trihydroxyflavone), reduced the glucose-induced lipid peroxidation by 30% and MDA-lipid adduct formation by 26%. Indomethacin, a cyclooxygenase pathway inhibitor, had no discernible effect on the lipid peroxidation in erythrocytes. However, the inhibitors of lipid peroxidation, 3-phenylpyrazolidone, metyrapone, and the inhibitors of lipoxygenase pathways did not ablate the glucose-induced reduction of Na(+)-K(+)-ATPase and Ca+2-ATPase activities in erythrocytes. Erythrocytes produce 15-HETE (15-hydroxy-eicosatetraenoic acid), which is augmented by glucose. These results suggest that the formation of lipoxygenase metabolites potentiate the glucose-induced lipid peroxidation and that the inactivation of Na(+)-K(+)-ATPase and Ca+2-ATPase occurs as a result of non-covalent interaction of glucose with these enzymes.