Preparation and characterisation of atorvastatin and curcumin-loaded chitosan nanoformulations for oral delivery in atherosclerosis.

Atorvastatin known to be a potential inhibitor of HMG-CoA reductase involved in the synthesis of cholesterol. It is touted as miracle drug due to its profound effect in decreasing the low-density lipoproteins in blood. Unfortunately, the high dosage used poses side-effects relatively in comparison to other statins. On the other hand, curcumin has a diverse therapeutic potential in health and disease. However, the poor aqueous solubility and low bioavailability hinders the therapeutic potential of it when administrated orally. Therefore, it was thought to minimise the frequency of atorvastatin doses to avoid the possibility of drug resistance and also to overcome the limitations of curcumin for desirable therapeutic effects by using nanocarriers in drug delivery. In this investigation, synergistic effect of atorvastatin and curcumin nanocarriers was encapsulated by chitosan polymer. The chitosan nanocarriers prepared by ionic gelation method were characterised for their particle size, zeta potential, and other parameters. The drug-loaded nanocarriers exhibited good encapsulation efficiency (74.25%) and showed a slow and sustained release of atorvastatin and curcumin 60.36 and 61.44%, respectively, in a span of 48 h. The drug-loaded nanocarriers found to be haemocompatible and qualified for drug delivery in atherosclerosis.

Development and in vitro evaluation of oxytetracycline-loaded PMMA nanoparticles for oral delivery against anaplasmosis.

Poly-methyl methacrylate (PMMA) polymer with remarkable properties and merits are being preferred in various biomedical applications due to its biocompatibility, non-toxicity and cost effectiveness. In this investigation, oxytetracycline-loaded PMMA nanoparticles were prepared using nano-precipitation method for the treatment of anaplasmosis. The prepared nanoparticles were characterised using dynamic light scattering (DLS), atomic force microscopy (AFM), differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. The mean average diameter of the nanoparticles ranged between 190-240 nm and zeta potential was found to be -19 mV. The drug loading capacity and entrapment efficiency of nanoparticles was found varied between 33.7-62.2% and 40.5-60.0%. The in vitro drug release profile exhibited a biphasic phenomenon indicating controlled drug release. The uptake of coumarin-6(C-6)-loaded PMMA nanoparticles in Plasmodium falciparum (Pf3D7) culture model was studied. The preferential uptake of C-6-loaded nanoparticles by the Plasmodium infected erythrocytes in comparison with the uninfected erythrocytes was observed under fluorescence microscopy. These findings suggest that oxytetracycline-loaded PMMA nanoparticles were found to be an effective oral delivery vehicle and an alternative pharmaceutical formulation in anaplasmosis treatment, too.

Tamoxifen citrate-loaded poly(d,l) lactic acid nanoparticles: Evaluation for their anticancer activity in vitro and in vivo.

The optimization of tamoxifen citrate entrapment and its release from biodegradable poly(d,l) lactic acid nanoparticles are prepared by modified spontaneous emulsification solvent diffusion method. Since the addition of tamoxifen citrate induces the formation of drug crystals from nanoparticle suspension the influence of several parameters on tamoxifen citrate encapsulation was investigated. In vitro studies for cytotoxicity, DNA ladder, and the expression of Bcl-2-Bax expression were also investigated for MCF-7 and MDA-MB-231 cells after the addition of tamoxifen citrate alone and tamoxifen citrate-poly(d,l) lactic acid-nanoparticles (encapsulated tamoxifen citrate). From results, it was noticed that the size and zeta potential of the drug loaded nanoparticles were not differed much in their physicochemical properties from drug free counterparts. The drug-loaded and drug-free nanoparticles exhibited size of in between 271.4 and 282.7 nm and zeta potential of -34 to -27.4 mV, respectively. There was significant increase in drug incorporation in the particles noticed in dichloromethane + methanol system in comparison to acetone + methanol and ethyl acetate + methanol systems. The drug was partly released from the nanoparticles after 48 h of incubation at 37℃. From Fourier transform infrared spectroscopy and differential scanning calorimetry data demonstrated drug-polymer characteristics within the nanoparticles and unincorporated drug that appeared in the form of crystals from polarized microscopic study. MCF-7 and MDA-MB-231 cells were more sensitive to tamoxifen citrate-poly(d,l) lactic acid-nanoparticles than tamoxifen citrate alone. DNA ladder and the expression of Bax to Bcl-2 ratio were much higher in tamoxifen citrate encapsulated in nanoparticles than that in tamoxifen citrate alone. These results demonstrated the feasibility of encapsulation of tamoxifen citrate and its enhanced efficiency in vitro and in vivo studies.

Evaluation of Surfactants-Assisted Folic Acid-Loaded Pectin Submicrospheres: Characterization and Hemocompatibility Assay.

Folic acid is used for preventing and treating multiple diseases and disorders, administered in the form of oral supplements. The present research work was aimed to study the influence of two non-ionic surfactants Poloxamer and Tween 80 (Polysorbate 80) on pectin submicrospheres formulations. Typical natural polymer pectin was used to encapsulate folic acid by cross linking method. The resultant submicrospheres contributed to improve the aqueous solubility to enhance the bioavailability of folic acid. During investigation, it was observed that pectin polymers influenced kinetics of the rate of reaction more intensively than the surfactants. The physical phenomenon caused the change in their size, shape and chemistry of pectin polymers transforming into submicrospheres in aqueous condition. The characteristic differences of submicrospheres were assessed by scanning electron microscopy, differential scanning calorimetry and Fourier-transform infrared spectroscopy. The average diameters of the submicrospheres ranged between 250 and 500 nm. The encapsulation efficiency of submicrospheres ranged between 80 and 96 %. The characteristic swelling behavior of lyophilized submicrospheres was influenced by the ratio of pectin polymers and folic acid used in the formulations. The submicrospheres systems exhibited controlled release of folic acid due to the pH-dependent solubility of pectin polymers in aqueous medium. The submicrospheres showed good haemocompatibility suggesting them to be promising candidates for oral delivery.

Curcuminoids-loaded liposomes in combination with arteether protects against Plasmodium berghei infection in mice.

Curcuminoids are poorly water-soluble compounds with promising antimalarial activity. To overcome some of the drawbacks of curcuminoids, we explored the potential of liposomes for the intravenous delivery of curcuminoids in a model of mouse malaria. The curcuminoids-loaded liposomes were formulated from phosphatidylcholine (soy PC) by the thin-film hydration method. Antimalarial activity of curcuminoids-loaded liposomes alone and in combination with α/ß arteether when administered intravenously, was evaluated in Plasmodium berghei infected mice. Animals treated with curcuminoids-loaded liposomes showed lower parasitemia and higher survival when compared to control group (no treatment). Importantly, the combination therapy of curcuminoids-loaded liposomes (40 mg/kg body wt) along with α/ß arteether (30 mg/kg body wt) was able to not only cure infected mice but also prevented recrudescence. These data suggest that curcuminoids-loaded liposomes may show promise as a formulation for anti-malarial therapy.

Curcuminoids-loaded lipid nanoparticles: novel approach towards malaria treatment.

In the present work, curcuminoids-loaded lipid nanoparticles for parenteral administration were successfully prepared by a nanoemulsion technique employing high-speed homogenizer and ultrasonic probe. For the production of nanoparticles, trimyristin, tristerin and glyceryl monostearate were selected as solid lipids and medium chain triglyceride (MCT) as liquid lipid. Scanning electron microscopy (SEM) revealed the spherical nature of the particles with sizes ranging between 120 and 250 nm measured by photon correlation spectroscopy (PCS). The zeta potential of the particles ranged between -28 and -45 mV depending on the nature of the lipid matrix produced, which also influenced the entrapment efficiency (EE) and drug loading capacity (LC) found to be in the range of 80-94% and 1.62-3.27%, respectively. The LC increased reciprocally on increasing the amount of MCT as confirmed by differential scanning calorimetry (DSC). DSC analyses revealed that increasing imperfections within the lipid matrix allowed for increasing encapsulation parameters. Nanoparticles were further sterilized by filtration process which was found to be superior over autoclaving in preventing thermal degradation of thermo-sensitive curcuminoids. The in vivo pharmacodynamic activity revealed 2-fold increase in antimalarial activity of curcuminoids entrapped in lipid nanoparticles when compared to free curcuminoids at the tested dosage level.

Assessment of in vivo antimalarial activity of rifampicin, isoniazide, and ethambutol combination therapy.

The existing armament of drugs for the treatment and prevention of malaria is inadequate due to development of resistance. In addition to this due to lack of economic enticement the rate of new drug development and new drug discovery in the segment of parasitic diseases is very low as compared to the other segments. This has necessitated the better deployment and usage of existing antimalarial drugs as well as discovery of antimalarial activity of drugs which are well characterized for other diseases; these approaches help to reduce the time and cost required for new drug discovery. The present study evaluated the antimalarial activity of antituberculosis drugs rifampicin, isoniazide, and ethambutol in monotherapy and combination in Plasmodium berghei-infected mice. Animals were observed for mortality, parasite progression, and toxicity for a period of 1 month. Rifampicin + isoniazide and rifampicin + isoniazide + ethambutol treatment resulted in an overall survival rate of 60% compared to 0% in vehicle-fed animals by 4 weeks after post-infection without showing any toxicity.

Hypocholesterolemic and hepatoprotective effects of flaxseed chutney: Evidence from animal studies.

Rats fed with hypercholesterolemic diet showed a significant increase in serum total-cholesterol, liver homogenate total-cholesterol, HDL-cholesterol and changed LDL-cholesterol, and HDL/LDL ratio in comparison to control. Flaxseedchutney (FC) supplemented diet (15%, w/w) was found to be more effective in restoring lipid profile changes in rats fed with cholesterol, (1.0%). The activities of serum marker enzymes glutamate oxaloacetate transminase (GOT), glutamate pyruvate transaminase (GPT) and alkaline phosphatase (ALP) were elevated significantly in carbon tetrachloride induced rats. Administration of flaxseedchutney (15%, w/w) resulted in depletion of serum marker enzymes and exhibited recoupment thus showing significant hepatoprotective effect. It was observed that flaxseedchutney supplemented diet could lower the serum cholesterol and as a potential source of antioxidants it could exert protection against hepatotoxic damage induced by carbon tetrachloride (CCl(4)) in rats.

Effects of flaxseed(Linum usitatissimum) chutney on gamma-glutamyl transpeptidase and micronuclei profile in azoxymethane treated rats.

Antioxidant property of flaxseed chutney was evident by decreasing lipid peroxidation (TBARS) and predictor enzyme γ-glutamyl transpeptidase profile and micronuclei formation in azoxymethane treated rats. After 10 weeks, rats fed with either fiber-free basal diet or Antioxidant diet exhibited over sevenfold increase in γ-glutamyl transpeptidase activity and nearly fourfold increase in micronuclei load in comparison to controls (p<0.001). A significant reduction in both γ-glutamyl transpeptidase level (52%) and micronuclei formation (47%) was observed in fiber-free basal diet/Antioxidant diet/flaxseed chutney diet fed rats. Relative to rats fed fiber-free basal diet, the profile of γ-glutamyl transpeptidase and micronuclei load was not significantly altered.

Association between paraoxonase activity and lipid levels in patients with premature coronary artery disease.

BACKGROUND: South Asians, especially Indians show increased risk for atherosclerosis and have the higher mortality rates due to coronary artery disease. The increasing incidence of coronary artery disease in young patients is possibly due to industrialization, stress of life, less exercise and increasing incidence of smoking and other factors. We attempted to determine an independent association of paraoxonase with coronary artery disease in young patients. METHOD: The lipid profile and serum paraoxonase were investigated in 120 angiographically-proven premature coronary artery disease patients (99 males and 21 females, all <45 years) with diabetes mellitus, smoking, hyperlipidemia, obesity, hypertension along with 50 (41 male and 9 female) normal subjects and compared. RESULTS: A significant increase was observed in the concentrations of total cholesterol, triglycerides and LDL cholesterol in premature coronary artery disease patients. The activities of paraoxonase and HDL cholesterol concentrations decreased in coronary artery disease patients compared to control subjects. CONCLUSION: A paraoxonase was an independent (p<0.001, OR 14.9 and 95% CI 5.6-35.9) risk factor for premature coronary artery disease patients along with lipid profiles. Paraoxonase activity should be evaluated in all coronary artery disease patients in the absence of traditional risk factors.

Antioxidant potentials of flaxseed by in vivo model.

The present study reports the antioxidant activity of flaxseed as measured by feeding weanling albino rats with 5.0% and 10.0% of flaxseed (constituting approximately 0.75 and 1.5 g kg(-)(1)) for 14 days followed by challenging animals with 2.0 g kg(-)(1) b.w. CCl(4) as toxin. Activity was assessed by measuring hepatic marker enzymes like catalase, superoxide dismutase (SOD), and peroxidase and comparing with those from the normal group and from a group receiving toxin without flaxseed. Treatment of CCl(4) at dose of 2.0 g kg(-)(1) b.w. decreased the activities of various antioxidant enzymes such as catalase, superoxide dismutase (SOD), and peroxidase by 35.6%, 47.76%, and 53.0%, respectively, compared to the control group, and the lipid peroxidation value increased nearly 1.2-fold compared to that of the group treated with toxin without flaxseed. Pretreatment of rats with 5.0% flaxseed followed by CCl(4) treatment caused restoration of catalase, SOD, and peroxidase by 39.7%, 181.42%, and 123.7%, respectively, as compared to control. The group treated with 10.0% flaxseed has shown the restoration of 95.02%, 182.31%, and 136.0% of catalase, SOD, and peroxidase. In the case of the group treated with toxin without flaxseed, the level of superoxide dismutase and the catalse value decreased 91.4% and 55.33%, respectively, in comparison with the control group. These results clearly indicate the beneficial effect of flaxseed components as an antioxidant as seen by restoration of hepatic enzymes, which were varied from normal to one due to toxicity induced by toxin (CCl(4)). Owing to this property, the flaxseed known for its functional properties can be further extended to exploit its possible application for various health benefits as nutraceuticals and food ingredient.