Plasma proteomic changes in response to surgical trauma and a novel transdermal analgesic treatment in dogs

Assessment of pain responses and inflammation during animal surgery is difficult because traditional methods, such as visual analogue scores, are not applicable while under anaesthesia. Acute phase proteins (APPs), such as C-reactive protein and haptoglobin, that are typically monitored in veterinary research, do not show a significant change until at least 2 h post-surgery and therefore, immediate pathophysiological changes are uncertain. The current study used sequential window acquisition of all theoretical mass spectra (SWATH-MS) to investigate plasma proteome changes that occur immediately following surgery in dogs and also to assess the efficacy of a novel transdermal ketoprofen (TK) formulation. Castration was chosen as surgical model in this study. The procedure was performed on twelve dogs (n = 6 in two groups) and blood samples were collected at 0 h, 1 and 2 h after surgery for proteomic analysis. Following surgery, there was a general downregulation of proteins, including complement C- 3, complement factor B, complement factor D, transthyretin, and proteins associated with lipid, cholesterol, and glucose metabolisms, reflecting the systemic response to surgical trauma. Many of these changes were diminished in the transdermal group (TD) since ketoprofen, a non-steroidal anti-inflammatory drug (NSAID), inhibits prostanoids and the associated chemotactic neutrophil migration to site of tissue injury. SIGNIFICANCE: SWATH-MS Proteomic analysis revealed significant changes in plasma proteins, predominantly involved in early acute phase and inflammatory response at 1 & 2 h after surgery in castrated dogs. Pre-operative application of transdermal ketoprofen formulation had reduced the systemic immune response, which was confirmed by negligible alteration of proteins in transdermal treated group. A key outcome of this experiment was studying the efficacy of a novel transdermal NSAID formulation in dogs.

Pharmacokinetic Evaluation of a Novel Transdermal Ketoprofen Formulation in Healthy Dogs

Dogs undergo various surgical procedures such as castration, ovariohysterectomy, and other orthopedic procedures, which are known to cause inflammation and pain. Non-steroidal anti-inflammatory drugs (NSAIDs) are very effective analgesics for alleviating postoperative pain in veterinary medicine. Ketoprofen is currently approved in Australia and the United States for treating different painful conditions in dogs. This study evaluated the pharmacokinetic parameters of ketoprofen after intravenous (IV) and transdermal (TD) administration in healthy dogs. A novel transdermal ketoprofen (TDK) formulation containing 20% ketoprofen, dissolved in a combination of 45:45% isopropanol and Transcutol, along with 10% eucalyptus oil, was developed and evaluated for in vitro dermal permeation using Franz diffusion cells. A crossover study was then conducted to determine the pharmacokinetic parameters of the formulation in six dogs following IV ketoprofen (1 mg/kg) and TDK (10 mg/kg) administration. A liquid chromatography–mass spectrometry (LC-M/MS) method was used to measure plasma concentrations of ketoprofen over time, and a non-compartmental analysis determined the pharmacokinetic parameters. The mean terminal elimination half-life (T_½ h), AUC_0-t (µg·h/mL), and mean residence time (MRT, h) between IV and TDK groups were 4.69 ± 1.33 and 25.77 ± 22.15 h, 15.75 ± 7.72 and 8.13 ± 4.28 µg·h/mL, and 4.86 ± 1.81 and 41.63 ± 32.33 h, respectively. The calculated bioavailability (F%) was ~7%, with a lag time of 30 min to achieve effective plasma concentrations after the application of TDK.

Bombesin conjugated solid lipid nanoparticles for improved delivery of epigallocatechin gallate for breast cancer treatment

Epigallocatechin-gallate (EGCG) is a potent anti-cancer therapeutic which effectively controls the growth of cancerous cells through a variety of different pathways. However, its molecular structure is susceptible to modifications due to cellular enzymes affecting its stability, bioavailability and hence, overall efficiency. In this study, we have initially encapsulated EGCG in the matrix of solid lipid nanoparticles to provide a stable drug carrier. To confer additional specificity towards gastrin releasing peptide receptors (GRPR) overexpressed in breast cancer, EGCG loaded nanoparticles were conjugated with a GRPR-specific peptide. In-vitro cytotoxicity studies showed that the peptide-conjugated formulations possessed greater cytotoxicity to cancer cell lines compared to the non-conjugated formulations. Further, in-vivo studies performed on C57/BL6 mice showed greater survivability and reduction in tumour volume in mice treated with peptide-conjugated formulation as compared to the mice treated with non-conjugated formulation or with plain EGCG. These results warrant the potential of the system designed in this study as a novel and effective drug delivery system in breast cancer therapy.

Capsaicin, the pungent principle of peppers, ameliorates alcohol-induced acute liver injury in mice via modulation of matrix metalloproteinases

Alcohol, the most common cause for hepatic injury, may further deteriorate the hepatic tissue when left unattended. Capsaicin, the pungent principle of chilli peppers, possesses antioxidant and anti-inflammatory properties and is a proven dietary antioxidant in various ailments. However, its role in alcohol-induced hepatic injury is unclear. In this study, we investigated the effects of capsaicin on the hepatic tissue of mice treated with alcohol. Acute liver injury was induced in mice by oral gavage of 5 doses of 10 mL/kg of 50% ethyl alcohol at an interval of 12 h. The tissue antioxidant levels along with the mitochondrial functional parameters and matrix metalloproteinase levels were evaluated in the hepatic tissues of mice following alcohol challenge. The results showed that alcohol intake significantly attenuated the hepatic antioxidant levels and mitochondrial function. These changes were accompanied by enhanced serum hepatic injury markers and matrix metalloproteinases. However, capsaicin treatment (10 and 20 mg/kg, oral) throughout the experimental period caused a drastic improvement in the hepatic tissue of the alcohol-treated mice, reflected by the normalization of hepatic enzyme and protein levels along with restored histological alterations. These results indicate that capsaicin, as a dietary intervention, may prevent alcohol-induced acute liver injury.

Fabrication of surfactant-stabilized nanosuspension of naringenin to surpass its poor physiochemical properties and low oral bioavailability

BACKGROUND

Nanosuspension is a biphasic system consisting of native drug particles dispersed in an aqueous surfactant or polymeric solution with a particle size between 10 to 1000 nm. In contrast to other drug delivery systems, nanosuspension offer the unique advantage of increasing solubility of the native drug resulting into faster drug absorption and hence achieving faster maximum plasma concentration.

HYPOTHESIS/PURPOSE

The present study aims to evaluate surfactants/polymer stabilized nanosuspensions of naringenin (NN), a phytomedicine, to surpass its poor physiochemical properties and low oral bioavailability.

STUDY DESIGN

Optimization and characterization (DLS, SEM, PXRD and DSC) of nanosuspensions followed by in-vitro drug dissolution studies and pharmacokinetic study in male Sprague-Dawley rats were performed.

METHODS

Nanosuspensions were prepared by precipitation-ultrasonication method with varying concentrations of different surfactants and polymer such as sodium cholate (SC), sodium lauryl sulphate (SLS), poly ethylene glycol 4000 (PEG), polysorbate 80 (Tween^® 80), poloxomer-188 and D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS or Vitamin E-TPGS).

RESULTS

Nanosuspension prepared with 0.5% w/v d-α-Tocopherol polyethylene glycol 1000 succinate (TPNS) and 7.5 mg NN, showed the smallest size of 118.1 ± 2.7 nm. TPNS showed increase in drug dissolution in simulated gastric fluid pH 1.2 (SGF) and phosphate buffer pH 6.8 (PB). TPNS demonstrated an improved pharmacokinetic profile compared to pure NN resulting 2.14 and 3.76 folds increase in C_max and AUC, respectively. In addition, TPNS were stable over a period of six months.

CONCLUSION

The developed formulation strategy of nanosuspension could be exploited to improve the solubility and bio-availability of poorly soluble NN and other phytomedicines.

Large Amino Acid Transporter 1 Selective Liposomes of l-DOPA Functionalized Amphiphile for Combating Glioblastoma

Despite significant progress in neurosurgery and radiation therapy during the past decade, overall survivability (OS) of glioblastoma patients continues to be less than 2 years. The scope of systemic chemotherapy is greatly limited by poor drug transport across the blood brain barrier (BBB) and, thereby, suboptimal drug accumulation in glioma tissue. To this end, use of large amino acid transporter-1 (LAT1) overexpressed both on brain capillary endothelial cells (BCECs) and glioma cells has begun. Prior reports on the use of LAT1 mediated delivery of model drugs showed their brain accumulations. However, in depth in vivo glioblastoma regression studies aimed at examining the therapeutic potential of LAT1 mediated delivery of potent chemotherapeutics to brain tumor tissues have not yet been undertaken. Herein, we report on the development of a nanometric (100-135 nm) promising LAT1 selective liposomal drug carrier prepared from a novel l-3,4-dihydroxyphenylalanine (l-DOPA) functionalized amphiphile (Amphi-DOPA). In vitro studies using Rh-PE labeled liposomes of Amphi-DOPA both in untreated glioma (GL261) cells and in GL261cells preincubated with LAT1 antibody revealed LAT1 mediated cellular uptake. Intravenously administered NIR-dye labeled liposomes of Amphi-DOPA in glioblastoma-bearing mice showed preferential accumulation of the dye in brain tissue. Notably iv administration of WP1066-loaded liposomes of Amphi-DOPA enhanced the overall survivability of C57BL/6J mice bearing orthotopically established mouse glioblastoma by ∼60% compared to that for the untreated mouse group. Furthermore, we show that the OS of established glioblastoma-bearing mice can be significantly enhanced (by >300% compared to that for the untreated mouse group) when the presently described LAT1 mediated targeted chemotherapy with WP1066-loaded liposomes of Amphi-DOPA is combined with in vivo DC-targeted DNA vaccination using a survivin (a glioblastoma antigen) encoded DNA vaccine. The present findings open a new door for LAT1 mediated systemic chemotherapy of glioblastoma.

Polydatin alleviates alcohol-induced acute liver injury in mice: Relevance of matrix metalloproteinases (MMPs) and hepatic antioxidants

BACKGROUND

Alcohol, a most commonly consumed beverage, is the foremost cause of liver injury throughout the world. Polydatin, a stilbenoid glucoside, was known to possess antioxidant and anti-inflammatory properties and is being investigated for use in various disorders.

PURPOSE

The present study was intended at investigating the hepatoprotective efficacy of polydatin against acute-alcohol induced liver injury model in mice.

STUDY DESIGN

C57BL/6 mice were fed with five doses of 50% ethyl alcohol (10ml/kg body weight) to induce acute liver injury. Effect of polydatin against alcohol induced hepatic injury was investigated by giving 50 or 100mg/kg polydatin, orally, for 8 days.

METHODS

Serum markers of liver injury, morphology, histology and fibrosis of liver tissue, levels of enzymatic and non-enzymatic antioxidants and the mitochondrial respiratory enzyme activities in liver tissue were investigated. The activities and the protein expression of matrix metalloproteinases (MMP-2 and -9), the expression of NF-κB in the liver tissue were also studied.

RESULTS

Polydatin pre-treatment significantly alleviated the alcohol induced hepatic injury by reducing the serum liver injury markers, alanine aminotransferase (ALT) and aspartate aminotransferase (AST), attenuating oxidative stress and restoring antioxidant balance in the hepatic tissue. Simultaneously, polydatin pre-treatment also prevented alcohol induced mitochondrial damage and refurbished the matrix metalloproteinases levels of the hepatic tissue.

CONCLUSION

The findings of the present study suggest that polydatin may have a potential benefit in preventing alcohol-induced acute hepatic injury.