Ehrlich's ascites fluid adsorbed over protein A containing Staphylococcus aureus Cowan I produces inhibition of tumor growth

Cysteine Supplementation Mitigates the Toxicity Associated with Antitumor Therapy of Ehrlich's Ascites Fluid Adsorbed over Protein A Containing Staphylococcus aureus Cowan I

Introduction:

Previously, we have reported the amelioration of ad-AF induced hepatotoxicity with the exogenous supplementation of glutathione (GSH) without compromising the anti-tumor effect of ad-AF in ascites tumor model of mice with transplantable Ehrlich’s Ascites Tumor cells. Cellular uptake of glutathione (GSH) has its own limitations, therefore exogenous supplementation of L-cysteine (Cys) was tried to reduce the toxicity of ad-AF by providing –SH contents without compromising the anti-tumor property of adsorbed ascites fluid (ad-AF).

Results:

A significant increase in mean survival time (MST) of tumor bearing mice from 18.1 days to 32.9 days with exogenous supplementation of Cys was observed. Cys supplementation did not alter decline in body-weight gain, tumor cell counts as well as decrease in the viability of tumor cells in ascites tumor bearing animals. Similarly, Cys has been helpful to restore the hepatic –SH contents upto the levels of –SH content in tumor control group. The exogenous supplementation of Cys along with ad-AF has been helpful to restore the decline in the activities of phase-I and enhanced levels of glutathione-S-transferase (GST). The changes in the activities of different enzymes of phase-I and phase-II indicate the reduction in toxic insult induced by the therapeutic material (ad-AF). However, ad-AF treatment could not prevent tumor bearers from natural death due to tumor progression but significantly reduced the rate of tumor progression.

Conclusions:

Our study suggests that exogenous supplementation of Cys alongwith ad-AF could have a potential to be developed as a modality for the treatment of ascites tumor at least at experimental level.

Exogenous supplementation of N-acetylcysteine Can Reduce Hepatotoxicity Induced by Ascites Fluid (Cell-Free) Adsorbed Over Protein-A-Containing Staphylococcus aureus Cowan-I Without Compromising Its Antitumor Effect

Introduction:

Hepatotoxicity along with enhanced mortality has remained a major concern during the development of antitumor therapy with the use of cell-free ascites fluid adsorbed (ad-AF) over Protein-A-containing Staphylococcus aureus Cowan I (SAC). Major issue with ad-AF inoculation is the significant depletion of hepatic glutathione (GSH). Exogenous supplementation of –SH contents to the host has offered an encouraging hope to explore the possibilities to use ad-AF as a therapeutic material due to its antitumor effects. GSH and l-cysteine have shown a promise with the recovery of –SH contents as well as the recovery of phase I and phase II biotransformation enzymes. Aforementioned observations prompted us to try other –SH donors.

Materials and Methods:

Therefore, in this study, N-acetylcysteine (NAC) was used as an exogenous source to provide –SH contents to reduce hepatotoxicity and mortality induced by ad-AF treatment.

Results:

Exogenous supplementation of NAC along with ad-AF treatment to ascites tumor bearers has shown a significant protection against hepatotoxicity and mortality caused by ad-AF. NAC substitution along with ad-AF has significantly enhanced the mean survival time (MST), without altering the antitumor effect of ad-AF as evident from tumor cell counts and viability.

Discussion:

NAC supplementation has been successful to recover hepatic –SH contents along with the significant recovery of phase I and phase II biotransformation enzymes. Marker enzymes for liver injury have also given clear-cut indications for the recovery of tumor bearers from hepatotoxicity induced by ad-AF.

Conclusion:

This study has shown that exogenous supplementation of NAC protects the host from the enhanced mortality and hepatotoxicity induced by ad-AF. These observations offer a hope to develop ad-AF as one of the probable treatment strategies for ascites tumors at least at experimental levels.

Bioactive coatings based on polyelectrolyte multilayer architectures functionalized by embedded proteins, peptides or drugs

In recent years, considerable effort has been devoted to the design and controlled fabrication of structured materials with functional properties. The layer by layer buildup of polyelectrolyte multilayer films (PEM films) from oppositely charged polyelectrolytes offers new opportunities for the preparation of functionalized biomaterial coatings. This technique allows the preparation of supramolecular nano-architectures exhibiting specific properties in terms of control of cell activation and may also play a role in the development of local drug delivery systems. Peptides, proteins, chemically bound to polyelectrolytes, adsorbed or embedded in PEM films, have been shown to retain their biological activities.

Glutathione reduces the toxicity associated with antitumor therapy of ascites fluid adsorbed over Staphylococcus aureus Cowan I in tumor bearing mice

It has been well documented in the literature that the removal of circulatory immune complexes (CICs) from the host circulation leads to the immunopotentiation as well as generation of antitumor responses in a variety of tumors in rats, cats, dogs and human patients. CICs are the major immunosuppressive factors in tumor bearing host. Protein A (PA) has been extensively used for the removal of these CICs from the sera/plasma of tumor bearers, because PA has the ability to bind with the Fc portion of mammalian immunoglobulins. Previously, we reported for the first time a potent antitumor response by the inoculation of cell free Ehrlich's ascites fluid adsorbed in vitro over PA containing Staphylococcus aureus Cowan I (SAC) in Ehrlich's ascites tumor model. However, there was toxicity associated with this form of therapy in terms of early death of treated animals and the depletion of hepatic glutathione pool as well as phase I biotransformation enzyme and increase in glutathione-S-transferase (GST) activities. In the present investigation, tumor bearing animals were treated intraperitoneally (i.p.) on alternate days for 15 days with adsorbed ascites fluid (ad-ASF) (0.1 ml) and glutathione (GSH) (250 mg/kg body weight) separately. We found that GSH supplementation increases mean survival time of GSH and ad-ASF treated mice up to 37.2 days in comparison with 19.9 days for only ad-ASF treated animals, while percent increase in body weight was found to be not affected by the GSH substitution, which remains significantly lower (P < 0.01) in comparison to the tumor control animals. GSH supplementation causes a significant decrease (P < 0.05) of glutathione-S-transferase and restoration of aniline hydroxylase activity (P < 0.05) and aminopyrine-N-demethylase activity. We have also observed that GSH supplementation does not alter the tumor cell viability and tumor cell counts in ad-ASF treated animals in comparison to only ad-ASF treated animals, which indicates that GSH supplementation does not alter the antitumor effect of the therapy. Treatment of Ehrlich's ascites tumor bearing mice with ad-ASF and glutathione increased their survival, but did not reduce the mortality of animals because of tumor.