Co-administration of immunomodulator tuftsin and liposomised nystatin can combat less susceptible Candida albicans infection in temporarily neutropenic mice

Immune-Boosting Potentiating Properties of Brassica nigra Hydroalcoholic Extract in Cyclophosphamide-Induced Immunosuppression in Rats

The antioxidative and immune-boosting properties of the hydroalcoholic extract of Brassica nigra sprouts in cyclophosphamide-induced immunosuppression in rats were investigated in this study. B. nigra sprouts were prepared in the lab to monitor the bio-changes in bioactive compounds during the sprouting period up to 7 days at 17 ± 1 °C and 90% relative humidity. The total phenolic content (TPC), antioxidant activity (AOA), total flavonoids (TFs), total flavonols (TFLs), and total carotenoids (TCs) were evaluated. Consequently, the identification and quantification of phenolic acids, their derivatives, and flavonoids were carried out using HPLC. Subsequently, the selected BN sprout (6-day-old sprout) was biologically examined, and oxidative stress biomarkers, hematological parameters, immunoglobulins (Igs), and pro-inflammatory and anti-inflammatory cytokines were investigated. An increase in TPC, AOA, TFs, TFLs, and TCs was observed by increasing the sprouting time. The HPLC analysis indicated that the B. nigra seeds contained 10 phenolic acids and 4 flavonoids, predominantly syringic acid and quercetin, respectively. After 3 days, the number of phenolic acids increased to 16, predominantly syringic acid, and the number of flavonoids increased to 7, predominantly quercetin. On the 6th day, 13 phenolic acids were estimated, with the highest being benzoic acid, and 6 flavonoids were estimated, with the highest being quercetin. The greatest rise in phenols was seen on the sixth day of sprouting. These included caffeic acid, chlorogenic acid, cinnamic acid, ferulic acid, coumaric acid, benzoic acid, and rosmarinic acid. Flavonoids such as kaempferol and myricetin increased. The sprouts on day 6 were recorded as having the highest bioactive compounds and AOA content. The selected B. nigra sprouts were examined for antioxidative and immunomodulatory properties in a rat model. Dosing 250 and 500 mg kg-1, the rats exhibited significant improvements in terms of antioxidative stress and the number of white blood cells (WBCs), lymphocytes, and neutrophils in the blood, indicating stimulation of the immune response in a dose-dependent manner. In addition, the production of immune proteins, such as IgG, IgM, and IgA, was enhanced in the blood. Moreover, the 500 mg kg-1 concentration of BN extract stimulated cytokine production in a stronger manner than the 250 mg kg-1 concentration, indicating that the extract significantly increased immune activity. In conclusion, the results indicate that mustard seed extracts have immunosuppressive properties against cyclophosphamide-induced immunosuppression in rats.

Potential of siRNA-Bearing Subtilosomes in the Treatment of Diethylnitrosamine-Induced Hepatocellular Carcinoma

Therapeutics, based on small interfering RNA (siRNA), have demonstrated tremendous potential for treating cancer. However, issues such as non-specific targeting, premature degradation, and the intrinsic toxicity of the siRNA, have to be solved before they are ready for use in translational medicines. To address these challenges, nanotechnology-based tools might help to shield siRNA and ensure its specific delivery to the target site. Besides playing a crucial role in prostaglandin synthesis, the cyclo-oxygenase-2 (COX-2) enzyme has been reported to mediate carcinogenesis in various types of cancer, including hepatocellular carcinoma (HCC). We encapsulated COX-2-specific siRNA in Bacillus subtilis membrane lipid-based liposomes (subtilosomes) and evaluated their potential in the treatment of diethylnitrosamine (DEN)-induced hepatocellular carcinoma. Our findings suggested that the subtilosome-based formulation was stable, releasing COX-2 siRNA in a sustained manner, and has the potential to abruptly release encapsulated material at acidic pH. The fusogenic property of subtilosomes was revealed by FRET, fluorescence dequenching, content-mixing assay, etc. The subtilosome-based siRNA formulation was successful in inhibiting TNF-α expression in the experimental animals. The apoptosis study indicated that the subtilosomized siRNA inhibits DEN-induced carcinogenesis more effectively than free siRNA. The as-developed formulation also suppressed COX-2 expression, which in turn up-regulated the expression of wild-type p53 and Bax on one hand and down-regulated Bcl-2 expression on the other. The survival data established the increased efficacy of subtilosome-encapsulated COX-2 siRNA against hepatocellular carcinoma.

Design of transfersomal nanocarriers of nystatin for combating vulvovaginal candidiasis; A different prospective

The objective of this study was to prepare and evaluate Nystatin (NYS) loaded transfersomes to achieve better treatment of vulvovaginal candidiasis. Nystatin transferosomes were formulated utilizing thin film hydration method. A 3² full factorial design was employed to evaluate the effect of different formulation variables. Two independent variables were chosen; the ratio between lecithin surfactant (X₁) was set at three levels (10-40), and the type of surfactants (X₂) was set at three levels (Span 60, Span 85 and Pluronic F-127). The dependent responses were; entrapment efficiency (Y₁: EE %), vesicles size (Y₂: VS) and release rate (Y₃: RR). Design Expert® software was utilized to statistically optimize formulation variables. The vesicles revealed high NYS encapsulation efficiency ranging from 97.35 ± 0.03 to 98.01 ± 0.20% whereas vesicle size ranged from 194.8 ± 20.42 to 400.8 ± 42.09 nm. High negative zeta potential values indicated good stability of the prepared formulations. NYS release from transfersomes was biphasic and the release pattern followed Higuchi's model. The optimized formulation (F7) exhibited spherical morphology under transmission electron microscopy (TEM). In-vitro and in-vivo antifungal efficiency studies revealed that the optimized formula F7 exhibited significant eradication of candida infestation in comparison to free NYS. The results revealed that the developed NYS transfersomes could be a promising drug delivery system to enhance antifungal efficacy of NYS.

Targeted Drug Delivery Using Tuftsin-bearing Liposomes: Implications in the Treatment of Infectious Diseases and Tumors

Tuftsin, a tetrapeptide (Thr-Lys-Pro-Arg), acts as an immunopotentiating molecule with its ability to bind and activate many immune cells, including macrophages or monocytes, neutrophils and dendritic cells. The specific targeting activity of tuftsin has been further increased by its palmitoylation followed by its incorporation into the lipid bilayer of liposomes. Tuftsin-bearing liposomes (Tuft-liposomes) possess several characteristics that enable them to act as a potential drug and vaccine carriers. Tuft-liposomes-loaded anti-microbial drugs have been shown to be highly effective against many infectious diseases, including tuberculosis, leishmaniasis, malaria, candidiasis and cryptococosis. Moreover, Tuft-liposomes also increased the activity of anticancer drug etoposide against fibrosarcoma in mice. Tuft-liposomes showed the immune-potentiating effect and rejuvenated the immune cells in the leukopenic mice. In addition, antigens encapsulated in Tuftsin-bearing liposomes demonstrated greater immunogenicity by increasing the T cell proliferation and antibody secretion. Keeping into consideration their specific targeting and immunopotentiating effects, Tuft-liposomes may potentially be used as promising drug and vaccine delivery systems.

Coadministration of liposomal methylglyoxal increases the activity of amphotericin B against Candida albicans in leukopoenic mice

In this study, we investigated the therapeutic efficacy of a combination of liposomal amphotericin B (Lip-Amp B) and Methylglyoxal (Lip-MG) against Candida albicans in the leukopoenic mice. The antifungal efficacy of Lip-Amp B or Lip-MG or a combination of Lip-Amp B and Lip-MG was evaluated by the analysis of the survival rate and the fungal load in the treated mice. The immune-stimulatory effect of Lip-MG on macrophages was evaluated by analysing the secretion of proinflammatory cytokines. C. albicans infected mice treated at the doses of 1 and 2 mg/kg of Lip-Amp B showed 20% and 50% survival rates, respectively. Whereas the mice treated with free Amp B at the same doses died within 40 days of treatment. Interestingly, C. albicans infected mice treated with a combination of Lip-Amp B and Lip-MG had 70% survival rate on day 40 postinfection. Moreover, treatment of macrophages with Lip-MG increased their fungicidal activity and the secretion of proinflammatory cytokines, including TNF-α and IL-1β. These findings suggested that co-treatment with Lip-Amp B and Lip-MG had a synergistic effect and could be effective against C. albicans in immunocompromised subjects.

Potential of Methylglyoxal-Conjugated Chitosan Nanoparticles in Treatment of Fluconazole-Resistant Candida albicans Infection in a Murine Model

Background

Fungal infections are becoming more prevalent and threatening because of the continuous emergence of azole-resistant fungal infections. The present study was aimed to assess the activity of free Methylglyoxal (MG) or MG-conjugated chitosan nanoparticles (MGCN) against fluconazole-resistant Candida albicans.

Materials and Methods

A novel formulation of MGCN was prepared and characterized to determine their size, shape and polydispersity index. Moreover, the efficacy of fluconazole or MG or MGCN was determined against intracellular C. albicans in macrophages and the systematic candidiasis in a murine model. The safety of MG or MGCN was tested in mice by analyzing the levels of hepatic and renal toxicity parameters.

Results

Candida albicans did not respond to fluconazole, even at the highest dose of 20 mg/kg, whereas MG and MGCN effectively eliminated C. albicans from the macrophages and infected mice. Mice in the group treated with MGCN at a dose of 10 mg/kg exhibited a 90% survival rate and showed the lowest fungal load in the kidney, whereas the mice treated with free MG at the same dose exhibited 50% survival rate. Moreover, the administration of MG or MGCN did not induce any liver and kidney toxicity in the treated mice.

Conclusion

The findings of the present work suggest that MGCN may be proved a promising therapeutic formulation to treat azole-resistant C. albicans infections.

Chemotherapeutic potential of curcumin-bearing microcells against hepatocellular carcinoma in model animals

Curcumin (diferuloylmethane) is found in large quantities in the roots of Curcuma longa. It possesses strong antioxidant and anti-inflammatory properties, and inhibits chemically-induced carcinogenesis in the skin, forestomach, colon, and liver. Unfortunately, the poor bioavailability and hydrophobicity of curcumin pose a major hurdle to its use as a potent anticancer agent. To circumvent some of these problems, we developed a novel, dual-core microcell formulation of curcumin. The encapsulation of curcumin in microcells increases its solubility and bioavailability, and facilitates slow release kinetics over extended periods. Besides being safe, these formulations do not bear any toxicity constraints, as revealed by in vitro and in vivo studies. Histopathological analysis revealed that curcumin-bearing microcells helped in regression of hepatocellular carcinoma and the maintenance of cellular architecture in liver tissue. Free curcumin had a very mild effect on cancer suppression. Empty (sham) microcells and microparticles failed to inhibit cancer cells. The novel curcumin formulation was found to suppress hepatocellular carcinoma efficiently in Swiss albino mice.

Potential use of liposomal diallyl sulfide in the treatment of experimental murine candidiasis

In the present study, we evaluated the potential of a liposomal formulation of the garlic oil component DAS (diallyl sulfide) in treating disseminated infection caused by the intracellular opportunistic pathogen Candida albicans in experimental mice. The PC (phosphatidylcholine) liposomal formulation of DAS was evaluated for size, ζ-potential, entrapment efficiency and release kinetics, toxicity etc. For therapeutic studies, mice were challenged with intravenous infection dosage of 107 blastospores of C. albicans followed by treatment with various doses of DAS formulations [12 and 6 mg/kg b.w. (body mass)] three times, on alternative days. The antifungal efficacy of liposomal DAS was assessed on the basis of survival of treated mice as well as the residual fungal load in vital organs like liver and spleen of mice. The results of the present study showed that treatment with DAS-bearing liposomes (12 mg/kg b.w.) resulted in the highest survival rate in animals. Liposomal DAS also significantly decreased residual fungal load in vital organs of experimental animals compared with the free form of DAS. The liposomal DAS was also found to be free of toxic manifestations as revealed by the erythrocyte lysis test and liver/kidney function tests. The results of the present study established that the antifungal activity of DAS, a poorly soluble compound, can be enhanced by the incorporation of it into liposomes. Further studies and optimizations are needed to build upon the promising findings of this study to enable the development of an effective plant-derived antifungal formulation that can provide an alternative to currently available antifungal drugs.

Efficacy of niosomal formulation of diallyl sulfide against experimental candidiasis in Swiss albino mice

Aim: We developed a niosomal formulation of diallyl sulfide (DAS), a garlic oil component, and evaluated its efficacy against experimental candidiasis in mice. Methods: DAS-bearing niosomes prepared from sorbitan monoester surfactants were evaluated for drug entrapment efficiency, release kinetics, toxicity, size, ζ-potential and others. Mice challenged with Candida albicans were treated with various DAS formulations. The efficacy of the formulations was assessed on the basis of reduction in mortality and decrease in residual fungal load in vital organs, such as liver and spleen, of treated mice. Results: Niosomal DAS (12 mg/kg body weight) significantly reduced fungal load and mortality in treated animals compared with the free form of DAS. Niosomal DAS was also found to be free of toxic manifestations, as revealed by histopathological studies, as well as liver/kidney function tests. Conclusion: Incorporation of DAS in niosomes enhances its antifungal efficacy. Further studies are needed to optimize the current findings to develop an efficient nature-derived alternative antifungal therapeutic strategy.

Immunomodulator tuftsin increases the susceptibility ofCryptococcus neoformansto liposomal amphotericin B in immunocompetent BALB/c mice

The co-administration of immunomodulators and antibiotics has been proved very successful for treatment of opportunistic infectious diseases. In the present study, we evaluated the combination of liposomal amphotericin B (lip-Amp B) and immunomodulator tuftsin to cure Cryptococcus neoformans infection in BALB/c mice. Mice infected with C. neoformans were treated with Amp B deoxycholate and tuftsin free or tuftsin-loaded Amp B liposomes. The results of the present study demonstrated higher efficacy of tuftsin-loaded Amp B liposomes against experimental murine cryptococcosis, in terms of enhanced survival rate and reduced fungal burden in organs (lungs and brain) of the treated mice. Interestingly, pre-treatment of mice with liposomal tuftsin before challenging them with the C. neoformans infection resulted in 100% survival of the treated animals followed by treatment with lip-Amp B. Immunomodulator-based therapy seems likely to be more beneficial for treatment of fungal infectious diseases.

Safety, efficacy and pharmacokinetics of tuftsin-loaded nystatin liposomes in murine model

Present study was performed to evaluate the efficacy, toxicity and pharmacokinetics of antifungal drug nystatin incorporated in immunomodulator tuftsin-bearing liposomes. In vitro toxicity of free nystatin and nystatin incorporated in tuftsin-free or tuftsin-loaded liposomes was assessed by incubation of nystatin formulations with human erythrocytes. The toxicity profile of free nystatin and liposomal formulations of nystatin with or without tuftsin was also analyzed by monitoring the level of blood urea nitrogen (BUN) and serum creatinine in the treated BALB/c mice. The results of the present work showed that tuftsin-loaded nystatin liposomes like conventional nystatin liposomes exerted less toxicity to human erythrocytes as compared with free nystatin. Moreover, mice treated with tuftsin-loaded nystatin liposomes showed insignificant elevation in the biochemical values of serum creatinine and blood urea. The stability of nystatin liposomes upon incorporation of tuftsin was evaluated by monitoring the leakage of the entrapped drug in human serum. Tuftsin-loaded liposomes held nystatin for longer duration in the presence of serum than identical nystatin liposomes without tuftsin. Pharmacokinetics of the both tuftsin-free or tuftsin-loaded liposomal formulations nystatin was analyzed by determining the level of nystatin in the systemic circulation of mice at different time points. Mice injected with tuftsin-loaded nystatin liposomes showed higher level of the drug in the systemic circulation compared with those treated with conventional nystatin liposomes. The efficacy of tuftsin-loaded nystatin liposomes against A. fumigatus was evaluated by assessing the fungal burden in the lungs of treated mice. Treatment with tuftsin-loaded nystatin liposomes was most effective in eliminating fungal burden from lung tissues of infected mice compared to those treated with free nystatin or nystatin liposomes without tuftsin. The immunopotentiating activity, increased stability and less toxicity of tuftsin-incorporated nystatin liposomes, supports the idea for its prophylactic and therapeutic use in the clinical setting.

Tuftsin augments antitumor efficacy of liposomized etoposide against fibrosarcoma in Swiss albino mice

Anticancer drugs are generally plagued by toxic manifestations at doses necessary for control of various forms of cancer. Incorporating such drugs into liposomes not only reduces toxicity but also enhances the therapeutic index. Some antioxidants and potent immunomodulators have also been shown to impart significant antitumor activity presumably by nonspecific activation of the host immune system. In the present study, we evaluated augmentation of the antitumor activity of etoposide (ETP) by the immunomodulator tuftsin in Swiss albino mice with fibrosarcoma. The efficacies of the free form of ETP, liposomized ETP (Lip-ETP), and tuftsin-bearing liposomized ETP (Tuft-Lip-ETP) formulations were evaluated on the basis of tumor regression, effect on expression level of p53wt and p53mut, and survival of the treated animals. Tuft-Lip-ETP, when administered at a dosage of 10 mg/kg body weight/day for five days, significantly reduced tumor volume, delayed tumor growth, and also up-regulated the expression of p53wt. In contrast, although Lip-ETP delayed tumor growth, it did not decrease tumor size. The results of the present study suggest that tuftsin incorporation in drug-loaded liposomes is a promising treatment strategy for various forms of cancers, including fibrosarcoma.

Tuftsin augments antitumor efficacy of liposomized etoposide against fibrosarcoma in Swiss albino mice

Anticancer drugs are generally plagued by toxic manifestations at doses necessary for control of various forms of cancer. Incorporating such drugs into liposomes not only reduces toxicity but also enhances the therapeutic index. Some antioxidants and potent immunomodulators have also been shown to impart significant antitumor activity presumably by nonspecific activation of the host immune system. In the present study, we evaluated augmentation of the antitumor activity of etoposide (ETP) by the immunomodulator tuftsin in Swiss albino mice with fibrosarcoma. The efficacies of the free form of ETP, liposomized ETP (Lip-ETP), and tuftsin-bearing liposomized ETP (Tuft-Lip-ETP) formulations were evaluated on the basis of tumor regression, effect on expression level of p53wt and p53mut, and survival of the treated animals. Tuft-Lip-ETP, when administered at a dosage of 10 mg/kg body weight/day for five days, significantly reduced tumor volume, delayed tumor growth, and also up-regulated the expression of p53wt. In contrast, although Lip-ETP delayed tumor growth, it did not decrease tumor size. The results of the present study suggest that tuftsin incorporation in drug-loaded liposomes is a promising treatment strategy for various forms of cancers, including fibrosarcoma.

Incorporation of amphotericin B in tuftsin-bearing liposomes showed enhanced efficacy against systemic cryptococcosis in leucopenic mice

OBJECTIVES

The role of the immunomodulator tuftsin in enhancing the antifungal activity of liposomal amphotericin B against Cryptococcus neoformans in leucopenic mice was assessed.

METHODS

In the present study, we investigated the antifungal activity of amphotericin B liposomes with tuftsin grafted on the surface. Mice were treated with free amphotericin B as well as liposomal formulations after C. neoformans infection. For prophylactic studies, mice were pre-treated with liposomal tuftsin (50 microg/mL) for three consecutive days prior to C. neoformans infection (7 x 10(5) cfu/mouse). Chemotherapy, with tuftsin-free and tuftsin-bearing amphotericin B liposomes, was started 24 h post C. neoformans infection. The role of tuftsin in immunoaugmentative therapy was assessed by survival and cfu of treated mice.

RESULTS

Amphotericin B entrapped in tuftsin-bearing liposomes showed increased anticryptococcal activity in the murine model. Moreover, tuftsin pre-treatment further augmented the antifungal activity of liposomal amphotericin B in leucopenic mice. Incorporation of tuftsin in liposomes resulted in increased anticryptococcal activity of liposomal amphotericin B compared with amphotericin B deoxycholate and conventional liposomal amphotericin B formulations.

CONCLUSIONS

The enhanced anticryptococcal activity of amphotericin B in tuftsin-liposomes can be attributed to the immune-stimulating property of tuftsin. Tuftsin activates the key immune cells, due to the presence of its receptors on macrophages and neutrophils, for a better fight against pathogens. Simultaneous liposome-mediated delivery of amphotericin B to the site of infection kills the pathogens more effectively.

Tuftsin-mediated immunoprophylaxis against an isolate ofAspergillus fumigatusshows less in vivo susceptibility to amphotericin B

In the present study, we evaluated the immunopotentiating efficacy of tuftsin against experimental murine aspergillosis in both normal and immunodebilitant BALB/c mice. The animals were challenged with an isolate of Aspergillus fumigatus (1x10(8) cfu/mouse) that was showing less susceptibility to lower doses of amphotericin B in murine animal model. Co-administration of the immunomodulator tuftsin and liposomised-amphotericin B was found to be highly effective in the treatment of systemic infection of A. fumigatus in both immunocompetent and leukopenic mice. Moreover, pre-treatment of mice with liposomised-tuftsin prior to challenging them with A. fumigatus infection and subsequent treatment with tuftsin-bearing liposomised-amphotericin B was found to be extremely efficient in successful elimination of fungal pathogen. In another set of experiments, tuftsin-mediated antigen-specific memory antibody response was also assessed by immunizing the animals with A. fumigatus cytosolic antigen. The animals that received a booster 150 days after the first immunization with tuftsin-liposomes-antigen showed more resistance to A. fumigatus infection in comparison with the naïve animals.