Organogel mediated co-delivery of nisin and 5-fluorouracil: a synergistic approach against skin cancer.

AIM: The present study aimed to develop topical combinatorial therapy of nisin and 5-fluorouracil in a single nanosized formulation against skin cancer. METHODS: Nisin and 5-fluorouracil were encapsulated in an organogel system (NF-OG) and investigated for morphology, physicochemical properties, cytotoxicity, encapsulation and release. NF-OG was evaluated against DMBA/TPA murine skin cancer in terms of tumour statistics, histoarchitecture, TUNEL and M1/M2 macrophages. RESULTS: The optimised NF-OG formulation exhibited particle size of 185.1 ± 11.24 nm, zeta potential of -7.93 ± 0.60 mV, offered substantial drug loading and temporal release. NF-OG therapy led to improved cytotoxicity of nisin and 5-FU against B16-F10 cells, significant decrease in tumour volume (84.983 mm3) in treated group as compared to untreated group (490.482 mm3) accompanied by restoration of histoarchitecture and repolarization of macrophages. CONCLUSION: The study yielded a promising delivery system exhibiting potent anticancer activity and forms the bases for further applications in clinical settings.

Antimicrobial peptides against colorectal cancer-a focused review.

Despite recent advances in the treatment of colorectal cancer (CRC), low patient survival rate due to emergence of drug resistant cancer cells, metastasis and multiple deleterious side effects of chemotherapy, is a cause of public concern globally. To negate these clinical conundrums, search for effective and harmless novel molecular entities for the treatment of CRC is an urgent necessity. Since antimicrobial peptides (AMPs) are part of innate immunity of living beings, it is quite imperative to look for essential attributes of these peptides which may contribute to their effectiveness against carcinogenesis. Once identified, those characteristics can be suitably modified using several synthetic and computational techniques to further enhance their selectivity and pharmacokinetic profiles. Hence, this review analyses scientific reports describing the antiproliferative action of AMPs derived from several sources, particularly focusing on various colon cancer in vitro/in vivo investigations. On perusal of the literature, it appears that AMPs based therapeutics would definitely find special place in CRC therapy in future either alone or as an adjunct to chemotherapy provided some necessary alterations are made in their natural structures to make them more compatible with modern clinical practice. In this context, further in-depth research is warranted in adequate in vivo models.

Nisin loaded carbopol gel against Pseudomonas aeruginosa infected third-degree burns: A therapeutic intervention.

The emergence of multidrug resistant strains of Pseudomonas aeruginosa necessitates the exploration of novel therapeutic intervention (s). The present study aimed to develop a nisin loaded carbopol gel formulation (NLCG) and explore its therapeutic efficacy against P. aeruginosa infected burn wounds. The formulation was prepared using Carbopol 940 as a polymer and characterized in terms of its appearance, stability, pH, rheology, spreadability, release, and permeation profiles. Disc diffusion assay and field emission scanning electron microscopy were carried out to establish in vitro antibacterial activity while the in vitro cytotoxicity was evaluated by hemolytic and trypan blue exclusion assay. Furthermore, in vivo efficacy was investigated by developing P. aeruginosa infected third-degree murine burn wound model followed by evaluation of parameters like bacterial loads, skin restoration, histopathological architecture, levels of hydroxyproline, myeloperoxidase and cytokines. Our studies yielded a stable formulation with pH, viscosity and drug release flux values as 6.5 ± 0.02, 382.4 p and 160.55 ± 3.64 µg h-1  cm-2 , respectively. Approximately, 84.02 ± 1.63% of nisin was found to permeate into murine skin, further, affirmed by confocal microscopic observations. Interestingly, no in vitro cytotoxicity of NLCG (to erythrocytes and/or to peritoneal macrophages) could be observed. The log units decrease (s) in CFUs of Pseudomonas in skin were found to be 1.5137, 4.2257, 6.456 after 12, 24 and 72 h of topical gel therapy, respectively. Percentage wound closure, tensile strength, histological, and scanning electron microscopic studies further provided a healing evidence with skin showing restoration of the epithelium. The gel therapy also led to a significant modulation (p ≤ 0.05) in hydroxyproline content, myeloperoxidase levels, and serum levels of IL-1, IL-10, and TNF-α. Our formulation revealed anti-Pseudomonas, wound healing, and immunomodulatory efficacy of NLCG. Further investigations are warranted to determine the underlying mechanism (s) of these displayed antibacterial and immunomodulatory effects.

Doxorubicin-Loaded Mixed Micelles for the Effective Management of Skin Carcinoma: In Vivo Anti-Tumor Activity and Biodistribution Studies.

Skin cancer is an alarming concern due to increased radiation and chemical exposure. Doxorubicin is a drug prescribed for various cancers by parenteral route. Apart from the pharmaceutical challenge of being a biopharmaceutical classification system (BCS) Class III drug, the side effects of doxorubicin are also a great concern. With an aim to enhance its safety and bioavailability, a phospholipid-based micellar system was developed. The developed nanometric and symmetric carriers not only offered substantial drug loading, but also offered a temporal drug release for longer durations. The pH-dependent drug release assured the spatial delivery at the target site, without loss of drug in the systemic circulation. The cancer cell toxicity studies along with the in vivo anti-tumor studies established the superior efficacy of the developed system. The blood profile studies and the biochemical estimations confirmed the safety of the developed nanocarriers. Lesser amount of drug was available for the microsomal degradation, as inferred by the biodistribution studies. The findings provide a proof of concept for the safer and effective doxorubicin delivery employing simple excipients like phospholipids for the management of skin cancer.

Augmented therapeutic efficacy of 5-fluorouracil in conjunction with lantibiotic nisin against skin cancer.

Chemotherapy, a gold standard for treating most of the cancers, involves drastic side-effects and multidrug resistance. An attractive alternative is development of combination therapy employing antimicrobial peptides with chemotherapeutic drugs. In vivo studies: Anti-cancer therapeutic efficacy of 5-fluororuacil (5-FU) in conjunction with nisin (50 mg/kg body weight) was evaluated against murine skin cancer, in terms of tumor biostatistics, histopathology, electron microscopy, infrared spectroscopy and transcriptional studies. In vitro studies: Dose and time dependent cytotoxicity of agents were assessed against A431 cell line using MTT assay, LDH assay and acridine orange/ethidium bromide dual staining. Significant percentage decrease(s) in mean tumor volume and tumor burden were observed in nisin+ 5-FU combination treated groups as compared to alone treated groups. Histoarchitecture of treated skins demonstrated restoration towards normal skin tissue (being highest in the combination group). Modulation of apoptotic, angiogenic and proliferative genes were observed in treated groups. IC50 of combination was found to be 2 µg/ml as compared to nisin alone (32µg/ml) and 5-FU alone (16µg/ml) with combination index of 0.188. Dual staining showed that rate of induction of apoptosis was higher in the combination group as compared to single agents. Nisin and 5-FU in combination were found to be synergistic both in vivo and in vitro.

Management of Staphylococcus Mediated Systemic Infection by Enhancing the Resurging Activity of Co-trimoxazole in Presence of Cryptdin-2.

Resurgence of sensitivity of the antibiotics, to which the pathogen had developed resistance in the past, requires special attention for strengthening the reservoir of antimicrobial compounds. Reports in the recent past have suggested that co-trimoxazole (COT) has regained its activity against methicillin resistant Staphylococcus aureus (MRSA). The present study exploited the use of COT in the presence of an antimicrobial peptide (AMP), cryptdin-2 (a murine Paneth cell alpha defensin), in order to reduce the selective pressure of the antibiotic on the pathogen. In vitro antibacterial activity and in vivo efficacy of the combination was ascertained against MRSA induced systemic infection using a murine model. Observations of the present study might help in restoring the regained activity of conventional antibiotics, such as COT, when used in combination with novel antimicrobial molecules like AMPs. This might prove as a viable strategy to eliminate the chances of re-occurrence of resistance due to their multi-prong targeting and synergistically combating infections caused by these resistant pathogens.

Effect of nisin and doxorubicin on DMBA-induced skin carcinogenesis--a possible adjunct therapy.

In view of the emergence of multidrug-resistant cancer cells, there is a need for therapeutic alternatives. Keeping this in mind, the present study was aimed at evaluating the synergism between nisin (an antimicrobial peptide) and doxorubicin (DOX) against DMBA-induced skin carcinogenesis. The possible tumoricidal activity of the combination was evaluated in terms of animal bioassay observations, changes in hisotological architecture of skin tissues, in situ apoptosis assay (TUNEL assay) and in terms of oxidant and antioxidant status of the skin tissues. In vivo additive effect of the combination was evidenced by larger decreases in mean tumour burden and tumour volume in mice treated with the combination than those treated with the drugs alone. Histological observations indicated that nisin-DOX therapy causes chromatin condensation and marginalisation of nuclear material in skin tissues of treated mice which correlated well with the results of TUNEL assay wherein a marked increase in the rate of apoptosis was revealed in tissues treated with the combination. A slightly increased oxidative stress in response to the adjunct therapy as compared to dox-alone-treated group was revealed by levels of lipid peroxidation (LPO) and nitrite generation in skin tissue-treated mice. An almost similar marginal enhancement in superoxide dismutase levels corresponding with a decrease in catalase activity could also be observed in nisin + DOX-treated groups as compared to nisin and dox-alone-treated groups. These results point towards the possible use of nisin as an adjunct to doxorubicin may help in developing alternate strategies to combat currently developing drug resistance in cancer cells.

Nisin/ß-lactam adjunct therapy against Salmonella enterica serovar Typhimurium: a mechanistic approach.

OBJECTIVES: Multidrug resistance exhibited by Salmonella strains has proved to be a big hurdle in the development of an effective anti-Salmonella therapy. In this context, we had previously demonstrated strong synergism of nisin/ceftriaxone and nisin/cefotaxime combinations against Salmonella enterica serovar Typhimurium. However, the mechanism remained unexplored. The present study was therefore planned in order to evaluate the underlying mechanisms responsible for the synergistic effect of nisin in combination with these ß-lactam antibiotics against serovar Typhimurium. METHODS: A membrane permeabilization assay along with pulse labelling studies were performed to confirm the ability of the combinations to permeabilize the bacterial membrane and to verify their effects on macromolecule synthesis. Additionally, analysis of peroxidative liver damage was performed and levels of nitric oxide, antioxidant enzymes, tumour necrosis factor-α and nuclear factor-κB were also measured. RESULTS: 1-N-phenylnapthylamine (NPN) uptake assay results confirmed a permeabilization-dependent mechanism, as NPN was taken up by treated cells in a time- and concentration-dependent manner, indicating that the combination influenced membrane permeability. Likewise, dose- and time-dependent inhibition of DNA, RNA and protein synthesis in the presence of both the combinations was observed. Interestingly, synergistic results inferred from in vivo assays confirmed the immuno-modulatory effects of the combinations in the treated mice. CONCLUSIONS: Nisin/ceftriaxone and nisin/cefotaxime combinations exert their antibacterial activity against Salmonella by multiple modes of action that involve membrane permeabilization, inhibition of DNA, RNA and protein synthesis and direct immuno-modulatory activity.

Human Intestinal Defensin 5 Ameliorates the Sensitization of Colonic Cancer Cells to 5-Fluorouracil.

BACKGROUND AND AIM: The increasing dilemma of multidrug-resistant cancer cells in response to currently available chemotherapeutic drugs and their associated side effect(s), calls for the investigation of alternative anticancer advances and molecules. Therefore, the present study aimed to elucidate the combinatorial potential against colon cancer of human defensin 5 in combination with 5-fluorouracil (5-FU), and against 5-FU resistant colon tumor cells. METHODS: The in vivo combinatorial potential of HD-5 with 5-FU was elucidated in terms of tumor morphometrics, apoptosis assay, surface morphology histology of the colon(s), and transcriptional alterations. Changes in membrane dynamics with mucin expression were evaluated by fluorescence microscopy and histochemistry. The in vitro activity of the peptide/drug conjunction was explored by phase contrast microscopy, MTT, LDH assay, and AO/EtBr staining. Chemoresistance to 5-FU was determined by phase contrast microscopy, MTT assay, annexin V-FITC/PI flow cytometry, and MDR-1, Bak, and Bax expression. RESULTS: In vivo decreases in tumor parameters, with a marked increase in apoptosis and neutrophil infiltrations indicated restoration of normal architecture with improved mucin content in the treated colons. This happened with substantial changes in key molecular markers of the intrinsic apoptotic cascade. Membrane dynamics revealed that peptides and chemotherapeutic drugs could bind to cancerous cells by taking advantage of altered levels of membrane fluidity. CONCLUSION: Peptide treatment of drug-resistant Caco-2 cells promotes enhanced 5-FU uptake, in contrast to when cells were treated with 5-FU alone. Hence, HD-5 as an adjunct to 5-FU, exhibited strong cancer cell killing even against 5-FU-resistant tumorigenic cells.

Lipid-based microemulsion gel for the topical delivery of methotrexate: an optimized, rheologically acceptable formulation with conducive dermatokinetics.

In the present study, we have formulated a methotrexate (MTX)-loaded microemulsion topical gel employing quality-by-design optimization. The optimized lipid-based microemulsion was incorporated into a 2% carbopol gel. The prepared formulation was characterized for micromeritics, surface charge, surface morphology, conductivity studies, rheology studies, texture analysis/spreadability, drug entrapment, and drug loading studies. The formulation was further evaluated for drug release and release kinetics, cytotoxicity assays, drug permeation and drug retention studies, and dermatokinetics. The developed nanosystem was not only rheologically acceptable but also offered substantial drug entrapment and loading. From drug release studies, it was observed that the nanogel showed higher drug release at pH 5.0 compared to plain MTX, plain gel, and plain microemulsion. The developed system with improved dermatokinetics, nanometric size, higher drug loading, and enhanced efficacy towards A314 squamous epithelial cells offers a huge promise in the topical delivery of methotrexate.

Strategic Approaches to Improvise Peptide Drugs as Next Generation Therapeutics.

In recent years, the occurrence of a wide variety of drug-resistant diseases has led to an increase in interest in alternate therapies. Peptide-based drugs as an alternate therapy hold researchers' attention in various therapeutic fields such as neurology, dermatology, oncology, metabolic diseases, etc. Previously, they had been overlooked by pharmaceutical companies due to certain limitations such as proteolytic degradation, poor membrane permeability, low oral bioavailability, shorter half-life, and poor target specificity. Over the last two decades, these limitations have been countered by introducing various modification strategies such as backbone and side-chain modifications, amino acid substitution, etc. which improve their functionality. This has led to a substantial interest of researchers and pharmaceutical companies, moving the next generation of these therapeutics from fundamental research to the market. Various chemical and computational approaches are aiding the production of more stable and long-lasting peptides guiding the formulation of novel and advanced therapeutic agents. However, there is not a single article that talks about various peptide design approaches i.e., in-silico and in-vitro along with their applications and strategies to improve their efficacy. In this review, we try to bring different aspects of peptide-based therapeutics under one article with a clear focus to cover the missing links in the literature. This review draws emphasis on various in-silico approaches and modification-based peptide design strategies. It also highlights the recent progress made in peptide delivery methods important for their enhanced clinical efficacy. The article would provide a bird's-eye view to researchers aiming to develop peptides with therapeutic applications.

Anticancer therapeutic potential of 5-fluorouracil and nisin co-loaded chitosan coated silver nanoparticles against murine skin cancer.

Cancer is a major health concern worldwide as conventional treatment modalities face several limitations such as drug resistance, toxicity etc. To overcome such deficits, combination therapy involving anticancer peptides and chemodrugs is being considered as an attractive strategy. Therefore, present study developed, characterized and evaluated the anticancer potential of a single nanoconstruct comprising of oligomeric chitosan coated silver nanoparticles co-loaded with nisin and 5-florouracil (5-FU/nisin-CHI-AgNPs) against DMBA/TPA-induced murine skin cancer. It was fabricated using wet reduction method of silver salt to form silver nanoparticles followed sequentially by oligomeric chitosan coating, nisin conjugation to deacetylated units of chitosan oligomers (EDC/NHS chemistry) and physical loading of 5-FU. Biophysical characterisation studies revealed that the developed nanoconstruct had UV-visible absorption maxima at 420 nm, zeta potential of + 32.90 mV and 72.39 nm particle size (TEM analysis). In vivo anticancer therapeutic potential was assessed in terms of tumor statistics, histopathological, scanning electron microscopic analyses and testing oxidant/antioxidant status which exhibited marked reduction both in mean tumor volume (68.34 %) and mean tumor burden (82.39 %); restored skin histoarchitecture and improved oxidant/antioxidant status. Interestingly, anticancer therapeutic potential of nisin and 5-florouracil was found to be enhanced in vivo when bound on single composite nanoconstruct. The study forms a basis for developing synergetic single platforms against variety of cancers.

Multidrug resistance crisis during COVID-19 pandemic: Role of anti-microbial peptides as next-generation therapeutics.

The decreasing effectiveness of conventional drugs due to multidrug-resistance is a major challenge for the scientific community, necessitating development of novel antimicrobial agents. In the present era of coronavirus 2 (COVID-19) pandemic, patients are being widely exposed to antimicrobial drugs and hence the problem of multidrug-resistance shall be aggravated in the days to come. Consequently, revisiting the phenomena of multidrug resistance leading to formulation of effective antimicrobial agents is the need of the hour. As a result, this review sheds light on the looming crisis of multidrug resistance in wake of the COVID-19 pandemic. It highlights the problem, significance and approaches for tackling microbial resistance with special emphasis on anti-microbial peptides as next-generation therapeutics against multidrug resistance associated diseases. Antimicrobial peptides exhibit exceptional mechanism of action enabling rapid killing of microbes at low concentration, antibiofilm activity, immunomodulatory properties along with a low tendency for resistance development providing them an edge over conventional antibiotics. The review is unique as it discusses the mode of action, pharmacodynamic properties and application of antimicrobial peptides in areas ranging from therapeutics to agriculture.

Design, characterization and structure-function analysis of novel antimicrobial peptides based on the N-terminal CATH-2 fragment.

The emergence of multidrug resistance coupled with shrinking antibiotic pipelines has increased the demand of antimicrobials with novel mechanisms of action. Therefore, researchers across the globe are striving to develop new antimicrobial substances to alleviate the pressure on conventional antibiotic therapies. Host-Defence Peptides (HDPs) and their derivatives are emerging as effective therapeutic agents against microbial resistance. In this study, five analogs (DP1-5) of the N-terminal (N-15) fragment of CATH-2 were designed based on the delicate balance between various physicochemical properties such as charge, aliphatic character, amphipathicity and hydrophobicity. By means of in-silico and in-vitro studies a novel peptide (DP1) with the sequence "RFGRFLRKILRFLKK" was found to be more effective and less toxic than the N-terminal CATH-2 peptide. Circular dichroism spectroscopy and differential scanning calorimetry were applied for structural insights. Antimicrobial, haemolytic, and cytotoxic activities were also assessed. The resulting peptide was characterized by low cytotoxicity, low haemolytic activity, and efficient anti-microbial activity. Structurally, it displayed strong helical properties irrespective of the solvent environment and was stable in membrane-mimicking environments. Taken together, the data suggests that DP1 can be explored as a promising therapeutic agent with possible clinical applications.

In vitro and in vivo synergistic effects of cryptdin 2 and ampicillin against Salmonella.

In view of the emergence of multidrug-resistant Salmonella strains, there is a need for therapeutic alternatives. To reduce the dose of antibiotic required in order to decrease the associated side effects, the present study was aimed at evaluating the synergism between cryptdin 2 (a Paneth cell antimicrobial peptide) and ampicillin (Amp) against Salmonella enterica serovar Typhimurium. The synergy was evaluated in terms of the fractional bactericidal concentration (FBC) index, time-kill assay results (in vitro), macrophage functions, i.e., intracellular killing, lipid peroxidation, superoxide dismutase activity, and generation of nitrite (ex vivo), and decreases in CFU of salmonellae in livers, spleens, and small intestines of infected mice treated with cryptdin 2 and/or Amp (in vivo). In vitro synergism between the two agents was observed on the basis of the FBC index and time-kill assays. When the agents were used in combination, ex vivo studies revealed an enhanced effect on macrophage functions, particularly exhibiting a synergetic effect in terms of SOD levels. In vivo synergy was indicated by larger log unit decreases in all target organs of mice treated with the combination than those for the drugs used alone. These results point toward the possible use of cryptdin 2 as an adjunct to ampicillin and may help in developing alternate strategies to combat Salmonella infections.

Effect of L. plantarum cell-free extract and co-trimoxazole against Salmonella Typhimurium: a possible adjunct therapy.

BACKGROUND: Frequent and indiscriminate use of antibiotics has led to the development of multi-drug resistant bacterial strains. It necessitates the exploitation of alternative therapeutic strategies. In order to reduce the dose of antibiotic required and to decrease the associated side effects, the present study was aimed at evaluating the synergism, if any, between a conventional antibiotic, co-trimoxazole (CTZ)) and cell free supernatant (CFS) of a probiotic (L. plantarum) against S. Typhimurium NCTC 74. This antimicrobial combination was selected on the basis of antibiotic susceptibility pattern of Salmonella and L. plantarum. METHODS: The synergy was evaluated in terms of size of zone of inhibition, fractional inhibitory concentration index, time-kill assay (in-vitro) as well as macrophage functions (ex-vivo). RESULTS: The concentration producing the same or higher antibacterial effect (size of zone of inhibition) was reduced to half when both the agents were used in combination with respect to the concentrations required when used separately. CTZ and CFS exhibited synergetic activity against Salmonella by checkerboard microtitre test and the time-kill test. Ex-vivo studies demonstrated a significantly higher intracellular killing of bacteria by macrophages treated with CFS (80 AU/ml) + (CTZ) (2 µg/ml) as compared to when treated with both separately at higher concentrations. Significant reduction in the extent of lipid peroxidation and nitrite levels generated by macrophages in presence of CFS and CTZ, in conjunction, further substantiated the synergistic efficacy of the combination. CONCLUSIONS: The antimicrobial efficacy of this combination indicates that it may serve as the basis in developing alternative strategies to combat Salmonella infections.

Potential of 1-(1-napthylmethyl)-piperazine, an efflux pump inhibitor against cadmium-induced multidrug resistance in Salmonella enterica serovar Typhi as an adjunct to antibiotics.

This study was focused on elucidating inhibition of antibiotic efflux mechanism of cadmium adapted (CdA) Salmonella Typhi Ty2 cells. Herein, upregulated expression of efflux genes (acrB, tolC) and their regulators (soxS, marA) was observed in CdA Ty2 cells by qRT-PCR. The pathogen further elevated the expression of these genes even in the presence of three efflux pump inhibitors (EPIs), i.e., Phe-Arg-ß-naphthylamide, 1-(1-naphthyl-methyl)piperazine, and 5-hydroxy-2-methyl-1,4-naphthoquinone, perhaps by sensing the pressure of the latter in addition to cadmium stress. Interaction of different EPIs with efflux pumps of CdA Ty2 cells was confirmed using ethidium bromide (EtBr) accumulation and efflux assay. All the EPIs could cause retention of EtBr which was indicated by increased fluorescence units. Considering this potential of EPIs, retention of antibiotics was evaluated in CdA Ty2 cells wherein EPIs were used in combination with selected antibiotics (instead of EtBr). A decrease in the effective concentration of antibiotics was observed. This was further validated using the clinical isolates. The data revealed the efficiency of EPIs as they could inhibit the efflux potential of even the overexpressed efflux pumps. Thus, combination of EPI(s)-antibiotics may be exploited in future as one of the strategies for combating metal induced antibiotic resistance.

Cryptdin-2: a novel therapeutic agent for experimental Salmonella Typhimurium infection.

OBJECTIVES: Salmonella infections represent a major health hazard and have been responsible for a number of epidemics. In view of the emergence of multidrug-resistant Salmonella strains, there is a need for therapeutic alternatives. The purpose of this study was to evaluate the therapeutic potential of cryptdin-2 (a Paneth cell antimicrobial peptide) against Salmonella infection. METHODS: The bactericidal activity of cryptdin-2 against Salmonella enterica serovar Typhimurium NCTC74 was evaluated in vitro, ex vivo and in vivo on the basis of cfu enumeration. RESULTS: The MBC of cryptdin-2 for Salmonella Typhimurium was found to be 19 mg/L. The ex vivo study demonstrated significantly higher intracellular killing of the bacteria by macrophages treated with cryptdin-2 as compared with untreated macrophages. Treatment of infected mice with cryptdin-2 resulted in significant clearance of Salmonella from livers, spleens and intestines. CONCLUSIONS: The therapeutic efficacy of cryptdin-2 suggests that it may be a promising option to combat Salmonella infections or at least may act as an adjunct to conventional antibiotics.

Anticancer potential of human intestinal defensin 5 against 1, 2-dimethylhydrazine dihydrochloride induced colon cancer: A therapeutic approach.

The escalating predicament of multidrug resistant cancer cells and associated side effects of conventional chemotherapy necessitates the exploration of alternative anticancer therapies. The present study evaluated anticancer therapeutic potential of human defensin 5 (HD-5) against colon cancer. The in vivo anticancer efficacy of HD-5 against 1,2-dimethylhydrazine (DMH) induced colon cancer was elucidated in terms of tumor biostatistics, number of aberrant crypt foci (ACF), in situ apoptosis assay,changes in morphological as well as histological architecture of colon(s). The direct interaction of peptide was investigated by incubating peptide with normal and/or cancerous colonocytes followed by phase contrast, Hoechst 3342 and AO/PI staining as well as confocal microscopy. Changes in membrane dynamics were evaluated by MC 540 and N-NBD-PE staining. In vivo decrease(s) in tumor parameters, number of aberrant crypt foci along with marked increase in the rate of apoptosis was observed.H&E staining revealed neutrophils infiltration and restoration of normal architecture in treated colon(s) which was consistent with scanning electron microscopic observations. Furthermore, non-membranolytic mechanism was found to be acquired by peptide as it could traverse cell membrane gaining access to nucleus and cytoplasm thereby disintegrating cellular architecture. MC 540 and NBD-PE staining revealed that peptide could bind to cancerous cells by taking advantage of altered fluidity levels. Our results indicated that HD-5 exhibited strong cancer cell killing and does not affect normal host cells. The peptide can be exploited as promising option to combat developing menace of colon cancer and/or can at least be used as an adjunct to present day chemotherapies.

Exploration of docetaxel palmitate and its solid lipid nanoparticles as a novel option for alleviating the rising concern of multi-drug resistance.

Docetaxel (DTX), a widely prescribed anticancer agent, is now associated with increased instances of multidrug resistance. Also, being a problematic BCS class IV drug, it poses challenges for the formulators. Henceforth, it was envisioned to synthesize an analogue of DTX with a biocompatible lipid, i.e., palmitic acid. The in-silico studies (molecular docking and simulation) inferred lesser binding of docetaxel palmitate (DTX-PL) with P-gp vis-à-vis DTX and paclitaxel, indicating it to be a poor substrate for P-gp efflux. Solid lipid nanoparticles (SLNs) of the conjugate were prepared using various lipids, viz. palmitic acid, stearic acid, cetyl palmitate and glyceryl monostearate. The characterization studies for the nanocarrier were performed for the surface charge, drug payload, micromeritics, release pattern of drug and surface morphology. From the cytotoxicity assays on resistant MCF-7 cells, it was established that the new analogue offered substantially decreased IC50 to that of DTX. Further, apoptosis assay also corroborated the results obtained in IC50 determination wherein, SA-SLNs showed the highest apoptotic index than free DTX. The conjugate not only enhanced the solubility but also offered lower plasma protein binding and improved pharmacokinetic and pharmacodynamic effect for DTX loaded SA-SLNs in apt animal models, and lower affinity to P-gp efflux. The studies provide preliminary evidence and a ray of hope for a better candidate in its nano version for safer and effective cancer chemotherapy.