Immunomodulatory activities and biomedical applications of melittin and its recent advances.

Melittin (MLT), a peptide containing 26 amino acids, is a key constituent of bee venom. It comprises ∼40%-60% of the venom's dry weight and is the main pricing index for bee venom, being the causative factor of pain. The unique properties of MLT extracted from bee venom have made it a very valuable active ingredient in the pharmaceutical industry as this cationic and amphipathic peptide has propitious effects on human health in diverse biological processes. It has the ability to strongly impact the membranes of cells and display hemolytic activity with anticancer characteristics. However, the clinical application of MLT has been limited by its severe hemolytic activity, which poses a challenge for therapeutic use. By employing more efficient mechanisms, such as modifying the MLT sequence, genetic engineering, and nano-delivery systems, it is anticipated that the limitations posed by MLT can be overcome, thereby enabling its wider application in therapeutic contexts. This review has outlined recent advancements in MLT's nano-delivery systems and genetically engineered cells expressing MLT and provided an overview of where the MLTMLT's platforms are and where they will go in the future with the challenges ahead. The focus is on exploring how these approaches can overcome the limitations associated with MLT's hemolytic activity and improve its selectivity and efficacy in targeting cancer cells. These advancements hold promise for the creation of innovative and enhanced therapeutic approaches based on MLT for the treatment of cancer.

Anti-cancer Effects of a Chitosan Based Nanoformulation Expressing miR-340 on 4T1 Breast Cancer Cells.

MicroRNAs (miRNAs) have a crucial role in the regulation of gene expression in tumor development, invasion, and metastasis. Herein, miRNA-340 (miR-340) has been shown to play tumor suppressor activity in breast cancer (BC). However, the clinical applications of miRNAs request the development of safe and effective delivery systems capable of protecting nucleic acids from degradation. In this study, biodegradable chitosan nanoparticles incorporating miR-340 plasmid DNA (pDNA) (miR-340 CNPs) were synthesized and characterized. Then, the anti-tumor effects of miR-340 CNPs were investigated using 4T1 BCE cells. The spherical nanoparticles (NPs) with an appropriate mean diameter of around 266 ± 9.3 nm and zeta potential of +17 ± 1.8 mV were successfully prepared. The NPs showed good stability, high entrapment efficiency and a reasonable release behavior, meanwhile their high resistance against enzymatic degradation was verified. Furthermore, NPs demonstrated appropriate transfection efficiency and could induce apoptosis, so had toxicity in 4T1 BCE cells. Also, CD47 expression on the surface of cancer cells was significantly reduced after treatment with miR-340 CNPs. The results showed that miR-340 CNPs augmented the expression of P-27 in BC cells. Furthermore, miR-340 CNPs caused down-regulation of BRP-39 (breast regression protein-39) increasingly suggested as a prognostic biomarker for neoplastic diseases like BC. In conclusion, our data show that miR-340 CNPs can be considered as a promising new platform for BC gene therapy.

Association of CD26/dipeptidyl peptidase IV mRNA level in peripheral blood mononuclear cells with disease activity and bone erosion in rheumatoid arthritis.

Dipeptidyl peptidase IV (DPP-IV, CD26) plays many roles in the pathogenesis of several autoimmune and inflammatory diseases. The current study evaluated the association of DPP-IV enzymatic activity and its gene expression with disease activity and bone erosion in rheumatoid arthritis. Blood samples were collected from 20 rheumatoid arthritis patients and 40 healthy volunteers. Patients were divided into four subgroups using DAS28 index. CD26 gene expression levels were analyzed in peripheral blood mononuclear cells by quantitative reverse transcription-polymerase chain reaction. Additionally, the enzymatic activity of this molecule in serum was determined using Gly-Pro-p-nitroanilide as substrate. Digital radiography was applied to obtain images for bone erosion assessment. No significant difference in serum DPP-IV activity level was seen between patients and controls (p = 0.140). However, patients exhibited an increase in CD26 mRNA expression (1.68 times) when compared to controls (p = 0.001). Moreover, a strong positive correlation between CD26 gene expression and DAS28 index as well as bone erosion in the hands was observed (r = 0.71, p = 0.002 and r = 0.61, p = 0.049, respectively). This study demonstrated that CD26 mRNA expression in rheumatoid arthritis patients is associated with disease activity and bone erosion, suggesting a potential role for this molecule in the immunopathology of rheumatoid arthritis and bone erosion.

Reduction toxicity of Amphotericin B through loading into a novel nanoformulation of anionic linear globular dendrimer for improve treatment of leishmania major.

Amphotericin B (A) as an antileishmanial drug has limited clinical application owing to severe side-effects and low-water solubility. This is the first study reported using Anionic Linear Globular Dendrimer (ALGD) as A carrier for the increase of A solubility rate, decrease its toxicity, and improve its therapeutic effects. ALGD was synthesized and A was loaded into nanoparticles for the first time with the drug-loading efficiency of 82%. Drug loading was confirmed using characterization methods. The drug solubility rate was increased by 478-folds. The results of the study showed that the A toxicity was significantly decreased by 95% in vitro and in vivo environments, which was confirmed by pathology findings and enzymatic evaluation. Furthermore, the nanodrug caused that mortality rate was reached to zero. Moreover, the nanodrug was as potent as the free drug and glucantime (GUL) in reducing the parasite burden and parasite number. These findings indicated the potency of ALGD to decrease the drug side-effects, increase the drug solubility rate, and improve the drug efficacy. Moreover, the nanoformulation was a non-toxic and cost-effective formulation. The conformity between in vitro and in vivo results suggested that the A-loaded ALGD could be considered as a promising candidate in reducing the side-effects of A in leishmaniasis treatment.

Immunotherapeutic effects of chitin in comparison with chitosan against Leishmania major infection.

Chitin and chitosan microparticles (MPs) are important immune system stimulators. The aim of this study was to evaluate the protective effects of these compounds in comparison with each other against Leishmania infection in BALB/c mice infected with Leishmania major (L. major). Female BALB/c mice were injected subcutaneously with 2×10(5) promastigotes. Chitin and/or chitosan MPs (<40 µm) were subcutaneously injected in the BALB/c mice with two-day intervals until two weeks. Mice in all groups were sacrificed at 12 weeks post-infection. Enumeration of viable parasites was performed using limiting dilution assay. Furthermore, the animals (5 mice/group) were sacrificed two weeks post-infection. The lymph node cells were isolated and the effects of the chitinous MPs on the proliferation and production of cytokines such as tumor necrosis factor alpha (TNF-α) and interleukin-10 (IL-10) were determined. The mean sizes of lesions were significantly smaller in chitin (0.6±0.12 mm) and chitosan treated groups (1.2±0.8 mm) than in the control group (6.2±1.7 mm) (P<0.05). The parasite load in the lymph nodes of the treated mice was significantly lower than that in the lymph nodes of controls (1.31×10(6) vs 8.24×10(7) parasite/lymph node [P=0.032] and 7.49×10(6) vs 8.24×10(7) parasite/lymph node [P=0.05] for chitin and chitosan MPs treatment, respectively). We found that chitinous MPs induced cell proliferation and that chitin but not chitosan increased TNF-α and IL-10 production. Chitin appears that it has more effect than chitosan against leishmaniasis. The current study revealed that chitinous MPs had significant activity against L. major and could be considered as new therapeutic modality in leishmaniasis.

Immunomodulatory effects of chitin microparticles on Leishmania major-infected BALB/c mice.

Chitin and its some derivatives are known to be non-allergic and non-toxic substances. It has been shown that chitin microparticles have immunomodulatory activities. In the present study, we investigated the in vivo immunomodulatory activities of chitin microparticles (CMPs) on Leishmania major-infected BALB/c mice. BALB/c mice were infected with L. major promastigotes at their base of the tail. CMPs (100µg/100µl) were injected into the site of infection from 3days before to 2 or 8 weeks after infection at two-day intervals. Cytokine concentrations (TNF-α, IFN-γ, IL-5 and IL-10) were measured using ELISA assays. Compared to the untreated group, production of TNF-α was significantly elevated in the CMPs-treated group. Moreover, the IFN-γ/IL-5 ratio was significantly elevated in CMPs-treated infected mice (P=0.023). Notably, the concentration of IL-10 was higher in CMPs-treated mice. These results showed that CMPs have in vivo immunomodulatory effects via the production of IFN-γ and IL-10. We also measured the onset and size of lesions in both treated and untreated mice. The average times taken for the onset of the lesion formation were 35 and 29days for CMPs-treated and untreated mice (P=0.023), respectively. The mean size of the lesions was smaller in CMPs-treated group. Our study serves as a basis for future investigations on the application of CMPs as a prophylactic (vaccine adjuvant) and/or therapeutic modality against leishmaniasis.

Using experimental autoimmune encephalomyelitis as a model to study the effect of prenatal stress on fetal programming.

OBJECTIVES: There is a growing evidence to suggest that the antecedents of some adult diseases can be traced back to their fetal origins. Despite extensive research on such diseases, to our knowledge, there has been no research investigating the relationship between the origins of multiple sclerosis (MS) disease and maternal infections. The aim of this study was to examine the role of prenatal exposure to endotoxin in fetal programming with respect to induction of susceptibility/vulnerability to MS. METHODS: The pregnant dams were administered a single intraperitoneal injection of lipopolysaccharide in gestational day 10. The male offspring were weighed and examined for clinical signs of experimental autoimmune encephalomyelitis in a blinded fashion within 36 days after immunization (postnatal day 63-98). RESULTS: Our data provide the evidence showing prenatal exposures to higher doses of Lipopolysaccharide resulted in an earlier onset of the disease, an augmentation of its clinical signs, and lower body weight in the prenatally Lipopolysaccharide -treated C57BL/6 mice after the immunization. DISCUSSION: Therefore, the present research can provide evidence that prenatal stress may play a role in enhancing the clinical symptoms of experimental autoimmune encephalomyelitis/MS.