Synergic Antibacterial Effect of Curcumin with Ampicillin; Free Drug Solutions in Comparison with SLN Dispersions

A comprehensive review of the therapeutic potential of curcumin nanoformulations

Today, due to the prevalence of various diseases such as the novel coronavirus (SARS-CoV-2), diabetes, central nervous system diseases, cancer, cardiovascular disorders, and so on, extensive studies have been conducted on therapeutic properties of natural and synthetic agents. A literature review on herbal medicine and commercial products in the global market showed that curcumin (Cur) has many therapeutic benefits compared to other natural ingredients. Despite the unique properties of Cur, its use in clinical trials is very limited. The poor biopharmaceutical properties of Cur such as short half-life in plasma, low bioavailability, poor absorption, rapid metabolism, very low solubility (at acidic and physiological pH), and the chemical instability in body fluids are major concerns associated with the clinical applications of Cur. Recently, nanoformulations are emerging as approaches to develop and improve the therapeutic efficacy of various drugs. Many studies have shown that Cur nanoformulations have tremendous therapeutic potential against various diseases such as SARS-CoV-2, cancer, inflammatory, osteoporosis, and so on. These nanoformulations can inhibit many diseases through several cellular and molecular mechanisms. However, successful long-term clinical results are required to confirm their safety and clinical efficacy. The present review aims to update and explain the therapeutic potential of Cur nanoformulations.

Incorporation of Antibiotics into Solid Lipid Nanoparticles: A Promising Approach to Reduce Antibiotic Resistance Emergence

Antimicrobial resistance is one of the biggest threats to global health as current antibiotics are becoming useless against resistant infectious pathogens. Consequently, new antimicrobial strategies are urgently required. Drug delivery systems represent a potential solution to improve current antibiotic properties and reverse resistance mechanisms. Among different drug delivery systems, solid lipid nanoparticles represent a highly interesting option as they offer many advantages for nontoxic targeted drug delivery. Several publications have demonstrated the capacity of SLNs to significantly improve antibiotic characteristics increasing treatment efficiency. In this review article, antibiotic-loaded solid lipid nanoparticle-related works are analyzed to summarize all information associated with applying these new formulations to tackle the antibiotic resistance problem. The main antimicrobial resistance mechanisms and relevant solid lipid nanoparticle characteristics are presented to later discuss the potential of these nanoparticles to improve current antibiotic treatment characteristics and overcome antimicrobial resistance mechanisms. Moreover, solid lipid nanoparticles also offer new possibilities for other antimicrobial agents that cannot be administrated as free drugs. The advantages and disadvantages of these new formulations are also discussed in this review. Finally, given the progress of the studies carried out to date, future directions are discussed.

Curcumin inhibits lipopolysaccharide and lipoteichoic acid-induced expression of proinflammatory cytokines and production of PGE2 in the primary bubaline endometrial stromal cells

Infection of the uterus with Gram-positive Trueperella pyogenes and Gram-negative Escherichia coli is a common cause of postpartum endometritis in the cattle and buffalo and the condition is treated with antimicrobial drugs. The presence of drug residues in the milk and development of resistant bacteria necessitate the evaluation of alternate therapies for endometritis. Accordingly, we tested the immunomodulatory effect of curcumin in the bubaline endometrial stromal cells after treatment with the lipoteichoic acid (LTA) of Gram-positive Staphylococcus aureus and lipopolysaccharide (LPS) of Gram-negative E. coli that activate toll-like receptors (TLR-2 and TLR-4, respectively). Confluent primary culture of endometrial stromal cells was treated with LTA (1 µg/mL) and/or LPS (0.1 µg/mL), in the presence or absence of curcumin (30 µM for 24 h). PGE₂ was assayed in the supernatant and the relative expression of proinflammatory cytokines (PICs) (IL1B, IL6, IL8 and TNFA) transcripts were quantified using real-time PCR. LTA was not effective in stimulating PGE₂ production or upregulating the PIC expression except IL8. LTA+LPS increased PGE₂ production and upregulated IL6 and IL8 genes. Curcumin inhibited the basal and LTA+LPS induced production of PGE₂ and upregulation of PIC production. It was apparent that LPS, but not LTA, is a potent stimulator of PGE₂ from the bubaline endometrial stromal cells. Curcumin downregulated the expression of LPS and/or LTA induced PICs and PGE₂ and may be an alternate to antimicrobial drugs for the therapeutic management of endometritis.

Lipid Nanoparticles as a Skin Wound Healing Drug Delivery System: Discoveries and Advances

Chronic wounds are a remarkable cause of morbidity, requiring long-time treatments with a significant impact on the quality of life and high costs for public health. Although there are a variety of topical skin preparations commercially available, they have several limitations that frequently impair wound healing, such as drug instability, toxicity, limited time of action and ineffective skin permeation. In recent years, researchers have focused on the development of new effective treatments for wound healing and shown frequent interest in nanometric drug delivery systems to overcome such obstacles. In dermatology, lipid nanoparticles (LNPs) have received great attention from researchers due to their great functionalities, greater adhesion to the skin and film formation, enabling the hydration and maintenance of skin integrity, as well as present a more effective penetration through the skin barrier. This review provides an update on topical formulations based on Solid Lipid Nanoparticles (SLNs) and Nanostructured Lipid Carriers (NLCs) as wound healing treatments. Both SLNs and NLCs are able to increase solubility and stability of active pharmaceutical ingredients and increase skin penetration compared to the free drugs. Additionally, SLNs and NLCs can increase pharmacological activity, increase the release profile of the drugs, promote synergistic effects and improve the sensory properties of the final formulation. Topical dosage forms containing nanoparticles have been extensively evaluated for wound healing activity, mainly the dressings, films and scaffolds. Therefore, lipid nanoparticles have contributed in improving wound healing therapies when incorporated into other dosage forms with better efficacy and lesser adverse effects than conventional formulations.

Anti-microbial activity of curcumin nanoformulations: New trends and future perspectives

Curcumin has been used in numerous anti-microbial research because of its low side effects and extensive traditional applications. Despite having a wide range of effects, the intrinsic physicochemical characteristics such as low bioavailability, poor water solubility, photodegradation, chemical instability, short half-life and fast metabolism of curcumin derivatives limit their pharmaceutical importance. To overcome these drawbacks and improve the therapeutic ability of curcuminoids, novel approaches have been attempted recently. Nanoparticulate drug delivery systems can increase the efficiency of curcumin in several diseases, especially infectious diseases. These innovative strategies include polymeric nanoparticles, hydrogels, nanoemulsion, nanocomposite, nanofibers, liposome, nanostructured lipid carriers (NLCs), polymeric micelles, quantum dots, polymeric blend films and nanomaterial-based combination of curcumin with other anti-bacterial agents. Integration of curcumin in these delivery systems has displayed to improve their solubility, bioavailability, transmembrane permeability, prolong plasma half-life, long-term stability, target-specific delivery and upgraded the therapeutic effects. In this review paper, a range of in vitro and in vivo studies have been critically discussed to explore the therapeutic viability and pharmaceutical significance of the nano-formulated delivery systems to elevate the anti-bacterial activities of curcumin and its derivatives.

Immunomodulatory effect of curcumin on lipopolysaccharide- and/or flagellin-induced production of prostaglandin E2 and relative expression of proinflammatory cytokines in the primary bubaline endometrial stromal cells

Developing alternate therapies for bovine endometritis is important in the context of drug residues in the milk and emergence of antimicrobial resistant bacteria. In this regard, we studied the immunomodulatory effect of curcumin 30 µM, on lipopolysaccharide- (LPS) and/or flagellin (100 ng/ml each)-induced prostaglandin E₂ (PGE₂ ) and proinflammatory cytokines (PIC) using primary bubaline endometrial stromal cells. After 24 hr treatment, the supernatant was assayed for PGE₂ while cells were used for relative quantification of cytokines like IL-1β, IL-6, IL-8 and TNF α transcripts using a control group as calibrator. LPS was found to possess potent stimulatory effect on PGE₂ production, whereas the flagellin was not as potent as LPS in stimulating the PGE₂ production either per se or in combination with LPS. LPS markedly up-regulated the transcripts of IL-8 and IL-6 as compared to IL-1β and TNF α in the bubaline endometrial stromal cells. Except for IL-8, flagellin did not up-regulate other PICs. There was no additive effect between LPS and flagellin on the up-regulation of inflammatory cytokines. Curcumin inhibited the LPS-induced up-regulation of PIC with strong down-regulation of IL-8. The inhibitory effects of curcumin on the inflammatory mediators suggest a potential in the treatment of bovine endometritis.

Nanotechnology in Wound Healing; Semisolid Dosage Forms Containing Curcumin-Ampicillin Solid Lipid Nanoparticles, in-Vitro, Ex-Vivo and in-Vivo Characteristics

Purpose: Wound healing is a natural biologic process, but the duration of it may take too long. Trying to shorten this process is one of the challenges for scientists. Many technologies were applied to achieve this goal as well as nanotechnology. In this study semi solid formulations containing curcumin and ampicillin solid lipid nanoparticles (SLNs) were prepared to evaluate as burn wound healing agent. Methods: Curcumin as an anti-inflammatory and anti-bacterial agent and ampicillin as an antibiotic were applied. In-vitro and in-vivo evaluations were carried out. Particle size, loading efficiency, release profile, morphology and anti-bacterial efficacy of desired nanoparticles were evaluated at first. Then the remaining of the antibacterial effect in semi solid preparations was studied. Animal studies for both toxicology using rabbits and skin burn model using rats were designed. Pathology studies after applying of formulations was done too. Results: Desired nanoparticles were spherical in shape and particle size in range of 112-121 nm, with low zeta potential. For increasing stability of particles they were freeze dried using cryoprotectant. Lyophilized particles show no significant size enlargement. Results showed that both ointment and gel preparations have reasonable anti-bacterial effects, both of them cause increasing in the rate of wound healing in comparison with placebos and control groups and none of the formulations showed acute toxicity. Conclusion: It seems that using nanotechnology could shorten wound healing process to reduce treatment costs and increase compliance of patients.