Recombinant R2-pyocin cream is effective in treating Pseudomonas aeruginosa-infected wounds.

Pseudomonas aeruginosa, a gram-negative opportunistic pathogen, is one of the major species isolated from infected chronic wounds. The multidrug resistance exhibited by P. aeruginosa and its ability to form biofilms that are difficult to eradicate, along with the rising cost of producing new antibiotics, has necessitated the search for alternatives to standard antibiotics. Pyocins are antimicrobial compounds produced by P. aeruginosa that protect themselves from their competitors. We synthesized and purified recombinant P. aeruginosa R2 pyocin and used it in an aqueous solution (rR2P) or formulated in polyethylene glycol (rR2PC) to treat P. aeruginosa-infected wounds. Clinical strains of P. aeruginosa were found to be sensitive (completely), partially sensitive, or resistant to rR2P. In the in vitro biofilm model, rR2P inhibited biofilm development by rR2P-sensitive isolates, while rR2PC eliminated partial biofilms formed by these strains in an in vitro wound biofilm model. In the murine model of excision wounds, and at 24 h post-infection, rR2PC application significantly reduced the bioburden of the clinical isolate BPI86. Application of rR2PC containing two glycoside hydrolase antibiofilm agents eliminated BPI86 from infected wounds. These results suggest that the topical application of rR2PC is an effective therapy for treating wounds infected with R2P-senstive P. aeruginosa strains.

Mechanisms Mediating Anti-Inflammatory Effects of Delta-Tocotrienol and Tart Cherry Anthocyanins in 3T3-L1 Adipocytes.

Chronic low-grade inflammation is a primary characteristic of obesity and can lead to other metabolic complications including insulin resistance and type 2 diabetes (T2D). Several anti-inflammatory dietary bioactives decrease inflammation that accompanies metabolic diseases. We are specifically interested in delta-tocotrienol, (DT3) an isomer of vitamin E, and tart cherry anthocyanins (TCA), both of which possess individual anti-inflammatory properties. We have previously demonstrated that DT3 and TCA, individually, reduced systemic and adipose tissue inflammation in rodent models of obesity. However, whether these compounds have combinatorial effects has not been determined yet. Hence, we hypothesize that a combined treatment of DT3 and TCA will have great effects in reducing inflammation in adipocytes, and that these effects are mediated via the nuclear factor kappa-light-chain-enhancer of activated B cells (NFkB), a major inflammatory transcription factor. We used 3T3-L1 adipocytes and treated them with 1-5 µM doses of DT3 along with tart cherry containing 18-36 µg anthocyanin/mL, to assess effects on inflammation. Neither DT3 nor TCA, nor their combinations had toxic effects on adipocytes. Furthermore, pro-inflammatory markers interleukin-6 (IL-6) and p-65 (subunit of NFkB) were reduced at the protein level in media collected from adipocytes with both individual and combined treatments. Additionally, other downstream targets of NFkB including macrophage inflammatory protein 2 (Mip2), and Cyclooxygenase-2 (Cox2) were also significantly downregulated (p ≤ 0.05) when treated with individual and combined doses of DT3 and TCA with no additional combinatorial effects. In summary, DT3 and TCA individually, are beneficial in reducing inflammation with no additional combinatorial effects.