Reduced Bacterial Burden of the Skin Surrounding the Shoulder Joint Following Topical Protocatechuic Acid Application: Results of a Pilot Study

Protective effects of protocatechuic acid against doxorubicin- and arsenic trioxide-induced toxicity in cardiomyocytes

Background and purpose

Some chemotherapeutic drugs are associated with an increased risk of cardiotoxicity in patients. Protocatechuic acid (PCA) is a phenolic acid with valuable cardiovascular, chemo-preventive, and anticancer activities. Recent studies have shown the cardioprotective effects of PCA in several pathological conditions. This investigation aimed to assess the possible protective effects of PCA on cardiomyocytes against toxicities caused by anti-neoplastic agents, doxorubicin (DOX), and arsenic trioxide (ATO).

Experimental approach

H9C2 cells were exposed to DOX (1 μM) or ATO (35 μM) after 24 h pretreatment with PCA (1-100 μM). MTT and lactate dehydrogenase (LDH) tests were used to define cell viability or cytotoxicity. Total oxidant and antioxidant capacities were evaluated by measuring hydroperoxides and ferric-reducing antioxidant power (FRAP) levels. Expression of the TLR4 gene was also quantitatively estimated by real-time polymerase chain reaction.

Findings/Results

PCA showed a proliferative effect on cardiomyocytes and significantly enhanced cell viability and reduced cytotoxicity of DOX and ATO during MTT and LDH assays. Pretreatment of cardiomyocytes with PCA significantly decreased hydroperoxide levels and elevated FRAP value. Moreover, PCA meaningfully decreased TLR4 expression in DOX-and ATO-treated cardiomyocytes.

Conclusions and implications

In conclusion, antioxidant and cytoprotective activities were found for PCA versus toxicities caused by DOX and ATO in cardiomyocytes. However, further in vivo investigations are recommended to assess its clinical value for the prevention and treatment of cardiotoxicity induced by chemotherapeutic agents.

Efficacy of antimicrobial washes before shoulder surgery against Cutibacterium: a systematic review and meta-analysis

Background

Cutibacterium acnes is a commensal intradermal microorganism that is commonly isolated at revision shoulder arthroplasty. Standard practice chlorhexidine gluconate (CHG) skin preparation agents have limited effectiveness at eradicating C. acnes in the dermis. Benzoyl peroxide (BPO) has demonstrated effectiveness against C. acnes. This meta-analysis compares the efficacy of at-home shoulder decolonization before surgery using CHG vs. BPO to reduce shoulder C. acnes burden.

Methods

This was a Preferred Reporting Items for Systematic Reviews and Meta-Analyses systematic review. PubMed and MEDLINE databases were searched for studies evaluating the effects of CHG and BPO in reducing C. acnes at the shoulder. Trial results were extracted and pooled using a random effects model, separating data from randomized controlled trials (RCTs) and non-RCTs. Methodologic quality of studies was assessed using the Cochrane Risk of Bias Assessment Tools.

Results

Ten studies (589 patients) were included. RCTs showed that both BPO and CHG led to significant reductions in culture positivity compared with negative controls (risk ratio [RR] with 95% confidence interval [CI] = 0.20 [0.13, 0.30], P < .0001 and 0.46 [0.37, 0.57], P < .0001, respectively). Non-RCT data demonstrated similar results comparing BPO and CHG to the control (RR with 95% CI = 0.34 [0.21, 0.57], P < .0001 and 0.31 [0.20, 0.49], P < .0001, respectively). Comparing BPO and CHG, RCT data showed a significant reduction in culture positivity with BPO (RR with 95% CI = 0.46 [0.27, 0.77], P < .009). Of RCTs, 5 were low and one was of moderate risk of bias. Of non-RCTs, 3 had low risk of bias, whereas one had moderate risk of bias.

Conclusion

This review demonstrated that preoperative CHG and BPO can reduce C. acnes at the shoulder. However, BPO exhibits greater efficacy than CHG, potentially because of the compound's ability to penetrate the dermis. BPO is a simple and economical agent that may reduce joint exposure to C. acnes in shoulder surgery.

Protocatechuic acid abrogates oxidative insults, inflammation, and apoptosis in liver and kidney associated with monosodium glutamate intoxication in rats

Monosodium glutamate (MSG), a commonly used flavor enhancer, has been reported to induce hepatic and renal dysfunctions. In this study, the palliative role of protocatechuic acid (PCA) in MSG-administered rats was elucidated. Adult male rats were assigned to four groups, namely control, MSG (4 g/kg), PCA (100 mg/kg), and the last group was co-administered MSG and PCA at aforementioned doses for 7 days. Results showed that MSG augmented the hepatic and renal functions markers as well as glucose, triglycerides, total cholesterol, and low-density lipoprotein levels. Moreover, marked increases in malondialdehyde levels accompanied by declines in glutathione levels and notable decreases in the activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase were observed in MSG-treated group. The MSG-mediated oxidative stress was further confirmed by downregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) gene expression levels in both tissues. In addition, MSG enhanced the hepatorenal inflammation as witnessed by increased inflammatory cytokines (interleukin-1b and tumor necrosis factor-α) and elevated nuclear factor-κB (NF-κB) levels. Further, significant increases in Bcl-2-associated X protein (Bax) levels together with decreases in B-cell lymphoma 2 (Bcl-2) levels were observed in MSG administration. Histopathological screening supported the biochemical and molecular findings. In contrast, co-treatment of rats with PCA resulted in remarkable enhancement of the antioxidant cellular capacity, suppression of inflammatory mediators, and apoptosis. These effects are possibly endorsed for activation of Nrf-2 and suppression of NF-kB signaling pathways. Collectively, addition of PCA counteracted MSG-induced hepatorenal injuries through modulation of oxidative, inflammatory and apoptotic alterations.

Protocatechuic Acid as a Topical Antimicrobial for Surgical Skin Antisepsis: Preclinical Investigations

Background

There is a need for novel skin antiseptic agents to combat the health-care burdens associated with surgical site infection (SSI) and bacterial resistance. The purpose of this proof-of-principle pilot study was to investigate the potential of the phenolic compound protocatechuic acid (PCA) as a topical antimicrobial for surgical skin antisepsis.

Methods

The Kirby-Bauer method of disc diffusion was used to investigate the in vitro antimicrobial activity and comparative effectiveness of PCA and 7 related compounds against SSI pathogens. To explore the in vivo efficacy of topical PCA for providing deep, penetrating skin antisepsis, living Cutibacterium acnes was intradermally injected into the skin of female BALB/c mice. Mice were assigned to treatment with daily applications of topical PCA at 3 doses (78, 39, and 19.5 mM) or no treatment (n = 2 mice per group). After 96 hours, infected skin samples were harvested to compare mean C. acnes counts by treatment.

Results

Compared with other polyphenols, PCA demonstrated the broadest spectrum of antimicrobial activity against tested SSI pathogens, including drug-resistant organisms. At 96 hours following infection, the mean C. acnes burden in untreated mice was 6.65 log colony-forming units (CFUs) per gram of skin. Compared with the untreated group, daily topical application of 78 mM of PCA was associated with a significantly lower C. acnes CFU burden in mice skin (mean, 5.51 log CFUs per gram of skin; p = 0.0295). Both lower dosages of topical PCA failed to show an effect.

Conclusions

PCA demonstrated laboratory efficacy against pathogens implicated in SSI, including drug-resistant organisms. In vivo, topical PCA demonstrated dose-dependent skin penetration and antimicrobial activity against mouse skin C. acnes loads. Human clinical studies exploring the antimicrobial efficacy of topical PCA for preoperative shoulder skin antisepsis are warranted.

Clinical Relevance

Topical PCA may have the potential to improve current shoulder SSI treatment and prevention protocols.