Activity of Drill® lozenges on the main microorganisms responsible for upper respiratory tract infections

Bactericidal and virucidal action of cetylpyridinium chloride and benzocaine lozenges against common oropharyngeal pathogens

Aim

Too often, antibiotics are prescribed in the treatment of pharyngitis, which can contribute to antimicrobial resistance. We aimed to assess the in vitro antiviral and antimicrobial activity of sugar-free cetylpyridinium chloride (CPC)/benzocaine lozenges, which can potentially offer a more suitable treatment for pharyngitis.

Methods

The antiviral activity of sugar-free CPC/benzocaine (1.4 mg/10 mg) lozenges (Dolo-Dobendan 1.4 mg/10 mg lozenges) was assessed using the DIN EN 14476:2019-10 suspension test against bovine coronavirus (S379 Reims) or influenza virus A (H1N1/Brisbane/59/2007) under clean and dirty conditions. Viral titers were measured after 1, 5, 10, and 30 min exposure; a reduction of ≥4 lg was considered virucidal. For bovine coronavirus, large volume plating was used due to cytotoxicity. Antimicrobial activity was measured against 11 microorganisms associated with pharyngitis, with contact times of 1, 5, and 10 min (+30 min for positive control).

Results

For influenza, sugar-free lozenges showed ≥4 lg efficacy from 5 and 10 min exposure under clean and dirty conditions, respectively. For bovine coronavirus, sugar-free lozenges exhibited ≥4 lg efficacy at 10 min under both conditions. Bactericidal activity was observed against nine of the challenge microorganisms within 5 min, with plate counts of <10 colony-forming units (CFU)/mL for Pseudomonas aeruginosa, Staphylococcus aureus, Arcanobacterium haemolyticum, Moraxella catarrhalis, Porphyromonas gingivalis, Prevotelia intermedia, Streptococcus dysgalactiae, and Streptococcus pyogenes, and <100 CFU/mL for Streptococcus pneumoniae. Candida albicans and Escherichia coli showed counts of <10 CFU/mL at 30 min.

Conclusions

Sugar-free CPC/benzocaine lozenges can be recommended for uncomplicated pharyngitis and may be more appropriate than antibiotics, helping to mitigate antimicrobial resistance.

The Acidic Fraction of Isatidis Radix Regulates Inflammatory Response in LPS-Stimulated RAW264.7 Macrophages through MAPKs and NF-κB Pathway

Isatidis Radix, the dried root of Isatidis indigotica Fort, is a traditional heat-clearing and detoxicating herb, which has the antiviral and anti-inflammatory activity and immune regulation. It has been widely used to treat cold, fever, sore throat, mumps, and tonsillitis in clinics. A previous study demonstrated that the acidic fraction of Isatidis Radix (RIAF) had strong anti-inflammatory activity, but the mechanism of action was not well elucidated. Lipopolysaccharide- (LPS-) induced RAW264.7 cells were employed to observe the anti-inflammatory activity of RIAF. The level of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), nitric oxide (NO), prostaglandin E₂ (PGE₂), and interleukin-6 (IL-6) was determined by enzyme-linked immunosorbent assay kits. Western blot was performed to quantify the expression of extracellular signal-regulated kinase (ERK) 1/2, c-jun NH2-termianl kinase (JNK), p38, inducible NO synthetase (iNOS), cyclooxygenase (COX)-2, andnuclear factor-κB (NF-κB). Immunofluorescence assay and electrophoretic mobility shift assay (EMSA) were used to quantify the translocation and the binding-DNA activity of NF-κB. RIAF could inhibit the secretion of inflammatory cytokines (PGE₂, IL-6, IL-1β, and NO, other than TNF-α) in a dose-dependent manner. Further investigation showed that the expression of iNOS and COX-2 induced by LPS were downregulated by treatment with RIAF. Meanwhile, data from the signal pathway exhibited that RIAF significantly suppressed the phosphorylation of ERK1/2, JNK, and p38 and reduced the translocation of NF-κB from the cytoplasm to nucleus, as well as the binding-DNA activity. The anti-inflammatory mechanism of action of RIAF was to reduce inflammation-associated gene expression (iNOS, COX-2, IL-1β, IL-6) by regulating the phosphorylation of the mitogen-activated protein kinases (MAPK) pathway and interventing the activation of the NF-κB pathway, which partly illustrated the basis of treatment of Isatidis Radix on cold, fever, sore throat, mumps, and tonsillitis in clinics.