Daily Cosmetic Research Analysis
A registered randomized trial shows Manuka honey oral rinse improves xerostomia symptoms and salivary flow in older adults. A multi-country biomonitoring study links adolescent exposure to benzophenone UV filters with higher odds of obesity, suggesting regulatory and preventive implications. Basic research reveals that complexing chitosan with phosvitin enhances antibacterial activity across pH ranges, informing antimicrobial cosmetic and topical formulations.
Summary
A registered randomized trial shows Manuka honey oral rinse improves xerostomia symptoms and salivary flow in older adults. A multi-country biomonitoring study links adolescent exposure to benzophenone UV filters with higher odds of obesity, suggesting regulatory and preventive implications. Basic research reveals that complexing chitosan with phosvitin enhances antibacterial activity across pH ranges, informing antimicrobial cosmetic and topical formulations.
Research Themes
- Natural-product-based therapeutics for oral health
- Cosmetic UV filter exposure and adolescent metabolic health
- Biopolymer complexation enhancing antimicrobial function for topical/cosmetic use
Selected Articles
1. Efficacy of Manuka honey oral rinse in treatment of xerostomia among elderly patients: a randomized controlled trial.
In a single-blinded randomized trial of 42 older adults, a Manuka honey mouth rinse used three times daily for one month significantly improved subjective xerostomia (SXI) and objective oral dryness (CODS) scores versus natural honey and saline. Salivary flow increased more with Manuka honey (1.51 ± 0.34) than with natural honey. Findings support Manuka honey as a low-cost, natural adjunct for xerostomia management.
Impact: Provides randomized evidence for a readily accessible natural intervention that improves both patient-reported and objective measures of xerostomia in older adults.
Clinical Implications: Clinicians may consider Manuka honey mouth rinse as an adjunctive option for symptomatic xerostomia in older adults, while awaiting larger, longer-term trials to confirm efficacy and safety.
Key Findings
- Randomized, single-blinded three-arm trial (n=42) comparing Manuka honey rinse, natural honey rinse, and saline over one month.
- Manuka honey significantly reduced SXI (2 ± 0.39) and CODS (5.71 ± 0.91) compared with the other groups.
- Salivary flow rate was higher after one month with Manuka honey (1.51 ± 0.34) than with natural honey.
- Trial was prospectively registered (NCT06240806).
Methodological Strengths
- Randomized design with active (natural honey) and saline control arms
- Use of both subjective (SXI, OHIP-14) and objective (CODS, salivary flow) outcomes and trial registration
Limitations
- Small sample size and single-center design limit generalizability
- Single-blinded design and short (1 month) follow-up
Future Directions: Conduct larger, multicenter, double-blind RCTs with longer follow-up to assess durability, safety, and comparative effectiveness versus standard xerostomia therapies.
2. Adolescent exposure to benzophenone ultraviolet filters: cross-sectional associations with obesity, cardiometabolic biomarkers, and asthma/allergy in six European biomonitoring studies.
Pooling six aligned European biomonitoring studies (n=1339), higher urinary BP-3 levels (CAS-adjusted) were associated with increased odds of obesity (OR 1.20), with sex-specific effects showing stronger associations for BP-1 and BP-3 among males. Associations with higher BMI z-scores were consistent, and BP-1 was negatively associated with adiponectin in females. Results support reducing benzophenone UV filter exposure while pursuing longitudinal confirmation.
Impact: Links widely used cosmetic UV filters to adolescent obesity risk in a large multi-country dataset using advanced exposure normalization, informing regulation and public health.
Clinical Implications: Healthcare providers can consider environmental UV filter exposures in adolescent obesity risk assessment and counseling, while advocating for policies that minimize benzophenone exposures.
Key Findings
- Across six European studies (n=1339), each log-unit increase in urinary BP-3 (CAS-adjusted) was associated with higher odds of obesity (OR 1.20; 95% CI 1.04–1.38).
- Sex-specific effects: in males, higher odds of obesity with BP-1 (OR 1.25; 95% CI 1.01–1.55) and BP-3 (OR 1.34; 95% CI 1.09–1.65).
- Consistent positive associations with BMI z-scores; BP-1 (CAS) was negatively associated with serum adiponectin in females.
- Advanced exposure adjustment using covariate-adjusted creatinine standardization (CAS) and mixed-effects modeling.
Methodological Strengths
- Multi-country pooled analysis with harmonized protocols and adequate sample size
- Use of CAS creatinine adjustment, GAMs, and mixed models; sex-interaction testing
Limitations
- Cross-sectional design precludes causal inference and is susceptible to reverse causation
- Exposure based on spot urine; cardiometabolic biomarkers available only in a subsample
Future Directions: Prospective longitudinal and intervention studies to test causality, clarify mechanisms, and evaluate health impacts of substituting benzophenones with safer alternatives.
3. Complexation with chicken yolk phosvitin modulates antibacterial activity of chitosan.
This mechanistic study shows for the first time that phosvitin–chitosan complexation preserves and enhances chitosan’s bacteriostatic activity by two- to fourfold across acidic and alkalescent media, lowering MICs. Complex formation depends on electrostatic and non-electrostatic forces, with composition and charge varying by pH. The findings inform design of antimicrobial drug-delivery systems and cosmetic formulations.
Impact: Demonstrates a novel strategy to boost chitosan’s antimicrobial performance via protein complexation, expanding options for preservative-free antimicrobial cosmetic and topical systems.
Clinical Implications: While preclinical, the approach may enable more effective antimicrobial dressings and topical vehicles that function across skin-relevant pH ranges, potentially reducing reliance on conventional preservatives.
Key Findings
- Phosvitin complexation did not restrict chitosan’s bacteriostatic activity and enhanced it two- to fourfold at 0.25–1.0 mg/ml phosvitin in acidic (pH 5.8) and alkalescent (pH 7.4) media.
- Minimal inhibitory concentrations of chitosan decreased in both pH conditions when complexed with phosvitin.
- Complex formation arises from electrostatic and non-electrostatic interactions; solely negatively charged complexes form in alkalescent medium.
- In acidic medium, interaction is faster; insoluble complexes contain five times more phosvitin than soluble ones, whereas soluble complexes enriched in chitosan form in both media.
- A proposed mechanism involves labile proton transfer from phosvitin to chitosan, strengthening electrostatic complexation.
Methodological Strengths
- Comprehensive physicochemical characterization across pH with mechanistic interpretation
- Quantitative antibacterial assessments demonstrating reduced MICs and enhanced activity
Limitations
- In vitro study without in vivo or clinical validation
- Specific bacterial spectra and formulation performance in real products were not evaluated
Future Directions: Test chitosan–phosvitin complexes in formulated topical/cosmetic systems and in vivo infection models, optimize ratios for maximal efficacy, and assess safety/biocompatibility.