Antimicrobial Cyclic Dipeptides from Japanese Quail (Coturnix japonica) Eggs Supplemented with Probiotic Lactobacillus plantarum.

Fifteen cyclic dipeptides (CDPs) containing proline, one cyclo(Phe-Ala) without proline, and a non-peptidyl DL-3-phenyllactic acid were previously identified in the culture filtrates of Lactobacillus plantarum LBP-K10, an isolate from kimchi. In this study, we used Japanese quail (Coturnix japonica) eggs to examine the effects of probiotic supplementation on the antimicrobial CDPs extracted from quail eggs (QE). Eggshell-free QE were obtained from two distinct groups of quails. The first group (K10N) comprised eggs from unsupplemented quails. The second group (K10S) comprised eggs from quails supplemented with Lb. plantarum LBP-K10. The QE samples were extracted using methylene chloride through a liquid-liquid extraction process. The resulting extract was fractionated into 16 parts using semi-preparative high-performance liquid chromatography. Two fractions, Q6 and Q9, were isolated from K10S and identified as cis-cyclo(L-Ser-L-Pro) and cis-cyclo(L-Leu-L-Pro). The Q9 fraction, containing cis-cyclo(L-Leu-L-Pro), has shown significant inhibitory properties against the proliferation of highly pathogenic multidrug-resistant bacteria, as well as human-specific and phytopathogenic fungi. Some of the ten combinations between the remaining fourteen unidentified fractions and two fractions, Q6 and Q9, containing cis-cyclo(L-Ser-L-Pro) and cis-cyclo(L-Leu-L-Pro) respectively, demonstrated a significant increase in activity against multidrug-resistant bacteria only when combined with Q9. The activity was 7.17 times higher compared to a single cis-cyclo(L-Leu-L-Pro). This study presents new findings on the efficacy of proline-containing CDPs in avian eggs. These CDPs provide antimicrobial properties when specific probiotics are supplemented.

Efficacy of a Quail Eggs-Based Dietary Supplement for Allergic Rhinitis: Results of a Single-Arm Trial.

Previous data suggested the potential treatment effect of a proprietary quail eggs-based blend on allergic rhinitis (AR) symptoms, induced by allergen challenge. We herein aimed to investigate the efficacy and safety of a similar dietary supplement, comprising the bioactive ingredients of quail eggs and the zinc mineral, in the setting of active AR. Adult patients (n = 77), aged 18- 60 years, with mild, intermittent AR were enrolled in this single-arm, open-label trial. Patients' responses were assessed based on peak nasal inspiratory flow (PNIF) measurements at two visits (Day 1/Visit 1 and Day 7/Visit 2) and self-rating of AR-associated symptoms on a Visual Analog Scale (VAS) throughout the entire 7-day study period. PNIF values at 15, 30, 60, 90 and 120 min (Visit 1) following administration of an oral dose of the study product were the primary efficacy endpoint. PNIF values (Visit 1) gradually increased from baseline (pre-treatment), with statistical significance first reached 30 min later (p = 0.002). VAS scores (Visit 1) for all AR symptoms gradually decreased with statistical significance first reached at 15 min (rhinorrhea, p = 0.042; itchy nose, p = 0.001; sneezing p < 0.001), 30 min (nasal congestion, p < 0.001; itchy eyes, p = 0.003) or 60 min (watery eyes, p = 0.04). PNIF improvement and decline of VAS scores were significantly more apparent at Visit one vs. Visit 2. Treatment-emergent adverse events were limited to cough and muscle strain (one patient each). Our results support the efficacy, rapid mode of action and tolerability of the investigated product for symptomatic treatment of mild intermittent AR.