Topical application of the bee hive protectant propolis is well tolerated and improves human diabetic foot ulcer healing in a prospective feasibility study

Aims - Propolis is a naturally occurring anti-inflammatory bee derived protectant resin. We have previously reported that topically applied propolis reduces inflammation and improves cutaneous ulcer healing in diabetic rodents. The aim of this study was to determine if propolis shows efficacy in a pilot study of human diabetic foot ulcer (DFU) healing and if it is well tolerated. Materials - Serial consenting subjects (n = 24) with DFU ≥ 4 week's duration had topical propolis applied at each clinic review for 6 weeks. Post-debridement wound fluid was analyzed for viable bacterial count and pro-inflammatory MMP-9 activity. Ulcer healing data were compared with a matched control cohort of n = 84 with comparable DFU treated recently at the same center. Results - Ulcer area was reduced by a mean 41% in the propolis group compared with 16% in the control group at week 1 (P < 0.001), and by 63 vs. 44% at week 3, respectively (P < 0.05). In addition, 10 vs. 2% (P < 0.001), then 19 vs. 12% (P < 0.05) of propolis treated vs. control ulcers had fully healed by weeks 3 and 7, respectively. Post-debridement wound fluid active MMP-9 was significantly reduced, by 18.1 vs. 2.8% week 3 from baseline in propolis treated ulcers vs. controls (P < 0.001), as were bacterial counts (P < 0.001). No adverse effects from propolis were reported. Conclusions - Topical propolis is a well-tolerated therapy for wound healing and this pilot in human DFU indicates for the first time that it may enhance wound closure in this setting when applied weekly. A multi-site randomized controlled of topical propolis now appears to be warranted in diabetic foot ulcers

Location of hydrogen atoms in hydronium jarosite

Various models for the crystal structure of hydronium jarosite were determined from Rietveld refinements against neutron powder diffraction patterns collected at ambient temperature and also single-crystal X-ray diffraction data. The possibility of a lower symmetry space group for hydronium jarosite that has been suggested by the literature was investigated. It was found the space group is best described as R3¯m, the same for other jarosite minerals. The hydronium oxygen atom was found to occupy the 3¯m site (3a Wyckoff site). Inadequately refined hydronium bond angles and bond distances without the use of restraints are due to thermal motion and disorder of the hydronium hydrogen atoms across numerous orientations. However, the acquired data do not permit a precise determination of these orientations; the main feature up/down disorder of hydronium is clear. Thus, the highest symmetry model with the least disorder necessary to explain all data was chosen: The hydronium hydrogen atoms were modeled to occupy an m (18 h Wyckoff site) with 50 % fractional occupancy, leading to disorder across two orientations. A rigid body description of the hydronium ion rotated by 60° with H–O–H bond angles of 112° and O–H distances of 0.96 Å was optimal. This rigid body refinement suggests that hydrogen bonds between hydronium hydrogen atoms and basal sulfate oxygen atoms are not predominant. Instead, hydrogen bonds are formed between hydronium hydrogen atoms and hydroxyl oxygen atoms. The structure of hydronium alunite is expected to be similar given that alunite supergroup minerals are isostructural