Effect of Catechins on Upper Respiratory Tract Infections in Winter: A Randomized, Placebo-Controlled, Double-Blinded Trial.

Tea catechins are plant-derived compounds that improve immune functions. Previous randomized control trials have demonstrated the efficacy of primarily epi-type catechins against upper respiratory tract infections (URTIs). Green tea can be consumed in several ways, including popular bottled beverages. These beverages, however, require sterilization during manufacturing, which results in catechin isomerization. We conducted a randomized, double-blinded, placebo-controlled trial involving healthy Japanese participants to evaluate whether catechin consumption via bottled beverages has an alleviating effect on the duration and severity of URTIs in winter. The catechin group (490 mg catechin, 0.14%, containing 59% epi-type catechin, n = 55) showed reduced durations of running nose, nasal congestion, and headache, compared with the placebo group (0 mg catechin, n = 54; p = 0.013, 0.018, and <0.001, respectively). Furthermore, when considering physical symptoms, the duration of nasopharyngeal symptoms improved significantly in the catechin group (p < 0.001) compared with that in the control group. The daily consumption of catechin thus reduced the duration and severity of URTIs in healthy men and women. Humans are regularly exposed to several potential infectious threats, and the oral administration of heat-epimerized tea catechins might help prevent and reduce the severity of URTIs.

The blood pressure-lowering effect and safety of chlorogenic acid from green coffee bean extract in essential hypertension.

Chlorogenic acids (CGA) in green coffee bean extract (GCE) reduce blood pressure in spontaneously hypertensive rats and humans. The authors examined the blood pressure-lowering effect and safety of CGA in patients with mild hypertension through a placebo-controlled, randomized clinical trial. Subjects (n = 28) were randomized to receive treatment with CGA (140 mg/day) from GCE or placebo. Blood pressure, pulse rate, body mass index, routine blood test, hematochemistry, urinalysis, and subjective symptoms were recorded throughout the study. In the CGA group, but not the placebo group, blood pressure (systolic and diastolic) decreased significantly during the ingestion period. There was no difference in body mass index and pulse rate between groups, nor were there any apparent side effects. Thus, CGA from GCE is effective in decreasing blood pressure and safe for patients with mild hypertension.

Chemiluminescence in autoxidation of phosphonate carbanions. Phospha-1,2-dioxetanes as the most likely high-energy intermediates.

Autoxidation of the phosphonate carbanions derived from 9-phosphono-10-hydroacridanes provided chemiluminescence ascribed to the excited acridone anion. The intramolecular CIEEL (chemically initiated electron exchange luminescence) mechanism can be applied to this chemiluminescence because of the much higher emission efficiency compared to that of 9-phosphono-10-methylacridanes. The effect of the phosphonate substituents on the emission efficiency and especially on the rates of the chemiluminescence decay can be interpreted to originate from the valence deviation of the phosphorus atoms, which is connected with the substituent effect on the geometrical selectivity in the olefination reaction of the phosphonate carbanions. The enhanced chemiluminescence in the presence of the fluorophores was also detected in autoxidation of the carbanions of diethyl diphenylmethylphosphonate and fluorenylphosphonate. Although the evidence is circumstantial, these results strongly support the belief that phospha-1,2-dioxetane is the most likely high-energy intermediate generating the excited molecules.