Rapid Bactericidal Action of Propolis against Porphyromonas gingivalis.

Propolis, a resinous substance produced by bees, is used as a folk medicine for treatment of periodontal diseases. However, its mode of the action and the compounds responsible for its activities remain obscure. In the present study, we comprehensively investigated the antibacterial activities of ethanol-extracted propolis (EEP) and EEP-derived compounds toward Porphyromonas gingivalis, a keystone pathogen for periodontal diseases. Broth microdilution and agar dilution assays were used to determine the minimum inhibitory concentrations of EEP against a range of oral bacterial species, of which P. gingivalis showed a higher level of sensitivity than oral commensals such as streptococci. Its antibacterial activity toward P. gingivalis was maintained even after extensive heat treatment, demonstrating a high level of thermostability. EEP also induced death of P. gingivalis cells by increasing membrane permeability within 30 min. Spatiotemporal analysis based on high-speed atomic force microscopy revealed that EEP immediately triggered development of aberrant membrane blebs, followed by bleb fusion events on the bacterial surface. Furthermore, we isolated artepillin C, baccharin, and ursolic acid from EEP as antibacterial compounds against P. gingivalis. Of those, artepillin C and baccharin showed bacteriostatic activities with membrane blebbing, while ursolic acid showed bactericidal activity with membrane rupture. In particular, ursolic acid demonstrated a greater ability to affect bacterial membrane potential with increased membrane permeability, probably because of its highly lipophilic nature as compared with other compounds. Taken together, these findings provide mechanistic insight into the antibacterial activities of EEP and its exquisite membrane-targeting antibacterial compounds and imply the applicability of narrow-spectrum therapeutics with EEP for treatment of periodontitis. In addition, the advanced technology utilized in the present study to visualize the nanometer-scale dynamics of microorganisms will contribute to expanding our understanding of the activities of antimicrobials and the mechanism of drug resistance in bacteria.

The effect of phosphatidylserine administration on memory and symptoms of attention-deficit hyperactivity disorder: a randomised, double-blind, placebo-controlled clinical trial.

BACKGROUND: Attention-deficit hyperactivity disorder (ADHD) is the most commonly diagnosed behavioural disorder of childhood, affecting 3-5% of school-age children. The present study investigated whether the supplementation of soy-derived phosphatidylserine (PS), a naturally occurring phospholipid, improves ADHD symptoms in children. METHODS: Thirty six children, aged 4-14 years, who had not previously received any drug treatment related to ADHD, received placebo (n = 17) or 200 mg day(-1) PS (n = 19) for 2 months in a randomised, double-blind manner. Main outcome measures included: (i) ADHD symptoms based on DSM-IV-TR; (ii) short-term auditory memory and working memory using the Digit Span Test of the Wechsler Intelligence Scale for Children; and (iii) mental performance to visual stimuli (GO/NO GO task). RESULTS: PS supplementation resulted in significant improvements in: (i) ADHD (P < 0.01), AD (P < 0.01) and HD (P < 0.01); (ii) short-term auditory memory (P < 0.05); and (iii) inattention (differentiation and reverse differentiation, P < 0.05) and inattention and impulsivity (P < 0.05). No significant differences were observed in other measurements and in the placebo group. PS was well-tolerated and showed no adverse effects. CONCLUSIONS: PS significantly improved ADHD symptoms and short-term auditory memory in children. PS supplementation might be a safe and natural nutritional strategy for improving mental performance in young children suffering from ADHD.

Effect of docosahexaenoic acid-containing food administration on symptoms of attention-deficit/hyperactivity disorder - a placebo-controlled double-blind study.

OBJECTIVES: To investigate whether docosahexaenoic acid (DHA) supplementation was able to ameliorate attention-deficit/hyperactivity disorder(AD/HD) symptoms in AD/HD children. DESIGN AND SUBJECTS: A placebo-controlled double-blind study with 40 AD/HD (including eight AD/HD-suspected) children of 6-12 y of age who were mostly without medication. Subjects of a DHA group (n=20) took active foods containing fish oil (fermented soybean milk, bread rolls and steamed bread; 3.6 g DHA/week from these foods) for 2 months, whereas those of a control group (n=20) took indistinguishable control foods without fish oil. The following items were measured at the start and end of the study: (1) attention deficit, hyperactivity and impulsivity (AD/HD-related symptoms according to DSM-IV criteria); (2) aggression assessed by both parents and teachers; (3) visual perception (finding symbols out of a table); (4) visual and auditory short-term memory; (5) development of visual-motor integration; (6) continuous performance; (7) impatience. RESULTS: Changes in tests 1, 2, 3, 5 and 7 over time did not significantly differ between the two groups. However, visual short-term memory and errors of commission (continuous performance) significantly improved in the control group compared with the changes over time in the DHA group (P=0.02 and 0.001, respectively). Recalculation without AD/HD-suspected subjects (n=4 each group) showed similar P-values with regard to both measures. CONCLUSION: DHA supplementation did not improve AD/HD-related symptoms. Treatment of ADHD with fatty acids deserves further investigation, but careful attention should be paid as to which fatty acid(s) is used.

Tumor targeting by arterial administration of lipids: rabbit model with VX2 carcinoma in the liver.

We previously found that a lipid contrast medium, Lipiodol, remained selectively in liver tumors for a prolonged time after injection via the hepatic artery. We now extend this technique to other lipids including linoleic acid, olive oil, tea seed oil, and medium-chain triglyceride (MCT). MCT is a semisynthetic triglyceride with a lower viscosity than that of the other lipids. Each lipid was mixed with 14C linoleic acid, and the mixture with or without anticancer agent smancs was injected via the proper hepatic artery of rabbits with VX2 carcinoma in the liver. The 14C count in the tumor tissue was always more than 100 times that of the plasma or kidney, and the radioactivity 15 min after injection of MCT was more than 2500 times greater than that of blood plasma. At 24 hr after injection, the radioactivity recovered in the tumor was 4.9-37.0% (average 19.6%) of the dose, which indicated the greatest retention in the tumor tissue; there was rapid clearance from the rest of the body primarily via the bile. Advantages of the administration of lipid-solubilized drugs are: (i) remarkable tumor-selective targeting (a decisive anticancer effect with fewer side effects); (ii) prolonged drug retention (resulting in infrequent administration); (iii) various choices of different fatty acids with various pharmacokinetic characteristics as the carriers of the anticancer agents; and (iv) arterial administration is practicable in most hospitals.

[Stability of high molecular weight anticancer agent SMANCS and its transfer from oil-phase to water-phase. Comparative study with neocarzinostatin].

SMANCS is a conjugate protein of copolymer of styrene-maleic acid [SMA] (molecular weight: 1,500) and an antitumor protein neocarzinostatin [NCS] (molecular weight: 11,700). It has an approximate molecular weight of 15,000. We report here stability of SMANCS in oil and in water, and NCS in water, under various physical conditions such as exposure to heat, UV, pH, and ultrasonic treatment. Then, we carried out an experiment of transfer of SMANCS in lipid contrast medium [lipiodol] (oil phase) to water phase (blood and physiological saline) in vitro. Results are summarized as follows: In aqueous condition, SMANCS is far more stable than NCS against the exposure to heat and UV, though it is inactivated by excessive exposures. SMANCS in an oily medium was found much more stable even at higher temperatures than in the aqueous phase. Both SMANCS and NCS are the most stable at pH 4.9-6.0. SMANCS dissolved in oil transferred to water phase slowly, having T1/10 of 24 hours (in case of lipiodol). This helps maintaining the anticancer effect of the drug in vivo for a long period of time. SMANCS in lipiodol was found to exert its action against cultured tumor cells as in an aqueous solution.