Influence of geography, seasons and pedology on chemical composition and anti-inflammatory activities of essential oils from Lippia multiflora Mold leaves.

ETHNOPHARMACOLOGICAL RELEVANCE: Lippia multiflora is a plant with nutritional and pharmaco-therapeutic properties that is native to central and occidental Africa. The potential effects of plants on health are associated with their chemical composition. Therefore, the present study aimed to identify chemical variations in essential oils of Lippia multiflora as a function of geographic origin and time of annual harvest to determine optimal chemical profiles for ethno-pharmacotherapeutic applications. MATERIALS AND METHODS: Experimental plants were cultivated at Abidjan (LPA), Toumodi (LPT) and Bondoukou (LPB). Natural Lippia multiflora seeds were sourced to produce standardized plants over a period of six months. Standard plants (n=40) were re-introduced into natural plots, cultivated for 12 months and leaves were sampled monthly in a standardized fashion. Essentials oils (n=36) were then extracted from these samples by hydro-distillation according to the European Pharmacopoeia and qualitatively and quantitatively analyzed using GC/FID and GC/MS. These data were then analyzed using Principal Component Analysis (PCA). Anti-inflammatory properties were also assessed against activated macrophages in vitro. RESULTS: The results indicated that chemical profiles and essential oil yields vary according to the location where the plants were cultivated. One essential oil chemotype corresponded to the LPA and LPT sites and one corresponded to the LPB site. Statistical analysis of the chemical profiles and monthly evolution of the three sites over a period of one year allowed assessment of variations in composition and the subsequent choice of the optimal harvest time for ethnopharmacological applications. Anti-inflammatory activity apparently correlated with chemical profiles of essential oils and the geographic origins of the plants. CONCLUSION: The optimal harvest time was associated with the maximum yield of pharmacological compounds with the most potential interest for health.

Calcium-strontium mixed phosphate as novel injectable and radio-opaque hydraulic cement.

Sterile calcium hydrogenophosphate dihydrate (DCPD) (CaHPO(4).2H(2)O), calcium oxide and strontium carbonate powders were mixed in various liquid phases. Among these, ammonium phosphate buffer (0.75 M, pH 6.9) led to a novel strontium-containing calcium phosphate cement. At a 6/2.5/1.5 M ratio and for a liquid to powder ratio (L/P) of 0.5 mlg(-1), the initial paste was fluid and remained injectable for 12 min at 25 degrees C. It was easily obtained by mixing sterile powders and the liquid phase using the push-pull technique, avoiding complex mixing apparatus. The cement set after 15 min at 37 degrees C and was hard after 1h. The compressive strength was in the 20 MPa range, a value higher than that generally assigned to trabecular bone (5-15MPa). This strength appeared sufficient for repairing non-loading sites or reinforcing osteoporotic vertebrae (vertebroplasty). After setting, the initial mixture formed a strontium-calcium-deficient carbonate apatite. The radio-opacity of the resulting cement was three times greater than that of cortical bone because of the presence of strontium ions, a feature that complies with the requirements for vertebroplasty. Furthermore, the cement powder remained stable and retained its properties for at least 4 years.

Quercetin exhibits a specific fluorescence in cellular milieu: a valuable tool for the study of its intracellular distribution.

The elaboration of novel techniques for flavonoid intracellular tracing would elucidate the compounds' absorption and bioavailability and assist molecular and pharmacological approaches, as they are promising candidates for drug development. This study exploited the properties of quercetin (3,3',4',5,7-pentahydroxyflavone), found in high concentrations in the majority of edible plants. Through the use of UV-vis spectroscopy, confocal microscopy, and HPLC-ESI-MS, native quercetin, at physiologically relevant concentrations, was found to exhibit a specific fluorescence (488 nmex/500-540 nmem) upon internalization. This fluorescence shift is due to a non-covalent binding to intracellular targets (probably proteins) and compatible with the settings applied in confocal microscopy. This property provides a valuable, selective alternative technique for quercetin tracing in cellular systems, permitting the quantitative evaluation of its transit at pharmacologically relevant concentrations and the validation of a number of already described molecular functions.

Study of a hydraulic dicalcium phosphate dihydrate/calcium oxide-based cement for dental applications.

By mixing CaHPO(4) x 2H(2)O (DCPD) and CaO with water or sodium phosphate buffers as liquid phase, a calcium phosphate cement was obtained. Its physical and mechanical properties, such as compressive strength, initial and final setting times, cohesion time, dough time, swelling time, dimensional and thermal behavior, and injectability were investigated by varying different parameters such as liquid to powder (L/P) ratio (0.35-0.7 ml g(-1)), molar calcium to phosphate (Ca/P) ratio (1.67-2.5) and the pH (4, 7, and 9) and the concentration (0-1 M) of the sodium phosphate buffer. The best results were obtained with the pH 7 sodium phosphate buffer at the concentration of 0.75 M. With this liquid phase, physical and mechanical properties depended on the Ca/P and L/P ratios, varying from 3 to 11 MPa (compressive strength), 6 to 10 min (initial setting time), 11 to 15 min (final setting time), 15 to 30 min (swelling time), 7 to 20 min (time of 100% injectability). The dough or working time was over 16 min. This cement expanded during its setting (1.2-5 % according to Ca/P and L/P ratios); this would allow a tight filling. Given the mechanical and rheological properties of this new DCPD/CaO-based cement, its use as root canal sealing material can be considered as classical calcium hydroxide or ZnO/eugenol-based pastes, without or with a gutta-percha point.