Comparison of antioxidant activities and total polyphenolic and methylxanthine contents between the unripe fruit and leaves of Ilex paraguariensis A. St. Hil.

Ilex paraguariensis is used in Brazil as a stimulating beverage called "mate". Leaves and immature fruit extracts of Ilex paraguariensis were evaluated for their radical scavenging capacity, total methylxanthine and polyphenol contents. Antimicrobial activity of two enriched saponin fractions obtained from the fruits were also evaluated. The radical scavenging activity of the fractioned extracts was determined spectrophotometrically using 1,1-diphenylpicrylhydrazyl free radical (DPPH). The IC50o of L-ascorbic acid, ethyl acetate and n-butanol fractions from the leaves and ethyl acetate fraction from the fruits were 6.48 microg/mL, 13.26 microg/mL, 27.22 microg/mL, and 285.78 microg/mL, respectively. Total methylxanthine content was 1.16 +/- 0.06 mg/g dry weight in the fruits and 8.78 +/- 0.01 mg/g in the leaves. Total polyphenol content varied from 86.82 +/- 3 x 10(-4) to 199.91 +/- 3 x 10(-3) mg/g in leaf fractions and from 54.25 +/- 1 x 10(-3) to 110.36 +/- 4 x 10(-4) mg/g in fruit fractions. Enriched saponin fractions from the fruits showed no antimicrobial activity. To our knowledge, this are the first data available on the antioxidant/antimicrobial activities and polyphenol/methylxanthine contents of Ilex paraguariensis fruits.

Evaluation of dentin root canal permeability after instrumentation and Er:YAG laser application.

BACKGROUND AND OBJECTIVES: Smear layer removal with EDTA from root canal walls allows greater cleaning and disinfection of root canals. However, because Er:YAG laser acts on the removal of the smear layer, the objective of investigation was to analyze in vitro the effect of Er:YAG laser on dentin root canal wall permeability after endodontic instrumentation and irrigation with water or sodium hypochlorite and Er:YAG laser application. STUDY DESIGN/MATERIALS AND METHODS: A total of 25 extracted human maxillary incisors were divided into five groups: Group I, instrumentation with deionized distilled water as the irrigating solution; Group II, instrumentation with 1% sodium hypochlorite as the irrigating solution; Group III, instrumentation with deionized distilled water as the irrigating solution and Er:YAG laser application; Group IV, instrumentation with 1% sodium hypochlorite solution as the irrigating solution and Er:YAG laser application; Group V, instrumentation only up to #20 file with deionized distilled water as the irrigating solution and Er:YAG laser irradiation. The laser parameters were 15 Hz, 140 mJ, total energy 42 J, 300 pulses (Kavo Key Laser). Copper sulfate (10%) was used to evaluate dentin permeability. The penetration of copper ions into the dentinal tubules was observed using 1% rubeanic acid, which reveals copper ions, forming a stained compound ranging in color from deep blue to black. Transverse sections (500-microm thick) were obtained with a diamond disk from the cervical, middle, and apical thirds. RESULTS: The instrumentation of the root canal that used water as the irrigating solution followed by Er:YAG laser irradiation promoted the greatest increase in dentin permeability. The use of Er:YAG laser, 1% sodium hypochlorite + Er:YAG, and 1% sodium hypochlorite used alone showed an intermediate capacity of increasing dentin permeability. The use of water as the irrigating solution without Er:YAG laser promoted the least dentin permeability. CONCLUSIONS: The use of water as the irrigating solution after instrumentation and Er:YAG laser irradiation was an effective procedure for increasing dentin permeability.