Antimicrobial efficacy of fruit extracts of two piper species against selected bacterial and oral fungal pathogens

Aim: To assess the antimicrobial efficacy of five solvent extracts of two Piper species commonly used in diet and traditional medicine, P. cubeba and P. longum, against selected bacterial and oral fungal pathogens i.e. Streptococcus mutans, Staphylococcus aureus, Candida albicans and Saccharomyces cerevisiae. Methods: The antimicrobial activity of five extracts of cubeb berries and Indian long pepper fruits was determined by the agar well diffusion method. The minimum inhibitory concentration (MIC) for the acetonic, methanolic and ethanolic extracts was determined by the modified agar well diffusion method. Results: Of the 5 fruit extracts evaluated, acetone, ethanol and methanol extracts of both the Piper spp. were found to have variable antimicrobial activities against all the four oral pathogens. The acetonic fruit extract of P. cubeba was the most effective against both the yeasts with the highest zone of inhibition (15.31 mm) against C. albicans followed by the methanolic (12.31 mm) and ethanolic (11.94 mm) extracts. C. albicans was found to be most sensitive pathogen, which survived up to 6.25 mg/mL in the acetonic extract (MIC = 12.5 mg/mL) followed by the methanolic and ethanolic extracts (MIC = 25 mg/mL). The acetonic, methanolic and ethanolic extracts of P. longum fruits showed almost equal inhibition zones of both yeasts, ranging between 10.64 and 14 mm. C. albicans survived up to 12.5 mg/mL (MIC= 25 mg/mL) while S.cerevisiae survived up to 25 mg/mL (MIC = 50 mg/mL). Conclusions: The crude extracts obtained from the fruits of the two Piper spp. may be used to treat oral fungal species, especially C. albicans, as they produced larger inhibition zones than antifungal drugs often used to treat these pathogens.

Cadmium Induced Acute Lung Injury and TUNEL Expression of Apoptosis in Respiratory Cells

We examined the ultrastructural features of the lung parenchyma and the expression of apoptosis of the respiratory cells by TUNEL technique. Male Sprague-Dawley rats (n=30) were intra-tracheally injected with cadmium (2.5 mg/kg) into both lungs. The light and electron microscopic features of the lung tissues were examined on Days 1, 3, 7 and 10 after the injection of cadmium. Specimen preparations for the light and electron microscopic TUNEL stains were performed. Ultrastructurally, on Days 1 and 3, the alveolar spaces were filled with edematous fluid, and desquamated type I epithelial cells. On Days 7 and 10, the alveolar spaces and interstitium were patchy infiltrated with young fibroblasts and some collagen deposition. The light microscopic TUNEL stain showed that apoptosis of the alveolar cells was most prominent on Day 1, and then the number of apoptosis was markedly decreased on Days 3, 7 and 10. The electron microscopic TUNEL stain showed the electron dense homogenous nuclear expression, and the formation of intra-nuclear blebs which protrude to the outside of nuclei. On Days 7 and 10, there are frequent apoptotic nuclear bodies in the alveolar macrophages. We could examine the identification of the equivocal apoptotic cells and various morphologic expression of apoptotic nuclei on the electron microscopic TUNEL stain.

Effects of dehydration on modulus of elasticity of demineralized human dentin

Dentin bars of approximately 0.7 X 0.7 X 5.0 mm were obtained from the crown of human third molars. The specimens had their ends covered with nail varnish and were subjected to demineralization in 0.5 M EDTA for 72 hours. The specimens were stressed in tension, griped by their mineralized ends. The load/displacement data was transformed to stress/strain data using the original cross-sectional area and the length of the demineralized area (gauge-length). A low strain (0-2%) and the maximum moduli were calculated for specimens tested in water (control), dehydrated in acetone and in HEMA and air-dried. All dehydration procedures caused significant stiffening of the collagen netword. Air-dried specimens were the most stiffer, followed by acetone-dehydrated and HEMA-dehydrated specimens. The stiffening effect of organic solvents on acid-etched dentin, may alter the permeability of the collagen network to adhesive resins

The efficacy of acetone in the sterilisation of ophthalmic instruments.

Acetone has been considered a quick, effective and less expensive chemical sterilising agent and continues to be used by ophthalmic surgeons, at least in developing countries. Its utility however has been questioned recently. This study was designed to assess the efficacy of acetone against Pseudomonas aeruginosa, Bacillus subtilis and Aspergillus flavus present on ophthalmic surgical instruments (forceps, sutures). The instruments were contaminated by immersion in standard suspensions of the organisms and thereafter were either unwashed (group-I), washed and dried (group-II) or only washed (group-III) before immersion in acetone. The exposure to acetone was kept at 3, 10 and 20 minutes in each group. The results showed that acetone could eliminate Pseudomonas (vegetative bacteria) after 10 minutes exposure in unwashed group and 3 minutes exposure in washed groups. It was ineffective against spore bearing bacteria (B. subtilis) and fungus (Aspergillus flavus) even after 20 minutes of exposure.

Effects of acetone and ethanol on the bioelectrical activity and ventilation rate of the eel, anguilla anguilla L

The effects of acetone and ethanol on the bioelectrical activity and ventilation rate of eel fish were studied. It has been found that intoxicating dose of acetone and ethanol does not cause any major changes in the bioelectrical activity of the fish. On the other hand, acetone and ethanol produced an increase in ventilation rate to a maximum of 127.9% and 133.8%, respectively of the control values. It was concluded that acetone and ethanol may affect the results of fish toxicity tests