[Concentrations of alkaloids, cyanogenic glycosides, polyphenols and saponins in selected medicinal plants from Ecuador and their relationship with acute toxicity against Artemia salina]. / Concentraciones de alcaloides, glucósidos cianogénicos, polifenoles y saponinas en plantas medicinales seleccionadas en Ecuador y su relación con la toxicidad aguda contra Artemia salina.

Alkaloids, polyphenols, cyanogenic glycosides and saponins are among the main chemical compounds synthesized by plants but not considered essential for their basic metabolism. These compounds have different functions in plants, and have been recognized with medicinal and pharmacological properties. In this research, concentrations of the mentioned secondary metabolites were determined in the medicinal plants Artemisia absinthium, Cnidoscolus aconitifolius, Parthenium hysterophorus, Piper carpunya and Taraxacum officinale, from Ecuador, and related with cytotoxic effects against Artemia salina. Alcoholic and aqueous extracts from leaves of these selected plants were prepared at different concentrations. To assess cytotoxicity of these extracts, different bioassays with A. salina were undertaken, and the mortality rates and LC50 were obtained. Besides, concentrations of alkaloids, cyanogenic glycosides, phenols, tannins and saponins were determined by spectrophotometric methods; this constituted the first report of quantification of secondary metabolites in the selected plants from Ecuador. T. officinale had the highest concentration of total phenols (22.30 ± 0.23 mg/g) and tannins (11.70 ± 0.10 mg/g), C. aconitifolius of cyanogenic glycosides (5.02 ± 0.37 µg/g) and P. hysterophorus of saponins (6.12 ± 0.02 mg/g). Tannins values obtained were not adverse to their consumption. Alcoholic and aqueous extracts of selected plants had hemolytic activity depending on the concentration of saponins. Although the values of cyanogenic glycosides were permissible, it was necessary to monitor the presence of this metabolite in plants to minimize health problems. LC50 values ranged from extremely toxic (3.37 µg/mL) to highly toxic (274.34 µg/mL), in P. carpunya and T. officinale, respectively. From correlation analysis, it was observed that increase values of alkaloids concentrations had highly significant (p<0.001) acute toxicity against A. salina, while at a higher polyphenol concentration the level of plants cytotoxicity decreased significantly (p<0.001). The results of principal component analysis showed that saponins apparently were in synergy with polyphenols to decrease cytotoxicity, but antagonize with alkaloids and cyanogenic glycosides, indicating that these secondary metabolites present variability in the mechanisms of action against A. salina, as cytotoxic compounds. These results also demonstrate that polyphenols and saponins can be lethal at low concentrations, demonstrating the potential of brine shrimp bioassay as a model to evaluate plant extracts containing low concentrations of chemical compounds with high polarities. The significant positive correlation between cytotoxicity and concentration of alkaloids confirmed by the bioassay of brine shrimp can be useful to identify promising sources of antitumor compounds, and to evaluate tolerable limits not affecting other benign cells. Contents of secondary metabolites found in the selected plants confer them great pharmacologic values.

Toxicological analysis and anti-inflammatory effects of essential oil from Piper vicosanum leaves.

This study assessed the anti-inflammatory effects of the essential oil from Piper vicosanum leaves (OPV) and evaluated the toxicological potential of this oil through acute toxicity, genotoxicity and mutagenicity tests. The acute toxicity of OPV was evaluated following oral administration to female rats at a single dose of 2 g/kg b.w. To evaluate the genotoxic and mutagenic potential, male mice were divided into five groups: I: negative control; II: positive control; III: 500 mg/kg of OPV; IV: 1000 mg/kg of OPV; V: 2000 mg/kg of OPV. The anti-inflammatory activity of OPV was evaluated in carrageenan-induced pleurisy and paw edema models in rats. No signs of acute toxicity were observed, indicating that the LD50 of this oil is greater than 2000 mg/kg. In the comet assay, OPV did not increase the frequency or rate of DNA damage in groups treated with any of the doses assessed compared to that in the negative control group. In the micronucleus test, the animals treated did not exhibit any cytotoxic or genotoxic changes in peripheral blood erythrocytes. OPV (100 and 300 mg/kg) significantly reduced edema formation and inhibited leukocyte migration analyzed in the carrageenan-induced edema and pleurisy models. These results show that OPV has anti-inflammatory potential without causing acute toxicity or genotoxicity.

Severity of periodontal disease in individuals chewing betel quid with and without tobacco.

BACKGROUND: The deleterious effects of chewing betel quid (BQ) with or without tobacco on periodontal health are poorly addressed. The aim of this study was to investigate the severity and extent of periodontal disease among individuals chewing BQ with and without tobacco. METHODS: One hundred twenty individuals (70 BQ chewers: 35 with tobacco and 35 without tobacco) and 50 control individuals (non-chewers) were included in this study. Sociodemographic data and information regarding BQ chewing habit were collected using a questionnaire. Plaque index, bleeding on probing and probing pocket depth were measured. Numbers of missing teeth were recorded and marginal bone loss was measured on panoramic radiographs. Statistical analyses were performed using 1-way analysis of variance and Bonferroni post hoc test. RESULTS: The socioeconomic status of subjects in the control group was significantly higher as compared with those chewing BQ either with or without tobacco. Plaque index, bleeding on probing and probing pocket depth were greater in subjects chewing BQ with tobacco than in those chewing BQ without tobacco and the controls. Subjects chewing BQ with tobacco had fewer teeth than those chewing BQ without tobacco and the controls. Marginal bone loss was higher in subjects chewing BQ with tobacco than in those chewing BQ without tobacco and the controls. CONCLUSIONS: The severity of periodontal disease is enhanced in subjects chewing BQ with tobacco as compared with those chewing BQ without tobacco. Subjects with a low socioeconomic status and poor education are significantly more likely than others to develop periodontal disease.

Schistosoma mansoni: In vitro schistosomicidal activity of piplartine

Schistosomiasis is one of the world’s greatly neglected tropical diseases, and its control is largely dependenton a single drug, praziquantel. Here, we report the in vitro effect of piplartine, an amide isolated from Piper tuberculatum (Piperaceae), on Schistosoma mansoni adult worms. A piplartine concentrationof 15.8 lM reduced the motor activity of worms and caused their death within 24 h in a RPMI 1640 medium.Similarly, the highest sub-lethal concentration of piplartine (6.3 lM) caused a 75% reduction in eggproduction in spite of coupling. Additionally, piplartine induced morphological changes on the tegument,and a quantitative analysis carried out by confocal microscopy revealed an extensive tegumental destructionand damage in the tubercles. This damage was dose-dependent in the range of 15.8–630.2 lM. At doses higher than 157.6 lM, piplartine induced morphological changes in the oral and ventral sucker regions of the worms. It is the first time that the schistosomicidal activity has been reported forpiplartine.

Molluscicidal and ovicidal activities ofplant extracts of the Piperaceae onBiomphalaria glabrata (Say, 1818)

Schistosomiasis is a tropical disease caused by Schistosoma and occurs in 54countries, mainly in South America, the Caribbean region, Africa and the easternMediterranean. Currently, 5 to 6 million Brazilian people are infected and 30,000are under infection risk. Typical of poor regions, this disease is associated withthe lack of basic sanitation and very frequently to the use of contaminated water in agriculture, housework and leisure. One of the most efficient methods of controlling the disease is application of molluscicides to eliminate or to reduce the population of the intermediate host snail Biomphalaria glabrata. Studies on molluscicidal activity of plant extracts have been stimulated by issues such as environmental preservation, high cost and recurrent resistance of snails tosynthetic molluscicides. The aim of this study was to determine the molluscicideaction of extracts from Piperaceae species on adult and embryonic stages ofB. glabrata. Fifteen extracts from 13 Piperaceae species were obtained from stems, leaves and roots. Toxicity of extracts was evaluated against snails at two different concentrations (500 and 100ppm) and those causing 100% mortality at 100ppm concentration were selected to obtain the LC90 (lethal concentration of 90% mortality). Piper aduncum, P. crassinervium, P. cuyabanum, P. diospyrifolium and P. hostmannianum gave 100% mortality of adult snails at concentrations ranging from 10 to 60 ppm. These extracts were also assayed on embryonic stages of B. glabrata and those from P. cuyabanum and P. hostmannianum showed 100%ovicidal action at 20ppm.

The tumor promoting effect of lime-piper betel quid in JB6 cells.

Betel quid chewing is a general behavior in Taiwan, India, southeastern Asian and South Africa. In this study, microculture tetrazolium test (MTT) showed that the extract of lime-piper betel quid (LPB) (1.0-20 mg/ml) was toxic to JB6 cells. Cells exposed of LPB (0.1, 0.5, 1.0 mg/ml) for 7 days resulted in changes in cytomorphology with characteristics of carcinogenesis. With a long-term treatment (approximately 30 days) of low doses of LPB (1, 5, 10 microg/ml), the production of H2O2 and the activity of myeloperoxidase (MPO) and ornithine decarboxylase (ODC) were increased in JB6 cells. Cell cycle analysis showed a decrease in the G1 phase and an accumulation in the S phase 48 h after LPB treatment. When treating with 0.5 mg/ml LPB for 15 days as a promoter, type III foci were formed in the JB6 culture. These results demonstrated the tumor promotional effect of LPB in JB6 cells.