Cytotoxic and mutagenic evaluation of extracts from plant species of the Miconia genus and their influence on doxorubicin-induced mutagenicity: An in vitro analysis

The Miconia genus, a plant widely used for medicine, occurs in tropical America and its extracts and isolated compounds have demonstrated antibiotic, antitumoral, analgesic and antimalarial activities. However, no study concerning its genotoxicity has been conducted and it is necessary to determine its potential mutagenic effects to develop products and chemicals from these extracts. This study assessed the cytotoxicity, mutagenicity and the protective effects of methanolic extracts from Miconia species on Chinese hamster lung fibroblast cell cultures (V79). The cytotoxicity was evaluated using a clonogenic assay. Cultures exposed to the extract of Miconia albicans up to a concentration of 30 μg/mL, M. cabucu up to 40 μg/mL, M. albicans up to 40 μg/mL and M. stenostachya up to 60 μg/mL exhibited a cytotoxic effect on the cells. The clonogenic assay used three non-cytotoxic concentrations (5, 10 and 20 μg/mL) to evaluate mutagenicity and antimutagenicity of the extracts. Cultures were treated with these three extract concentrations (mutagenicity test) or the extract associated with doxorubicin (DXR) (antimutagenicity test) in three protocols (pre-, simultaneous and post-treatments). Distilled water and DXR were used as negative and positive controls, respectively. In the micronucleus (MN) test, a significant reduction was observed in MN frequency in cultures treated with DXR and extracts compared to those receiving only DXR; a significant reduction was also observed for the presence of mutagenicity in all treatments. This study confirmed the safe use of Miconia extracts at the concentrations tested and reinforced the therapeutic properties previously described for Miconia species by showing their protective effects on doxorubicin-induced mutagenicity.     

Mutagenic activity promoted by amentoflavone and methanolic extract of Byrsonima crassa Niedenzu

Byrsonima crassa is a plant pertaining to the Brazilian central savannah-like belt of vegetation and popularly used for the treatment of gastric dysfunctions and diarrhoea. The methanol extract contains catechin, tannins, terpenes and flavonoids; both mutagenic potential and antioxidant properties have been ascribed to flavonoids. The mutagenicity of some flavonoids is believed to be associated with the formation of reactive oxygen species and seems to depend on the number and position of hydroxyl groups. In the present study the mutagenic activity of the methanol, chloroform and 80% aqueous methanol extracts, as well as acetate and aqueous sub-fractions, of this medicinal plant were evaluated by Salmonella typhimurium assay, using strains TA100, TA98, TA102 and TA97a, and in mouse reticulocytes. The results showed mutagenic activity of the methanolic extract in the TA98 strain without S9, but no mutagenicity to mouse cells in any of the extracts. The acetate fraction showed strong signs of mutagenicity without S9, suggesting that in this enriched fraction were concentrated the compounds that induced mutagenic activity. The aqueous fraction showed no mutagenic activity. The TLC and HSCCC analyses of the acetate fraction with some standard compounds permitted the isolation of the quercetin-3-O-beta-D-galactopyranoside, quercetin-3-O-alpha-L-arabinopyranoside, amentoflavone, methyl gallate and (+)-catechin, of which only the amentoflavone exhibited positive mutagenicity to TA98 (+S9, -S9).     

In vivo assessment of DNA damage and protective effects of extracts from Miconia species using the comet assay and micronucleus test

The genus Miconia comprises approximately 1000 species belonging to the Melastomataceae family. Several crude plant extracts from Miconia and their isolated compounds have shown biological activities, such as analgesic and anti-neoplastic action; however, no studies concerning their effects on DNA are available. The present study aimed to evaluate, in vivo, the genotoxic and mutagenic effects of four species of plants from Miconia genus using the comet assay and micronucleus test. Their possible protective effects were also evaluated in experiments associating the plant extracts with cyclophosphamide (CPA). The methanolic extracts of Miconia albicans, Miconia cabucu, Miconia rubiginosa, Miconia stenostachya and the chloroformic extract of M. albicans were investigated. For genotoxic and mutagenic evaluations, three concentrations were tested, 200, 400 and 540 mg/kg body weight (bw), based on the solubility limit of the extract in distilled water. For the protective effects, only the highest dose was evaluated against 40 mg/kg bw of CPA. Blood was removed from mice tails pre- (T0) and post-treatment (T1-30 h) for the micronucleus test and 24 h post-treatment for the comet assay. The Student's t-test was used to compare data obtained at T0 and T1, the analysis of variance-Tukey test was used to compare between groups in the micronucleus test and the Kruskal-Wallis and Dunn's test were used to compare different groups in the comet assay. All the extracts induced alterations in DNA migration (comet assay); however, no mutagenic effect was observed in the micronucleus assay. All extracts showed a protective effect against CPA in both assays. Our study showed that the use of crude extracts could be more advantageous than the use of isolated compounds. The interaction between phytochemicals in the extracts showed efficacy in reducing mutagenicity and improving the protective effects.     

Risk Factors for Pilonidal Sinus Disease in Teenagers

Objective

To investigate the risk factors for pilonidal sinus in teenagers.

Methods

Between January 2013 and September 2015, 55 teenage patients who underwent surgery due to pilonidal sinus disease (PSD) in the Department of Pediatric Surgery, Sakarya University Teaching and Research Hospital were included in this study. Age, gender, body mass index (BMI), number of baths taken per week, time spent sitting per day, family history, and skin color were examined as risk factors. The control group comprised of healthy teenagers without pilonidal sinus disease.

Results

Out of the total 42 teenagers, 23 (54.8 %) were girls and 19 (45.2 %) were boys. Patients were classified as obese, overweight, or normal according to their BMI (14.3 %, 31 %, and 54.8 %, respectively). The number of baths taken per week in the PSD group was lower than that in the control group [odds ratio (OR): 3.690; p = 0.004]. The family history of PSD was significantly higher in teenagers with PSD, compared to the control group (OR: 8.652; p = 0.005). No differences were detected between the PSD and control groups with respect to sitting for ≥ 6 h per day (OR: 3.212; p = 0.028). Skin color was not found to be affected by PSD in teenagers (OR: 1.294; p = 0.392).

Conclusions

Heredity and the number of baths taken per week were found to significantly affect the incidence of PSD, whereas other variables (gender, age, BMI, skin color, and time spent sitting per day) did not exhibit any significant influence on the rate of incidence.

     

Effects of desflurane on middle ear pressure

OBJECTIVE: To evaluate the effects of desflurane on middle ear pressure. STUDY DESIGN: A prospective clinical study. METHODS: In this study, 38 ears of 19 male children that were scheduled for circumcision were included. Baseline tympanometry reading was performed on each ear just before anesthesia. After induction anesthesia with propofol a laryngeal mask was applied and desflurane administration was started. The next tympanometry reading was taken at 5th, 10th and 15th minute after administration and at the 10th minute after the cessation of desflurane. Data were analysed using Wilcoxon test. RESULTS: Mean MEP values before anesthesia in 38 ears of 19 boys were -10.32+/-33.14. After starting the administration of desflurane 5th minute mean value was 71.15+/-60.42, at the 10 th minute 111.56+/-59.03 and at the 15th minute it increased to 120.50+/-54.14, and these measurements were significantly higher than the starting value (p<0.001). After cessation of desflurane mean MEP value dropped to 57.56+/-79.06, but compared with the starting value this was also significantly higher (p<0.001). CONCLUSION: Desflurane may increase the middle ear pressure and it may be unsuitable for certain middle ear surgeries.     

Decrease of the incidence of human and canine visceral leishmaniasis after dog vaccination with Leishmune in Brazilian endemic areas

Leishmune^®, the first prophylactic vaccine licensed against canine visceral leishmaniasis (CVL), has been used in Brazil since 2004, where seropositive dogs are sacrificed in order to control human visceral leishmaniasis (VL). We demonstrate here that vaccination with Leishmune^® does not interfere with the serological control campaign (110,000 dogs). Only 1.3% of positivity (76 among 5860) was detected among Leishmune^® uninfected vaccinees. We also analyzed the possible additive effect of Leishmune^® vaccination over dog culling, on the decrease of the incidence of CVL and VL in two Brazilian endemic areas, from 2004 to 2006. In Araçatuba, a 25% of decline was seen in CVL with a 61% decline in human cases, indicating the additive effect of Leishmune^® vaccination of 5.7% of the healthy dogs (1419 dogs), on regular dog culling. In Belo Horizonte (BH), rising curves of canine and human incidence were observed in the districts of Barreiro, Venda Nova and Noroeste, while the canine and human incidence of Centro Sul, Leste, Nordeste, Norte, Pampulha and Oeste, started to decrease or maintained a stabilized plateau after Leishmune^® vaccination. Among the districts showing a percent decrease of human incidence (−36.5%), Centro Sul and Pampulha showed the highest dog vaccination percents (63.27% and 27.27%, respectively) and the lowest dog incidence (−3.36% and 1.89%, respectively). They were followed by Oeste, that vaccinated 25.30% of the animals and experienced an increase of only 12.86% of dog incidence and by Leste and Nordeste, with lower proportions of vaccinees (11.72% and 10.76%, respectively) and probably because of that, slightly higher canine incidences (42.77% and 35.73%). The only exception was found in Norte district where the reduced human and canine incidence were not correlated to Leishmune^® vaccination. Much lower proportions of dogs were vaccinated in Venda Nova (4.35%), Noroeste (10.27%) and Barreiro (0.09%) districts, which according to that exhibited very increased canine incidences (24.48%, 21.85% and 328.57%, respectively), and pronounced increases in human incidence (14%, 4% and 17%, respectively). The decrease of canine (p = −0.008) and human incidences (p = −0.048) is directly correlated to the increase of the number of vaccinated dogs, confirming the additive control effect of Leishmune^® vaccination over dog culling, reducing the parasite reservoir, protecting dogs and, in this way, reducing the risk of transmission of VL to humans and becoming a new effective control tool.     

Effects of sevoflurane and TIVA with propofol on middle ear pressure

OBJECTIVE: To evaluate the effects of sevoflurane and TIVA with propofol on middle ear pressure and to show the importance of anesthesia without using any inhalational agents during middle ear surgery. STUDY DESIGN: A prospective, randomized controlled clinical study. METHODS: In this study, 25 male children that were scheduled for circumcision were randomised into two groups. Group I (n=13) received TIVA with propofol and group II (n=12) received sevoflurane. Baseline tympanometry reading was performed on each ear just before anesthesia. The next tympanometry reading was taken 10min after applying the laryngeal mask. Data were analysed by Mann-Whitney U (between groups) and Wilcoxon tests (within groups). RESULTS: Mean MEP values in 26 ears of 13 boys in group I did not show any significant difference before and after the anesthesia with propofol (p>0.05). In group II mean MEP values in 24 ears of 12 boys showed a significant increase after the anesthesia with sevoflurane (p<0.001). No significant difference was found between the MEP values of the two groups before the anesthesia (p>0.05), and MEP values measured during the anesthesia were significantly higher in group II (p=0.007). CONCLUSION: Sevoflurane may increase the middle ear pressure and TIVA with propofol may be used in middle ear operations more safely than sevoflurane.     

Evaluation of the influence of polymorphic variants CYP1A1 2B, CYP1B1 2, CYP3A4 1B, GSTM1 0, and GSTT1 0 in prostate cancer

Background/objectiveGenetic polymorphisms in cytochrome P-450 (CYPs) and glutathione S-transferase (GSTs) genes can influence the appearance of tumors by the formation of new enzymes with altered activities. In the present study, 5 polymorphic variants were examined in 154 patients with prostate carcinoma and in 154 controls.Materials and methodsDNA analysis was carried out through PCR-based methods. The statistical methods used were odds ratio and confidence interval (95% CI), χ², Fisher, and Mann-Whitney.ResultsThe study showed absence of association for CYP1A1*2B, CYP1B1*2, GSTM1*0, and GSTT1*0. The statistical analysis implied a positive association of variant CYP3A4*1B for prostate cancer. The combined analysis of CYP1A1*2B, CYP1B1*2, and CYP3A4*1B genotypes showed positive association. The analysis of histopathologic parameters detected statistically significant differences for Gleason score and biochemistry recurrence risk. The presence of the GSTT1*0 genotype in red meat consumers increased the risk for this disease.ConclusionSome polymorphic variants analyzed can influence the development and the progression of prostate cancer.     

Letter to the editor: “The association of CD40 polymorphism (rs1883832C/T) and soluble CD40 with the risk of systemic lupus erythematosus among Egyptian patients”

Clinical Rheumatology -