Alleviation of cadmium-induced phytotoxicity and growth improvement by exogenous melatonin pretreatment in mallow (Malva parviflora) plants.

The present work was aimed to study the effect of melatonin pretreatments on growth, oxidative stress modulation, cadmium (Cd) accumulation, and tolerance in mallow (Malva parviflora, Malvaceae) plants under the hydroponic system. Application of substances that can modulate the harmful effects of Cd on plant yield and reduce its accumulation in the edible parts is of particular importance. Therefore, the mallow plants pretreated with 15, 50, and 100 µM of melatonin were exposed to 50 µM Cd. Our results showed that melatonin, especially at 15 and 50 µM, led to positive effects on Cd tolerance, including a significant increase in growth, photosynthetic pigments, and soluble protein content. Exogenous melatonin could improve relative water content (RWC) and stomatal conductance in the plants treated with Cd, probably through an increase in proline. Further, lower concentrations of melatonin led to a decrease in Cd translocation to the shoots. Based on the results, melatonin considerably increased catalase (CAT), superoxide dismutase (SOD), and guaiacol peroxidase (GPX) activities as well as the production of phenols. The increased activity of antioxidant enzymes led to a decrease in electrolyte leakage (EL), lipid peroxidation, and H2O2 content in the plants exposed to Cd stress. Under Cd stress, the increased phenols content in melatonin-pretreated plants could be due to the induction of phenylalanine ammonia-lyase (PAL) activity and an increase in shoot soluble carbohydrates. The results showed that the use of melatonin could reduce oxidative stress and improve biomass in the plants exposed to Cd. At least in our experimental conditions, this information appears to be useful for healthy food production.

Modification of oxidative stress through changes in some indicators related to phenolic metabolism in Malva parviflora exposed to cadmium.

This study was conducted to investigate the role of phenolic compounds in the antioxidant defense system in Malva parviflora L. plants treated with cadmium (Cd). After surface sterilization, the seeds were sown on seedling trays. Forty-day-old plants were then transferred to hydroponic cultures with Cd (40 µM) or without Cd (control). Some biochemical and physiological parameters were assayed on the sixth day after Cd treatment. Based on the results, the plants showed an increase in leaf soluble carbohydrates, total phenolic compounds, total flavonoids, and phenylalanine ammonia-lyase (PAL) activity at the end of the exposure period. However, length, fresh weight, chlorophyll (Chl) b, total Chl, stomatal conductance and starch content decreased under Cd treatment. There was no significant difference between the plants exposed to Cd and the control group for Chl a, SPAD index, carotenoids, and anthocyanins as well as the H2O2 content six days after treatment. The Cd content in the roots was considerably higher than that in the shoots. In assessing the antioxidant capacity of plant extracts, different results were observed using 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) test and beta-carotene/linoleic acid bleaching assay. According to the results of this study, it seems that increased activity of PAL enzyme leads to an increase in biosynthesis of phenolic compounds in M. parviflora. This mechanism probably increases the antioxidant capacity of the plant to suppress Cd-induced toxicity and oxidative stress.

Screening ornamental plants to identify potential Cd hyperaccumulators for bioremediation.

To identify possible cadmium (Cd) accumulators or hyperaccumulators among ornamental plants, a pot experiment involving increasing Cd concentration (0, 5, 15, 30, 60, and 100 mg kg-1) was conducted among seven species. The principal objective was to screen for ornamental plants with an exceptional ability to accumulate and translocate Cd ions as well as sufficient biomass for harvesting. Regarding shoot biomass, root biomass, plant height and tolerance index (TI), Malva rotundifolia showed high tolerance to Cd and Malva crispa, Sida rhombifolia, Celosia argentea and Celosia cristata medium tolerance; Althaea rosea and Abutilon theophrasti were more sensitive to Cd than the other plants. A hormetic response was induced by Cd in M. crispa, C. argentea, C. cristata and M. rotundifolia. Based on its capacity for Cd accumulation, bioaccumulation coefficients (BCFs) and translocation factors (TFs), M. rotundifolia was selected from candidate plants after 60 days of exposure to Cd-contaminated soil and found to have accumulated more than 200 mg kg-1 Cd in its roots and 900 mg kg-1 in its shoots. Moreover, M. rotundifolia BCFs and TFs were higher than 1.0, with the former ranging from 1.41 to 3.31 and the latter from 1.03 to 7.37. Taken together, these results indicate that M. rotundifolia can be classified as a model hyperaccumulator.

Prevention of Oral Mucositis in Patients undergoing Chemotherapy / Prevenção da Mucosite Oral em Pacientes submetidos à Quimioterapia / Prevención de la Mucositis Oral en Pacientes sometidos a la Quimioterapia

Introduction: The chemotherapy is one of the cancer possible treatments and use chemotherapeutic drugs as 5-fluorouracil (5-FU), major cause of oral mucositis. This complication is the most common cause of pain. There is still no specific protocol for the prevention of this complication, but there are substances used empirically and palliative. Objective: Assessing the degree of mucositis during the 10 days after each chemotherapy cycle using the self-perception of each patient and the pain level reported with the use of the two substances studied: mallow tea and 0,12% chlorhexidine. Method: The selected patients were randomly randomized to perform mouthwash with 10 ml of the test substance, 3 times a day, during the infusion time of chemotherapy. In each accompanied cycle one of the studied substances were used. During the 10 days after chemotherapy, patients answered a questionnaire with closed questions about their pain and self-perception of their oral mucosa. Results: in cycles where mallow tea was used, self-perception of patients seems to be better with your oral mucositis is grade 1 and 2. However, in cycles where 0,12% chlorhexidine was used, patients experienced less pain. Conclusion:In both cycles that was used at 0.12% chlorhexidine was used as those where the mauve tea, most of the patients reported oral mucositis present. However, when used mauve tea was obtained mucositis in minor degrees. The 0.12% chlorhexidine it appeared to have less pain symptoms, although the difference was small when compared to the two substances.

Introdução: A quimioterapia é uma das formas de tratar o câncer, na qual utilizam-se drogas como o 5-fluorouracil (5-FU), maior causador da mucosite oral. Essa complicação é a causa mais comum de dor. Objetivo.Avaliar o grau de mucosite oral durante os dez dias após cada ciclo de quimioterapia, segundo a autopercepção de cada paciente e o nível de dor relatada com o uso das duas substâncias estudo: chá de malva e clorexidina 0,12%. Método. Os pacientes foram randomizados por sorteio para a realização de bochechos com 10 ml da substância determinada, três vezes ao dia, durante o período de infusão da quimioterapia. Em cada ciclo, utilizou-se uma das substâncias. Durante os dez dias após a quimioterapia, os pacientes responderam a um questionário com perguntas fechadas sobre a sua dor e a autopercepção da sua mucosa oral. Resultados. Nos ciclos utilizando o chá de malva, a autopercepção do paciente pareceu ser melhor, com sua mucosite oral sendo de graus 1 e 2. Contudo, nos ciclos utilizando clorexidina 0,12%, os pacientes apresentaram menos dor. Conclusão. Tanto nos ciclos em que foi utilizado a clorexidina 0,12% quanto naqueles onde foi utilizado o chá de malva, a maioria dos pacientes referiu apresentar mucosite oral. Porém, quando utilizado o chá de malva, a frequência de mucosite foi em menores graus. A clorexidina 0,12% pareceu apresentar menos sintomatologia dolorosa, apesar da diferença, comparando as duas substâncias, ter sido pequena.

Introducción: La quimioterapia es una forma de tratamiento de cáncer y se utilizan drogas como el 5-fluorouracilo (5-FU), mayor causante de la mucositis oral. Aún no hay un protocolo específico para la prevención de esta complicación. Objetivo: Evaluar el grado de mucositis oral durante los 10 días después de cada ciclo de quimioterapia según la auto-percepción de cada paciente y el nivel de dolor relatado con el uso de las dos sustancias estudio: té de malva y clorexidina 0,12%. Método: Los pacientes fueron aleatorizados por sorteo para la realización de enjuague con 10ml de la sustancia determinada, 3 veces al día, durante el período de infusión de la quimioterapia. En cada ciclo se utilizó una de las sustancias. Durante los 10 días después de la quimioterapia los pacientes respondieron a un cuestionario con preguntas cerradas sobre su dolor y la autopercepción de su mucosa oral. Resultados: En los ciclos utilizando el té de malva la auto-percepción del paciente pareció ser mejor, con su mucositis oral siendo de grado 1 y 2. En los ciclos utilizando clorexidina 0,12% los pacientes presentaron menos dolor. Conclusión: Tanto en los ciclos en que se utilizó la clorexidina 0,12% como en aquellos donde se utilizó el té de malva, la mayoría de los pacientes refirió presentar mucositis oral. Sin embargo, cuando se utilizó el té de malva la frecuencia de mucositis fue en menores grados. La clorexidina 0,12% pareció presentar menos sintomatología dolorosa, a pesar de la diferencia comparando las dos sustancias haber sido pequeña.

The response of some common Egyptian plants to ozone and their use as biomonitors.

Relative sensitivity of five common Egyptian plant species namely, Senecio vulgaris, Malva parviflora, Sonchus oleraceus, Medicago sativa and Melilotus indicus to elevated levels of ozone has been studied. The plants were exposed to charcoal filtered air (CFA) and different levels of O3 (50 and 100 ppb) for 5 h per day. The studied parameters were recorded for five consecutive days after fumigation. The foliar injury varied significantly among species in a dose-dependent manner. Severe injury symptoms were recorded on the leaves of M. sativa. With the exception of M. parviflora, all species exhibited significant increases in the percentage reduction of the above-ground dry weight as a result of reductions in both leaf and stem dry weights. M. sativa showed a marked reduction in its relative growth rate at elevated levels of O3. The extent of chlorophyll a destruction was higher in both M. sativa and S. oleraceus than in the other species tested. No differences in the sensitivity of chlorophylls a+b and carotenoids to ozone levels were recorded in this work. Percentage reduction of ascorbic acid was higher in M. sativa and S. oleraceus, compared with the other species studied. With respect to relative percentages of proline, there was a significant difference in the responses of plants to ozone. According to the ozone resistance (R%), measured as relative growth rate, the test species were arranged in the descending order: M. parviflora>M. Indicus>S. Vulgaris>S. Oleraceus>M. sativa. In M. sativa, both determinant and correlation coefficients are well reflected in the relationship between its physiological response, its performance and ozone levels, supporting its recommendation as a candidate for biomonitoring in Egypt.