Oriented growth of poly(m-phenylenediamine) on Calotropis gigantea fiber for rapid adsorption of ciprofloxacin.

A facile polymerization of m-phenylenediamine (mPD) in methanol/water (50:50, v/v) was performed via conventional chemical oxidative method by using Calotropis gigantea fiber (CGF) as the natural biotemplate. The as-prepared CGF oriented poly(m-phenylenediamine) (PmPD), i.e. CGF-O-PmPD, exhibits a well defined fiber-oriented morphology. The presence of PmPD layer enables CGF-O-PmPD to present roughen surface with N-rich functional groups that can show high performance for the adsorption of ciprofloxacin. The variables affecting the adsorption capacity were systematically investigated, including contact time, initial concentration, initial pH, ion strength, and so forth. The experimental data reveal that with increasing the amount of mPD from 0.2, 0.5 to 2.0 g, the adsorption capacity for ciprofloxacin shows a monotonic decrease, while the adsorption kinetics show a monotonic increase, with the adsorption percentage from >50%, >60% to >70% within 10 s, demonstrating its superfast adsorption kinetics for ciprofloxacin. In addition, an increasing adsorption capacity is observed over the pH range studied, with the adsorption capacity from 0.73 to 6.7 mg g-1 at pH 2.0 to 64.9-77.3 mg g-1 at pH 10.0. After five adsorption-desorption cycles, the adsorption capacity of CGF-O-PmPD for ciprofloxacin shows no significant decrease, indicating its excellent reusability and potential application in treating antibiotic-containing wastewater.

Metabolomic response of Calotropis procera growing in the desert to changes in water availability.

Water availability is a major limitation for agricultural productivity. Plants growing in severe arid climates such as deserts provide tools for studying plant growth and performance under extreme drought conditions. The perennial species Calotropis procera used in this study is a shrub growing in many arid areas which has an exceptional ability to adapt and be productive in severe arid conditions. We describe the results of studying the metabolomic response of wild C procera plants growing in the desert to a one time water supply. Leaves of C. procera plants were taken at three time points before and 1 hour, 6 hours and 12 hours after watering and subjected to a metabolomics and lipidomics analysis. Analysis of the data reveals that within one hour after watering C. procera has already responded on the metabolic level to the sudden water availability as evidenced by major changes such as increased levels of most amino acids, a decrease in sucrose, raffinose and maltitol, a decrease in storage lipids (triacylglycerols) and an increase in membrane lipids including photosynthetic membranes. These changes still prevail at the 6 hour time point after watering however 12 hours after watering the metabolomics data are essentially indistinguishable from the prewatering state thus demonstrating not only a rapid response to water availability but also a rapid response to loss of water. Taken together these data suggest that the ability of C. procera to survive under the very harsh drought conditions prevailing in the desert might be associated with its rapid adjustments to water availability and losses.

Germination responses of the invasive Calotropis procera (Ait.) R. Br. (Apocynaceae): comparisons with seeds from two ecosystems in Northeastern Brazil.

Life history traits are considered key indicators of plant invasibility. Among them, the germination behavior of seeds is of major relevance because it is influenced by environmental factors of invaded ecosystem. Here, we investigated how seed traits and seed tolerance to environmental factors on seed germination of Calotropis procera vary depending on the invaded ecosystems in northeastern Brazil. We have tested seeds from two vegetation types - Caatinga and Restinga - to different levels of light intensity, salinity, and water stress. Previous to those experiments, seed-set and morphometric analysis were carried out for both studied populations. We have observed a higher seed-set in Caatinga. Seeds produced in this ecosystem had lower seed moisture content. Seeds from Restinga showed lower germination time when light intensity decreased. We observed a reduction in both the germinability and the synchronization index with decreasing osmotic potential and increasing salinity. Nevertheless, both populations exhibited changes in photoblastism when seeds were submitted to water and saline stress. In conclusion, C. procera seeds are tolerant to environmental factors assessed. That characteristic ensures the colonization success and wide distribution of this plant species in the studied ecosystems.

In vivo growth inhibition of sarcoma 180 by latex proteins from Calotropis procera.

Latex of Calotropis procera has been described as a relevant source of pharmacologically active proteins, including proteins with anticancer activity. A previous in vitro study of laticifer proteins (LP) from C. procera reported that they had selective cytotoxic effects on human cancer cell lines. The aim of this study was to determine the effects of LP in vivo using mice transplanted with sarcoma 180. Biochemical, hematological, histopathological, and morphological analyses were performed in animals given LP by oral or intraperitoneal routes. LP significantly reduced tumor growth (51.83%) and augmented the survival time of animals for up to 4 days. Tumor growth inhibitory activity was lost when LP fraction was submitted to proteolysis, acidic treatment, or pretreated with iodoacetamide. However, LP retained its inhibitory activities on sarcoma 180 growth after heat treatment. Thus, it seems that heat-stable proteins are involved in tumor suppression. Biochemical parameters, such as the enzymatic activity of aspartate aminotransferase and alanine aminotransferase and urea content in serum were not affected in treated mice. It is worth noting that LP completely eliminated the 5-FU-induced depletion of leukocytes in mice even when given orally. The active proteins were recovered in a single fraction by ion exchange chromatography and still exhibited anticancer activity. This study confirms the pharmacological potential of proteins from the latex of C. procera to control sarcoma cell proliferation.

Phytoextraction capacity of the plants growing on tannery sludge dumping sites.

The study was undertaken to assess the phytoremediation potential of four plants (Sida acuta, Ricinus communis, Calotropis procera, Cassia fistula) growing at a tannery sludge disposal site. Results showed that maximum amount of K, Fe and Ni was associated with residual fraction, whereas, Zn, Mn, Cr, Pb, Cd and Co was found in Fe-Mn oxide fraction. Cu and Na were mostly associated with organic matter and carbonate fraction, respectively. The results demonstrated that the levels of accumulation of metals was found high in all the studied plants and followed the order; C. procera>S. acuta>R. communis=C. fistula. The principal components analysis (PCA) revealed that translocation behavior of Cu, Zn and Mn, Cr were found similar in the plants. Correlation analysis between metal accumulation in the plants with DTPA extractable metals emphasized that S. acuta and C. fistula provide better value of correlation for most of the tested metals. The values of transfer factor were also found high for most of the tested metals in the plants of S. acuta. Overall, the plants of S. acuta and C. fistula were found suitable for the decontamination of most of the metals from tannery waste contaminated sites.