Measuring antioxidant potential in corals using the FRAP assay

In this paper, we standardized a method for determining antioxidant potential in corals. This was determined using a simple, reproducible and inexpensive method: the ferric reducing/antioxidant potential (FRAP) assay. This procedure involves the reduction of Fe^III-TPTZ to a blue colored Fe^II-TPTZ by biological antioxidants and chemical reductants, some of which might have no antioxidant activity in a sample. The FRAP assay compares the change in absorbance at 600 nm of a sample compared with the change in absorbance of a known standard (FeSO₄·7H₂O) to determine antioxidant levels. This assay was used to determine changes in antioxidant potential in the corals Pocillopora damicornis and Pocillopora meandrina exposed to different temperatures (28, 29, 30 and 31 °C) for 3 h. Corals were also incubated at 31 °C for time intervals of a 0.5, 1 and 3 h. Antioxidant potential in the coral host increased with temperature and time, as indicated by FRAP values, compared to control samples at ambient sea surface temperatures (26.5-27 °C). Lower FRAP values could be a response to lower production of reactive oxygen species (ROS) or the result of an increase in ROS that react with the antioxidants. Because of the complex interactions within cells, one test is normally not enough to understand precisely what is going on within the cell. Rather, a broad array of tests is required to determine the different cellular parameters that are occurring within a biological system. To our knowledge, this is the first time that FRAP has been used to determine antioxidant status in a marine organism. The FRAP technique can potentially be a useful and inexpensive tool for marine biologists engaged in ecotoxicological studies.     

Plant growth activity of guaianolides with C-4 oxygen-containing groups

The plant growth activity of guaianolides with C-4 oxygen-containing functions has been studied. It was found that the presence of an epoxy or an ether link at C-4 enhanced the plant growth activity of the parent compound. The presence of a hydroxyl group at C-4 had no effect.     

Sanguinarine suppresses IgE induced inflammatory responses through inhibition of type II PtdIns 4-kinase(s)

The effects of sanguinarine on IgE mediated early signaling mechanisms leading to inflammatory mediators release were investigated. Pretreatment of RBL 2H3 cells with sanguinarine inhibited IgE induced activation of type II PtdIns 4-kinase activity. Concomitant with type II PtdIns 4-kinase inhibition, sanguinarine also inhibited IgE induced degranulation and β hexosaminidase release in RBL 2H3 cells. In vitro assays showed sanguinarine inhibited type II PtdIns 4-kinase activity in a dose dependent fashion with no effect on PtdIns 3-kinase activity. Fluorescence spectroscopic studies suggested that sanguinarine binds to type II PtdIns 4-kinases α and β isoforms with a K_d of 2.4 and 1.8 μM, respectively. Kinetic studies showed that sanguinarine competes with PtdIns binding site of type II PtdIns 4-kinase β. These results suggest that the anti-inflammatory effects of sanguinarine on PtdIns 3-kinase signaling pathway are more likely an indirect effect and emphasize the importance of the cross talk between type II PtdIns 4-kinases and PtdIns 3-kinases.     

Chickpea Seed Proteins as Affected by Mineral Supply Levels

Accumulation of different protein fractions in chickpea seed harvested from plants grown under four concentration levels (0, 25, 50 and 100 mM) of sulphur, nitrogen, potassium and phosphorus has been studied. Whereas globulins showed an increase with the increasing concentration of all the four minerals, albumins increased under sulphur, nitrogen and potassium, and glutelins increased under potassium and phosphorus. An increase in nitrogen regime led to increased contribution of tryptophan in the seed protein due to albumins and globulins and methionine contribution due to albumins, globulins and glutelins. Under higher supplies of sulphur, relative contribution of tryptophan due to albumins and methionine contribution due to albumins and globulins had increased.     

First record of the Mayan Cichlid Mayaheros urophthalmus (Günther, 1862) in South Asia and its potential implications

We provide the first record of the Mayan Cichlid, Mayaheros urophthalmus from South Asia, based on specimens collected from the River Chalakudy in Kerala, India. Genetic analysis of the Indian sample showed close affinity with those from Philippines suggesting their potential South East Asian origin, and introduction through the unmanaged aquarium trade. Ecological plasticity, opportunistic predatory behaviour and eurytopic nature of M. urophthalmus could facilitate colonization in the new environment, unless urgent management strategies are developed and implemented.