Sardine oil loaded vanillic acid grafted chitosan microparticles,a new functional food ingredient: attenuates myocardial oxidative stress and apoptosis in cardiomyoblast cell lines (H9c2)

Fish oil has been widely recognized as an excellent dietary source of polyunsaturated n-3 fatty acids such as EPA and DHA. However, it can undergo oxidation easily resulting in the formation of toxic off flavor compounds such as hydroperoxides. These compounds adversely affect the nutritional quality and may induce several stress reactions in body. To solve this problem, a new antioxidant bio-material, vanillic acid-grafted chitosan (Va-g-Ch), was synthesized and used as a wall material for microencapsulation of fish oil. The sardine oil loaded Va-g-Ch microparticles could be a potential functional food ingredient considering the numerous health benefits of fish oil, chitosan, and vanillic acid. The current study aimed to investigate the possible protective effect of sardine oil-loaded Va-g-Ch microparticles against doxorubicin-induced cardiotoxicity and the underlying mechanisms. In vitro cytotoxicity evaluation was conducted using H9c2 cardiomyocytes. MTT assay revealed that effective cytoprotective effect was induced by a sample concentration of 12.5 μg/mL. Results of apoptosis by double fluorescent staining with acridine orange/ethidium bromide and caspase-3 evaluation by ELISA substantiated the above findings. Further, flow cytometric determination of membrane potential, relative expression of NF-κB by PCR, and ROS determination using DCFH-DA also confirmed the protective effect of encapsulated sardine oil against doxorubicin-induced cardiotoxicity. NF-κB expression was down-regulated nearly by 50% on cells treated with encapsulated sardine oil. Altogether, the results revealed that sardine oil-loaded Va-g-Ch microparticles demonstrated potential cell protection against doxorubicin-induced oxidative stress     

Monsoon-dependent breeding in the field crab Paratelphusa hydrodromous (Herbst)

The reproductive cycle of the field crab Paratelphusa hydrodromous (Herbst) was determined by direct field observations as well as by calculating the percentage of ovigerous females in a Madras population for a period of three years. The females breed annually in a single spawning. These observations, corroborated by histological studies on the nature of the ovary, indicate that gametogenic activity starts in December and vitellogenesis is completed during January-May. Spawning commences in the last week of June or first week of July with the release of brood in the month of September (1979), October (1978) or November (1980) during northeast monsoon. The smallest female crab showing spawning had a carapace width of 3.1 cm and the largest spawning crabs measured 5.5 mm. The mean number of eggs spawned in the smallest crab was 247 and that in the largest crab was 417. Mean incubation was 41 ± 12.388 days. Vitellogenesis and spawning occurred at peak temperature conditions. Though the time taken for vitellogenesis and commencement of spawning were constant for the study period, the duration of retention of the juveniles in the brood varied with the onset of monsoon.     

SB203580 Modulates p38 MAPK Signaling and Dengue Virus-Induced Liver Injury by Reducing MAPKAPK2, HSP27, and ATF2 Phosphorylation

Dengue virus (DENV) infection causes organ injuries, and the liver is one of the most important sites of DENV infection, where viral replication generates a high viral load. The molecular mechanism of DENV-induced liver injury is still under investigation. The mitogen activated protein kinases (MAPKs), including p38 MAPK, have roles in the hepatic cell apoptosis induced by DENV. However, the in vivo role of p38 MAPK in DENV-induced liver injury is not fully understood. In this study, we investigated the role of SB203580, a p38 MAPK inhibitor, in a mouse model of DENV infection. Both the hematological parameters, leucopenia and thrombocytopenia, were improved by SB203580 treatment and liver transaminases and histopathology were also improved. We used a real-time PCR microarray to profile the expression of apoptosis-related genes. Tumor necrosis factor α, caspase 9, caspase 8, and caspase 3 proteins were significantly lower in the SB203580-treated DENV-infected mice than that in the infected control mice. Increased expressions of cytokines including TNF-α, IL-6 and IL-10, and chemokines including RANTES and IP-10 in DENV infection were reduced by SB203580 treatment. DENV infection induced the phosphorylation of p38MAPK, and its downstream signals including MAPKAPK2, HSP27 and ATF-2. SB203580 treatment did not decrease the phosphorylation of p38 MAPK, but it significantly reduced the phosphorylation of MAPKAPK2, HSP27, and ATF2. Therefore, SB203580 modulates the downstream signals to p38 MAPK and reduces DENV-induced liver injury.     

Effect of ayurvedic medicines on beta-glucuronidase activity of Brunner's glands during recovery from cysteamine induced duodenal ulcers in rats

Biochemical and histochemical studies revealed decreased beta-glucuronidase activity in the Brunner's glands of duodenal ulcerated rats. The enzyme activity showed gradual increase during recovery. Rats treated with a mixture of Ayurvedic medicines (Glycyrrhiza glabra, Terminalia chebula, Piper longum and Shanka Bhasma) recovered faster with concomitant increase in beta-glucuronidase activity in the Brunner's glands. It can be concluded that Ayurvedic medicines used do not act as antacid but improve the secretory status of Brunner's glands involved in the protection against duodenal ulcer.     

Microplate assay of elevated esterase activity in individual pyrethroid-resistant mosquitoes

Involvement of esterase-mediated hydrolysis as a mechanism of pyrethroidresistance in three species of mosquitoes,viz., Aedes aegypti, Culex quinquefasciatus andAnopheles Stephensi was investigated by microplate assay of Β-esterases in individual larva and adult female and male mosquitoes. Assuming an absorbance value of 0.4 and above at 555 nm as the threshold level of elevated esterase activity which confers resistance, frequency distributions of such individual test mosquitoes were constructed in resistant and susceptible populations. The results indicate the involvement of ester hydrolysis of Pyrethroids as a predominant mechanism of pyrethroid-resistance in the larvae ofCulex quinquefasciatus but not inAedes aegypti. However, a marginal role of esterases is indicated in the larvae ofAnopheles stephensi.