Tea and Mint Extracts Modulate the HSP70 Expression in Preeclamptic Placental Explant.

Heat shock protein 70 is a molecular chaperone which expressed during oxidative stress to protect the cell from damage. Preeclampsia is a hypertensive disorder with an oxidative stress imbalance. Antioxidant defenses appear to be depleted during preeclampsia resulting in increased oxidative stress. Various alternative medicines are employed to increase the endogenous antioxidant level during preeclampsia. The aim of the present study was to determine the modulatory effect of medicinal plants, Camellia sinensis and Mentha spicata on oxidative stress, antioxidant and thiol status using placental explant as the model system. Placental explants were cultured from the placental tissues of both normotensive and preeclamptic subjects. The lipid peroxide, total antioxidant capacity, glutathione redox ratio, HSP70 levels were measured in the placental explants with and without incubation with tea, mint and mint-tea. The addition of these three extracts increased the TAC and GRR in both placental explants with decrease in the LPO level. The expression of HSP70 also decreased more significantly in preeclamptic explants on addition of tea and mint extracts due to the restoration of cell homeostasis via maintaining the antioxidant status. In view of the above results, mint-tea may emerge as an effective antioxidant, preventing cell damage during stress condition.

Liver oxidative stress of the grey mullet Mugil cephalus presents seasonal variations in Ennore estuary

The objective of this study was to determine the liver oxidative stress status of grey mullets living in heavy-metal-rich polluted Ennore estuary compared with unpolluted Kovalam estuary. Fish were collected from both estuaries during the monsoon and summer seasons from October 2004 to September 2006. Fish liver homogenate (N = 20 per group) was prepared for evaluating oxidative stress parameters. Fish living in the polluted estuary had significantly higher lipid oxidation products, conjugated dienes (0.346 ± 0.017 vs 0.141 ± 0.012 DA233/mg protein), lipid hydroperoxides (0.752 ± 0.032 vs 0.443 ± 0.03 nmol/mg protein), and lipid peroxides (3.447 ± 0.14vs 1.456 ± 0.096 nmol MDA/mg protein) than those of the unpolluted estuary during the summer. In contrast, significantly lower levels of superoxide dismutase (20.39 ± 1.14 vs 53.63 ± 1.48 units/mg protein) and catalase (116 ± 6.87vs 153 ± 8.92 units/mg protein) were detected in the liver of fish from the polluted estuary (Ennore) compared to fish from the unpolluted estuary (Kovalam) during the summer. Variations in most of the oxidative stress parameters were observed between the summer and monsoon seasons, indicating the importance of seasonal variation for estuaries and their inhabitants.

Effect of a Siddha drug (Vatharasavangam) on insulin release from isolated pancreatic islets in rabbits.

The Siddha drug--Vatharasavangam (VRV) was studied in rabbits for its hypoglycemic activity. The insulin level in alloxan-induced hyperglycemic animals increased significantly after treatment with VRV. The insulin release from the isolated islets to glucose stimulus and acid phosphatase activity in islets as an index to islet function were measured. The insulin released from the islets in hyperglycemic rabbits decreased from 70 microU/ml (control) to 32 microU/ml to low glucose stimulus. VRV-treated rabbits showed a significant increase in the insulin released from the islet cells (65 microU/ml) to the low glucose stimulus. Similarly, a significant increase of insulin secretion was observed for high glucose stimulus after 30 min in VRV treated rabbits (100 microU/ml), when compared to hyperglycemic rabbits (70 microU/ml). The islet cell acid phosphatase activity in the hyperglycemic rabbits increased significantly after VRV treatment. These findings suggest that VRV acts by stimulating beta-cells to secrete insulin to the glucose signal and improves blood glucose homeostasis.

Effect of vatharasavangam on U14C-glucose absorption and utilization in hyperglycemic rabbits.

Vatharasavangam (VRV) is a hypoglycemic drug mentioned in the Siddha Literature. Previous studies showed that VRV therapy brings down the blood glucose levels in the hyperglycemic rabbits. The present intestinal perfusion studies with labelled glucose indicate that the blood glucose homeostatis in VRV treated animals is brought about by a significant reduction in the rate of glucose absorption in the intestine. Further an enhanced incorporation of 14C glucose into tissue glycogen is observed in the VRV treated rabbits when compared to the hyperglycemic rabbits.