Polycyclic aromatic hydrocarbons in ambient air at Agra: distribution and toxicity assessment.

Polycyclic Aromatic Hydrocarbons (PAHs) are a class of organic pollutants that are commonly found in the environment, largely due to combustion or processing of hydrocarbon fuels. PAHs are considered highly toxic for human beings and several of these compounds are carcinogenic, mutagenic and teratogenic. Human exposure to PAHs occurs principally by direct inhalation, ingestion or dermal contact as a result of the widespread presence and persistence of PAHs in the urban environment. With increasing awareness that PAHs are known and suspected carcinogens, this study was undertaken to monitor PAH compounds in Total Suspended Particulate Matter (TSPM) at the industrial site--Nunhai, Agra. For this purpose, TSPM samples were collected on glass fibre filter papers (EPM 2000) using High Volume Sampler (HVS 430) at Nunhai, Agra. 16 EPA priority PAH compounds were analyzed by a Gas Chromatograph equipped with FID detector. PAHs having high molecular weight, i.e., BghiP, BbF, DbA, BaA, BaP and IP, were the most abundant with concentrations ranging between 0.026 to 0.56 ng m(-3). The calculated mean TPAH value was 0.32 ng m(-3). The probably carcinogenic and possibly carcinogenic PAH as classified by International Agency for Research on Cancer (IARC) accounted for 42% and 38% respectively of the total PAH. The health risk associated with inhalatory exposure to PAHs was assessed on the basis of Benzo(a)pyrene concentration in air and Toxic Equivalency Factor (TEF) for individual PAH. In the present study, BaP concentrations ranged from 0.005 to 0.23 ng m(-3) with a mean value of 0.04 ng m(-3). Carcinogenic potencies for DbA and BaP in PAH mixtures based on TEF concept were 45% and 39% respectively. This underlines the importance of DbA and BaPas a surrogate compound of a PAH mixture in our environment in assessing human health risk.

Hypoglycemic effect of Hibiscus rosa sinensis L. leaf extract in glucose and streptozotocin induced hyperglycemic rats.

Investigations were carried out to evaluate the effect of aqueous extract of H. rosa sinensis leaves on blood glucose level and glucose tolerance using Wistar rats. Repeated administration of the extract (once a day for seven consecutive days), at an oral dose equivalent to 250 mg kg(-1), significantly improved glucose tolerance in rats. The peak blood glucose level was obtained at 30 min of glucose load (2 g kg(-1)), thereafter a decreasing trend was recorded up to 120 min. The data exhibit that repeated ingestion of the reference drug tolbutamide, a sulphonylurea and the extract brings about 2-3 fold decrease in blood glucose concentration as compared to single oral treatment. The results clearly indicate that tolbutamide improves the glucose tolerance by 91% and extract does so only by 47%. At 250 mg kg(-1), the efficacy of the extract was 51.5% of tolbutamide (100mg kg(-1)). In streptozotocin diabetic rats, no significant effect was observed with the extract, while glibenclamide significantly lowered the glucose level up to 7 hr. These data suggest that hypoglycemic activity of H. rosa sinensis leaf extract is comparable to tolbutamide and not to glibenclamide treatment.

Effect of Aegle marmelos and Hibiscus rosa sinensis leaf extract on glucose tolerance in glucose induced hyperglycemic rats (Charles foster).

In an effort to test the hypoglycemic activity of Aegle marmelos and Hibiscus rosa sinensis in glucose induced hyperglycemic rats, their alcoholic leaf extracts were studied. Both the groups of animals receiving either. A. marmelos or H. rosa sinensis leaf extract for seven consecutive days, at an oral dose equivalent to 250 mg kg-1 showed significant improvements in their ability to utilize the external glucose load. Average blood glucose lowering caused by A. marmelos and H. rosa sinensis was 67% and 39% respectively, which shows that former significantly (p < 0.001) improves the glucose tolerance curve. The magnitude of this effect showed time related variation with both the plants. Efficacy of A. marmelos and H. rosa sinensis was 71% and 41% of glybenclamide, respectively. These data throw some light on the possible mechanism of hypoglycemic activity of both the plants. The mechanism of action could be speculated partly to increased utilization of glucose, either by direct stimulation of glucose uptake or via the mediation of enhanced insulin secretion.