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.

Effect of Hibiscus rosa sinensis Linn. ethanol flower extract on blood glucose and lipid profile in streptozotocin induced diabetes in rats.

Blood glucose and total lipid levels were determined in streptozotocin induced diabetic rats after oral administration of an ethanol flower extract of Hibiscus rosa sinensis. A comparable hypoglycemic effect was evidenced from the data obtained after 7 and 21 days of oral administration of the extract and glibenclamide. Maximal diminution in blood glucose (41-46%) and insulin level (14%) was noticed after 21 days. The extract lowered the total cholesterol and serum triglycerides by 22 and 30%, respectively. The increase in HDL-cholesterol was much higher (12%) under the influence of the extract as compared to that of glibenclamide (1%). The hypoglycemic activity of this extract is comparable to that of glibenclamide but is not mediated through insulin release. Other possible mechanisms are discussed.

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.

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.

A preliminary investigation of the possible hypoglycemic activity of Hibiscus rosa-sinensis.

The hypoglycemic activity of an ethanol extract of Hibiscus rosa-sinensis was studied in glucose located rats. After a single dose of the extract, a slight but insignificant hypoglycemic effect was observed at 30 and 90 min. At 120 min it was mild but significant. After repeated administration of the extract (once a day for seven consecutive days) a statistically significant (P < 0.001) reduction in blood glucose levels was observed at 30, 90 and 120 min after glucose loading. The average hypoglycemic activity, after repeated administration of 250 mg kg-1 leaf extract was 81%, under similar conditions average activity of tolbutamide was 96%. At 250 mg.kg-1 the efficacy of the extract was found to be 84% of tolbutamide (100 mg.kg-1). Repeated treatment of animals either with tolbutamide a sulphonylurea or H. rosa-sinensis caused a 2-3-fold improvement in glucose tolerance as compared to those receiving only once. These data suggest that the leaf extract acts like tolbutamide and the mechanism of action may be a stimulation of pancreatic beta cells to produce more insulin or an increase of the glycogen deposition in liver. It appears that the active principle in the tested extract has the sulphonylurea skeleton in which-SO2-NH-CO-group and the substituents (S1 and S2) may be the possible active sites responsible for its hypoglycemic activity.

Survey amongst workers in pesticide factories.

Blood samples of 75 pesticide factory workers in Agra Division, India, were analyzed for biochemical parameters of clinical importance. About 75% of the subjects had significantly low levels of serum cholinesterase activity. Several subjects had below average blood sugar and urea values. The majority had elevated levels of serum cholesterol, phospholipid and SGOT activity. 52 workers reported general toxic symptoms. A correlation between the clinical manifestations and blood biochemical parameters has been attempted.