An open-label, randomized, crossover study to evaluate the bioavailability of nanoemulsion versus conventional fat-soluble formulation of cholecalciferol in healthy participants.

Background: Nanoemulsion preparations of cholecalciferol available in the market claim to have better bioavailability than the conventional fat-soluble cholecalciferol. However, limited data are available in humans for such preparations. We, therefore, compared the relative bioavailability of two formulations of 60,000 IU cholecalciferol (nanoemulsion oral solution, water-miscible vitamin D3 [test] vs soft gelatin capsules [reference]) in healthy adult participants. Methods: In this randomized, open-label, two sequence, single-dose, two-way crossover study (CTRI/2018/05/013839), Indian participants aged 18-45 years received single dose of nanoemulsion and capsule formulations, under fasting conditions. Blood samples collected over 120 h were assessed to determine cholecalciferol concentrations. Pharmacokinetic parameters (area under the concentration-time curve up to 120 h [AUC0-120h], maximum observed drug concentration [Cmax], time to reach maximum drug concentration [Tmax], terminal half-life [T½el], and terminal elimination rate constant [Kel]) were estimated using baseline corrected data and analyzed using analysis of variance. Results: Among the 24 eligible participants, the relative bioavailability of nanoemulsion was significantly higher than the capsules by 36% (p = 0.0001) based on AUC0-120h. Similarly, Cmax of the nanoemulsion was significantly higher by 43% (p = 0.0001) than that of the capsules. The intra-participant variability for AUC0-120h and Cmax were 23.22% and 26.51%, respectively. The Tmax, T½el, and Kel were comparable for both the formulations. No adverse effects were noted with either of the two formulations. Conclusions: Nanoemulsion oral solution of cholecalciferol showed a greater bioavailability compared with soft gelatin capsules, under fasting conditions, in healthy human participants.

Role of 5-HT2 receptors in diabetes: Swertiamarin seco-iridoid glycoside might be a possible 5-HT2 receptor modulator.

In the present review, we are focusing on modulators of 5-HT2 receptors, swertiamarin and their role in diabetes. These drugs possess both central and peripheral actions in various animal models of depression, diabetes and obesity. Swertiamarin and 5-HT2 antagonist are reported antidepressant, hypolipidemic and beneficial in peripheral vasculopathy. In contrast to this, 5-HT2C selective agonist decreases hyperglycemia, hyperlipidemia and insulin secretogogue by action. Selective serotonin reuptake inhibitors (SSRIs) are known antidepressant having weight gain as an adverse effect. Swertiamarin has similar pharmacological actions as 5-HT2 antagonist and 5-HT2C selective agonist. This warrants that swertiamarin might modulate 5-HT2 receptors rather than affecting the uptake of serotonin. In the light of present investigation, the mechanism of these drugs can correlate the role of central and peripheral 5-HT2 receptors in diabetes.

Evaluation of effect of aqueous extract of Enicostemma littorale Blume in streptozotocin-induced type 1 diabetic rats.

The present investigation was undertaken to standardize and study the dose-dependent effect of three weeks treatment with hot and cold aqueous extract of E. littorale (0.5, 1 and 2 g/kg, po) on streptozotocin (STZ) induced type I diabetic (confirmed by histopathology) rats (45 mg/kg, iv single dose). Treatment of rats with STZ produced cardinal signs of diabetes-mellitus like a significant loss of body weight, polyuria and polydipsia. There was also a significant increase in fasting blood glucose levels and AUC(glucose) associated with decrease in insulin levels and AUC(insulin) in STZ-diabetic rats. Treatment with E. littorale hot extract (1 and 2 g/kg) significantly reduced the elevated food intake and water intake, glucose and AUC(glucose) levels of diabetic rats. There was also a significant increase in serum cholesterol, serum triglyceride in the STZ diabetic rats. Treatment with E. littorale hot extract (1 and 2 g/kg) significantly decreased all these elevated levels in diabetic rats. Hot aqueous extract of E. littorale at 0.5 g/kg produced a significant decrease in serum glucose and triglycerides. At this doses serum cholesterol and AUC(glucose) were not found to be altered significantly.TLC finger-print profiles were established for the aqueous extract using HPTLC. Swertiamarin, which was used as a chemical marker, was found to be one of the major components in the hot extract while it was absent in cold extract. The results suggest that E. littorale possesses potential antidiabetic activity and improves lipid profile at a small dose of 0.5 g/kg.

Amelioration of STZ-induced type 1 diabetic nephropathy by aqueous extract of Enicostemma littorale Blume and swertiamarin in rats.

Diabetic nephropathy (DN) is one of the foremost causes of renal failure and a primary cause of diabetes mellitus related death. Previously, we have reported that aqueous extract of Enicostemma littorale has potential antidiabetic activity. In the present study, we have investigated the effect of aqueous extract of E. littorale 1 g/kg, p.o. and swertiamarin 50 mg/kg, p.o. daily for 3 weeks in type 1 DN complications in SD rats. DN was assessed by serum urea, creatinine, lipid profile and water intake levels. Treatment with aqueous extract of E. littorale and swertiamarin significantly decreased serum urea and creatinine and other parameters associated with the development of DN in type 1 diabetic rats. We have also found considerable improvement in histology of glomerular function of aqueous extract of E. littorale and swertiamarin-treated animals.