In silico and In vitro evaluation of the anti-inflammatory potential of Centratherum punctatum Cass-A.

Centratherum punctatum Cass., a herb belonging to the family Asteraceae has been traditionally used as a curative against diverse disorders like inflammation, tumor, depression, and hypertension. Though the medicinal properties of this plant have been attributed to the presence of flavonoids, glucosides, alkaloids, Vitamin C, etc., the molecular constituents of this plant and of the flavonoids that contribute to its medicinal activity have not been explored yet. This work attempts to evaluate the potential of Centratherum punctatum extract as an anti-inflammatory agent. Ethanolic extracts of Centratherum punctatum analyzed by High Performance Thin Layer Chromatography (HPTLC) and Liquid Chromatography-Mass Spectrometry (LC-MS/MS) identified the presence of the flavones kaempferol, glycoside Isorhamnetin-3-O-rutinoside, and kaempferol-3-glucoside. The plant extract exhibited anti-oxidant property as confirmed by DPPH assay and IC50 value of 271.6 µg/mL during inhibition of protein denaturation, 186.8 µg/mL during RBC membrane stabilization, and 278.2 µg/mL for proteinase inhibition. Membrane stabilizing functions of flavones and flavones glycosides validated the anti-inflammatory potential of the extract. In silico evaluation using a rigorous molecular docking protocol with receptors of Cox2, TNF-α, Interleukin 1ß convertase, and Histamine H1 predicted high binding affinity of the isoflavones and isoflavone glycosides of Centratherum punctatum Cass. The interactions have also been shown to compare well with that of known drugs valdecoxib through Gln178, His342, and Gly340, desloratadine (through Lys191 and Thr194) and belnacasin (through Asp288 and Gly287) proven to function through the anti-inflammatory pathway. This work establishes the anti-inflammatory potential of Centratherum punctatum Cass. extract as an alternative to existing therapeutic approach to inflammation through a systematic in silico approach supplementing the findings.

Pharmacokinetic drug interaction between gemfibrozil and sitagliptin in healthy Indian male volunteers.

PURPOSE: To study the impact of gemfibrozil co-administration on the pharmacokinetics of sitagliptin in healthy Indian male volunteers. METHODS: A randomized open label two-period crossover study involving 12 healthy Indian male volunteers was conducted at a single center. In each phase, the volunteers were administered sitagliptin as 100 mg tablets, either alone or co-administered with gemfibrozil as 600 mg tablets twice daily for 3 days. There was a 2-week washout period between phases. The venous blood samples were serially collected at 0-12 h post-dose, and plasma concentrations of the study drugs were estimated by a validated high-performance liquid chromatography-ultraviolet method. RESULTS: Relative to the administration of sitagliptin alone, co-administration with gemfibrozil increased the AUC0₋12 (2,167 ± 82.9 vs. 2,970 ± 76.4 ng h/ml; p < 0.0001), AUC(0-∞) (3,621 ± 222.5 vs. 5,574 ± 249.6 ng h/ml; p < 0.0002), C(max) (282.9 ± 7.7 vs. 344.1 ± 5.9 ng/ml; p < 0.0001), and t(½) (7.4 ± 0.6 vs. 10 ± 0.6 h; p = 0.0076) to statistically significant levels. The interindividual differences in the pharmacokinetic parameters of sitagliptin were found to be within acceptable limits (coefficient of variation <20%). No adverse drug events associated with sitagliptin occurred in the subjects during the study period. CONCLUSION: Although the bioavailability of sitagliptin was increased by 54% when co-administered with gemfibrozil, this interaction may not have any clinical significance as sitagliptin has a wide therapeutic index. Hence, in clinical practice, sitagliptin as 100 mg tablets and gemfibrozil as 600 mg tablets may be co-prescribed without much threat of sitagliptin toxicity. However, these results may not hold if the dose of sitagliptin is increased or if is co-prescribed with other antidiabetic drugs and/or cytochrome P450 2C8/human organic anion transporter-3 inhibitors. Further studies are needed to confirm these results in patients.