Objective: To investigate the association between frailty and type 2 diabetes mellitus (T2DM) using a bidirectional two-sample Mendelian randomization (MR) analysis, so as to provide the evidence for the prevention and control of frailty and T2DM. Methods: Frailty status was assessed using the Fried Frailty Score (FFS), with aggregated data sourced from 386 565 European samples in the UK Biobank. The T2DM data were obtained from the summary results of genome-wide analysis published by the Diabetes Genetics Replication and Meta-analysis Consortium, excluding the UK Biobank data, including 455 313 European samples. Eligible single nucleotide polymorphism site were selected from the FFS and T2DM summary data as instrumental variables. The bidirectional MR analysis was performed using the inverse-variance weighted method. The heterogeneity was assessed using the modified Cochran Q test. The horizontal pleiotropy of instrumental variables was examined using MR-Egger regression. The robustness of the results was evaluated using the leave-one-out method. The bias was tested using funnel plot. Results: The forward MR analysis revealed a statistically significant association between increased FFS and an increased risk of T2DM (OR=2.280, 95%CI: 1.169-4.447). The reverse MR analysis showed a statistically significant association between T2DM and increased FFS (β=0.026, 95%CI: 0.012-0.041). Both bidirectional MR results were robust, with no horizontal pleiotropy of the instrumental variables was found (all P>0.5); and the funnel plots did not show significant basis. Conclusion The study found a bidirectional causal association between frailty and T2DM.

OBJECTIVETo identify the tyrosinase inhibitory constituent quickly from Potentilla bifurca.

METHODThe active constituent was found through fraction collecting and tyrosinase inhibitory activity by bioassay-linked HPLC method.

RESULTThe methanol extracts and BuOH fraction of Potentilla bifurca showed strong tyrosinase inhibitory activities. From BuOH fraction of Potentilla bifurca, the tyrosinase inhibitory constituent was isolated and identified as flavonoid, quercetin-4'-O-beta-D-glucoside. It express stronger tyrosinase inhibition than the known tyrosinase inhibitor, kojic acid (IC50 = 0.28 mmol x L(-1)) with IC50 value of 0.001 9 mmol x L(-1).

CONCLUSIONBioassay-linked HPLC fractionation method was provided for determination the active constituents quickly from herbal medicines.

Enzyme Inhibitors ; chemistry ; isolation & purification ; Kinetics ; Peptides ; chemistry ; isolation & purification ; Plant Extracts ; chemistry ; isolation & purification ; Potentilla ; chemistry