Red clover (Trifolium pratense L., Fabaceae; RCL), a perennial plant rich in isoflavones, is a natural alternative for menopausal symptoms, as well as antiaging and antioxidant. Isoflavone preparations usually contain aglycones and β-glycosides. Aglycones, the active moieties, are absorbed slowly and unevenly due to reduced water solubility and biotransformation from β-glycosides. NeoSolTMRCL40 is a novel RCL isoflavone aglycones preparation based on active solubilization technologies [1].
Using in vitro models, we evaluated NeoSolTMRCL40-induced isoflavones solubilization, estrogenic and antioxidative effects in comparison to a standard RCL extract (RCLE).
Isoflavones aglycones, either as RCLE or as NeoSolTMRCL40, were dissolved in water (100 mg/50 mL). Total aglycones in solution, assayed by HPLC [2], were (mean±SD) 0.009476±0.001202 mg/ml with RCLE and 0.047401±0.005760 mg/ml with NeoSolTMRCL40 (n = 11-13, P<0.0001). Estrogenicity, assessed in MCF-7 cells [2], was: potency (EC50, mean dilution x 1000 [95% CI]) 1.237 (0.981-1.558) with RCLE and 0.361 (0.248-0.527) with NeoSolTMRCL40, and efficacy (EMAX, % of response to estradiol 0.1 nM) 116.0% (104.6-127.3%) with RCLE and 110.6% (98.2-123.0%) with NeoSolTMRCL40. NeoSolTMRCL40 was more antioxidant than RCLE (FRAP assay: 660.4±51.3 vs 328.3±46.3 μM FeSO4 equivalents, n = 6, P<0.0001; DPPH assay: 69.6±5.3 vs 84.2±3.3 arbitrary units, n = 5, P = 0.0001) [3].
Results support the ability of NeoSolTMRCL40 to promote isoflavones solubilization and availability. The ratio NeoSolTMRCL40/RCLE for isoflavones solubilization was 5.0 and NeoSolTMRCL40 had 3.4-fold higher estrogenic potency and was more antioxidant than RCLE. NeoSolTMRCL40 is therefore an interesting novel preparation providing improved availability of active isoflavones aglycones.
References
[1] Cram DJ. Science 1988; 240: 760-767
[2] Spagnuolo P, et al. Fitoterapia 2014; 94: 62-69
[3] Cosentino M, et al. Pharmacol Res 2007; 56: 140-147