In vitro and in silico evaluation of hedera helix extract for mutagenic/antimutagenic activities and protective effects against inflammation

Hedera helix is a perennial woody plant with known medicinal properties for centuries. There have been several in vitro/in vivo studies examining the antibacterial, antifungal, antivirus, antileishmanial, anthelmintic, anti-inflammatory, antispasmodic, and anticancer/antitumor effects of this plant. In this study, it is aimed to evaluate the protective effects of 50% hydroalcoholic (50% EtOH) dry extract of H. helix leaves against LPS-induced inflammation, mutagenic/antimutagenic effects, and in silico predictions for genotoxicity/mutagenicity endpoints and anti-inflammatory properties. Stable nitrite levels were measured via a microplate reader and cell viability was examined via MTT assay using RAW 264.7 murine macrophage cell culture. Mutagenicity/antimutagenicity assays were conducted on Salmonella tester strain TA98 and TA100 with and without S9 in the Ames test. In addition, seven different platforms including Danish (Q)SAR Database, pkCSM web server, OCHEM web platform, ProTox-II web service, T.E.S.T. software, PASS online freeware, and VEGA (Q)SAR platform were used to conduct an in silico analysis of known compounds of H. helix leaves. The extract was found to be non-mutagenic on all of the strains tested. The predictions run in all of the in silico platforms supported this finding with negative predictions for Ames test and other in vivo/in vitro genotoxicity/cancer endpoints. A strong antimutagenic activity was only demonstrated at the concentration of 5000 µg/plate. The extract showed a similar effect when compared with indomethacin and L-NAME which was concentration-dependent. Anti-inflammatory activity predictions were positive for 36 compounds previously isolated from H. helix leaves. However, compounds with positive predictions for an activity like a nitric oxide antagonist, nitrite reductase (NO-forming) inhibitor and nitric-oxide synthase inhibitor were low. These findings suggested that the anti-inflammatory activity of the H. helix leaves extract was not likely seemed to be only dependent on NO inhibition. Further research may be warranted to address the other contributory anti-inflammatory mechanisms.