Chromatographical fingerprint analysis, in silico investigation, and identification of hepatoprotective active compounds from Capparis decidua Edgwe (Forssk.)

Liver disorders are globally distributed with a high burden of disease costs. The methanolic extract of Capparis decidua stem part and its dichloromethane (DCM) and ethylacetate fractions showed significant hepatoprotective activity, so this study aimed to develop gas chromatography/mass spectrometry (GC/MS), high-performance thin layer chromatography (HPTLC) fingerprint profile and in silico docking of identified compounds from both fractions responsible for hepatoprotective activity. Hexadecanoic acid, 9-octadecenoic acid, 9, 12, 15-octadecatrienoic acid, and dihydrolinalool are known hepatoprotective and antioxidant agents that were identified from both fractions by GC/MS, they have various degrees of hepatoprotective and antioxidant properties, this is the first time to identify hexadecanoic acid in C. decidua stem. Both fractions were chromatogramed with known hepatoprotective standard compounds, they were rutin, quercetin, kaempferol, ferulic acid, oleanolic acid, and β-sitosterol; β-sitosterol and oleanolic were isolated and identified in the DCM fraction by HPTLC, but nothing of these standard compounds were identified in the ethylacetate fraction. According to International Council for Harmonization guidelines, the HPTLC fingerprint profile method was validated to confirm our isolation and identification process of β-sitosterol and oleanolic acid in the DCM fraction, also their contents were quantified and they were 9.21 and 7.73 μg/mg, respectively, in the total dry fraction weight, this was the first time to isolate and identify oleanolic acid from C. decidua stem part. In silico docking was carried and was found that hexadecanoic acid showed significant predicted binding properties on Nrf2, p38 mitogen-activated protein kinase, and IL-1 receptor proteins. 9-octadecenoic acid (elaidic acid) showed significant predicted interactions with IL-1 receptor, Nrf2, and peroxisome proliferator- activated receptor-α (PPAR-α) proteins. Oleanolic acid showed significant predicted bindings with p65, JNK, and NF-kb. β-sitosterol showed significant predicted interaction with IL-6α protein, while 9, 12, 15-octadecatrienoic acid revealed significant binding with PPAR-α protein. Therefore, we recommend considering our active compounds in the field of drug development (structure activity relationship) and the possibility of the presence of synergism if they are combined and administered together. Moreover, we recommend liquid chromatography–mass spectrometry and nuclear magnetic resonance on both fractions to search for the possibility of the presence of other hepatoprotective compounds.