The Free Radical Scavenging Property of the Leaves, Branches, and Roots of Mansoa hirsuta DC: In Vitro Assessment, 3D Pharmacophore, and Molecular Docking Study

Abstract

In this work, a metabolic profile of Mansoa hirsuta was investigated, and in vitro assays and theoretical approaches were carried out to evaluate its antioxidant potential. The phytochemical screening detected saponins, organic acids, phenols, tannins, flavonoids, and alkaloids in extracts of leaves, branches, and roots. Through LC-MS analysis, the triterpenes oleanolic acid (m/z 455 [M-H]−) and ursolic acid (m/z 455 [M-H]−) were identified as the main bioactive components. The extracts of the leaves, branches, and roots revealed moderate antioxidant potential in the DPPH test and all extracts were more active in the ABTS test. The leaf extracts showed better antioxidant capacity, displaying IC50 values of 43.5 ± 0.14, 63.6 ± 0.54, and 56.1 ± 0.05 µg mL−1 for DPPH, ABTS, and kinetics assays, respectively. The leaf extract showed higher total flavonoid content (TFC) (5.12 ± 1.02 mg QR/g), followed by branches (3.16 ± 0.88 QR/g) and roots (2.04 ± 0.52 QR/g/g). The extract of the branches exhibited higher total phenolic content (TPC) (1.07 ± 0.77 GAE/g), followed by leaves (0.58 ± 0.30 GAE/g) and roots (0.19 ± 0.47 GAE/g). Pharmacophore and molecular docking analysis were performed in order to better understand the potential mechanism of the antioxidant activity of its major metabolites.

Screening for Bioactive Metabolites in Leaves, Branches, and Roots of Mansoa hirsuta: Phytochemical, Toxicological and Antioxidant Aspects

“…The HPLC-PDA chromatographic profile of the chloroform fractions of M. hirsuta provided information about the significant metabolic composition and the polarity of different compounds present in other parts of the plant. The UV spectra associated with these peaks showed similar profiles, such as those of Rt at 23.8 and 24.18 min with λ max 280 nm and 320 nm, and peaks with R t at 4 min, 13 min 17 min, 19 min, 21 min, and 26 min with λ max 200 and 206, 328, 208 and 307, 309 and 325, 223 and 334 nm that may be characteristic of phenolic compounds or suggest the presence of flavonoids, proanthocyanidins, tannins, isoflavones, flavanones and dihydro flavonols by comparison with characteristic wavelengths of each class of secondary metabolites, similar to the study carried out by Alves et al [17].…”

“…Molecular docking took place in two stages; the first consisted of predicting the ligand's conformations and orientations around the receptor's active site, followed by obtaining the binding energy values of the formed receptor-ligand complex [17]. LigandScout by (Inte Ligand) 4.4/ADV was used to identify binding pockets [27].…”

“…Pharmacophore model generation was performed using the same approach [17]. LigandScout by Inte Ligand, Advanced software [27], Vienna, Austria, Europe [27], was used to generate a pharmacophore model.…”

“…According to the literature, isoorientin-2″-O-arabinoside and phytosphingosine bind directly to protein receptors, data shown in research on [57][58][59][60]. Concerning the triterpenes oleanolic acid and ursolic acid, a molecular docking approach was used in our previous research [17], in which these triterpenes were also identified in the methanolic extracts, it was possible to verify that both triterpenes fitted with favorable energy with ligand/protein interaction, through the enzymes tyrosinase, human peroxiredoxin 5 and superoxide dismutase, with the standard quercetin, a powerful antioxidant flavonoid, thus suggesting that the triterpenes had considerable antioxidant action. Concerning the triterpenes oleanolic acid and ursolic acid, a molecular docking approach was used in our previous research [17], in which these triterpenes were also identified in the methanolic extracts, it was possible to verify that both triterpenes fitted with favorable energy with ligand/protein interaction, through the enzymes tyrosinase, human peroxiredoxin 5 and superoxide dismutase, with the standard quercetin, a powerful antioxidant flavonoid, thus suggesting that the triterpenes had considerable antioxidant action.…”

“…The presence of secondary metabolites in extracts of leaves, branches and roots of M. hirsuta, such as saponins, organic acids, phenols, tannins, flavonoids and alkaloids is noteworthy [17], and their medicinal importance reported in its genus Mansoa for the treatment of pathologies such as inflammation, pain, flu and rheumatic diseases [18][19][20], as well as the importance of its family Bignoniaceae, in which they have several activities, pharmacological as anti-inflammatory, antitumor, antioxidant, healing, antidiabetic, antimalarial and antimicrobial [21], motivated us to explore the M. hirsuta species.…”