Antioxidant and Leishmanicidal Evaluation of Pulicaria Inuloides Root Extracts: A Bioguided Fractionation

Abstract

Leishmaniasis remains a major world health problem, and in particular, Algeria ranks second for the incidence of cutaneous leishmaniasis. Pulicaria inuloides is a well-known Arabian Peninsula medicinal plant. In the present study, the chloroform, ethyl acetate and n-butanol extracts from the roots of Pulicaria inuloides were analyzed for antioxidant activity and its correlation with the total phenolic and flavonoid contents. The highest antioxidant activity using a DPPH assay was showed by the ethyl acetate extract (IC 50 4.08 µg/mL), which also had the highest total phenolic content (307.12 µgAGE). Furthermore, P. inuloides root extracts were evaluated against Leishmania amazonensis and Leishmania donovani. The results highlighted the chloroform extract as the most active one against both tested Leishmania strains. A bioguided fractionation of the chloroform extract led to the isolation of (8R:8S)-(75:25 er)-10-isobutyryloxy-8,9-epoxy-thymol isobutyrate as the main bioactive component, showing a potent leishmanicidal activity on L. amazonensis promatigote and amastigote stages (IC 50 5.03 and 2.87 µM, respectively) and a good selectivity index on murine macrophages (CC 50 19.37 µM). This study provides the first report of the antioxidant and leishmanicidal activities of P. inuloides root extracts and the results point to this species as a source of potential bioactive agents.

Essential Oil Chemical Characterization and Antioxidant Potential of Pulicaria inuloides from the Southwest of Algeria

“…Previously, our work on P. inuloides root extracts [16] indicated that the highest antioxidant activity by DPPH assay was reported for the ethyl acetate extract (IC 50 = 4.08 µg/ mL) which also had the highest total phenol content (307.12 µgAGE). Furthermore, previously published results of Al-Hajj et al [18] showed a significant antioxidant activity by DPPH and β-carotene assays for P. inuloides extracts (81.0 and 72.2%, respectively) which had also the highest total phenol and flavonoid contents (91.2 mgAGE/g and 75.0 mgQE/g, respectively).…”

“…The DPPH (2,2-diphenyl-1-picrylhydrazyl) solution (0.04 mg/mL) was used to evaluate the antioxidant properties of extracts [16]. Samples were prepared at 5.0 mg/mL, then, 30 μL of sample solutions at different concentrations were added to 3.0 mL of the DPPH solution.…”

“…Recently, some biological evaluations have been reported for P. inuloides such as anticancer and antibacterial activities [14]. In addition, our previous studies revealed the leishmanicidal properties of P. inuloides aerial and root extracts; including the antioxidant capacity of its root extracts [15,16]. Whereas, only few authors have reported the chemical composition of P. inuloides essential oil from Yemen, where they identified the presence of 2-methyl-5-(1-methyl) and 2-cyclohexen-1-one as its main components [17,18].…”

Chemical Composition and Cytotoxic Activity of Extracts from Carpesium divaricatum: In Vitro- versus Field-Grown Plants

“…The results of RP-HPLC-DAD analysis ( Figure 2 e) showed that 10-isobutyryloxy-8,9-epoxy-thymyl isobutyrate is a major terpenoid constituent of the plant roots. The compound has been recently described as an inhibitor of aberrant proliferative signaling in melanoma cells [ 38 ] and antileishmanial agent [ 39 ] and is known as a secondary metabolite synthesized by numerous species from the Asteraceae [ 40 ].…”

Constituents of Pulicaria inuloides and Cytotoxic Activities of Two Methoxylated Flavonols

“…The flowers of the plant are used in Yemen as a spice [ 21 ]. Recently, the evaluation of the leishmanicidal potential of P. inuloides has led to the isolation of its active constituents: quercetagetin-3,5,7,3’-tetramethyl ether and 8,9-epoxy-10-isobutyryloxythymyl isobutyrate [ 22 , 23 ]. Data on the chemical composition of the plant are sparse.…”