Ethnomedicinal documentation and anti-inflammatory effects of n-butanol extract and of four compounds isolated from the stems of Pituranthos scoparius: An in vitro and in vivo investigation

ETHNOPHARMACOLOGICAL RELEVANCE

Pituranthos scoparius is a medicinal plant belonging to the Apiaceae family. It thrives in North Africa, and is widely distributed in the high plateau of most parts of the Sahara in Algeria. This plant is widely used in the Algerian traditional medicine to treat numerous infectious diseases, dermatoses, nervous breakdowns, digestive disorders, and calm abdominal pain.

AIM OF THE STUDY

The aim of the present work was to examine the ethnomedicinal uses of Pituranthos scoparius in Setif region, Algeria, isolate and identify the chemical constituents of the n-butanol stem extract of P. scoparius (BEPS), and to determine the toxicity and anti-inflammatory effects of these compounds in addition to the extract.

MATERIALS AND METHODS

The anti-inflammatory effects of BEPS and the four compounds isolated from the extract were evaluated using the in vitro protein denaturation assay, whereas the topical anti-inflammatory activity was assessed using the croton oil-induced ear edema in mice. Toxicity was determined based on assessment of in vitro cytotoxicity using hemolytic activity against human red blood cells (RBCs).

RESULTS

Four compounds, identified as the rare isorhamnetin-3-O-β-apiofuranosyl (1 → 2)-β glucopyranoside (2), in addition to three known compounds, namely isorhamnetin-3-O-β-glucoside (1), D-mannitol (3), and isorhamnetin-3-O-β-glucopyranosyl-(1 → 6)-β-glucopyranoside (4) were isolated from BEPS. These compounds were characterized by means of NMR and high-resolution mass spectral (HRMS) data. These four compounds were isolated for the first time from this traditional Algerian medicinal plant. Screening of the extract indicated the presence of alkaloids, polyphenols, flavonoids, free quinones, coumarins and tannins. Topical anti-inflammatory effect showed that the four isolated compounds, as well as BEPS, exhibit a significant (p < 0.05) dose-dependent (0.5 and 1 mg/ear) anti-inflammatory effect. At a dose of 1 mg/ear, compounds 1, 2, and 4, exhibited remarkable anti-inflammatory effect with a percentage inhibition of 85.50 ± 2.78, 79.78 ± 4.68, and 75.78 ± 2.98%, respectively. Results from in vitro cytotoxicity showed that the % lysis of the extract, along with isolated compounds was found to be virtually nontoxic.

CONCLUSIONS

These results suggest that BEPS and isolated compounds are safe, nontoxic, and exert remarkable anti-inflammatory effects, and can be new sources of natural anti-inflammatory agents.

Anti-inflammatory, analgesic activity, and toxicity of Pituranthos scoparius stem extract: An ethnopharmacological study in rat and mouse models

ETHNOPHARMACOLOGICAL RELEVANCE

Pituranthos scoparius is a medicinal plant that is used in traditional medicine in Algeria and other North African nations to treat several diseases such as asthma, rheumatism, measles, dermatoses, jaundice, and digestive disorders.

AIM OF THE STUDY

The present investigation was designed to investigate an ethnobotanical survey about Pituranthos scoparius in Setif region, Algeria, and assess the acute toxicity, in vivo anti-inflammatory potential and analgesic effect of Pituranthos scoparius hydromethanolic stem extract (PSSE) in rats and mice models.

MATERIALS AND METHODS

Acute toxicity of PSSE was carried out based on OECD guidelines 425. Both possible death and signs accompanying toxicity of animals were monitored for 14 days to establish the median lethal dose (LD₅₀) of PSSE. Anti-inflammatory effect of the extract was evaluated using the xylene, croton oil-induced ear edema, and carrageenan-induced paw edema, whereas the analgesic activity was evaluated using acetic acid-induced abdominal constriction in mice model.

RESULTS

Data from the ethnopharmacological survey showed that 24.47% of people used this plant in traditional (folk) medicine. Results also revealed that PSSE contains high amounts of polyphenols, flavonoids, and tannins, and that the extract did not cause any deaths or changes in the behavior of treated animals; LD₅₀ values were found to be higher than 5 g/kg BW. Additionally, no significant variations were observed in the alkaline phosphatase (ALP), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) enzymes, or in the levels of urea and creatinine. Oral administration of PSSE at the doses of 100, 300, and 600 mg/kg produced a significant dose-dependent inhibition effect in both xylene and croton oil-induced ear edema in mice. Administration of PSSE at a dose of 100, 250, and 500 mg/kg significantly (P < 0.05) exhibited anti-edematogenic effect in the carrageenan-induced rat paw edema after 3 h. In acetic acid-induced writhing model, PSSE significantly (P < 0.05) reduced writhing at a dose of 500 mg/kg with 69.92% of inhibition.

CONCLUSIONS

Taken all together, PSSE is non-toxic, and exhibits potent anti-inflammatory and analgesic activities. Through the ethnomedicinal study, our findings highlight the medicinal use of PSSE in traditional medicine and as an additional source of natural and safe anti-inflammatory agents.