Phenolic profile, acute and subacute oral toxicity of the aqueous extract from Moroccan Mentha longifolia L. aerial part in Swiss Albino mice model

Abstract

Ethnopharmacological relevance: Mentha longifolia (L.) (Lamiaceae) is a native plant in Morocco, traditionally used in different countries to treat several disorders notably gastrointestinal illnesses, respiratory disorders, infectious diseases, inflammatory diseases, and menstrual problems. Robust scientific evidence has confirmed multiple pharmacological properties of M. longifolia including antihemolytic, anti-inflammatory, antibacterial, hepatoprotective, anti-cancer, antidiabetic, gastroprotective effect, and antispasmodic activity.

Aim of the study: The current study aimed to determine the phytochemical profile and assess the toxic effect of an aqueous extract of the arial parts of M. longifolia in male and female Swiss albino mice during acute and subacute oral toxicity.

Materials and methods: High-performance Liquid Chromatography Diode Array Detector (HPLC-DAD) was used to provide qualitative and quantitative analyses of phenolic compounds of M. longifolia aqueous extract. In acute toxicity experiments, four distinct groups of mice (n = 5/group/sex) were administered Mentha longifolia aqueous extract at single oral dosages of 0.5; 1; 2; 4, and 8 g/kg BW given by gavage and intraperitoneal for up to 14 days. Regarding the subacute toxicity investigation, Swiss albino mice were given M. longifolia aqueous extract orally at dosages of 100; 500; and 1000 mg/kg BW daily for 28 days. Body weight is measured every 7 days and suggested biochemical and hematological parameters were quantified, at the finish of 28 days of daily administration, sections of the liver, kidney, and spleen were histologically evaluated for showing damage to organs.

Results: The data of High-performance Liquid chromatography analysis revealed that M. longifolia aqueous extract was rich in interesting phytochemical compounds, mainly quercetin, and rutin, followed by a hydroxybenzoic acid-like syringic acid. Regarding the acute test in mice, no mortality or symptoms of toxicity were detected following oral administration with a single dose of M. longifolia aqueous extract at any dosage limit up to 4 g/kg, which was the no-observed side effect threshold (NOAEL). The mortality rate as well as acute toxicity of the M. longifolia aqueous extract delivered intraperitoneally, are increased progressively with increasing dosage. The non-observed adverse effect level (NOAEL) for the intraperitoneal dosage was 1 g/kg BW, and the lowest observed adverse effect level (LOAEL) was 2 g/kg BW, the estimated acute toxicity (LD₅₀) of intraperitoneally given M. longifolia aqueous extract in mice was 4.800 g/kg BW. Concerning subacute examinations in mice, the M. longifolia aqueous extract did not induce substantial modifications in biochemical or hematological indicators, preserving a slight increase in creatinine and urea levels. At the end of the experiment, a histopathological examination of the kidneys, liver, and spleen revealed normal architecture, suggesting no morphological damage.

Conclusion: The data we obtained indicate that acute or subacute administration of Mentha longifolia aqueous extract is relatively non-toxic in male and female Swiss albino mice.

Keywords: Acute toxicity; Hematological, and biochemical parameters; Mentha longifolia L.; Subacute oral toxicity.