The metabolites from the coumarin class, present in tissues of plants belonging mainly to the Rutaceae and Apiaceae families, included compounds with high chemical diversity such as simple coumarins and furocoumarins. These health-promoting components are recognized for their valuable biological activities in herbal preparations but also for their phototoxic effects. In this work, a targeted liquid chromatography (LC) coupled with tandem mass spectrometry (MS²) was developed for the screening of 39 reference standards of coumarins and furocoumarins in essential oils and plant extracts. Chromatographic separation was accomplished on reversed phase column using water/acetonitrile as the mobile phase and detection was performed on a hybrid QqQ/linear ion trap spectrometer fitted with an atmospheric pressure chemical ionization (APCI) source operating in positive ion mode. This analytical approach was applied to investigate the coumarin compositions of fruit essential oils and methanolic extracts obtained from separated parts (fruit, leaf, stem, trunk, and root) of Zanthoxylum zanthoxyloides. Ten coumarins and six furanocoumarins were reported in this species and data analyses were used to assess the suitability of these compounds to the metabolomics-based differentiation of plant organs. The quantification criteria of the metabolites in extract samples included linearity, limit of quantification, limit of detection, and matrix effect were validated. As reported for other species of the Rutaceae family, the concentration of coumarins was drastically higher in Z. zanthoxyloides fruits than in other plant organs.

Flavonoids are a large group of phenolic secondary metabolites having a wide range of biochemical and pharmacological effects. In this work, a targeted liquid chromatography (LC) coupled with tandem mass spectrometry (MS²) was used to characterize the flavonoid compositions of methanolic plant extracts from separated parts (fruits, leaves, stems, trunk barks, and root barks) of Zanthoxylum zanthoxyloides. Nine flavonoids were reported in this species, including three flavanones, five flavonols and one flavone. Quantitative analysis of flavonoid profiles from Z. zanthoxyloides extracts is useful to a better understanding of the pattern and distribution of metabolites in extract samples. The concentrations of two glycosylated flavanones (neohesperidin and hesperidin) and one flavonol (quercetin) were higher in root and trunk samples compared to fruit samples. These compounds were reported in small amounts in the stem and leaf samples. In contrast, four flavonols (hyperoside, quercetin-3- O-glucopyranoside, datiscin and quercitrin) were present in significant levels only in the leaf extracts. The presence of glycosylated flavanone (eriocitrin) has been reported only in fruit extract. The antioxidant properties of different extracts were tested regarding their scavenging activities on ABTS^•+ radical. Leaf and trunk bark extracts exhibited antioxidant activities, while the extracts obtained from other organs (fruits, stems, and root barks) showed low antioxidant properties.

Use of medicinal plants is common and widespread throughout Africa, including in Senegal. Because efficacy has been demonstrated, public policies have been instituted that have allowed plant‐based therapies to have an important role in general primary care. However, little is known about the cutaneous safety of many plant‐based therapies. In this 6‐month prospective study all cases of dermatitis induced or aggravated by exclusive use of medicinal plants were evaluated via skin allergy testing. The results were classified and compared with the available literature. Forty‐three cases of plant‐therapy‐associated cutaneous reactions were identified, including worsening of existing conditions (56%), recurrence of a previously resolved condition (16%) and new dermatitis arising spontaneously (28%). In the cases where the condition was new, generalized exfoliative dermatitis occurred in 42% of cases with an average time of onset of 9 days. Specific plants were identified in 65% of cases and included 18 varieties. The frequency and severity of plant‐induced cutaneous reactions should be the basis for the creation of a phytovigilance programme and re‐evaluation of how traditional medicine is used in the general population. When irritation occurs, identification of the responsible plant and allergy testing should be the first steps towards relieving symptoms.

This study aimed to determine the chemical composition, antibacterial and anti-inflammatory activities of Melaleuca leucadendra leaf essential oils. Ten samples of leaves from M. leucadendra were collected on the salt zone of Fatick (Senegal). The corresponding oils were obtained by hydrodistillation and analyzed by GC/FID and GC/MS. Oil yields from dried leaves were ranged from 1.64% to 2.75%. The almost exclusive compound in all samples of M. leucadendra oils was methyleugenol (98.4–99.5%). The oil exhibited moderate activity against S. aureus and E. coli and no activity against E. faecalis and P. aeruginosa. Anti-inflammatory properties of oil (25, 100 and 150 mg/kg, bw) showed significant inhibition of rat paw oedema induced by carrageenan at the 3^rd and 5^th h (p < 0.001 and 0.0001, respectively) when compared with control and standard drug (acetylsalicylic acid). The experimental study revealed that M. leucadendra oil, a natural source of methyleugenol, displayed remarkable anti-inflammatory activity.