Background: Tanacetum vulgare L. (Asteraceae) is a perennial herb that has been used to treat multiple ailments. Regional variability of the chemical composition of T. vulgare essential oils is well-known. Despite these regional chemotypes, most relevant studies did not analyze the complete chemical composition of the T. vulgare essential oil and its constituents in relation to their biological activities. Here, we assess the anti-inflammatory, antioxidant, antibacterial, and cytotoxic activities of T. vulgare collected from northern Quebec (Saguenay-Lac-St-Jean), Canada. Methods: Essential oil was extracted from plants by steam distillation and analyzed using GC-FID. Biological activities of essential oil and its main constituents were evaluated in vitro. Results: We identified the major compounds as camphor, borneol, and 1,8-cineole. The oil possesses anti-inflammatory activity inhibiting NO production. It also inhibits intracellular DCFH oxidation induced by tert-butylhydroperoxide. Anti-inflammatory activity of essential oil appears driven mainly by α-humulene while antioxidant activity is provided by α-pinene and caryophyllene oxide. Essential oil from T vulgare was active against both Escherichia coli and Staphylococcus aureus with camphor and caryophyllene oxide responsible for antibacterial activity. Finally, T. vulgare essential oil was slightly cytotoxic against the human healthy cell line WS1 while α-humulene and caryophyllene oxide were moderately cytotoxic against A-549, DLD-1, and WS1. Conclusion: We report, for the first time, links between the specific compounds found in T. vulgare essential oil and anti-inflammatory, antioxidant, antibacterial, and cytotoxic activities. T. vulgare essential oil possesses interesting biological properties.

Many plants of boreal forest of Quebec have been used by Native Americans to treat a variety of microbial infections. However, the antiviral activities of these plants have been seldom evaluated on cellular models to validate their in vitro efficiencies. In this study, Cornus canadensis L. (Cornaceae), a plant used in Native American traditional medicine to treat possible antiviral infections, has been selected for further examination. The plant was extracted by decoction and infusion with water, water/ethanol 1:1 and ethanol to obtain extracts similar to those used by Native Americans. The effects of the extracts were tested on herpes simplex virus type-1 (HSV-1) using a plaque reduction assay. Moreover, bioassay-guided fractionation was achieved to isolate bioactive compounds. Water/ethanol 1:1 infusion of C. canadensis leaves were the most active extracts to inhibit virus absorption with EC50 of about 9 μg mL−1, whereas for direct mode, both extraction methods using water or water/ethanol 1:1 as solvent were relatively similar with EC50 ranging from 11 to 17 μg mL−1. The fractionation led to the identification of active fractions containing hydrolysable tannins. Tellimagrandin I was found the most active compound with an EC50 of 2.6 μM for the direct mode and 5.0 μM for the absorption mode. Altogether, the results presented in this work support the antiviral activity of Cornus canadensis used in Native American traditional medicine.

Betulinic acid and ursolic acid are ubiquitous, naturally-occurring triterpenoids exhibiting various pharmacological activities including cytotoxic and anti-inflammatory activities. However, these triterpenoids display unfavorable pharmacokinetic properties as well as low aqueous solubility. It has been shown that the presence of α-L-rhamnose moieties positively modulates the anticancer activity of secondary metabolites. Herein we report the synthesis and in vitro evaluation of cytotoxic and anti-inflammatory activities of a series of rhamnose-containing ursolic and betulinic acid saponins. Relying on Schmidt's normal and inverse procedures, monorhamnosides, (1→4)-linked dirhamnosides as well as branched trirhamnosides and tetrarhamnosides were synthesized in high yields with full control of stereoselectivity. A betulinic acid saponin bearing a 3-O-α-L-rhamnopyranosyl-(1→4)-α-L-rhamnopyranosyl residue was found to be a potent cytotoxic agent against human colorectal adenocarcinoma cells without damaging the healthy cells (selectivity ratio > 20) whereas rhamnose-containing ursolic acid saponins potently inhibited NO overproduction induced by LPS-stimulated macrophages. Our results reveal that rhamnose-containing ursolic and betulinic acid saponins represent promising therapeutic agents.

The bark of boreal forest conifers has been traditionally used by Native Americans to treat various ailments and diseases. Some of these diseases involve reactive oxygen species (ROS) that can be prevented by the consumption of antioxidants such as phenolic compounds that can be found in medicinal plants. In this study, ultrasonic assisted extraction has been performed under various solvent conditions (water:ethanol mixtures) on the bark of seven boreal forest conifers used by Native Americans including: Pinus strobus, Pinus resinosa, Pinus banksiana, Picea mariana, Picea glauca, Larix laricina, and Abies balsamea. The total phenolic content, as well as ORAC_FL potency and cellular antioxidant activity (IC₅₀), were evaluated for all bark extracts, and compared with the standardized water extract of Pinus maritima bark (Pycnogenol), which showed clinical efficiency to prevent ROS deleterious effects. The best overall phenolic extraction yield and antioxidant potential was obtained with Picea glauca and Picea mariana. Interestingly, total phenolic content of these bark extracts was similar to Pycnogenol but their antioxidant activity were higher. Moreover, most of the extracts did not inhibit the growth of human skin fibroblasts, WS1. A significant correlation was found between the total phenolic content and the antioxidant activity for water extracts suggesting that these compounds are involved in the activity.