Cytotoxic and Anti-Inflammatory Effects of Ent-Kaurane Derivatives Isolated from the Alpine Plant Sideritis hyssopifolia

This paper reports the isolation and structural characterization of four new ent-kaurane derivatives from the Lamiaceae plant Sideritis hyssopifolia. Planar structures and relative configurations were determined using both mass spectrometry and nuclear magnetic resonance (1D and 2D). Absolute configurations were determined by comparing experimental and theoretical electronic circular dichroism spectra. The cytotoxic and microbial activities of all new compounds were tested. Compounds that were non-cytotoxic were further evaluated for anti-inflammatory activity.

Assessment of the Antioxidant/Hypolipidemic Relationship of Sideritis hyssopifolia in an Experimental Animal Model

Many publications have described the potential cardioprotective action of different medicinal plants, relating this effect with blood lipid levels. However, these publications do not justify the right amount of plant administered, which can vary greatly. Sideritis hyssopifolia is a little woody plant endemic to western and southwestern Europe. We have quantified its antioxidant activity, which can be used as an indicator of its cardioprotective action. This study evaluates the antioxidant capacity of Sideritis hyssopifolia to design a feed whose hypolipidemic effects are proven in cholesterol-fed New Zealand rabbits. Antioxidant action was assessed in infusions, which were prepared with 1 or 3 g of plant in 200 mL of water by using an ABTS assay and expressed as Ascorbic acid Equivalent Antioxidant Capacity (AEAC). Aqueous infusions with infusion times of 10 min and prepared with 3 g plant exhibited the strongest antioxidant activity. Sideritis hyssopifolia showed an intermediate antioxidant capacity for the concentrations and times of the infusion tested. According to our results, we suggest incorporating 2.36 g of S. hyssopifolia every 150 g of rabbit feeding stuff (15.73 g/kg). This chow decreased cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides levels in cholesterol-fed rabbits, as well as the atherogenic index. This reduction was similar to that obtained with simvastatin.