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Extracts and compounds from the Chilean plants canelo, Drimys winteri J.R. Forst. & G. Forst. (Winteraceae), tabaco del diablo, Lobelia tupa L. (Campanulaceae), huevil, Vestia foetida Hoffmans. (Solanaceae) and violeta, Viola portalesia Gay (Violaceae) were evaluated against Sitophilus granarius L. (Coleoptera: Curculionidae), one of the most widespread and destructive primary pests of stored cereals. Total extracts at concentrations of 2.5%w/w in diets, over 6-days, display insecticidal effects against S. granarius. D. winteri caused the mortality of 87.5% of insects; L. tupa 80%, V. foetida 56% whereas V. portalesia killed 45% of insects under the same conditions. In an effort to determine the active compounds, the extracts of Lobelia tupa and Drimys winteri were purified by preparative chromatography. The piperidine alkaloid lobelanidine was isolated from L. tupa and the drimane sesquiterpenes drimenin, drimenol and polygodial were isolated as the major components in the extract from D. winteri. The purified compounds compounds displayed insecticidal activity against S. granarius in a concentration/dependent-time manner (% mortality at 0.5%w/w over 6-days): polygodial 80%, drimenol 60%, lobelanidine 47%, and drimenin 20%. In agreement with these results, grains treated with polygodial showed greater protection against the feeding attack by the granary weevil. These results provide evidence of the importance of elements of the native Chilean flora as new potential sources of botanical pesticides for the insect pest control.

It is reported in this study the effect of isolates from leaves of Aristotelia chilensis as inhibitors of acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and tyrosinase enzymes. The aim of the paper was to evaluate the activity of A. chilensis towards different enzymes. In addition to pure compounds, extracts rich in alkaloids and phenolics were tested. The most active F5 inhibited AChE (79.5% and 89.8% at 10.0 and 20.0 μg/mL) and against BChE (89.5% and 97.8% at 10.0 and 20.0 μg/mL), showing a strong mixed-type inhibition against AChE and BChE. F3 (a mixture of flavonoids and phenolics acids), showed IC50 of 90.7 and 59.6 μg/mL of inhibitory activity against AChE and BChE, inhibiting the acetylcholinesterase competitively. Additionally, F3 showed and high potency as tyrosinase inhibitor with IC50 at 8.4 μg/mL. Sample F4 (anthocyanidins and phenolic composition) presented a complex, mixed-type inhibition of tyrosinase with a IC50 of 39.8 μg/mL. The findings in this investigation show that this natural resource has a strong potential for future research in the search of new phytotherapeutic treatments for cholinergic deterioration ailments avoiding the side effects of synthetic drugs. This is the first report as cholinesterases and tyrosinase inhibitors of alkaloids and phenolics from A. chilensis leaves.

The vascular endothelium is a continuous monolayer of endothelial cells that are in direct contact with the blood and its dysfunction is the starting process in the development of many pathological inflammatory disorders, such as atherosclerosis, which can result in death. The expression of adhesion molecules such as vascular cell adhesion molecule 1 (VCAM1) and intercellular adhesion molecule 1 (ICAM1) is a key stage in modulating vascular inflammation, where the adhesion of monocytes and their transmigration into the intima starting a cascade of inflammatory reactions. Looking for natural compounds with inhibitory activity of VCAM1 and ICAM1, we isolated drimenol, isodrimeninol and polygodial as the main secondary metabolites from barks of Drimys winteri (Dw) and evaluated their effects in the adhesion response of monocytes cells (THP1) to a monolayer of human umbilical vein endothelial cells (HUVEC) in coculture assays. The results showed that the molecules and total extract Dw decrease the adhesion of THP1 to HUVECs, at 10 μg/mL. The adhesion activity is explained due to the inhibition of VCAM1 and ICAM1 evidenced by qRT-PCR and Western-blot assays. In conclusion, drimane sesquiterpenoids could be used as a molecular scaffold in the development of drugs for inflammatory vascular diseases.

Early stages of atherosclerosis are characterizated for the uptake of oxidate low-density lipoprotein (oxLDL) by inflammatory macrophages in the arteries, promoting the foam cell formation. Drimys winteri is a native tree of Chile that produce drimane sesquiterpenoids, here it was evaluated the inhibitory foam cell formation by the total extract of barks of Drimys winteri and isodrimeninol, a sesquiterpenoid isolated from the tree. The results showed that Dw and isodrimeninol inhibited the foam cell formation on macrophage M1, by Oil Red O staining. Moreover, Dw reduced the gene expression of pro-inflammatory cytokine TNF-α, in contrast to isodrimeninol that showed not effect on the gene expression of this cytokine, also Dw enhanced the expression of the anti-inflammatory cytokine IL-10, in more significant manner than isodrimeninol at 20 μg/mL. While, Dw and isodrimeninol significantly reduced the expression of IL1-β at concentrations of 20 μg/mL, but not affecting the MMP-9 levels, assessed by RT-qPCR. In conclusion, Drimys winteri and isodrimeninol induce anti-atherosclerotic effects, inhibiting foam cell formation, as well as promoting anti-inflammatory responses. This study confirm the relevance of this tree as a medicinal source for the Mapuche people, and suggesting that Drimys winteri could be used in early stages of atherosclerosis.