Antioxidant activity and cholinesterase inhibition studies if four flavoring herb from Alentejo.

In Alzheimer’s disease, the most common form of dementia, the loss of cholinergic neurons leads to the progressive reduction of acetylcholine in the brain, resulting cognitive impairment. Inhibition of the hydrolysis of acetylcholine by blocking acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) has been considered as a potential target in the treatment of Alzheimer’s disease. Essential oils and extracts of aromatic plants may have an important role in the oxidative stress protection. Traditionally, in Alentejo (Portugal), aromatic herbs Calamintha nepeta, Foeniculum vulgare, Mentha spicata and Thymus mastichina are often used by local population as condiments in food preparations. In this study, essential oils (EOs) and aqueous extracts (decoction waters) of these flavouring herbs were selected in order to evaluate its antioxidant potential and ability to inhibit AChE and BChE activities. Results suggest the potential use of EOs and extracts as nutraceutical or pharmaceutical preparations in the prevention of the oxidative stress and degenerative diseases.

First report on Meloidogyne chitwoodi hatching inhibition activity of essential oils and essential oils fractions

The Columbia root-knot nematode (CRKN), Meloidogyne chitwoodi, is an EPPO A2 type quarantine pest since 1998. This nematode causes severe damage in economically important crops such as potato and tomato, making agricultural products unacceptable for the fresh market and food processing. Commonly used nematicidal synthetic chemicals are often environmentally unsafe. Essential oils (EOs) may constitute safer alternatives against RKN. EOs, isolated from 56 plant samples, were tested against CRKN hatching, in direct contact bioassays. Some of the most successful EOs were fractionated and the hydrocarbon molecules (HM) and oxygen-containing molecules (OCM) fractions tested separately. 24 EOs displayed very strong hatching inhibitions (≥90 %) at 2 µL mL−1 and were further tested at lower concentrations. Dysphaniaambrosioides, Filipendula ulmaria, Ruta graveolens, Satureja montana and Thymbra capitata EOs revealed the lowest EC50 values (<0.15 µL mL−1). The main compounds of these EOs, namely 2-undecanone, ascaridol, carvacrol, isoascaridol, methyl salicylate, p-cymene and/or γ-terpinene, were putatively considered responsible for CRKN hatching inhibition. S. montana and T. capitata OCM fractions showed hatching inhibitions higher than HM fractions. The comparison of EO and corresponding fractions EC50 values suggests interactions between OCM and HM fractions against CRKN hatching. These species EOs showed to be potential environmentally friendly CRKN hatching inhibitors; nonetheless, bioactivity should be considered globally, since its HM and OCM fractions may contribute, diversely, to the full anti-hatching activity.