Marija Kindl

Acetylcholinesterase Inhibitory, Antioxidant and Phytochemical Properties of Selected Medicinal Plants of the Lamiaceae Family

The present study aimed to evaluate acetylcholinesterase (AChE) inhibitory and antioxidant activities of Lamiaceae medicinal plants growing wild in Croatia. Using Ellman’s colorimetric assay all tested ethanolic extracts and their hydroxycinnamic acid constituents demonstrated in vitro AChE inhibitory properties in a dose dependent manner. The extracts of Mentha x piperita, M. longifolia, Salvia officinalis, Satureja montana, Teucrium arduini, T. chamaedrys, T. montanum, T. polium and Thymus vulgaris at 1 mg/mL showed strong inhibitory activity against AChE. The antioxidant potential of the investigated Lamiaceae species was assessed by DPPH• scavenging activity and total antioxidant capacity assays, in comparison with hydroxycinnamic acids and trolox. The extracts differed greatly in their total hydroxycinnamic derivatives content, determined spectrophotometrically. Rosmarinic acid was found to be the predominant constituent in most of the investigated medicinal plants (by RP-HPLC) and had a substantial influence on their AChE inhibitory and antioxidant properties, with the exception of Teucrium species. These findings indicate that Lamiaceae species are a rich source of various natural AChE inhibitors and antioxidants that could be useful in the prevention and treatment of Alzheimer’s and other related diseases.

Antioxidant and Anticholinesterase Potential of Six Thymus Species

The present study aimed to evaluate antioxidant and acetylcholinesterase (AChE) inhibitory activities of the ethanolic extracts of six selected Thymus species growing in Croatia (T. longicaulis, T. praecox subsp. polytrichus, T. pulegioides, T. serpyllum subsp. serpyllum, T. striatus, and T. vulgaris). Antioxidant effectiveness was assessed using six different assays, in comparison with rosmarinic acid, luteolin, and reference antioxidants. All tested Thymus extracts possessed DPPH (IC50 = 3–6 μg/mL) and nitric oxide (IC50 = 70–177 μg/mL) free radical scavenging activities, strong reducing properties (IC50 = 11–15 μg/mL), ferrous ion chelating activity (IC50 = 126–389 μg/mL), ability to inhibit lipid peroxidation (IC50 = 34–80 μg/mL), and high total antioxidant capacities (238–294 mg AAE/g). AChE inhibitory activity was examined using Ellmans colorimetric method and all tested extracts showed anti-AChE activity in a dose dependent manner. The values of 10–28%, 23–39%, and 64–86% were obtained for tested concentrations of 0.25, 0.5, and 1 mg/mL, respectively. Additionally, the contents of total hydroxycinnamic derivatives, flavonoids, and tannins in dried plant samples were determined spectrophotometrically. Our results highlighted Thymus species as a rich source of natural antioxidants and AChE inhibitors that could be useful in preventing and treating Alzheimers disease and other neurodegenerative disorders.

Phytochemical Aspects and Therapeutic Perspective of Cannabinoids in Cancer Treatment

Cannabinoids comprise the plant‐derived compounds and their synthetic derivatives as well as endogenously produced lipophilic mediators. Phytocannabinoids are terpenophe‐ nolic secondary metabolites predominantly produced in Cannabis sativa L. The principal active constituent is delta‐9‐tetrahydrocannabinol (THC), which binds to endocannabinoid receptors to exert its pharmacological activity, including psychoactive effect. The other important molecule of current interest is non‐psychotropic cannabidiol (CBD). Since 1970s, phytocannabinoids have been known for their palliative effects on some cancer‐associated symptoms such as nausea and vomiting reduction, appetite stimulation and pain relief. More recently, these molecules have gained special attention for their role in cancer cell proliferation and death. A large body of evidence suggests that cannabinoids affect mul‐ tiple signalling pathways involved in the development of cancer, displaying an anti‐prolif‐ erative, proapoptotic, anti‐angiogenic and anti‐metastatic activity on a wide range of cell lines and animal models of cancer. These findings have led to the development of clinical studies to investigate potential anti‐cancer activity in humans, but reliable clinical evidence for this therapeutic option is still missing.