Effects of the dose of administration, co-antioxidants, food matrix, and digestion-related factors on the in vitro bioaccessibility of rosmarinic acid - A model study.

This study aimed to determine the effect of the administration dose, combinations with co-antioxidants (vitamin C, caffeic acid, chlorogenic acid, catechin, rutin), and different food matrices (cooked and lyophilized hen eggs, chicken breast, soybean seeds, potatoes) on the potential bioaccessibility of rosmarinic acid (RA) in simulated digestion conditions, depending on the digestion stage (gastric and intestinal) and the contribution of physicochemical and biochemical digestion factors. The in vitro bioaccessibility of RA depended on the digestion stage and conditions. The physicochemical factors were mainly responsible for the bioaccessibility of RA applied alone. The higher RA doses improved its bioaccessibility, especially at the intestinal stage of digestion. Furthermore, the addition of vitamin C and protein-rich food matrices resulted in enhanced intestinal bioaccessibility of RA. In the future, the knowledge of factors influencing the bioaccessibility of RA can help enhance its favorable biological effects and therapeutic potential.

Bioaccessibility of Rosmarinic Acid and Basil (Ocimum basilicum L.) Co-Compounds in a Simulated Digestion Model-The Influence of the Endogenous Plant Matrix, Dose of Administration and Physicochemical and Biochemical Digestion Environment.

The objective of this study is to determine the effect of endogenous plant matrix components, dose and digestion-related factors on the bioaccessibility of rosmarinic acid and basil co-compounds in in vitro digestion conditions. Different forms of administration, i.e., basil raw plant material, dry extract, and isolated rosmarinic acid at various doses, were applied for the digestion experiment. To evaluate the contribution of biochemical and physicochemical digestion factors, samples were subjected to a full digestion process or treated only with a digestion fluid electrolyte composition without using biochemical components (i.e., digestion enzymes and bile salts), and bioaccessibility was monitored at the gastric and intestinal steps of digestion. The results showed that the components of the endogenous raw plant matrix significantly limited the bioaccessibility of rosmarinic acid and basil co-compounds, especially at the gastric stage of digestion. Physicochemical digestion factors were mainly responsible for the bioaccessibility of basil phytochemicals. Higher doses allowed maintenance of bioaccessibility at a relatively similar level, whereas the most negative changes in bioaccessibility were induced by the lowest doses. In conclusion, the determination of the bioaccessibility of bioactive phytochemicals from basil and factors influencing bioaccessibility may help in better prediction of the pro-health potential of this plant.

Phytochemical profile, in vitro bioaccessibility, and anticancer potential of golden root (Rhodiola rosea L.) extracts.

The effects of water and ethanolic (40 %, 70 %, and 96 %) extraction on the Rhodiola rosea L. phytochemical profile (HPLC analysis), stability during extract drying, potential bioaccessibility in simulated gastric and intestinal conditions, and cytotoxic activity against human colorectal adenocarcinoma cells (Caco-2 and HT-29 cell lines) were investigated. The phytochemical profile, extractability, and stability during extract processing depend on the solvent type. In general, compounds derived from dry extracts were characterized by higher bioaccessibility than those extracted from powdered plant material. In the case of salidroside, tyrosol, and rosavins, one of the highest bioaccessibilities (often about 100 %) were found for the 70 % ethanolic extract after gastric digestion. Furthermore, the 70 % ethanolic extract most effectively reduced the viability of Caco-2 cells (IC50 85.8 µg∙mL-1). The results suggest that golden root extracts, in particular 70 % ethanolic extract, seem to be promising supplements for the food industry.

In vitro bioaccessibility and activity of basil (Ocimum basilicum L.) phytochemicals as affected by cultivar and postharvest preservation method - Convection drying, freezing, and freeze-drying.

The effects of convection drying, freezing, and freeze-drying, on phytochemicals content, in vitro activity and bioaccessibility of sweet basil, cinnamon basil, red rubin basil, and lemon basil were investigated. For evaluation of bioaccessibility, rosmarinic acid content, phenolic content, and antioxidant potential of samples before and after gastric and intestinal steps of digestion were determined. Results showed that the content, activity and bioaccessibility of basil phytochemicals varied depending on the cultivar as well as the applied postharvest preservation. It was found that the frozen and freeze-dried plant materials were characterized by a higher phenolic level and antioxidant activity compared to the convection dried. However, in general, convection drying allows obtaining samples with higher bioaccessibility of phytochemicals compared to the low-temperature processed samples. These findings highlight the need for evaluation of basil cultivars and postharvest preservation methods regarding phytochemicals bioaccessibility, which might help in the classification in terms of pro-health quality.

Chemical Characteristics and Anticancer Activity of Essential Oil from Arnica Montana L. Rhizomes and Roots.

Arnica montana L. is a medicinal plant with diverse biological activities commonly used in pharmacy and cosmetics. The attributes of A. montana are mainly related to the concentration and chemical composition of essential oils (EOs). Therefore, the objective of this study was to characterize the chemical composition of EOs derived from A. montana rhizomes and roots taking into account the age of the plants and to investigate the effect of the analyzed EOs on induction of apoptosis, necrosis, and autophagy in human glioblastoma multiforme T98G and anaplastic astrocytoma MOGGCCM cell lines. Rhizomes and roots of mountain arnica were harvested at the end of the third and fourth vegetation periods. The chemical composition of essential oils was determined with the GC-MS technique. Among the 37 components of the essential oil of A. montana, 2,5-dimethoxy-p-cymene (46.47%-60.31%), 2,6-diisopropylanisole (14.48%-23.10%), thymol methyl ether (5.31%-17.79%), p-methoxyheptanophenone (5.07%-9.65%), and α-isocomene (0.68%-2.87%), were detected in the rhizomes and roots of the three-year-old plants and in the rhizomes and roots of the four-year-old plants. The plant part (rhizome, root) and plant age can be determinants of the essential oil composition and, consequently, their biological activity. The induction of apoptosis (but not autophagy nor necrosis) at a level of 28.5%-32.3% is a promising result, for which 2,5-dimethoxy-p-cymene, 2,6-diisopropylanisole, thymol methyl ether, and p-methoxyheptanophenone are probably mainly responsible. The present study is the first report on the anticancer activities of essential oils from A. montana rhizomes and roots.