Abstract:Cornaceae plants are known for their edible berries, and their leaves are used as tea. In the present study aqueous leaf extracts from Cornus mas (CM), C. alba (CA), C. flaviramea (CF), C. kousa (CK), and C. officinalis (CO) were tested for their antiproliferative activity in human breast cancer cells (MCF-7). Dose-(50-750 µg/mL) and time (24, 48, 72 h)-dependent antiproliferative effects were measured by WST-1, and correlated with the content of flavonoids (FL), total hydroxycinnamic derivatives (THD), total polyphenols (TP) and tannins (T). Extracts induced time dependent decreases in cell survival; CA, CO and CM were the most effective (11.2%, 10.3% and 11.1%, after 72 h). The ED 50 (effective dose) values were similar for all extracts and times tested. The THD and TP were identical in all samples, while a two-fold higher T content was present in CK and CO, and of FL in CF. The maximal effects (% of surviving cells) negatively correlated with the T and TP levels, and positively with FL and THD. The results demonstrate the significant antiproliferative effects of the tested water extracts in MCF-7 cells, in which CA, CO and CM are the most effective; and the effectiveness is related to the T and TP contents.

The basal production of secondary metabolites in medicinal plants is limited. One of the effective approaches that encourages plants to produce a remarkable amount of precious compounds is an application of elicitors. Our work was focused on the elicitation of Eschscholzia californica Cham. suspension cultures using various concentrations of MnCl2 (5; 10; 15 mg/L) with the aim of evaluating its effect on sanguinarine, chelerythrine, and macarpine production and gene expression of enzymes involved in the biosynthesis of mentioned secondary metabolites (BBE, 4′-OMT, CYP80B1) or in defense processes (LOX). Suspension cultures were exposed to elicitor for 24, 48, and 72 h. The content of alkaloids in phytomass was determined on the basis of their fluorescence properties. The relative mRNA expression of selected genes was analyzed using the ΔΔCt value method. PCR products were evaluated by melting curve analysis to confirm the specific amplification. Our results demonstrated that Eschscholzia californica Cham. cell suspension cultures evince sensitivity to the presence of MnCl2 in growth media resulting in the increased production of benzophenanthridine alkaloids and gene expression of selected enzymes. Manganese chloride seems to be a potential elicitor supporting natural biosynthetic properties in plant cell cultures and can be applied for the sustained production of valuable secondary metabolites.

Macarpine is a minor benzophenanthridine alkaloid with interesting biological activities, which is produced in only a few species of the Papaveraceae family, including Eschscholzia californica. Our present study was focused on the enhancement of macarpine production in E. californica suspension cultures using three elicitation models: salicylic acid (SA) (4; 6; 8 mg/L) elicitation, and simultaneous or sequential combinations of SA and L-tyrosine (1 mmol/L). Sanguinarine production was assessed along with macarpine formation in elicited suspension cultures. Alkaloid production was evaluated after 24, 48 and 72 h of elicitation. Among the tested elicitation models, the SA (4 mg/L), supported by L-tyrosine, stimulated sanguinarine and macarpine production the most efficiently. While sequential treatment led to a peak accumulation of sanguinarine at 24 h and macarpine at 48 h, simultaneous treatment resulted in maximum sanguinarine accumulation at 48 h and macarpine at 72 h. The effect of SA elicitation and precursor supplementation was evaluated also based on the gene expression of 4′-OMT, CYP719A2, and CYP719A3. The gene expression of investigated enzymes was increased at all used elicitation models and their changes correlated with sanguinarine but not macarpine accumulation.

Particular Cornus species are known for their edible fruits and their leaves are used as a tea in some countries. In the present study, the immunomodulatory activity of water infusions of leaves of Cornus mas (CM), C. kousa (CK), C. alba (CA), C. flaviramea (CF), C. coreana (CC) and C. amomum (CU) was tested on human leukocytes. Phagocytic and antimicrobial activity was determined for concentrations of 0.17 and 0.25 mg.mL-1. All samples significantly enhanced the phagocytic activity of cells. Samples at the concentration of 0.17 mg.mL-1 were in all cases, except CK, slightly more effective than those at 0.25 mg.mL-1. The strongest bactericidal (E. coli) and also candidacidal (C. albicans) activity was exerted by CM at 0.25 mg.mL-1. The most potent samples at the lower concentration were CF (for E. coli) and CK (for C. albicans). CC and CU were antimicrobially non-effective.

Leaves of selected species of the Cornaceae family (Swida alba, Swida australis, Swida controversa, Swida coreana, Swida baileyi, Cornus kousa, Cornus mas) were investigated in this study. These shrubs or small trees with hard wood are cultivated in Slovakia (Tesarske Mlyňany Arboretum). Some species (C. mas and C. kousa) have edible fruits. Cornels find broad ethnopharmacological use, for example, in Traditional Chinese Medicine (TCM), where fruits of C. officinalis are used for the treatment of several disorders, such as organ hypersecretion or diabetes. They are also used as tonics and for astringent effects. Leaves and fruits of C. kousa have been reported to possess antioxidative, anti-inflammatory and antidiabetic properties. The aim of our study is to compare the content of selected secondary metabolites groups in the leaves of above-mentioned species. The plant material was collected in the Tesarske Mlyňany Arboretum, Slovakia, in September 2010. Modified spectrophotometric methods of the European Pharmacopoeia, 8th edition (Ph. Eur. 8) were used for all assays. Results show that the total hydroxycinnamic derivatives (THD) content varied from 1.14 (S. alba) to 2.86% (S. coreana) when expressed as rosmarinic acid, and from 1.01 (S. alba) to 2.55% (S. coreana) when expressed as caffeic acid. The flavonoids content ranged from 0.21 (C. mas) to 1.37% (S. coreana), total polyphenols content from 9.6 (C. kousa) to 7.27% (S. coreana), and tannins content from 7.17 (C. kousa) to 4.04% (S. coreana). Leaves of Korean dogwood (S. coreana) were observed to show the highest content of THD expressed as rosmarinic acid (2.86%) and caffeic acid (2.55%), as well as of flavonoids (1.37%). Kousa dogwood (C. kousa) contained the highest amounts of tannins (7.17%) and total polyphenols (9.6%) on the other hand.