Wirginia Janiszowska

Antibacterial and antiparasitic activity of oleanolic acid and its glycosides isolated from marigold (Calendula officinalis).

The antibacterial and antiparasitic activities of free oleanolic acid and its glucosides and glucuronides isolated from marigold (Calendula officinalis) were investigated. The MIC of oleanolic acid and the effect on bacterial growth were estimated by A600 measurements. Oleanolic acids influence on bacterial survival and the ability to induce autolysis were measured by counting the number of cfu. Cell morphology and the presence of endospores were observed under electron and light microscopy, respectively. Oleanolic acid inhibited bacterial growth and survival, influenced cell morphology and enhanced the autolysis of Gram-positive bacteria suggesting that bacterial envelopes are the target of its activity. On the other hand, glycosides of oleanolic acid inhibited the development of L3 Heligmosomoides polygyrus larvae, the infective stage of this intestinal parasitic nematode. In addition, both oleanolic acid and its glycosides reduced the rate of L3 survival during prolonged storage, but only oleanolic acid glucuronides affected nematode infectivity. The presented results suggest that oleanolic acid and its glycosides can be considered as potential therapeutic agents.

Oleanolic acid and ursolic acid affect peptidoglycan metabolism in Listeria monocytogenes

The plant pentacyclic triterpenoids, oleanolic and ursolic acids, inhibit the growth and survival of many bacteria, particularly Gram-positive species, including pathogenic ones. The effect of these compounds on the facultative human pathogen Listeria monocytogenes was examined. Both acids affected cell morphology and enhanced autolysis of the bacterial cells. Autolysis of isolated cell walls was inhibited by oleanolic acid, but the inhibitory activity of ursolic acid was less pronounced. Both compounds inhibited peptidoglycan turnover and quantitatively affected the profile of muropeptides obtained after digestion of peptidoglycan with mutanolysin. These results suggest that peptidoglycan metabolism is a cellular target of oleanolic and ursolic acids.

Saponins in Calendula officinalis L. - structure, biosynthesis, transport and biological activity

Trends in research on Calendula officinalis L. saponins performed in Department of Plant Biochemistry at Warsaw University are reviewed. Calendula officinalis, a well known medicinal plant, contains significant amounts of oleanane saponins, which form two distinct series of related compounds, called “glucosides” and “glucuronides” according to the structure of the respective precursor. Both series differ in the pathway of their biosynthesis and further metabolism, i.e. the rate of formation and stages of possible degradation; distribution in the single cell and in the whole plant, including accumulation sites; and the possible physiological role played in the plant according to appropriate biological activities.

Triterpenoid saponins affect the function of P-glycoprotein and reduce the survival of the free-living stages of Heligmosomoides bakeri

We studied the effect of triterpenoid saponins on the development of free-living stages of Heligmosomoides bakeri, a parasitic nematode of the mouse intestine. We evaluated the effectiveness of oleane-type glucuronides (GlcUAOA) isolated from Calendula officinalis and Beta vulgaris. The rhodamine 123 retention assay was used to detect dysfunctions of the major membrane transporter for xenobiotics, P-glycoprotein (Pgp). Both C. officinals and B. vulgaris GlcUAOA affect the development of the free living stages and function of Pgp in H. bakeri. The GlcUAOA inhibits egg hatching and moulting of larvae and also changes their morphology. These saponin fractions reversed the toxic effect of thiabendazole on the nematode; the function of Pgp was also inhibited.

Intracellular distribution and origin of sterols in Calendula officinalis leaves

Abstract In Calendula officinalis leaves 66% of all steryl forms are present in the ‘microsomal fraction’ (IV), 24% in the mitochondrial and Golgi membranes (III), 5% in the ‘chloroplast’ (II), 4% in the ‘cell wall and membrane’ (I) fraction and 1%. in the cytosol. Free sterols, their esters, glycosides and acylated glycosides are present in varying proportions in all cellular subtractions. Mevalonate-[2 14 C] labelling of sterols derived from various steryl forms showed that free sterols and all their derivatives, i.e. steryl esters and glucosides, are formed in fraction IV and are then translocated to other organelles. Fraction III is the main site of glycosylation of transported sterols as well as of acylation of steryl glycosides.

Incorporation of 1-14C-acetate into glycosides of oleanolic acid in calendula officinalis

Abstract The rate of formation of the five glycosides of oleanolic acid ( A, B, C, D and F ) in shoots of Calendula officinalis was determined by incorporation of 1- 14 C-acetate into the aglycone moiety. It was shown that sugars are probably incorporated into oleanolic acid glycosides in the following sequence: glucuronic acid in position 3 ( F from oleanolic acid), galactose in position 3′(2′) ( D from F ), glucose in position 28 ( C from D ) and glucose in position 4′ ( B from D and A from C ).

Initiation and growth characteristics of suspension cultures of Calendula officinalis cells

Callus cultures of marigold (Calendula officinalis L.) were induced on Murashige and Skoog medium with different concentrations of auxin (dichlorophenoxyacetic acid (2,4-D) or indole-3-acetic acid (IAA) and cytokinin (kinetin or 6-(γ,γ-dimethylallylamino)purine (2iP). Of all hormone combinations used in the medium, two were the most efficient in promoting callus development: 1.81 μM (0.4 mg l−1) 2,4-D and 1.85 μM (0.4 mg l−1) kinetin (0.4d–0.4k culture) or 0.45 μM (0.1 mg l−1) 2,4-D and 2.02 μM (0.5 mg l−1) 2iP (0.1d–0.5p culture). These combinations were selected to induce cell suspension cultures. The suspension cultures were maintained under light or dark conditions. The light stimulated cell aggregation in the cultures. In both cultures cells were undifferentiated under darkness, whereas in the light, rhyzogenesis was observed in 0.1d–0.5p culture. The cell growth and protein and oleanolic acid contents were determined. Initially, biomass production was similar under light and dark conditions, but after 7–8 months from the induction the cell growth was reduced by approximately 30% in the light, whereas the cell growth of the cultures maintained under darkness did not reveal any changes. The presence of oleanolic acid was detected in the suspension cultures kept in darkness. This compound reached two quantitative peaks: in the lag and stationary phases –- beyond the active growth phase of the culture cycle and its concentration was several times higher in 0.1d–0.5p culture than that in 0.4d–0.4k culture. It was for the first time that callus and suspension cultures were induced from the marigold plant.

Intracellular distribution and origin of pentacyclic triterpenes in Calendula officinalis leaves

Abstract In Calendula officinalis leaves the cyclization of squalene to β-amyrin and its further oxidation to oleanolic acid as well as the biosynthesis of all derivatives of oleanolic acid 3-glucoside and some derivatives of oleanolic acid 3-glucuronoside occur in the microsomal fraction. The final metabolites of oleanolic acid 3-glucoside series i.e. pentaglycosides, are translocated from this fraction, one to the cell wall and plasmalemma fraction and the other to the cytosol. The derivatives of oleanolic acid 3-glucoronoside are synthesized partially in other fractions and accumulate in the different membraneous structures of the cell.

Intracellular localization of tocopherol biosynthesis in calendula officinalis

Abstract [ 3 H]Phytol was administered to protoplasts from Calendula officinalis leaves, and in the subcellular fractions the dynamics of labelling of 7-monomethyltocol, 8-monomethyltocol (δ-tocopherol), 7,8-dimethyltocol (γ-tocopherol) and 5,7,8-trimethyltocol (α-tocopherol) and related phytylquinones, as well as those of vitamin K 1 , were determined. By condensation with homogentisic acid two isomeric methylphytylquinones (2-methyl-5-phytylbenzoquinone and 2-methyl-6-phytylbenzoquinone) were formed. These compounds were cyclized to 7- and 8-methyltocol, respectively, or methylated to yield 2,3-dimethyl-5-phytylbenzoquinone. The latter appeared to be cyclized to γ-tocopherol which could be methylated to α-tocopherol. The prenylation reaction took place in the chloroplasts and microsomes. Some monomethyltocols and methylphytylbenzoquinones as well as vitamin K 1 which appeared to be formed in microsomes may have been transported to chloroplasts and mitochondria.

Polyprenyl quinones and α-tocopherol in Calendula officinalis

Abstract In various cellular subfractions of Calendula officinalis leaves a study was made of the distribution of polyprenyl quinones and α-tocopherol and the dynamics of their labelling with 14 CO 2 and acetate-[1- 14 C] and incorporation of mevalonate-[2- 14 C] after 3 hr. It was confirmed that plastoquinone occurs only in the chloroplasts, ubiquinone only in the mitochondria and α-tocopherol in both these subfractions. Phylloquinone was found in the chloroplast and mitochondrial fractions as well as in the post-mitochondrial supernatant. Studies of the dynamics of radioactive precursor incorporation indicated that α-tocopherol is metabolized more rapidly than the polyprenyl quinones studied; the incorporation of mevalonate-[2- 14 C] suggests that the side chain of plastoquinone can be synthesized in the cytoplasm and transported to the chloroplasts.