Phytochemical Profiles and Antimicrobial Activity of Selected Populus spp. Bud Extracts

Buds of poplar trees (Populus species) are often covered with sticky, usually polyphenol-rich, exudates. Moreover, accessible data showed that some Populus bud extracts may be excellent antibacterial agents, especially against Gram-positive bacteria. Due to the fragmentary nature of the data found, we conducted a systematic screening study. The antimicrobial activity of two extract types (semi-polar-ethanolic and polar-ethanolic-water (50/50; V/V)) from 27 bud samples of different poplar taxons were compared. Antimicrobial assays were performed against Gram-positive (five strains) and Gram-negative (six strains) bacteria as well as fungi (three strains) and covered the determination of minimal inhibitory, bactericidal, and fungicidal concentrations. The composition of extracts was later investigated by ultra-high-performance liquid chromatography coupled with ultraviolet detection (UHPLC-DAD) and with electrospray-quadrupole-time-of-flight tandem mass spectrometry (UHPLC-ESI-qTOF-MS). As a result, most of the extracts exhibited good (MIC ≤ 62.5 µg/mL) or moderate (62.5 < MIC ≤ 500 µg/mL) activity against Gram-positives and Helicobacter pylori, as well as fungi. The most active were ethanolic extracts from P. trichocarpa, P. trichocarpa clone 'Robusta', and P. tacamahaca × P. trichocarpa. The strongest activity was observed for P. tacamahaca × P. trichocarpa. Antibacterial activity was supposedly connected with the abundant presence of flavonoids (pinobanksin, pinobanksin 3-acetate, chrysin, pinocembrin, galangin, isosakuranetin dihydrochalcone, pinocembrin dihydrochalcone, and 2',6'-dihydroxy-4'-methoxydihydrochalcone), hydroxycinnamic acids monoesters (p-methoxycinnamic acid cinnamyl ester, caffeic acid phenethylate and different isomers of prenyl esters), and some minor components (balsacones).

Polyphenol Profile of Cistus × incanus L. and Its Relevance to Antioxidant Effect and α-Glucosidase Inhibition

The European Food Safety Authority recommends C. incanus as a natural source of antioxidants. Its activity is essentially determined by polyphenols, although specific compounds are not finally indicated. The available plant material comes from different subspecies and locations, which can lead to differences in chemical composition and potency. For this reason, we conducted a detailed analysis of the polyphenol content and antioxidant activity of 52 different C. incanus teas from Turkey, Albania, Greece, and unspecified regions. We focused special attention on ellagitannins, which have not been properly determined so far. Besides oxidative stress, hyperglycemia is an essential component of cardiometabolic diseases. Therefore, in subsequent experiments, we evaluated the ability of C. incanus extracts and individual polyphenols to inhibit α-glucosidase. Using statistical methods, we analyzed how differences in chemical composition affect activity. The results showed that C. incanus is a rich source of ellagitannins (2.5–19%), which dominate among polyphenols (5.5–23%). Turkish-origin products had higher ellagitannin content and a greater antioxidant effect (FRAP, ABTS) than Albanian and Greek products. In contrast, the flavonoid and phenolic acid contents and DPPH values were at similar levels in all products. An in-depth analysis of their composition indicated that all groups of polyphenols are involved in the antioxidant effect, but a significant contribution can be attributed to ellagitannins and flavonoids. C. incanus extracts showed a high capacity to inhibit α-glucosidase activity (IC50 125–145 μg/mL). Ellagitannins were the most effective inhibitors (IC50 0.7–1.1 μM), with a potency exceeding acarbose (3.3 mM). In conclusion, C. incanus, due to the presence of ellagitannins and flavonoids, exhibits powerful antioxidant and α-glucosidase inhibitory effects.

An in-depth look into a well-known herbal drug: Fingerprinting, isolation, identification, and content estimation of saponins in different Strophanthus seeds

Seeds of Strophanthus species are known as a source of rapid-acting cardenolides. These water-soluble glycosides are listed as the sole critical constituents of this raw herbal drug. A non-standard cardioprotective medication with ouabain-containing oral remedies has become popular in Europe as a result of the withdrawal of corresponding registered drugs from the market. However, the bioequivalence of pure ouabain solutions, tinctures, and home-made extracts from Strophanthus seeds is unknown. Thus, this study aimed to update the information on the composition of Strophanthus seeds used for this purpose. The distribution of two main saponins and about 90 previously unreported compounds, tentatively identified as saponins in eleven Strophanthus species, was systematically evaluated by ultra-high-performance liquid chromatography mass spectrometry (UHPLC-MS) and -MS/MS. Seeds of S. gratus were selected to isolate the dominant unreported triterpenoids, bidesmosides of echinocystic and oleanolic acid. Their structures were established by HRMS, MS/MS, as well as by NMR techniques. The total saponin content, estimated by UHPLC-MS, was up to 1%. The detected saponins could influence the peroral bioavailability of hardly absorbable Strophanthus cardenolides and exhibit their own activity. This finding may be relevant when Strophanthus preparations (containing both saponins and cardiac glycosides) are used, particularly when homemade preparations are administered.

Quantification of Salicylates and Flavonoids in Poplar Bark and Leaves Based on IR, NIR, and Raman Spectra

Poplar bark and leaves can be an attractive source of salicylates and other biologically active compounds used in medicine. However, the biochemical variability of poplar material requires a standardization prior to processing. The official analytical protocols used in the pharmaceutical industry rely on the extraction of active compounds, which makes their determination long and costly. An analysis of plant materials in their native state can be performed using vibrational spectroscopy. This paper presents for the first time a comparison of diffuse reflectance in the near- and mid-infrared regions, attenuated total reflection, and Raman spectroscopy used for the simultaneous determination of salicylates and flavonoids in poplar bark and leaves. Based on 185 spectra of various poplar species and hybrid powdered samples, partial least squares regression models, characterized by the relative standard errors of prediction in the 4.5-9.9% range for both calibration and validation sets, were developed. These models allow for fast and precise quantification of the studied active compounds in poplar bark and leaves without any chemical sample treatment.

Biochemical and Molecular Investigation of the Effect of Saponins and Terpenoids Derived from Leaves of Ilex aquifolium on Lipid Metabolism of Obese Zucker Rats

Ilex paraguariensis, the holly tree, is a plant with recognized biological properties, whose aqueous infusions are known as “Yerba mate”, that regulate lipid metabolism, reduce obesity, and improve brain stimulation. In the present study, the effect of standardized saponin and terpenoid fractions of a European taxon, Ilex aquifolium, on blood biochemical parameters in a rat model of metabolic disorder, (fa/fa) Zucker, are presented. The profiles of the volatile fractions of two species and six European varieties of Ilex were investigated. After selecting the best variety, the saponin and terpenoid fractions were isolated and standardized, and animals were fed 10 mg kg−1 b.w. for 8 weeks. A statistically significant decrease in liver adiposity was observed, confirmed by histology and quantitative identification (gas chromatography−mass spectrometry analyses of hepatic lipids. RT-qPCR analysis of gene expression in the aorta revealed that the administration of the terpenoid fraction downregulated LOX-1, suggesting a reduction in atherosclerotic stimuli. In addition, a statistically significant reduction (p < 0.05) in PPARγ for the saponin fraction was observed in the liver. The expression of the ACAT-1 gene in the liver, responsible for the formation of cholesterol esters, increased significantly in the group receiving the terpenoid fraction compared to the control, which was also confirmed by the analysis of individual blood biochemical parameters. The opposite effect was observed for saponins. Taking the above into account, it is shown for the first time that Ilex aquifolium can be a source of compounds that positively influence lipid metabolism.

Composition and Antimicrobial Activity of Ilex Leaves Water Extracts

Plants from the Ilex genus are known for properties such as antimicrobial and anti-inflammatory activity, can act as antiobesity agents and thus can be helpful in medicine. Some holly species, such as Ilex paraguariensis (widely known in the form of popular beverage: yerba mate), have been investigated, while others have been partially researched or remain unknown. Therefore, we performed qualitative and quantitative phytochemical analyses and screened antimicrobial properties of lesser-studied species (I. aquifolium L., I. aquifolium ‘Argentea Marginata’ and I. × meserveae ‘Blue Angel’). I. paraguariensis was used as a standard species for comparison purposes. Investigations were performed on water extracts due to their expected activity and composition. Antimicrobial research included evaluating minimal inhibitory, bactericidal (Staphylococcus aureus and Escherichia coli) and fungicidal concentration (Candida albicans, Alternaria alternata, Fusarium oxysporum, and Aspergillus niger) of extracts. The influence of the extracts on the production, eradication, and viability of bacterial biofilms was also analysed. It was established that Ilex paraguariensis possesses the richest profile of hydroxycinnamic acids derivatives in terms of component concentration and diversity. Ilex spp., especially I. × meserveae, contain a slightly higher amount of flavonoids and more different flavonoid derivatives than I. paraguariensis. However, the strongest antibacterial activity was shown by I. aquifolium L. and its cultivar ‘Argentea Marginata’ in terms of minimal inhibitory, bactericidal and fungicidal concentration, and biofilm assays. Extracts from both species significantly reduced the biofilm viability of S. aureus as well, which may be of use in the production of multicomponent lavaseptics, antiseptics, diuretics (supporting urinary tract infection therapy) and, due to their action on fungi, additives to growth media for specific fungi. The significant content of saponins enables Ilex extracts to be used as natural emulsifiers, for example, in cosmetics. Moreover, relatively high chlorogenic acid and rutin content may suggest use of Ilex spp. to treat obesity, digestive problems, in chemoprevention, and as preservatives in the food industry.

The real Theriac - panacea, poisonous drug or quackery?

ETHNOPHARMACOLOGICAL RELEVANCE

Theriac is considered the most popular cure-all multi-ingredient medicine and has been used for more than two millennia. It has also been used as one of the most important anti-epidemic drugs up to the 19th c., treated as an emergency medicine in case of e.g. bubonic plague.

AIM OF THE STUDY

Until now, no reliable information regarding the pharmacological effect of the treacle was available, including its possible toxic or narcotic properties. In order to change the state of knowledge in this matter we have selected the Theriac recipe that had been actually used for producing the treacle in 1630, which was confirmed by the official municipal documents of the time.

METHODS

The recipe was written in Latin, with the use of pre-Linnean nomenclature and then apothecary common names, which required translation into the modern scientific language in order to get reliable pharmacological conclusions. The information from historical sources has been compiled with the pharmacological data concerning the most potent compounds, which for the first time made it possible to calculate the amounts of active compounds in the doses taken by then patients.

RESULTS

Only two species included in Theriac can be harmful in humans: poppy and sea squill, but in both cases the calculated quantity of morphine and cardiac glycosides, respectively, were below toxic level. There are no indications, both from the historical and pharmacological point of view, for Theriac being toxic or narcotic in patients, when used as prescribed.

CONCLUSIONS

As for now, the most probable is that the treacle owed its postulated efficacy in the main indications to the placebo effect. Still, the results should be further confirmed by reconstructing the actual Theriac and subjecting it to modern tests and analyses.

Allogeneic Stem Cell Transplantation for Relapsed and Refractory Hodgkin Lymphoma: Real World Experience of a Single Center

Introduction: Refractory and relapsed Hodgkin lymphoma (R/R HL) is associated with poor prognosis, and allogeneic stem cell transplantation (allo-SCT) remains the only potentially curative approach.

Aim: The aim of the study was to evaluate the feasibility of allotransplantation in R/R HL setting.

Material: Overall, 24 patients (17 men and 7 women) at a median age of 27 years (range 18–44) underwent allo-SCT between 2002 and 2020.

Results: Nineteen patients received prior autologous stem cell transplantation (ASCT1) whereas eight patients received second ASCT (ASCT2) after failure of ASCT1. Six patients received only brentuximab vedotin (BV; n = 4) or BV followed by checkpoint inhibitors (CPI; n = 2) before entering allo-SCT. Median time from ASCT1 to allo-SCT was 17.1 months. Fifteen patients received grafts from unrelated donors. Peripheral blood was a source of stem cells for 16 patients. Reduced-intensity conditioning was used for all patients. Disease status at transplant entry was as follows: complete remission (CR; n = 4), partial response (PR; n = 10), and stable disease (SD; n = 10). Acute and chronic graft-versus-host disease (GVHD) developed in 13 (54%) and 4 (16%) patients, respectively. Median follow-up for the entire cohort was 13.3 months. At the last follow-up, 17 (71%) patients died. The main causes of death were disease progression (n = 10), infectious complications (n = 6), and steroid-resistant GVHD (n = 1). Non-relapse mortality at 12 months was 25%. At the last follow-up, seven patients were alive; six patients were in CR, and one had PR. The 2-year overall survival (OS) was 40%.

Conclusion: Chemosensitive disease at transplant was associated with better outcome. Allo-SCT allows for long-term survival in refractory and relapsed HL.

The Effect of Ilex × meserveae S. Y. Hu Extract and Its Fractions on Renal Morphology in Rats Fed with Normal and High-Cholesterol Diet

Therapeutic properties of Ilex species are widely used in natural medicine. Ilex × meserveae may become a potential substitute for Ilex paraguariensis (Yerba Mate). As a part of the preliminary safety verification of this European Ilex hybrid vs. Yerba Mate, an eight-week study concerning the impact of regular administration of leaves of both species on kidneys was conducted. The standard water infusion and three dominant fractions of Ilex × meserveae leaves’ constituents (polyphenols, saponins and less polar terpenoids) were separately tried on 96 male Wistar rats divided into 8-member groups. Animals were divided into two basic nutritional groups: the first one was rats fed standard feed and the second on was rats fed with high-cholesterol diet (20 g of cholesterol per kg of standard feed). Postmortem morphometric evaluation of stained kidney samples concerned the filtration barrier elements, which are crucial in proper diuresis. The results showed that saponins present in the hydroalcoholic dry extract (administered in a dose of 10 mg/kg of body weight/day) as well as in water infusions (1:20) from Ilex × meserveae and Ilex paraguariensis do not demonstrate nephrotoxicity but conversely, have a protective role on kidney status in animals fed with a normal diet and in a high-cholesterol diet.

Treatment of an oronasal fistula in a patient on bisphosphonate therapy: A case study

Bisphophonates (BPs) are a group of drugs used in treating bone diseases, which may lead to the development of the osteonecrosis of the jaw (ONJ). The negative impact of BPs on angiogenesis is among the causes of ONJ. The specific mechanisms of complications are unknown. What is taken into consideration is the trauma background, which, in combination with the implemented BP treatment, can induce bone necrosis. One of the possible consequences of necrotic change progression is the development of an oronasal fistula. Treatment generally requires a surgical intervention.The paper describes the course of treatment of an oronasal fistula in a patient with BP osteitis, currently using an upper denture. The fistula arose a year after the removal of a protruding sequestrum in the region of the hard palate. An attempt was made to treat the fistula by the mobilization of soft tissues from the palate and the bilayered closure of the fistula with the use of a pedicled connective tissue graft on the greater palatine artery, along with a Tinti-Parma-Benfenati (TPB) flap. The patient was subjected to appropriate post-procedural measures. Regular follow-ups did not reveal any abnormalities in the course of healing.The use of the abovementioned procedure proved to be an effective method of treatment of an oronasal fistula. The use of a pedicled connective tissue graft for the closure of the oronasal fistula caused by BP therapy had a significant effect on the treatment outcome.

Isolation and structural determination of flavan-3-ol derivatives from the Polypodium vulgare L. rhizomes water extract

Polypodium vulgare L. (Polypodiaceae) is a fern used in traditional Polish medicine as an expectorant to treat cough and pertussis. Additionally, it was used as a diuretic in renal diseases, especially in chronic nephritis and pyelonephritis. In our study, a water extract was prepared from the rhizome of common polypody and subsequently fractionated on a resin column. As a result, the mixture of flavan-3-ol derivatives was obtained after the column elution with 60% methanol. Further purification by various chromatographic techniques led us to the isolation of (+)-afzelechin (1), a new previously not reported (+)-afzelechin-7-O-α-l-arabinofuranoside (2), and three other monomer flavan-3-ol glycosides: (+)-afzelechin-7-O-β-d-apiofuranoside (3), (+)-catechin-7-O-α-l-arabinofuranoside (4) and (+)-catechin-7-O-β-d-apiofuranoside (5). Structures of the compounds were established by HR-ESI-MS, 1D and 2D NMR spectroscopy. The HSQC and HMBC NMR techniques were used in the structure elucidation of the position of sugar attachment.

Lanostane-Type Saponins from Vitaliana primuliflora

The phytochemistry of the genera Androsace, Cortusa, Soldanella, and Vitaliana, belonging to the Primulaceae family is not well studied so far. Hence, in this paper, we present the results of UHPLC-MS/MS analysis of several primrose family members as well as isolation and structure determination of two new saponins from Vitaliana primuliflora subsp. praetutiana. These two nor-triterpenoid saponins were characterized as (23S)-17α,23-epoxy-29-hydroxy-3β-[(O-β-d-glucopyranosyl-(1→2)-O-α-l-rhamnopyranosyl-(1→2)-O-β-d-glucopyranosyl-(1→2)-O-α-l-arabinopyranosyl-(1→6)-β-d-glucopyranosyl)oxy]-27-nor-lanost-8-en-25-one and (23S)-17α,23-epoxy-29-hydroxy-3β-[(O-α-l-rhamnopyranosyl-(1→2)-O-β-d-glucopyranosyl-(1→2)-O-α-l-arabinopyranosyl-(1→6)-β-d-glucopyranosyl)oxy]-27-nor-lanost-8-en-25-one, respectively. Their structures were determined by high resolution mass spectrometry (HRMS), tandem mass spectrometry (MS/MS), one- and two-dimensional nuclear magnetic resonance spectroscopy (1D-, and 2D-NMR) analyses. So far, the 27-nor-lanostane monodesmosides were rarely found in dicotyledon plants. Therefore their presence in Vitaliana and also in Androsace species belonging to the Aretia section is unique and reported here for the first time. Additionally, eleven other saponins were determined by HRMS and MS/MS spectra. The isolated lanostane saponins can be considered as chemotaxonomic markers of the family Primulaceae.

Determination of Oleanolic and Ursolic Acids in Sambuci flos Using HPLC with a New Reversed-phase Column Packed with Naphthalene Bounded Silica

Elder flowers have traditionally been used for their anti-inflammatory properties. However little is known about triterpenoid components in this Pharmacopoeial herbal drug. Herein, we report the quantification of ursolic and oleanolic acid in Sambuci flos by HPLC method. These biologically active triterpenoids were effectively separated and quantified using the elaborated HPLC chromatographic method with a naphthalene bounded silica reversed phase column. In this study, a very simple mobile phase for HPLC was developed to simultaneously determine both acids and the factors affecting separation were also discussed. The average content of oleanolic acid and ursolic acid in the elder flowers determined by proposed method was 2.06 mg/g and 11.56 mg/g respectively. This study showed both successful applications of the new type of reversed phase column and important contribution of mentioned triterpenoids to elder flower composition presumably resulting in its pharmacological action.

Triterpenoid Acids as Important Antiproliferative Constituents of European Elderberry Fruits

In Europe, both the fruits and flowers of Sambucus nigra L. have been used against cold, as well as laxative, diaphoretic, and diuretic remedies. There are also a number of commercially available food products that contain elderberry juice, puréed or dried elderberries. Recent comprehensive literature data on pharmacology and chemistry of Sambuci fructus have encouraged us to screen extracts with different polarities from this plant material against cancer cell lines. The cytotoxic activity of the ethyl acetate and aqueous acetone extracts from elderberries as well as detected triterpenoids on human colon adenocarcinoma cell line (LoVo) and human breast cancer cell line (MCF-7) was investigated by sulforhodamine B assay. Moreover, cell migration assay was conducted for triterpenoid fraction and pure compounds. Aqueous acetone extract possessed much lower IC50 value in cancer cell lines compared to ethyl acetate extract. The latter manifested high cytotoxicity against studied cell lines, suggesting that nonpolar compounds are responsible for the cytotoxic activity. Indeed, the phytochemical analysis revealed that ursolic and oleanolic acids are the main triterpenoids in the mentioned extract of which ursolic acid showed the highest activity with IC50 values of 10.7 µg/mL on MCF-7 and 7.7 µg/mL on LoVo cells.

β-Aescin at subinhibitory concentration (sub-MIC) enhances susceptibility of Candida glabrata clinical isolates to nystatin

Aescin (escin) derived from the seeds of horse chestnut (Aesculus hippocastanum L.) is a natural mixture of triterpene saponins exhibiting a wide variety of pharmacological properties, including antiinflammatory, analgesic, and antipyretic activities. However, data concerning antifungal activities of these compounds are limited. This study aims to evaluate the in vitro antifungal susceptibility of Candida glabrata clinical isolates to α-aescin sodium, β-aescin crystalline and β-aescin sodium using the disk diffusion (DD) and broth microdilution (BMD) methods. Moreover, the influence of subinhibitory concentration (0.5×MIC) of β-aescins on the nystatin MIC was also studied. In general, the results obtained by the DD assay correlated well with those obtained by the BMD method. Both β-aescins effectively inhibited the growth of all 24 strains tested. The minimum inhibitory concentration (MIC) values ranging from 8 to 32 μg/ml for β-aescin crystalline, whereas those of β-aescin sodium were slightly lower and ranged from 4 to 16 μg/ml. In contrast, α-aescin sodium was found to be completely ineffective against the strains studied. MIC values of nystatin were reduced 2-16-fold and 2-4-fold in the presence of subinhibitory concentration of β-aescin crystalline and β-aescin sodium, respectively. Results of the present study may suggest the additive interaction between β-aescin and nystatin.

Determination of ursolic and oleanolic acid in Sambuci fructus

Elderberries are used in the preparation of pie, jelly, punch, wine, or liqueur, as well as in many herbal remedies and food supplements. Elderberry products may provide diaphoretic, diuretic, antioxidant, and immunostimulant activities that offer protection against cold and flu. Herein, we report for the first time the qualitative and quantitative evaluation of two isomeric triterpenoids isolated from Sambuci fructus. The analysis revealed that ursolic acid and oleanolic acid are present in Sambuci fructus. The average concentration of ursolic acid was ca. three times higher than the concentration of oleanolic acid. The triterpenoids were detected and quantified using chromatographic methods such as TLC and HPLC. Spectroscopic techniques, including HR-MS and 2D-NMR, allowed unequivocal structure determination.

A Major Saponin from Leaves Extract of Acer velutinum

A major triterpenoid saponin was isolated from the leaves extract of Acer velutinum. This compound was characterized as 21β ,22α-O-diangeloylprotoaescigenin 3-O-[β -D-glucopyranosyl- (1→2)][β -D-glucopyranosyl-(1→4)]-β -D-glucuronopyranosyl acid.

Its structure was elucidated by 1H, gCOSY, ROESY, gHSQC, gHMBC NMR as well as ESI-MS experiments. Isolated saponin exhibited in vitro cytotoxicity against HL-60, B16-F0 and BALB/3T3 cell lines.

Immunomodulatory and Anti-Inflammatory Activity of Selected Osthole Derivatives

From osthole [7-methoxy-8-(3-methyl-but-2-enyl)-chromen-2-one] (), obtained by selective extraction of Peucedanum ostruthium (L.) W. Koch roots, ostholic acid (II) was synthetized as a result of its oxidation with chromium trioxide. From ostholic acid, through its chloride, four amides were obtained: the morpholide 1, the p-chloro-benzylamide 2, the piperidine 3 and the N-methyl-piperazide 4. Except for 1, other compounds have not been described before. The amides 1 - 4 and their precursor osthole (I) were tested for their potential activities in selected immunological assays. The compounds showed moderate inhibitory activity in the humoral immune response to sheep erythrocytes in mice in vitro, and 4 was the most suppressive. The effects of 1 and 3 on concanavalin A- and pokeweed mitogen-induced mouse splenocyte proliferation were inhibitory and those of 4 stimulatory. The compounds were also tested for their activity on tumour necrosis factor α and interleukin 6 production, induced by lipopolysaccharide, in cultures of rat peritoneal cells and human peripheral blood mononuclear cells. Compounds 1, 3 and 4 inhibited tumour necrosis factor α (rat cells), whereas compound 2 stimulated the production of both cytokines. Compounds 1, 2 and 3 were also strongly inhibitory on tumour necrosis factor α production in human blood cells (73, 78 and 80% inhibition at 10 μg/ml, respectively). On the other hand, 2 and 4 stimulated the interleukin 6 production (2- to 3-fold stimulation). In addition, 2 and 4 suppressed the carrageenan-induced inflammation in mice (56.5% and 68.3% inhibition, respectively). In summary, the compounds predominantly displayed suppressive and anti inflammatory activities in the investigated models

Cytotoxic Effects of Four Aescin Types on Human Colon Adenocarcinoma Cell Lines

Four types of aescin that are available on the pharmaceutical market, β-aescin crystalline, β-aescin amorphous, β-aescin sodium and aescin polysulfate, have been analyzed for their cytotoxic effects on human colon adenocarcinoma (LoVo) and doxorubicin-resistant human colon adenocarcinoma cell lines (LoVo/Dx). Their cytotoxic activities were evaluated by sulforhodamine B (SRB) and methyl tetrazolium (MTT) assays. All four types of aescin exerted strong dose-dependent cytotoxicity to LoVo and, to a lesser degree, LoVo/Dx cell lines. The IC50 value for the LoVo/Dx cell line was higher, but still dose-dependent. Results from both assays demonstrated that β-aescin crystalline has the most cytotoxic activity toward human colon adenocarcinoma cell lines.

Plasmid occurrence and diversity in the genus Paracoccus

The results of screening for the occurrence of plasmids in several strains representing 11 out of 13 species of the genus Paracoccus are presented. We show that plasmids (ranging in size from 2.7 to above 450 kb) are widely distributed in this genus. Only one tested strain (P. alkenifer) appears to be plasmid-free. The majority of the strains harbour at least two plasmids, one of which usually fits into the class of megaplasmids.

Construction of mobilizable cloning vectors derived from pBGS18 and their application for analysis of replicator region of a pTAV202 mini-derivative of Paracoccus versutus pTAV1 plasmid

Two mobilizable cloning vectors, designated pABW1 and pAWB2, were constructed basing on the E. coli vector pBGS18 and oriT originating from RK2. In pABW2 the kanamycin resistance gene was replaced by a novel tetracycline resistance cassette derived from Tn1721. Both vectors, specific for E. coli, allow to perform the cloning steps in E. coli and then to efficiently transfer the constructs by conjugation to the host of choice. A vector which cannot propagate in the given host can be applied for identification of the host specific plasmid replicator regions. With the use of pABW2 we defined the minimal replicator region of pTAV202-a mini-derivative of the large pTAV1 plasmid of P. versutus. We also proved that RepC' encoded on this fragment is the principal initiator replication protein and that oriV is located along its coding sequence.

Excess benign melanocytic naevi in renal transplant recipients

BACKGROUND

Some studies indicate that malignant melanoma occurs more frequently in renal transplant recipients than in the normal population. The development of excess benign melanocytic naevi is regarded as an indicator of the risk for malignant melanoma.

OBJECTIVE

This study was undertaken to evaluate the prevalence of benign melanocytic naevi in adult renal transplant patients.

METHOD

All benign melanocytic naevi irrespective of size were counted in 76 patients with renal transplants and were compared to naevus counts in 55 sex- and age-matched healthy controls.

RESULTS

The mean total number of benign melanocytic naevi was significantly higher (p < 0.001) in renal transplant patients than in the control group: 93.6 +/- 52.2 and 36.1 +/- 29.9, respectively. The most evident increase occurred on the palms/soles and back/buttocks. A positive, although not significant, correlation between naevus counts and duration of immunosuppression was found.

CONCLUSION

Renal transplant recipients have an increased number of benign melanocytic naevi and should be considered as a risk group for malignant melanoma.