Sok-Siya Bun

In vitro Antimicrobial Activity of Plants used in Cambodian Traditional Medicine

The purpose of the present study was to screen 27 plant species used in the traditional medicine of Cambodia for in vitro antibacterial and antifungal activities. Thirty-three methanolic extracts were tested against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Mycobacterium smegmatis and Candida albicans. Screened by disk diffusion assay, the extracts showed antimicrobial activity especially on Gram-positive bacteria. None of the crude methanolic extracts showed activity against P. aeruginosa. Twenty-five selected extracts were evaluated using a micro-dilution test. Harrisonia perforata (roots) and Hymenodictyon excelsum (bark) exhibited a bactericidal effect against S. aureus at a concentration of 500 microg/ml. Azadirachta indica (bark), Harrisonia perforata (roots and stem) and Shorea obtusa (roots) exhibited a bactericidal effect against M. smegmatis at 250 microg/ml.

New antiplasmodial alkaloids from Stephania rotunda

ETHNOPHARMACOLOGICAL RELEVANCE Stephania rotunda Lour. (Menispermaceae) is a creeper growing in many countries of Asia and commonly found in the mountainous areas of Cambodia. As a folk medicine, it has been mainly used for the treatment of fever and malaria. The pharmacological activity is mostly due to alkaloids. Thus the aim of this study is to isolate new bioactive alkaloids from Stephania rotunda and to evaluate their in vitro antiplasmodial activity. MATERIALS AND METHODS Alkaloids were isolated and identified from dichloromethane and aqueous extracts using a combination of flash chromatography, high performance liquid chromatography, mass spectrometry and nuclear magnetic resonance. The purified compounds were tested for in vitro antiplasmodial activity on chloroquine-resistant W2 strain of Plasmodium falciparum. RESULTS A new aporphine alkaloid named vireakine (2) along with two known alkaloids stephanine (1) and pseudopalmatine (8), described for the first time in Stephania rotunda, and together five known alkaloids tetrahydropalmatine (3), xylopinine (4), roemerine (5), cepharanthine (6) and palmatine (7) were isolated and identified. The structure of the new alkaloid was established on the basis of 1D and 2D NMR experiments and mass spectrometry. The compounds were evaluated for their in vitro antiplasmodial and cytotoxic activities. All tested compounds showed significant antiplasmodial activities with IC(50) ranged from 1.2 μM to 52.3 μM with a good selectivity index for pseudopalmatine with IC(50) of 2.8 μM against W2 strain of Plasmodium falciparum and IC(50)>25 μM on K562S cells. CONCLUSIONS This study provides evidence to support the use of Stephania rotunda for the treatment of malaria and/or fever by the healers. Alkaloids of the tuber exhibited antiplasmodial activity and particularly cepharanthine and pseudopalmatine.

Cytotoxic Activity of Alkaloids Isolated from Stephania rotunda In vitro cytotoxic activity of cepharanthine

Three major alkaloids: cepharanthine (1), tetrahydropalmatine (2) and xylopinine (3) isolated from Stephania rotunda tuber were investigated for their cytotoxic activity in a panel of human cancer cells (HT29, LS174T, SW620 and HepG2) using MTT assay. In the present study, cepharanthine (1) exerted potent cytotoxicity against colon and hepatoma cancer cell lines with IC(50) values between 2.4 and 5.3 microM while tetrahydropalmatine (2) and xylopinine (3) displayed weak cytotoxicity. In addition, the mutagenic activity of cepharanthine (1) was investigated using a modified liquid incubation technique of the Salmonella/microsomal assay. This alkaloid (1) was found to be non-mutagenic for doses up to 8.2 microM.

α‐hederin potentiates 5‐FU antitumor activity in human colon adenocarcinoma cells

The aim of this study was to investigate the ability of α‐hederin to improve the efficacy of widely prescribed 5‐fluorouracil (5‐FU) in a human colon adenocarcinoma model. Drug combinations of α‐hederin and 5‐FU using both fixed‐concentration and combination index methods were performed in vitro in HT‐29 cells. The results showed that α‐hederin at sub‐IC50 cytotoxic concentrations enhanced 5‐FU cytotoxicity about 3.3‐fold (p < 0.001). Simultaneous combination of α‐hederin and 5‐FU at their IC50 ratio showed either a synergistic effect at a moderate cytotoxic range (25% of cell growth inhibition) or an antagonistic effect at a high level of growth inhibition. The data indicate therefore that it is possible to optimize colorectal cancer cell sensitivity to 5‐FU with α‐hederin. Copyright

Ethnobotany, phytochemistry and pharmacology of Stephania rotunda Lour.

ETHNOPHARMACOLOGICAL RELEVANCE Stephania rotunda Lour. (Menispermaceae) is an important traditional medicinal plant that is grown in Southeast Asia. The stems, leaves, and tubers have been used in the Cambodian, Lao, Indian and Vietnamese folk medicine systems for years to treat a wide range of ailments, including asthma, headache, fever, and diarrhoea. AIM OF THE REVIEW To provide an up-to-date, comprehensive overview and analysis of the ethnobotany, phytochemistry, and pharmacology of Stephania rotunda for its potential benefits in human health, as well as to assess the scientific evidence of traditional use and provide a basis for future research directions. MATERIAL AND METHODS Peer-reviewed articles on Stephania rotunda were acquired via an electronic search of the major scientific databases (Pubmed, Google Scholar, and ScienceDirect). Data were collected from scientific journals, theses, and books. RESULTS The traditional uses of Stephania rotunda were recorded in countries throughout Southeast Asia (Cambodia, Vietnam, Laos, and India). Different parts of Stephania rotunda were used in traditional medicine to treat about twenty health disorders. Phytochemical analyses identified forty alkaloids. The roots primarily contain l-tetrahydropalmatine (l-THP), whereas the tubers contain cepharanthine and xylopinine. Furthermore, the chemical composition differs from one region to another and according to the harvest period. The alkaloids exhibited approximately ten different pharmacological activities. The main pharmacological activities of Stephania rotunda alkaloids are antiplasmodial, anticancer, and immunomodulatory effects. Sinomenine, cepharanthine, and l-stepholidine are the most promising components and have been tested in humans. The pharmacokinetic parameters have been studied for seven compounds, including the three most promising compounds. The toxicity has been evaluated for liriodenine, roemerine, cycleanine, l-tetrahydropalmatine, and oxostephanine. CONCLUSION Stephania rotunda is traditionally used for the treatment of a wide range of ailments. Pharmacological investigations have validated different uses of Stephania rotunda in folk medicine. The present review highlights the three most promising compounds of Stephania rotunda, which could constitute potential leads in various medicinal fields, including malaria and cancer.

Chemical profiling of the tuber of Stephania cambodica Gagnep. (Menispermaceae) and analytical control by UHPLC-DAD

Abstract A new aporphine glycoside (1), named ‘angkorwatine’, and eight known alkaloids: oblongine (2), stepharine (3), asimilobine-β-d-glucopyranoside (4), isocorydine (5), tetrahydropalmatine (THP) (6), jatrorrhizine (7), palmatine (PAL) (8), and roemerine (ROE) (9) were simultaneously isolated from the tuber of Stephania cambodica. The development and validation of UHPLC-DAD method was carried out for the quantification of marker compounds (PAL, ROE, THP) of S. cambodica. In addition to good selectivity and linearity (r2 > 0.997), trueness, precision, and accuracy of the method did not exceed the acceptance limit of ±10% for ROE, THP and ±20% for PAL. Consequently, this method is able to provide accurate results between 1.39–4.18 μg/mL, 2.01–30.72 μg/mL, and 4.29–64.42 μg/mL for PAL, ROE, and THP, respectively. This study shows that the validated UHPLC method is a rapid, innovative and effective analytical approach to control quality of tubers of S. cambodica and to regulate the usage of this plant in traditional medicine.

Effect of several compounds on biliary excretion of paclitaxel and its metabolites in guinea-pigs.

The objective of this study was to evaluate the in vivo metabolic profile of paclitaxel and to examine the effect of potential co-administered drugs on the biliary secretion of paclitaxel and its metabolites in guinea-pigs. We first investigated in vitro paclitaxel metabolism using liver microsomes obtained from various species to identify the most suitable animal model with a similar metabolism to humans. Then, in vivo paclitaxel metabolism was investigated in male guinea-pigs. The levels of paclitaxel and its metabolites were measured by high-performance liquid chromatography in bile samples from guinea-pigs after paclitaxel i.v. injection (6 mg/kg). We further evaluated the effects of various drugs (quercetin, ketoconazole, dexamethasone, cotrimoxazole) on the biliary secretion of paclitaxel and its metabolites in guinea-pigs. This work demonstrated significant in vitro interspecies differences in paclitaxel metabolism. Our findings showed both in vitro and in vivo similarities between human and guinea-pig biotransformation of paclitaxel. 6&agr;-Hydroxypaclitaxel, the main human metabolite of paclitaxel, was found in guinea-pig bile. After paclitaxel combination with ketoconazole or quercetin in guinea-pigs, the cumulative biliary excretion of paclitaxel and its metabolites up to 6 h was significantly decreased by 62 and 76%, respectively. The co-administration of cotrimoxazole or pretreatment with dexamethasone did not alter significantly cumulative biliary excretion. The guinea-pig is a suitable model to study metabolism and biliary excretion of paclitaxel, and to investigate in vivo drug interactions.

HPLC Analysis of Stephania rotunda Extracts and Correlation with Antiplasmodial Activity

Stephania rotunda (Menispermaceae), a creeper commonly found in the mountainous areas of Cambodia, has been mainly used for the treatment of fever and malaria. Thus, the aim of this study is to investigate the chemical composition and antiplasmodial activity of different samples of S. rotunda and compare their antiplasmodial activity with their alkaloid content. Sixteen samples from different parts (roots, stem, and tuber) of S. rotunda were collected from four regions of Cambodia (Battambang, Pailin, Siem Reap, and Kampot). Reversed‐phase HPLC was used to determine the content of three bioactive alkaloids (cepharanthine, tetrahydropalmatine, and xylopinine). These three alkaloids have been found in all samples from Battambang and Pailin (samples I–IX), whereas only tetrahydropalmatine was present in samples from Siem Reap and Kampot (samples X–XVI). The analyzed extracts were evaluated for their antiplasmodial activity on W2 strain of Plasmodium falciparum. Among them, 13 extracts were significantly active with inhibitory concentration 50 (IC50) from 1.2 to 3.7 µg/mL and 2 extracts were moderately active (IC50 = 6.1 and 10 µg/mL, respectively), whereas sample XI was not active (IC50 = 19.6 µg/mL). A comparison between antiplasmodial activity and concentration of the three bioactive alkaloids in S. rotunda extracts has been realized. Copyright

Cytotoxic withanolides from the leaves of Moroccan Withania frutescens

Abstract Context: Withania species are a rich source of interesting phytochemical substances (withanolides) which have shown several biological properties. Objective: To investigate the cytotoxic potential of Withania frutescens (L.) Pauquy (Solanaceae) leaf extracts and isolated active compounds against cultured tumor cell lines. Materials and methods: The crude methanol extract of W. frutescens leaves was partitioned with dichloromethane, ethyl acetate and n-butanol. MeOH extract and its fractions were tested for their cytotoxic activity against cancer cell lines (HepG2 and HT29) using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. Bioassay-guided fractionation was performed for the active CH2Cl2 fraction employing column chromatography and preparative high-performance liquid chromatography. Structural elucidation of the isolated active compounds was carried out mainly by 1D and 2D NMR and mass spectrometry. The compounds were then tested for their cytotoxic activity. Results: The CH2Cl2 fraction was the most active against HT29 cell line. The fractionation procedure resulted in the isolation of 4β,17α,27-trihydroxy-1-oxo-22-R-witha-2,5,24-trienolide (1), 5β,6β-epoxy-4β,17α,27-trihydroxy-1-oxowitha-2,24-dienolide (2) and 2,3-dihydroxywithaferin A-3β-O-sulfate (3). The latter exhibited the strongest cytotoxic activity against HT29 cancer cell lines (IC50 of 1.78 ± 0.09 µM) which was comparable to that of 5-fluorouracil (5-FU) used as the positive antimitotic control. Discussion and conclusion: Compounds 2 and 3 were isolated from W. frutescens for the first time. Data obtained suggest that the sulfated steroidal lactone (3) can be considered as a compound with potential application in the new anticancer drugs development field.

Prescription errors related to the use of computerized provider order-entry system for pediatric patients

OBJECTIVES To evaluate the nature and frequency of medication errors resulting from the use of a computerized provider order-entry (CPOE) system in a pediatric department. METHODS We conducted a retrospective study to examine errors related to computerized orders using the software Pharma® (Computer Engineering, France) in pediatric department between 31/05/2015 to 01/12/2015. These errors were signaled by pharmacists who examine CPOEs daily. RESULTS A total of 302 pharmacist interventions (PharmInt) were carried out by clinical pharmacists during the study period. Of the 302 PharmInts, a total of 95 (31.5%) contained no data on the patients bodyweight, which should have been provided by the prescriber (Table 1). After the PharmInt, information on bodyweight was then provided in 47 of these cases (15.6%). Incomplete information about administration frequency accounted for 19.9% of total PharmInts. Prescribing an excessive dose occurred in 17.6% of PharmInts, inappropriate modifications of prescription unit accounted for 9.9% of PharmInts, and incorrect dosage was prescribed in 8.3% of PharmInts. Of the 302 PharmInts, 255 concerned prescription errors and bodyweight missing not provided after PharmInt. Paracetamol, in its different forms (injectable, solid or liquid oral forms) accounted for 35.7% of total PharmInts. Noted errors for paracetamol included an incorrect dosage form, co-administration of two paracetamol-containing drugs, modification of the prescription unit, incorrect frequency of administrations, and absence of the patients bodyweight. Inconsistent use of a contradicted or a non-used drug for pediatric patients was noted along with prescriptions for inadequate dosages. DISCUSSION AND CONCLUSION Our work revealed several error types in prescribing for pediatric patients, mainly absence of bodyweight, incorrect frequency of administration and excessive doses. Information on bodyweight is crucial in pediatric patients: our study highlights the need to make it mandatory to complete prescriptions via CPOE systems. The role of better software design is pivotal to avoiding these errors. In addition to optimizing the quality of CPOE-entries, well-designed software, better-trained users, and improved communication among healthcare will reduce errors.