Comparison of regimens of treatment with sodium stibogluconate in kala-azar.

One hundred and twenty six patients with kala-azar (visceral leishmaniasis) were allocated at random to one of two groups for treatment with sodium stibogluconate. One group was treated for 20 days; in the other group the patients were assessed after 20 days'' treatment and treatment was continued if necessary. Both groups were followed up for six months. There was no significant difference in symptomatic outcome between the two groups at 20 days. At six months eight of the patients in the group treated for 20 days had relapsed and 54 were cured. Of the group given more than 20 days'' treatment if necessary, 62 were cured and none had relapsed (12 required more than 20 days'' treatment). This difference between the two groups was significant. One patient in each group did not respond to sodium stibogluconate, but both were were cured with pentamidine. Altogether 104 patients were cured after 20 days'' treatment; 20, including the eight who relapsed, were cured after more than 20 days'' treatment. There was no significant difference between the two groups in the side effects of the drug, which were minor. The longer courses of treatment (50 days in one patient) were well tolerated. It is suggested that the traditional six day course of treatment with sodium stibogluconate for kala-azar is grossly inadequate and that a longer course is required to prevent relapse.     

Inhibition of authentic hepatitis C virus replication by sodium stibogluconate

Using a hepatitis C virus (HCV) subgenomic RNA replicon system, drugs currently being used to treat other human diseases were examined for their antiviral activities against HCV. Several drugs including sodium stibogluconate, a compound used to treat leishmaniasis, were capable of suppressing replication of HCV replicon. The antiviral effect of sodium stibogluconate was subsequently verified using a cell line (293EBNA-Sip-L) previously proved to be permissive for HCV infection/replication. An ex vivo assay using fresh human liver slices established and a panel of human liver slices was obtained from biopsy samples of patients infected with HCV was used to examine the antiviral activity of this drug. A nearly complete suppression effect was achieved in four of six human liver slices at the drug concentration of 100 microg/ml, lower than what was required to treat leishmaniasis. A human trial is mandatory to understand its clinical value in treating chronic hepatitis C.     

Rationalisation of regimens of treatment of kala-azar with sodium stibogluconate in India: a randomised study

The efficacy and safety of six regimens of treatment for kala-azar (visceral leishmaniasis) with sodium stibogluconate were evaluated in a prospective randomised study to ascertain the optimal treatment for Indian patients. Altogether 371 patients with kala-azar were randomised to receive sodium stibogluconate intramuscularly at a dose of 10 mg/kg body weight/day for 20 or 40 days (groups A and A1, respectively), 15 mg/kg body weight/day for 20 or 40 days (groups B and B1, respectively), or 20 mg/kg body weight/day for 20 or 40 days (groups C and C1, respectively). Patients were examined blind before and at the end of treatment and every month for six months. The number of patients who were apparently cured—that is, those whose temperature had returned to normal at the end of their regimen of treatment—was 45 (78%) in group A, 53 (87%) in group A1, 50 (81%) in group B, 60 (95%) in group B1, 58 (92%) in group C, and 62 (97%) in group C1.At six months 62 patients (97%) in group C1, 51 (81%) in group C, 54 (86%) in group B1, 42 (68%) in group B, 45 (74%) in group A1, and 33 (57%) in group A had not relapsed and were cured as confirmed by a bone marrow aspirate free of parasites. The differences between groups C1 and C, B1 and B, and A1 and A were significant. Logistic regression of the proportion cured with the dose and length of treatment showed that both factors were significant in improving the rate of cure; the highest dose for the longer time (group C1) had the best rate of cure. One patient in group C1, 12 in group C, nine in group B1, 18 in group B, 15 in group A1, and 23 in group A were cured with extended courses of 20 mg sodium stibogluconate. One patient in each of groups C1, B, A1, and A became unresponsive to antimony and were cured with pentamidine. One patient in each of groups C1, B, and A became unresponsive to both antimony and pentamidine. The patients tolerated the longer duration of treatment safely, and side effects were minor.Sodium stibogluconate should be given intramuscularly in the dosage of 20 mg/kg for at least 40 days, when patients should be assessed for further treatment if necessary. Such a regimen should achieve the highest rate of cure with low toxicity and low rates of relapse and unresponsiveness.     

Leishmania mexicana: chemistry and biochemistry of sodium stibogluconate (Pentostam)

The chemical properties of the primary antileishmanial agent sodium stibogluconate (Pentostam), and the interaction of Pentostam with Leishmania mexicana amastigotes, have been investigated with the aid of [125Sb]Pentostam. The molecular weight by P2 chromatography showed [125Sb]Pentostam to be of multiple species of MW = 100-4000 Da, rather than the one species of 746 Da predicted by the commonly hypothesized structural formula. Nonradioactive Pentostam had a lower osmolarity (789 mOsm for a 100 mg Sb/ml solution) than predicted (1644 mOsm), which indicates that the multiple components of Pentostam (Sb and derivatives of gluconic acid) are more closely complexed with each other than previously thought. When incubated with L. mexicana amastigotes, labeled drug was bound to at least six polypeptides of molecular weights ranging from 14,000 to 68,000 Da as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Interaction with the polypeptides is presumed to contribute to the antileishmanial action of Pentostam.     

Monitoring toxicity associated with parenteral sodium stibogluconate in the day-case management of returned travellers with New World cutaneous leishmaniasi

Background

Patients with New World cutaneous leishmaniasis (NWCL) caused by Leishmania Viannia are treated with parenteral sodium stibogluconate (SbV) to reduce the risk of development of mucocutanous leishmaniasis. Our centre manages patients with NWCL on an outpatient-basis. This study was conducted to assess the safety and efficacy of this approach.

Methodology

We reviewed records of 67 consecutive NWCL patients, aged 17–61 years, treated as day-cases with 20 mg/kg/day SbV for up to 28 days at our UK centre. Data had been collected in a standardised format at the time of treatment using a care-record tool. Patients reported adverse-effects daily using a structured questionnaire. Blood tests and electrocardiograms were performed twice weekly to monitor for toxicity.

Principal Findings

Parenteral SbV treatment was associated with an early, significant suppression of mean lymphocyte and platelet counts. By day four of treatment, lymphocytes reduced by 0.53×10⁹/L (CI 0.29×10⁹/L to 0.76×10⁹/L, p<0.001), and platelets by 31,000/µL (CI 16,000/µL to 46,000/µL, p<0.001). SbV was further associated with significant elevation of serum alanine transaminase concentrations, with a mean peak rise of 107 iu/L by day 13 (CI 52 iu/L to 161 iu/L, p<0.001). These disturbances were temporary and did not result in adverse clinical events. Patient-described symptoms were cumulative and at three weeks of treatment, 59.6% of patients experienced myalgia and 29.8% malaise. Treatment adherence and clinical outcomes were comparable to inpatient treatment studies. A total of 1407 individual doses of SbV resulted in only 26 nights'' hospital admission, a saving of 1381 bed-days compared to inpatient treatment.

Conclusions/Significance

In specialist centres, NWCL patients aged below 65 years and without co-morbidities can be safely and effectively treated without hospital admission. This reduces the cost of treatment, and is much preferred by patients. Twice weekly blood and electrocardiographic monitoring may be surplus to requirement in clinically well, low-risk patients.     

Therapy with sodium stibogluconate in stearylamine-bearing liposomes confers cure against SSG-resistant Leishmania donovani in BALB/c mice

Background

Resistance of Leishmania donovani to pentavalent antimonials, the first-line treatment of visceral leishmaniasis (VL), has become a critical issue worldwide. Second-line and new drugs are also not devoid of limitations. Suitable drug-delivery systems can improve the mode of administration and action of the existing antimonials, thus increasing their clinical life.

Methodology/Principal Findings

We investigated the efficacy of sodium stibogluconate (SSG) in phosphatidylcholine (PC)–stearylamine-bearing liposomes (PC-SA-SSG), PC-cholesterol liposomes (PC-Chol-SSG) and free amphotericin B (AmB) against SSG-resistant L. donovani strains in 8-wk infected BALB/c mice. Animals were sacrificed and parasites in liver, spleen and bone marrow were estimated 4-wk post-treatment by microscopic examination of stamp smears and limiting dilution assay. A set of PC-SA-SSG and AmB treated mice were further studied for protection against reinfection. Serum antibodies and cytokine profiles of ex-vivo cultured splenocytes were determined by ELISA. Uptake of free and liposomal SSG in intracellular amastigotes was determined by atomic absorption spectroscopy. Rhodamine 123 and 5-carboxyfluorescein, known substrates of Pgp and MRP transporter proteins, respectively, were used in free and liposomal forms for efflux studies to estimate intracellular drug retention. Unlike free and PC-Chol-SSG, PC-SA-SSG was effective in curing mice infected with two differentially originated SSG-unresponsive parasite strains at significantly higher levels than AmB. Successful therapy correlated with complete suppression of disease-promoting IL-10 and TGF-β, upregulation of Th1 cytokines and expression of macrophage microbicidal NO. Cure due to elevated accumulation of SSG in intracellular parasites, irrespective of SSG-resistance, occurs as a result of increased drug retention and improved therapy when administered as PC-SA-SSG versus free SSG.

Conclusions/Significance

The design of this single-dose combination therapy with PC-SA-SSG for VL, having reduced toxicity and long-term efficacy, irrespective of SSG-sensitivity may prove promising, not only to overcome SSG-resistance in Leishmania, but also for drugs with similar resistance-related problems in other diseases.     

Anticancer activity of some bisbenzimidazoles

The discovery of DNA topoisomerases has added a new dimension to the study of anticancer drugs. Bisbenzimidazole derivatives are important compounds known as DNA topoisomerase I inhibitors. In the present study, some symmetrical bisbenzimidazole derivatives were synthesized and investigated for their anticancer activity. Anticancer activity screening was applied on HT-29 (colon carcinoma) and MCF-7 (breast carcinoma) cell lines by investigation of cytotoxicity, analysis of DNA synthesis, and DNA fragmentation assays. One of the seven compounds tested showed significant cytotoxicity in both cell lines and caused DNA degradation in the HT-29 cell line.     

Anticancer activity of oxovanadium compounds

Cytotoxic and antitumor activities of the biligand vanadyl derivative of L-malic acid, (bis-(L-malato)oxovanadium(IV) (VO(mal)₂), the inorganic vanadium(IV) compound, vanadyl sulfate (VOSO₄), the oxovanadium monocomplex with L-malic acid (VO(mal)), and the vanadyl biscomplex with acetylacetonate (VO(acac)₂) were investigated using several tumor cell lines: mouse fibrosarcoma (L929), rat pheochromocytoma (PC12), human liver carcinoma (HepG2), mouse embryonic fibroblasts (NIH/3T3), and also normal human skin fibroblasts. The results showed that VO(mal)₂ effectively inhibited growth of cancer cell cultures without any toxic effect on normal human skin fibroblasts. The cytotoxic anticancer effect of vanadium complexes depended on concentration of the compounds studied, incubation time, types of cell cultures, and nature of ligands surrounding the central group of the complex (VO²⁺). These studies provide evidence that VO(mal)₂ may be considered as a potential anticancer agent due to its low toxicity for non-tumor cells and significant anticancer activity.     

Anticancer activity of Hemsleya amabilis extract

Hemsleya amabilis extract is derived from the medicinal herb Hemsleya amabilis, which has long been used to treat cancer and many other conditions. The underlying mechanism is not clear. To investigate Hemsleya amabili's anticancer activity, we have treated different types of cancer cells including human astrocytoma U87 cells, breast cancer cells MDA-MB-231and Jurkat cells with Hemsleya amabilis extract. This agent significantly inhibited tumor cell growth and colony formation at various concentrations. When astrocytoma cells were seeded in the presence of Hemsleya amabilis extract at very low concentrations, cell spreading was greatly inhibited. Hemsleya amabilis extract also promoted tumor cell death in all the tested cell lines, but with varied sensitivities. Apoptotic assays with Annexin V staining demonstrated that Hemsleya amabilis extract induced astrocytoma cell apoptosis at different concentrations.     

Leishmania donovani: isolation and characterization of sodium stibogluconate (Pentostam)-resistant cell lines

Leishmania donovani promastigotes were generated by virtue of their resistance to incrementing concentrations of sodium stibogluconate (Pentostam) under completely defined growth conditions. The PENT0400 and PENT03200 cell lines were isolated after prolonged exposure to 0.4 mg/ml and 3.2 mg/ml Pentostam (Sb concentration), respectively. Whereas the effective concentration of Pentostam which inhibited the growth of wild type cells by 50% (EC50 value) was 0.1-0.15 mg/ml, the EC50 values for the PENT0400 and PENT03200 cells were approximately 1 and 4 mg/ml, respectively. The decreased sensitivities of both PENT0400 and PENT03200 cells to Pentostam were maintained after 6 months of continuous culture in the absence of selective pressure, indicating that the Pentostam resistance in the mutant organisms was a stable genetic trait. Interestingly, wild type and PENT03200 cells were equally sensitive to growth inhibition and cytotoxicity caused by SbCl5 and SbCl3, as well as to a variety of other cations such as Cd, Zn, and As. Wild type and PENT03200 cells also displayed equivalent growth sensitivities to a spectrum of other antiprotozoal agents, including antimony potassium tartrate, melarsoprol, pyrimethamine, pentamidine, formycin B, and difluoromethylornithine. These results illustrate a potentially useful model system to study Pentostam resistance in Leishmania and suggest that Pentostam resistance in vitro may be independent of antimony toxicity.     

Anticancer and antiproliferative activity of natural brassinosteroids

Brassinosteroids (BRs) are steroid plant hormones that are essential for many plant growth and developmental processes, including cell expansion, vascular differentiation and stress responses. Up to now the inhibitory effects of BRs on cell division of mammalian cells are unknown. To determine basic anticancer structure-activity relationships of natural BRs on human cells, several normal and cancer cell lines have been used. Several of the tested BRs were found to have high cytotoxic activity. Therefore, in our next series of experiments, we tested the effects of the most promising and readily available BR analogues with interesting anticancer properties, 28-homocastasterone (1) and 24-epibrassinolide (2), on the viability, proliferation, and cycling of hormone-sensitive/insensitive (MCF-7/MDA-MB-468) breast and (LNCaP/DU-145) prostate cancer cell lines to determine whether the discovered cytotoxic activity of BRs could be, at least partially, related to brassinosteroid-nuclear receptor interactions. Both BRs inhibited cell growth in a dose-dependent manner in the cancer cell lines. Flow cytometry analysis showed that BR treatment arrested MCF-7, MDA-MB-468 and LNCaP cells in G(1) phase of the cell cycle and induced apoptosis in MDA-MB-468, LNCaP, and slightly in the DU-145 cells. Our results provide the first evidence that natural BRs can inhibit the growth, at micromolar concentrations, of several human cancer cell lines without affecting the growth of normal cells. Therefore, these plant hormones are promising leads for potential anticancer drugs.     

Bacterial DNA containing methylated CpG motifs retains immunostimulatory activity in synergy with modified lipopolysaccharides

We previously described the immunostimulatory activity of CIA07, a combination of bacterial DNA fragments and modified LPS, and demonstrated that CIA07 has antitumor activity in a mouse bladder cancer model. In this study, we investigated whether methylation of the CpG motifs on the bacterial DNA fragments affects the immunostimulatory potential of CIA07. E. coli DNA fragments were methylated with CpG methylase, and then combined with modified LPS for experiments. Our results revealed that methylated CIA07 (mCIA07) and unmethylated CIA07 were equally active in inducing cytokine secretion from human whole blood cells. In addition, both methylated DNA fragments and mCIA07 retained the ability to activate expression and nuclear translocation of NF-kappaB in RAW 264.7 cells. Finally, methylated DNA fragments and mCIA07 exhibited an antitumor activity comparable to those of their unmethylated counterparts in our mouse bladder cancer model. These data demonstrate that CpG methylation of E. coli DNA does not abrogate the immunostimulatory activity of DNA fragments or CIA07, suggesting that the synergistic activity by bacterial DNA in combination with LPS may be independent of the methylation status of CpG motifs.     

Anticancer activity of synthetic analogues of the phorboxazoles

The phorboxazoles are recently described natural products that are extremely cytostatic towards the National Cancer Institute's panel of 60 tumor cell lines. We report here the results of preliminary structure-activity studies of synthetic analogues of the phorboxazoles against BT-20 breast cancer, NALM-6 B-lineage ALL, U373 brain tumor, and U373 glioblastoma cell lines. These data indicate the importance of several of the natural products' structural moieties for potent anticancer activity.     

Anticancer activity of tirucallane triterpenoids from Amoora dasyclada

A new tetranortriterpene 3alpha-acetoxy-24,25,26,27-tetranortirucalla-7-ene-23(21)-lactone (3), and eleven other compounds were isolated from the twigs of Amoora dasyclada. The structure of compound 3 was identified on the basis of spectroscopic data, and the bioactive experiments of 1 and 3-5 against AGZY 83-a (human lung cancer cells) and SMMC-7721 (human liver cancer cells) are documented. Among them, compound 5 exhibited a strong activity against SMMC-7721.     

Anticancer activity of monoterpenes: a systematic review

Molecular Biology Reports - Secondary metabolites have been recognized for centuries as medicinal agents, in particular monoterpenes which have been the target of research in the discovery of...     

Anticancer activity of hydrophobic peptides from soy proteins

An anticancer peptide from soy protein was purified and isolated. Defatted soy protein was hydrolyzed with thermoase and hydrophobic peptides were extracted with ethanol. The peptide extract was fractionated by XAD-2 hydrophobic, gel filtration chromatography, and different C18 HPLCs. Anticancer activity of each fraction was assayed by measuring in vitro cytotoxicity on P388D1, a mouse monocyte macrophage cell line. IC50 value of a peptide fraction from Sephadex G-25 chromatography was 0.16 mg/ml. This peptide fraction at 1 mg/ml significantly affected cell cycle progression by arresting P388D1 at G2/M phases. Finally purified peptide from analytical C18 HPLC was nonapeptide of which molecular weight was 1157 Da and the sequence was X-Met-Leu-Pro-Ser-Tye-Ser-Pro-Tyr.