Photodynamic therapy with bengal rose and derivatives against leishmania amazonensis

Introduction: The treatment of cutaneous leishmaniasis [CL] is based primarily on the use of pentavalent antimonials, which may lead to many side effects limiting their use. Photodynamic therapy [PDT] is an alternative for the treatment of CL, and some xanthene dyes have the potential for use in PDT

Methods: The xanthenes rose bengal B [RB] and its derivatives rose bengal methyl ester [RBMET], and butyl ester [RBBUT] were analyzed for leishmanicidal activity against promastigotes and intracellular amastigotes of Leishmania amazonensis. Cytotoxicity was assessed in J774.A1 macrophages

Results: RB derivates RBMET [IC50 9.83 microM], and RBBUT [IC50 45.08 microM] showed leishmanicidal activity, however, were toxic to J774.A1 macrophages, resulting in low selectivity index

Conclusion: The RBMET and RBBUT showed to be effective against the L. amazonensis and the low selectivity index presented may not be a limitation for their use in PDT to CL treatment

Dormancy models for Mycobacterium tuberculosis: A minireview

Dormancy models for Mycobacterium tuberculosis play important roles in understanding various aspects of tuberculosis pathogenesis and in the testing of novel therapeutic regimens. By simulating the latent tuberculosis infection, in which the bacteria exist in a non-replicative state, the models demonstrate reduced susceptibility to antimycobacterial agents. This minireview outlines the models available for simulating latent tuberculosis both in vitro and in several animal species. Additionally, this minireview discusses the advantages and disadvantages of these models for investigating the bacterial subpopulations and susceptibilities to sterilization by various antituberculosis drugs.

Early responses of the STAT3 pathway to platinum drugs are associated with cisplatin resistance in epithelial ovarian cancer

Cisplatin resistance remains one of the major obstacles when treating epithelial ovarian cancer. Because oxaliplatin and nedaplatin are effective against cisplatin-resistant ovarian cancer in clinical trials and signal transducer and activator of transcription 3 (STAT3) is associated with cisplatin resistance, we investigated whether overcoming cisplatin resistance by oxaliplatin and nedaplatin was associated with the STAT3 pathway in ovarian cancer. Alamar blue, clonogenic, and wound healing assays, and Western blot analysis were used to compare the effects of platinum drugs in SKOV-3 cells. At an equitoxic dose, oxaliplatin and nedaplatin exhibited similar inhibitory effects on colony-forming ability and greater inhibition on cell motility than cisplatin in ovarian cancer. Early in the time course of drug administration, cisplatin increased the expression of pSTAT3 (Tyr705), STAT3α, VEGF, survivin, and Bcl-XL, while oxaliplatin and nedaplatin exhibited the opposite effects, and upregulated pSTAT3 (Ser727) and STAT3β. The STAT3 pathway responded early to platinum drugs associated with cisplatin resistance in epithelial ovarian cancer and provided a rationale for new therapeutic strategies to reverse cisplatin resistance.

Swerchirin induced blood sugar lowering of streptozotocin treated hyperglycemic rats.

Effect of Swerchirin (1:8 dihydroxy 3:5 dimethoxy xanthone) isolated from hexane fraction of Swertia chirayita on the blood sugar level of healthy and streptozotocin treated rats was studied. Streptozotocin was administered in citrate buffer (pH-4.5) intravenously / 35 and 65 mg/kg body wt to Charles Foster strain albino rats. Swerchirin (50 mg/kg, po) suspended in gum acacia was fed through cannula to the above rats and to a group of healthy rats. Blood sugar estimated at 0, 1, 3 and 7 hr after, indicated a very significant lowering in healthy and streptozotocin (35 mg/kg iv) but not in streptozotocin (65 mg/kg) treated rats.