Molecular mechanisms associated with Fluconazole resistance in clinical Candida albicans isolates from India

Resistance to azole antifungals is a significant problem in Candida albicans. An understanding of resistance at molecular level is essential for the development of strategies to tackle resistance and rationale design of newer antifungals and target‐based molecular approaches. This study presents the first evaluation of molecular mechanisms associated with fluconazole resistance in clinical C.albicans isolates from India. Target site (ERG11) alterations were determined by DNA sequencing, whereas real‐time PCRs were performed to quantify target and efflux pump genes (CDR1, CDR2, MDR1) in 87 [Fluconazole susceptible (n = 30), susceptible‐dose dependent (n = 30) and resistant (n = 27)] C.albicans isolates. Cross‐resistance to fluconazole, ketoconazole and itraconazole was observed in 74.1% isolates. Six amino acid substitutions were identified, including 4 (E116D, F145L, E226D, I437V) previously reported ones and 2 (P406L, Q474H) new ones. CDR1 over‐expression was seen in 77.7% resistant isolates. CDR2 was exclusively expressed with CDR1 and their concomitant over‐expression was associated with azole cross‐resistance. MDR1 and ERG11 over‐expression did not seem to be associated with resistance. Our results show that drug efflux mediated by Adenosine‐5′‐triphosphate (ATP)‐binding cassette transporters, especially CDR1 is the predominant mechanism of fluconazole resistance and azole cross‐resistance in C. albicans and indicate the need for research directed towards developing strategies to tackle efflux mediated resistance to salvage azoles.     

Development and evaluation of co-formulated docetaxel and curcumin biodegradable nanoparticles for parenteral administration

Context: Technology for development of biodegradable nanoparticles encapsulating combinations for enhanced efficacy.

Objective: To develop docetaxel (DTX) and curcumin (CRM) co-encapsulated biodegradable nanoparticles for parenteral administration with potential for prolonged release and decreased toxicity.

Materials and methods: Modified emulsion solvent-evaporation technique was employed in the preparation of the nanoparticles optimized by the face centered-central composite design (FC-CCD). The uptake potential was studied in MCF-7 cells, while the toxicity was evaluated by in vitro hemolysis test. In vivo pharmacokinetic was evaluated in male Wistar rats.

Results and discussion: Co-encapsulated nanoparticles were developed of 219?nm size, 0.154 PDI, ?13.74?mV zeta potential and 67.02% entrapment efficiency. Efficient uptake was observed by the nanoparticles in MCF-7 cells with decreased toxicity in comparison with the commercial DTX intravenous injection, Taxotere®. The nanoparticles exhibited biphasic release with initial burst release followed by sustained release for 5 days. The nanoparticles displayed a 4.3-fold increase in AUC (391.10?±?32.94 versus 89.77?±?10.58?μg/ml min) in comparison to Taxotere® with a 6.2-fold increase in MRT (24.78?±?2.36 versus 3.58?±?0.21?h).

Conclusion: The nanoparticles exhibited increased uptake, prolonged in vitro and in vivo release, with decreased toxicity thus exhibiting potential for enhanced efficacy.     

Tramadol as a local anaesthetic agent in dentistry: A systematic review of local and systemic adverse effects

Tramadol is an effective alternative local anaesthetic (LA) agent available in dentistry. This review aims to help guide practice by providing clinicians with relevant data regarding adverse effects (AE) associated with locally administered tramadol in the oral environment. A systematic search of three electronic databases was performed to identify relevant studies reporting AE associated with locally administered tramadol in the oral setting. Selected studies were reviewed and included based on inclusion and exclusion criteria. Data collected included: publication year, study design, participant numbers, adverse effects and follow-up duration. Fifteen articles were included comprising of 547 tramadol participants across eight exodontia and seven non-exodontia studies. Thirty-eight associated AE were reported. Nausea was the most commonly reported (4.6%), followed by dizziness (1.3%), vomiting (0.7%) and local erythema (0.4%). No other AE were reported. The prevalence of total AE was similar in ≥ 50 mg tramadol doses (7.2–7.3%); however the total affected number is not dose dependent. The prevalence of AE and affected participants was less when tramadol was used as a sole LA rather than as an adjunct (5.6% vs. 7.9% and 3.4–5.6% vs. 6.3%, respectively). Thus, tramadol is a safe LA agent with a low prevalence of AE when administered in the dental setting.     

Protective effect of aqueous extract of Oroxylum indicum Linn. (root bark) against DNBS-induced colitis in rats

Objective:

Aqueous root extract of Oroxylum indicum was evaluated in rats against dinitrobenzene sulfonic acid (DNBS) induced colitis.

Materials and Methods:

Rats were pre-treated orally for seven days and continued for four days after the induction of colitis with OI_aq (100, 200, and 400 mg/kg) or vehicle. Colitis was induced by intracolonic instillation of 25 mg of DNBS per rat dissolved in 50% alcohol and 4 days later, the colonic mucosal damage was analyzed along with food intake, body weight, colon weight, spleen weight, histological damage, myeloperoxidase (MPO) activity, malondialdehyde (MDA) levels, reduced glutathione (GSH), and nitric oxide levels in colonic tissue homogenate.

Results:

Significant reduction in gross damage area, weight loss and increase in colonic and spleen weight were evident in test substance-pretreated animals’ dose dependently as compared to vehicle treated control. These effects were confirmed biochemically by a reduction in colonic myeloperoxidase activity, malondialdehyde levels, nitric oxide levels, and increase in reduced glutathione (GSH) levels. Furthermore, microscopic examination revealed diminution of inflammatory cell infiltration and submucosal edema in colon segments of rats treated with OI_aq.

Conclusion:

The results demonstrate the protective effect of OI_aq in the animal model of acute colitis possibly through an antioxidant, anti-lipoperoxidative or due to reduction in nitric oxide generation.KEY WORDS: Oroxylum indicum, DNBS, colitis, rats     

Temsirolimus, an mTOR inhibitor, enhances anti-tumour effects of heat shock protein cancer vaccines

Background:

Temsirolimus is a mammalian target of rapamycin (mTOR) inhibitor and rapamycin analogue that is approved for treating advanced renal cell carcinoma (RCC). It is being actively evaluated in clinical trials for melanoma. The mTOR inhibitors are also immunosuppressants and are used clinically to prevent rejection following solid-organ transplant. Novel immunotherapies are being actively developed for immunoresponsive tumours, such as RCC and melanoma.

Methods:

Immune-modulating effects of temsirolimus were characterised when used in combination with cancer vaccines targeting RCC (RENCA) and melanoma (B16). Cancer vaccines were recombinant tumour-specific proteins (CA9 or gp100), and recombinant heat shock protein (HSP; hsp110) served as the immune adjuvant.

Results:

In murine models, temsirolimus enhanced the anti-tumour activity of cancer vaccines used to treat established RENCA and B16 tumours. A tumour prevention model established that the enhanced anti-tumour activity associated with temsirolimus was immune mediated. In mice treated with an HSP-based anti-tumour vaccine, temsirolimus-treated CD8 T cells had greater interferon-γ and cytotoxic T-cell responses when compared with mice treated with vaccine alone. Temsirolimus also enhanced the formation of CD8 memory cells following administration of HSP-based cancer vaccine.

Conclusion:

These results provide a rationale for combining mTOR inhibitor with immunotherapy when treating immunoresponsive tumours.     

Crocetin: an agent derived from saffron for prevention and therapy for cancer

Cancer is one of the leading causes of death in the United States and accounts for approximately 8 million deaths per year worldwide. Although there is an increasing number of therapeutic options available for patients with cancer, their efficacy is time-limited and non-curative. Approximately 50-60% cancer patients in the United States utilize agents derived from different parts of plants or nutrients (complementary and alternative medicine), exclusively or concurrently with traditional therapeutic regime such as chemotherapy and/or radiation therapy. The need for new drugs has prompted studies evaluating possible anti-cancer agents in fruits, vegetables, herbs and spices. Saffron, a spice and a food colorant present in the dry stigmas of the plant Crocus sativus L., has been used as an herbal remedy for various ailments including cancer by the ancient Arabian, Indian and Chinese cultures. Crocetin, an important carotenoid constituent of saffron, has shown significant potential as an anti-tumor agent in animal models and cell culture systems. Crocetin affects the growth of cancer cells by inhibiting nucleic acid synthesis, enhancing anti-oxidative system, inducing apoptosis and hindering growth factor signaling pathways. This review discusses the studies on cancer preventive potential of crocetin and its future use as an anticancer agent.