Monoterpene bisindole alkaloids,from the African medicinal plant Tabernaemontana elegans, induce apoptosis in HCT116 human colon carcinoma cells

Ethnopharmacological relevance

Tabernaemontana elegans is a medicinal plant used in African traditional medicine to treat several ailments including cancer. The aims of the present study were to identify anti-cancer compounds, namely apoptosis inducers, from Tabernaemontana elegans, and hence to validate its usage in traditional medicine.

Methods and materials

Six alkaloids, including four monomeric indole (1–3, and 6) and two bisindole (4 and 5) alkaloids, were isolated from the methanolic extract of Tabernaemontana elegans roots. The structures of these compounds were characterized by 1D and 2D NMR spectroscopic and mass spectrometric data. Compounds 1−6 along with compound 7, previously isolated from the leaves of the same species, were evaluated for in vitro cytotoxicity against HCT116 human colon carcinoma cells by the MTS metabolism assay. The cytotoxicity of the most promising compounds was corroborated by Guava-ViaCount flow cytometry assays. Selected compounds were next studied for apoptosis induction activity in HCT116 cells, by evaluation of nuclear morphology following Hoechst staining, and by caspase-3 like activity assays.

Results

Among the tested compounds (1−7), the bisindole alkaloids tabernaelegantine C (4) and tabernaelegantinine B (5) were found to be cytotoxic to HCT116 cells at 20 µM, with compound 5 being more cytotoxic than the positive control 5-Fluorouracil (5-FU), at a similar dose. In fact, even at 0.5 µM, compound 5 was more potent than 5-FU. Compounds 4 and 5 induced characteristic patterns of apoptosis in HCT116 cancer cells including, cell shrinkage, condensation, fragmentation of the nucleus, blebbing of the plasma membrane and chromatin condensation. Further, general caspase-3-like activity was increased in cells exposed to compounds 4 and 5, corroborating the nuclear morphology evaluation assays.

Conclusions

Bisindole alkaloids tabernaelegantine C (4) and tabernaelegantinine B (5) were characterized as potent apoptosis inducers in HCT116 human colon carcinoma cells and as possible lead/scaffolds for the development of anti-cancer drugs. This study substantiates the usage of Tabernaemontana elegans in traditional medicine to treat cancer.     

Factors influencing the retention of midwives in the public sector in Afghanistan: A qualitative assessment of midwives in eight provinces

Objective

to examine factors that affect retention of public sector midwives throughout their career in Afghanistan.

Design

qualitative assessment using semi-structured in-depth interviews (IDIs) and focus group discussions (FGDs).

Setting

health clinics in eight provinces in Afghanistan, midwifery education schools in three provinces, and stakeholder organisations in Kabul.

Participants

purposively sampled midwifery profession stakeholders in Kabul (n=14 IDIs); purposively selected community midwifery students in Kabul (n=3 FGDs), Parwan (n=1 FGD) and Wardak (n=1 FGD) provinces (six participants per FGD); public sector midwives, health facility managers, and community health workers from randomly selected clinics in eight provinces (n=48 IDIs); midwives who had left the public sector midwifery service (n=5 IDIs).

Measurements and findings

several factors affect a midwife throughout her career in the public sector, including her selection as a trainee, the training itself, deployment to her pre-assigned post, and working in clinics. Overall, appropriate selection is the key to ensuring deployment and retention later on in a midwife's career. Other factors that affect retention of midwives include civil security concerns in rural areas, support of family and community, salary levels, professional development opportunities and workplace support, and inefficient human resources planning in the public sector.

Key conclusions

Factors affecting midwife retention are linked to problems within the community midwifery education (CME) programme and those reflecting the wider Afghan context. Civil insecurity and traditional attitudes towards women were major factors identified that negatively affect midwifery retention.

Implications for practice

Factors such as civil insecurity and traditional attitudes towards women require a multisectoral response and innovative strategies to reduce their impact. However, factors inherent to midwife career development also impact retention and may be more readily modified.     

Midwifery retention and coverage and impact on service utilisation in Afghanistan

Objective

to measure the rate of and determine factors associated with community midwifery education (CME) graduate retention in public sector health care in Afghanistan.

Design

cross-sectional.

Setting

performed in public health facilities of 11 Afghan provinces purposively selected by geographic location and security conditions, between October 2011 and April 2012. Facilities were selected by one of two criteria: either a registered deployment site for a CME graduate or randomly selected through population-proportionate sampling.

Participants

facility managers and midwives employed in public facilities at the time of data collection.

Measurements

three quantitative instruments were used: a facility checklist assessed staffing and service volume, and two separate questionnaires for midwives and facility managers, which measured employment duration and perceived barriers to midwife retention.

Findings

at 456 surveyed facilities, 570 midwives were interviewed. Overall, 61.3% (n=209/341) of CME graduates deployed in surveyed provinces were working in public sector facilities, whereas 36.8% were working at their assigned site. Facilities without midwife staff had lower average monthly volumes of antenatal care visits (14.6 (SD±22.7) versus 71.5 (SD±72.5)), family planning visits (10.4 (SD+13.9) versus 56.8 (SD+85.0)), or facility-based deliveries (0.55 (SD±2.2) versus 15.7 (SD±18.7)). Perceived reasons for leaving employment were insecurity (civil unrest/armed conflict) (46.4%), family disagreement (28.1%), increased workload without compensation (9.9%), and lack of appropriate housing (7.8%).

Key conclusions

CME graduate retention in public sector positions was relatively low and significantly impacted by insecurity and cultural issues related to women working outside the home.

Implications for practice

culturally appropriate measures are needed to attract and retain skilled female health care providers for rural public facilities in Afghanistan and similar settings. Advocacy to encourage family and community support for midwives working in rural facilities and providing amenities such as housing, education for children, and employment for the accompanying male family member are measures most likely to improve midwife retention.     

Preparation and characterization of a customized cellulose acetate butyrate dispersion for controlled drug delivery

The purpose of the present experiment was to prepare and characterize the aqueous-based pseudolatex system of cellulose acetate butyrate (CAB) for controlled drug delivery. Aqueous pseudolatex systems are advantageous over organic-based coating systems because these systems are devoid of criteria pollutants such as carbon monoxide, nitrogen oxides, nonmethane volatile organic compounds, and sulfur dioxide. Pseudolatex was prepared with CAB and polyvinyl alcohol (stabilizer) by a polymer emulsification technique. The stability of pseudolatex was evaluated. Particle size was measured and rheological experiments were conducted. The glass transition temperature, microscopic free volume, permeation coefficient, and mechanical properties of plasticized pseudolatex films were estimated. Surface roughness of coating on inert Nu-Pareil beads (Ingredient Technology Corp., Mahwah, NJ) was measured as a function of coating weight gain. The CAB Pseudolatex was found to be stabilized by steric forces. From intrinsic viscosity, the thickness of the stabilization layer was estimated. An increase in polymeric particles proportionately decreased the thickness of the stabilization layer. All the essential properties of a coating membrane such as microscopic free-volume fraction, permeability coefficient, mechanical properties, and glass transition temperature were fairly controllable as a function of plasticizer concentration. The pseudolatex dispersion of CAB was stable with negligible sedimentation volume and a particle size of 300 nm. Because CAB is water insoluble and non-ionizable, this pseudolatex can be used for pH-independent coating. The films obtained were strong and flexible for controlled drug delivery applications. Coating with the CAB dispersion reduced the surface roughness of beads but it remained stable as a function of increase in coating weight gain.     

Adherence Support Approaches in Biomedical HIV Prevention Trials: Experiences, Insights and Future Directions from Four Multisite Prevention Trials

Adherence is a critical component of the success of antiretroviral-based pre-exposure prophylaxis (PrEP) in averting new HIV-infections. Ensuring drug availability at the time of potential HIV exposure relies on self-directed product use. A deeper understanding of how to best support sustained PrEP adherence remains critical to current and future PrEP efforts. This paper provides a succinct synthesis of the adherence support experiences from four pivotal PrEP trials—Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004, FEM-PrEP, Iniciativa Prophylaxis (iPrEx), and Vaginal and Oral Interventions to Control the Epidemic (VOICE). Notwithstanding variability in the design, population/cohort, formulation, drug, dosing strategy, and operationalization of adherence approaches utilized in each trial, the theoretical basis and experiences in implementation and monitoring of the approaches used by these trials provide key lessons for optimizing adherence in future research and programmatic scale-up of PrEP. Recommendations from across these trials include participant-centered approaches, separating measurement of adherence from adherence counseling, incorporating tailored strategies that go beyond education, fostering motivation, and addressing the specific context in which an individual incorporates and negotiates PrEP use.     

Development and Evaluation of Paclitaxel Nanoparticles Using a Quality-by-Design Approach

The aims of this study were to develop and characterize paclitaxel nanoparticles, to identify and control critical sources of variability in the process, and to understand the impact of formulation and process parameters on the critical quality attributes (CQAs) using a quality-by-design (QbD) approach. For this, a risk assessment study was performed with various formulation and process parameters to determine their impact on CQAs of nanoparticles, which were determined to be average particle size, zeta potential, and encapsulation efficiency. Potential risk factors were identified using an Ishikawa diagram and screened by Plackett–Burman design and finally nanoparticles were optimized using Box–Behnken design. The optimized formulation was further characterized by Fourier transform infrared spectroscopy, X-ray diffractometry, differential scanning calorimetry, scanning electron microscopy, atomic force microscopy, and gas chromatography. It was observed that paclitaxel transformed from crystalline state to amorphous state while totally encapsulating into the nanoparticles. The nanoparticles were spherical, smooth, and homogenous with no dichloromethane residue. In vitro cytotoxicity test showed that the developed nanoparticles are more efficient than free paclitaxel in terms of antitumor activity (more than 25%). In conclusion, this study demonstrated that understanding formulation and process parameters with the philosophy of QbD is useful for the optimization of complex drug delivery systems. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 102:3748–3761, 2013     

A case of SLE with bilateral osteonecrosis of femoral heads and bone infarct in distal of femur

Osteonecrosis of bone is a major cause of morbidity in lupus patients, and is most common in the femoral head. It has been reported in wide range of patients (2–30%). In different studies presence of arthritis, Raynaud phenomenon, vasculitis, pleuritis, antiphospholipid and other factors were associated with this occurrence. Bone infarcts were also associated with these factors. We report a 21-year-old patient who was diagnosed as SLE about 3 years ago. When the patient was stable with hydroxychloroquine and prednisolone referred to rheumatologic clinic for mechanical knee pain, in evaluation she had bone infarct in distal femur. Two months later she came back with bilateral hip pain, and in evaluation she had bilateral osteonecrosis of femoral heads. There are many reports of femoral head osteonecrosis in lupus patients, and also one report of multiple bone infarct and pain in SLE, but we did not find any report of these two phenomena together in a patient whose disease was controlled and she took minimum of steroid and DMARD in the about 2-month follow-up, and this was very interesting for us.     

Relationship of plasma lactoferrin content to neutrophil regeneration and bone marrow infusion

Plasma concentrations of lactoferrin were measured in immediately separated EDTA samples from 5 subjects who had received HLA identical bone marrow transplants for leukaemia or aplastic anaemia and from 7 subjects who were leukopenic as a consequence of chemotherapy for a variety of malignant conditions. Plasma lactoferrin concentrations were found to closely parallel the leucocyte count and were not found to either predict or to antedate leucocyte regeneration. Serial measurements of plasma lactoferrin in a subject with no circulating neutrophils who received a bone marrow graft revealed that the clearance of lactoferrin followed an exponential pattern and had an initial half time of 2.2 h.     

Plasma membrane calcium ATPase overexpression in arterial smooth muscle increases vasomotor responsiveness and blood pressure

In vascular smooth muscle cells (SMCs), several mechanisms act in concert to regulate the intracellular calcium concentration [Ca2+]i, which may in turn affect vascular tone. One such mechanism is the extrusion of Ca2+ by the plasma membrane calcium ATPase (PMCA). To address, in particular, the role of the neuronal nitric oxide synthase (nNOS)-associating isoform PMCA4b in regulating vascular tone, a doxycycline-responsive transgene for human PMCA4b was overexpressed in arterial SMCs of mice. Overexpression of hPMCA4b resulted in a 2-fold increase in total aortic PMCA4 protein expression and significant real-time RT-PCR-documented differences in the levels of endogenous mouse PMCA1, PMCA4, SERCA2, and IP3R1 gene expression in arterial SMCs. Whereas no significant difference in basal [Ca2+]i or Ca2+ sensitivity was observed in vascular SMCs or mesenteric arteries, respectively, from hPMCA4b-overexpressing versus control mice, hPMCA4b-overexpressing mice revealed a reduced set-point and increased extent of myogenic response and heightened sensitivity to vasoconstrictors. Treatment of arteries with an nNOS inhibitor resulted in a reduced set-point and increased extent of the myogenic response in control but not hPMCA4b-overexpressing mice. Moreover, aortic SMCs from hPMCA4b-overexpressing mice exhibited reduced levels of cGMP under both basal and phenylephrine-stimulated conditions. These changes were associated with significant doxycycline-reversible elevations in blood pressure. Taken together, these data show that overexpression of hPMCA4b in arterial SMCs increases vascular reactivity and blood pressure, an effect that may be mediated in part by negative regulation of nNOS.