Equilibrium between anti-oxidants and reactive oxygen species: a requisite for oocyte development and maturation.

Reactive oxygen species (ROS) are required for cellular functioning and are controlled by anti-oxidants. The ROS influence the follicles, oocytes, endometrium, and their environment. The luteinizing hormone surge initiates a massive recruitment of ROS that modulates major reproductive functions namely, oocyte maturation, ovarian steroidogenesis, corpus luteal function, and luteolysis. The anti-oxidant system balances ROS generation and maintains the cellular functions. Both enzymatic and non-enzymatic anti-oxidants namely, vitamins and minerals are present in the follicles and protect the oocytes from the damaging effects of ROS. The overproduction of ROS leads to oxidative stress that affects the quality of oocytes and subsequent anovulation. Although researchers have tried to establish the role of ROS and anti-oxidants in oocyte development, still this aspect needs to be revisited. This review discusses the importance of the ROS and anti-oxidant balance that is required for the development and maturation of oocytes. There are increasing data on the activity of ROS and anti-oxidants in supporting oocyte development and maturation. However, extensive research is required to identify the safe physiological concentration and duration of both the ROS and anti-oxidants that are required to facilitate oocyte development and maturation during in vitro and in vivo conditions.

Implication of Formulation Strategies on the Bioavailability of Selected Plant-Derived Hepatoprotectants.

Plant-derived active ingredients with hepatoprotective activity have been used extensively in the treatment of various liver diseases. These compounds are used either in their natural form or the chemical constituents present therein serve as templates for the development of synthetic-based therapeutic entities. Current research interests are focused on formulation development and pharmacokinetic studies of herbal medicines. This article provides a comprehensive review on formulation influences on the preclinical/clinical pharmacokinetics of selected hepatoprotectants such as silymarin, curcumin, glycyrrhizin, andrographolide, phyllanthin, hypophyllanthin, and picroside I and II. Both the formulation and pharmacokinetic factors could affect the target-site concentrations of the active herbal components and, thus, the therapeutic responses. This review contributes to the establishment of a comprehensive understanding of the influence of formulation/dosage form on the pharmacokinetic profile of the hepatoprotective compounds.

Formulation and optimization of doxorubicin loaded polymeric nanoparticles using Box-Behnken design: ex-vivo stability and in-vitro activity.

Biodegradable nanoparticles (NPs) have gained tremendous interest for targeting chemotherapeutic drugs to the tumor environment. Inspite of several advances sufficient encapsulation along with the controlled release and desired size range have remained as considerable challenges. Hence, the present study examines the formulation optimization of doxorubicin loaded PLGA NPs (DOX-PLGA-NPs), prepared by single emulsion method for cancer targeting. Critical process parameters (CPP) were selected by initial screening. Later, Box-Behnken design (BBD) was used for analyzing the effect of the selected CPP on critical quality attributes (CQA) and to generate a design space. The optimized formulation was stabilized by lyophilization and was used for in-vitro drug release and in-vitro activity on A549 cell line. Moreover, colloidal stability of the NPs in the biological milieu was assessed. Amount of PLGA and PVA, oil:water ratio and sonication time were the selected independent factors for BBD. The statistical data showed that a quadratic model was fitted to the data obtained. Additionally, the lack of fit values for the models was not significant. The delivery system showed sustained release behavior over a period of 120h and was governed by Fickian diffusion. The multipoint analysis at 24, 48 and 72h showed gradual reduction in IC50 value of DOX-PLGA-NPs (p<0.05, Fig. 9). DOX-PLGA-NPs were found to be stable in the biological fluids indicating their in-vivo applicability. In conclusion, optimization of the DOX-PLGA-NPs by BBD yielded in a promising drug carrier for doxorubicin that could provide a novel treatment modality for cancer.

Development and Optimization of an Ex Vivo Colloidal Stability Model for Nanoformulations.

Nanotechnology is having a significant impact in the drug delivery systems and diagnostic devices. As most of the nanosystems are intended to be administered in vivo, there is a need for stability models, which could simulate the biological environment. Instability issues could lead to particle aggregation and in turn could affect the release of the drug from the nanosystems and even lead to clogging of the systemic blood circulation leading to life-threatening situation. We have developed an ex vivo colloidal stability model for testing the stability of nanosystems over a period of 48 h, which is the typical residence time of the nanoparticles in vivo. Tissue homogenates of rat spleen, brain, kidney, and liver were stabilized and optimized for the study; additionally, plasma and serum were used for the same. Poly (lactide-co-glycolic acid) nanoparticles were used as model nanosystem, and no significant change was found in the size and polydispersity index of the nanoparticles in the biological solutions. Moreover, no change in morphology was observed after 48 h as observed by TEM microscopy. Hence, the developed model could prevent the failure of the developed nanosystem during clinical and preclinical application by serving as an initial checkpoint to study their interaction with the complex milieu.

Development and optimization of psychological stress model in mice using 2 level full factorial design.

INTRODUCTION: Psychological stress has long been a silent killer, impairing normal physiological functions and leading to a variety of diseased conditions. However, the existing animal models for studying psychological stress have been marred by their inherent limitations warranting further research in their development and optimization. METHODS: In this study 25 full factorial design was utilized for the development and optimization of psychological stress model in mice by applying different stressors viz., slanted cage(X1), restraint(X2), no bedding(X3), dirty bedding(X4) and isolation(X5) at two time duration levels of 30 and 60min. The development of behavioral changes like depression, anxiety and anhedonia was taken as criteria for development of stress. These responses were analyzed using Design Expert 7.1.6. (Stat-Ease, Inc., USA). The maximum effective responses obtained were taken as a criterion for optimization. The optimized model was applied to measure the change in serum cortisol level to confirm the stress development. RESULTS: The statistical data showed that a quadratic model was fitted to the data obtained. All the factors were found to have a significant role in the development of stress among which restraint, slanted cage and dirty bedding were found to be more causal (p<0.05). Serum cortisol level was increased significantly in the stressed mice of optimized model (p<0.05). DISCUSSION: Utilizing the magnitude of responses from the quadratic equations, it can be concluded that slanted cage, restraint and dirty bedding stressors should be applied for longer duration than other stressors for psychological stress development in mice. The study could lay a strong platform for the use of quality by design approach in the development of robust, efficient and resourceful animal models.

CD90 a potential cancer stem cell marker and a therapeutic target.

Cancer Stem Cells (CSCs) have been recently identified and their role in carcinogenesis has been ascertained. CSCs have been correlated with high relapse in certain cancers, multiple drug resistance against chemotherapy and metastasis. Several markers such as CD133, CD24, CD44, EpCAM, and CD26 have been identified to isolate and characterize CSCs. None of these markers or their combinations are universal in nature and can be used to isolate CSCs from all types of cancer. CD90 is one such marker whose expression has been extensively studied in recent years. CD90+ cells have been isolated from several types of tumors and shown to exhibit cardinal properties of CSCs such as proliferation, differentiation, spheroid formation, metastasis and ability to form tumor xenograft in immunodeficient mice. It is also found to be co-expressed with several other CSC markers. CD90 is therefore, suggested as a candidate marker as well as a potential therapeutic target for elimination of CSCs.

Role of cortisol and superoxide dismutase in psychological stress induced anovulation.

Stress has been identified as a potential trigger for reproductive dysfunctions, but the psycho-physiological pathway behind the effect of stress on ovulation remains unexplored. The present research work highlights the plausible mechanism of psychological stress on ovulation in mice by targeting superoxide dismutase (SOD), an enzyme involved in ovulation. For this, three consecutive studies were carried out. The first study aimed to determine the effect of psychological stress induced change in cortisol level, behavioral parameters and normal estrous cyclicity. The effect on mRNA expression of SOD subtypes, follicular growth in histological sections of ovaries and the difference in oocyte quality and number, upon superovulation were assessed in the subsequent studies. The results indicate that psychological stress model causes an increase in cortisol level (p⩽0.05) with development of anhedonia, depression and anxiety. An irregular estrous cycle was observed in stressed mice with an upregulation in mRNA expression of SOD subtypes. Histological sections revealed an increase in atretic antral follicle with an impaired follicular development. Moreover, immature oocytes were obtained from superovulated stressed mice. The study concludes that psychological stress results in anovulation which may be due to increase in cortisol level and SOD activity in stressed mice.

Abortifacient potential of methanolic extract of Anthocephalus cadamba stem bark in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Medicinal plants possessing abortifacient activity have been used traditionally for a long time in folk medicine. Anthocephalus cadamba, is one such herb that has been known to possess abortifacient potential in ethnobotanical literature, but has not been validated scientifically. MATERIALS AND METHODS: The methanolic extract of Anthocephalus cadamba stem bark (MEAC) was prepared and tested for abortifacient, estrogenic and uterotrophic activity. Pregnant Swiss albino mice were randomized into 5 groups (1-5). Group 1 (negative control) received 0.2% w/v agar, group 2-4 (received extract at the dose of 500, 1000 and 1500mg/kg b.w.) and group 5 received mifepristone at a dose of 5.86mg/kg b.w. respectively, by oral route from 10(th) to 18(th) day post-coitum daily, and various parameters recorded. The uterotrophic bioassay was performed in bilaterally ovariectomized mice dosed from 9(th) to 15(th) day of ovariectomy and change in uterotrophic parameters was observed. RESULTS: Preliminary phytochemical screening revealed presence of glycosides, alkaloids, steroids, saponins, triterpenoids, flavonoids and tannins. No signs of clinical toxicity were observed at any time during the period of treatment. The extract significantly reduced (P<0.05) the number of live fetus, weight and survival ratio of the fetus, number of corpora lutea, progesterone, estradiol and luteinizing hormone whereas the number of dead fetus, number of mice that aborted, percentage vaginal opening and post-implantation loss increased significantly (P<0.05). The estrogenicity experiments showed increase in uterine weight (P<0.05), ballooning of uterus, uterine glucose (P<0.05) and ALP (P<0.001) in extract treated group dose dependently. In addition, the extract also induced vaginal bleeding preceding parturition. CONCLUSION: This study has substantiated the abortifacient potential of the methanolic extract of Anthocephalus cadamba stem bark. The activity was more marked in 1000 and 1500mg/kg b.w. of the extract and was comparable to that of mifepristone. The mechanism of abortion could possibly be through changes in the uterine mileu, altered hormone levels, luteolysis and partly, estrogenicity. This study thus justifies the ethnobotanical claim of MEAC as an abortifacient.