Year-round sustainable biomass production potential of Nannochloris sp. in outdoor raceway pond enabled through strategic photobiological screening.

Microalgae cultivation utilizes the energy of sunlight to reduce carbon dioxide (CO2) for producing renewable energy feedstock. The commercial success of the biological fixation of carbon in a consistent manner depends upon the availability of a robust microalgae strain. In the present work, we report the identification of a novel marine Nannochloris sp. through multiparametric photosynthetic evaluation. Detailed photobiological analysis of this strain has revealed a smaller functional antenna, faster relaxation kinetics of non-photochemical quenching, and a high photosynthetic rate with increasing light and temperatures. Furthermore, laboratory scale growth assessment demonstrated a broad range halotolerance of 10-70 parts per thousand (PPT) and high-temperature tolerance up to 45 °C. Such traits led to the translation of biomass productivity potential from the laboratory scale (0.2-3.0 L) to the outdoor 50,000 L raceway pond scale (500-m2) without any pond crashes. The current investigation revealed outdoor single-day peak areal biomass productivity of 43 g m-2 d-1 in summer with an annual (March 2019-February 2020) average productivity of 20 g m-2 d-1 in seawater. From a sustainability perspective, this is the first report of successful round-the-year (> 347 days) multi-season (summer, monsoon, and winter) outdoor cultivation of Nannochloris sp. in broad seawater salinity (1-57 PPT), wide temperature ranges (15-40 °C), and in fluctuating light conditions. Concurrently, outdoor cultivation of this strain demonstrated conducive fatty acid distribution, including increased unsaturated fatty acids in winter. This inherent characteristic might play a role in protecting photosynthesis machinery at low temperatures and in high light stress. Altogether, our marine Nannochloris sp. showed tremendous potential for commercial scale cultivation to produce biofuels, food ingredients, and a sustainable source for vegetarian protein.

Entropy-Based Variational Scheme with Component Splitting for the Efficient Learning of Gamma Mixtures.

Finite Gamma mixture models have proved to be flexible and can take prior information into account to improve generalization capability, which make them interesting for several machine learning and data mining applications. In this study, an efficient Gamma mixture model-based approach for proportional vector clustering is proposed. In particular, a sophisticated entropy-based variational algorithm is developed to learn the model and optimize its complexity simultaneously. Moreover, a component-splitting principle is investigated, here, to handle the problem of model selection and to prevent over-fitting, which is an added advantage, as it is done within the variational framework. The performance and merits of the proposed framework are evaluated on multiple, real-challenging applications including dynamic textures clustering, objects categorization and human gesture recognition.

Discovery of isoquinolinone and naphthyridinone-based inhibitors of poly(ADP-ribose) polymerase-1 (PARP1) as anticancer agents: Structure activity relationship and preclinical characterization.

The exploitation of GLU988 and LYS903 residues in PARP1 as targets to design isoquinolinone (I & II) and naphthyridinone (III) analogues is described. Compounds of structure I have good biochemical and cellular potency but suffered from inferior PK. Constraining the linear propylene linker of structure I into a cyclopentene ring (II) offered improved PK parameters, while maintaining potency for PARP1. Finally, to avoid potential issues that may arise from the presence of an anilinic moiety, the nitrogen substituent on the isoquinolinone ring was incorporated as part of the bicyclic ring. This afforded a naphthyridinone scaffold, as shown in structure III. Further optimization of naphthyridinone series led to identification of a novel and highly potent PARP1 inhibitor 34, which was further characterized as preclinical candidate molecule. Compound 34 is orally bioavailable and displayed favorable pharmacokinetic (PK) properties. Compound 34 demonstrated remarkable antitumor efficacy both as a single-agent as well as in combination with chemotherapeutic agents in the BRCA1 mutant MDA-MB-436 breast cancer xenograft model. Additionally, compound 34 also potentiated the effect of agents such as temozolomide in breast cancer, pancreatic cancer and Ewing's sarcoma models.

Oral bioavailability and pharmacodynamic activity of hesperetin nanocrystals generated using a novel bottom-up technology.

In the present study, nanocrystalline solid dispersion (NSD) was developed to enhance the release rate and oral bioavailability of hesperetin (HRN). NSD of HRN was prepared using a novel bottom-up technology platform. It is a spray drying based technology to generate solid particles, containing drug nanocrystals dispersed in small molecule excipients. HRN and mannitol were used in a 5:5 ratio, and an average crystallite size of HRN in NSD with mannitol was found to be 137.3 ± 90.0 nm. An in vitro release study revealed a statistically significant release rate enhancement for HRN nanocrystals (46.3 µg/mL/min) as compared to that of the control (29.5 µg/mL/min). Further, a comparative oral bioavailability study of NSD and control in Sprague-Dawley rats established significant improvement in Cmax and oral bioavailability (AUC0-∞) by 1.79- and 2.25-fold, respectively, for HRN nanocrystals. The findings of oral bioavailability were corroborated by intestinal uptake and Caco-2 cell uptake studies, wherein HRN, when administered in nanocrystalline form, showed higher penetration in intestinal mucosa and higher uptake in Caco-2 cells. Finally, the therapeutic efficacy of HRN nanocrystals was tested by a reactive oxygen species (ROS) generation assay and carrageenan induced anti-inflammatory model. HRN nanocrystals markedly inhibited ROS generation in MCF-7 cells, and carrageenan induced inflammation in rats. The process of NSD formation was found to be based on classical nucleation theory wherein mannitol contributed to NSD formation by acting as a plasticizer and crystallization inducer, and by providing sites for heterogeneous nucleation/crystallization.

SNEDDS curcumin formulation leads to enhanced protection from pain and functional deficits associated with diabetic neuropathy: an insight into its mechanism for neuroprotection.

Curcumin has shown to be effective against various diabetes related complications. However major limitation with curcumin is its low bioavailability. In this study we formulated and characterized self nano emulsifying drug delivery system (SNEDDS) curcumin formulation to enhance its bioavailability and then evaluated its efficacy in experimental diabetic neuropathy. Bioavailability studies were performed in male Sprague Dawley rats. Further to evaluate the efficacy of formulation in diabetic neuropathy various parameters like nerve function and sensorimotor perception were assessed along with study of inflammatory proteins (NF-κB, IKK-ß, COX-2, iNOS, TNF-α and IL-6). Nanotechnology based formulation resulted in prolonged plasma exposure and bioavailability. SNEDDS curcumin provided better results against functional, behavioural and biochemical deficits in experimental diabetic neuropathy, when compared with naive curcumin. Further western blot analysis confirmed the greater neuroprotective action of SNEDDS curcumin. SNEDDS curcumin formulation due to higher bioavailability was found to afford enhanced protection in diabetic neuropathy. FROM THE CLINICAL EDITOR: In this study the authors formulated and characterized a self-emulsifying drug delivery system for formulation to enhance curcumin bioavailability in experimental diabetic neuropathy. Enhanced efficacy was demonstrated in a rat model.

Effect of counterions on physicochemical properties of prazosin salts.

This study evaluated the effect of counterions on the physicochemical properties of prazosin salts. Salt forms of prazosin, namely, mesylate, besylate, tosylate, camsylate, oxalate, and maleate, were prepared and compared with the marketed anhydrous and polyhydrate forms of prazosin hydrochloride. Physicochemical characterization was performed in the order of crystallinity, hygroscopicity, solubility, and stability to select the optimal salt(s). Permeability study in Caco-2 cell lines and in vivo bioavailability study in rat model were investigated to ascertain their biopharmaceutical advantage. All salt forms were crystalline, nonhygroscopic (except the anhydrous hydrochloride salt), and had solubility in the range of 0.2 to 1.6 mg/ml. All salts were physically and chemically stable at 40°C/75% relative humidity, but degraded in UV-visible light, except the anhydrous hydrochloride salt. Prazosin mesylate was selected as the optimal salt, as it possessed higher solubility, permeability, and bioavailability, compared to the commercial hydrochloride salts. Hydrochloride salt is reported to have poor bioavailability that is partially attributed to its low solubility and extensive common-ion effect in the gastric region. Factors like hydrophilicity of the counterion, hydration state of the salt, and melting point of the salt contribute to the physicochemical properties of the salts. This study has implications in the selection of an optimal salt form for prazosin, which is suitable for further development.

Impact of Hemodialysis on Sleep Disorders in Patients With End-Stage Renal Disease in a Tertiary Care Academic Hospital.

INTRODUCTION: Although hemodialysis (HD) has prolonged the survival of patients with end-stage renal disease (ESRD), it has also adversely affected the sleep and emotional state of these patients. We evaluated the impact of HD on sleep duration, quality, and other sleep-related disorders. METHODS: We recruited consecutive adult patients visiting our tertiary care dialysis unit. We included only ESRD patients who had an estimated glomerular filtration rate (eGFR) of <15 mL/min/1.73m2. We excluded patients with unrelated comorbidities or on medications that could affect sleep. Basic demographic information, anthropometric data, and appropriate lab investigations were obtained. Objective information related to their sleep duration and quality was asked using a predefined proforma. Subjective sleep scores were obtained by using the Pittsburgh sleep quality index (PSQI), Epworth sleepiness scale (ESS), and insomnia severity index (ISI). For comparison, the patients were divided into HD and conservative treatment (CT) groups based on their treatment modality. The baseline characteristics of the patients were noted. The Shapiro-Wilk test was used to test normality. Correlations were obtained by using Student's t-test for parameters that were normally distributed and the Mann-Whitney-Wilcoxon test for those that were not. RESULTS: Of the 56 patients we studied, 59% were males. The average age and body mass index (BMI) were 45.7 years and 20.98 kg/m2, respectively. Overall, 41% of patients were assigned to the HD group, and the remaining to the CT group. The CT group had fewer comorbidities compared to the HD group. The average sleep duration was similar in both groups (HD: 6.64 hours, CT: 6.49 hours). There was a weak-to-moderate positive correlation between the sleep scores. Overall, one-half of the patients had excessive daytime sleepiness (EDS) (46.43%) and insomnia (48.21%), and two-thirds of them were poor sleepers (66.07%). Symptoms suggestive of sleep-disordered breathing (SDB) were seen in 25% of patients, restless legs syndrome (RLS) in 19.64% of patients, and periodic limb movement disorder (PLMD) in 44.64% of patients. Patients undergoing HD had poorer sleep quality compared to the CT group (p=0.038). The odds of developing poor sleep were 3.6 times higher in the HD group. CONCLUSION: This cross-sectional study focuses on the quantification of objective and subjective deterioration of sleep quality in ESRD patients on HD. The prevalence of EDS (63.64%), insomnia (51.52%), and poor sleep quality (84.84%) in the HD group was more than the previously reported values. The PSQI, ESS, and ISI scores were higher in HD patients, indicating poorer sleep quality. Our study highlights the underestimation of sleep disorders in HD patients in underserved areas. The results warrant a meticulous evaluation of the same by a keen nephrologist, followed by referral to sleep providers where necessary.

Exploring the Aggressiveness of Sarcomatoid Carcinoma of the Oral Cavity - an Institutional Experience.

Background: Sarcomatoid variant of squamous cell carcinoma in the oral cavity is a rare biphasic variant of squamous cell carcinoma. This aggressive variant of squamous cell carcinoma is characterized by invasive growth with marked local recurrence and distant metastasis resulting in poor prognosis. Sarcomatoid carcinoma can occur over a wide age range, incidence increases with older age and is a male-predominant disease. Methods: 23 patients with histologically proven Sarcomatoid SCC or with a sarcomatoid component (Group A) were compared with 23 randomly chosen patients with clinical stage IV (Group B) disease at the time of diagnosis, within the same time period and comparison was made between disease free survival and overall survival. Results: In group A, the mean DFS was found to be 12.4 months raging from 1 month to 36 months. 6 patients were therafter lost to follow follow up, in 11 patients the mean overall survival was found to be 8.72 months (ranging from 2 to 18 months) whereas 6 patients are alive till date. In group B, the mean DFS was found to be 19.56 months ranging from 6 months to 33 months. 4 patients succumbed to the disease with a mean overall survival of 24.25 years (ranging from 18 to 33 months), 4 patients were lost to follow up and the rest are alive till date. Conclusion: Sarcomatoid carcinoma of the oral cavity is an extremely rare but aggressive variant of conventional squamous cell carcinoma. We have to systematically understand their clinical, morphological and immunohistochemical features which is critical for their accurate diagnosis which aids in correct patient management. After radical surgery and adjuvant radiation therapy, strict follow up for development of recurrence and distant metastasis should be done.

Mechanistic insights into PEPT1-mediated transport of a novel antiepileptic, NP-647.

The present study, in general, is aimed to uncover the properties of the transport mechanism or mechanisms responsible for the uptake of NP-647 into Caco-2 cells and, in particular, to understand whether it is a substrate for the intestinal oligopeptide transporter, PEPT1 (SLC15A1). NP-647 showed a carrier-mediated, saturable transport with Michaelis-Menten parameters K(m) = 1.2 mM and V(max) = 2.2 µM/min. The effect of pH, sodium ion (Na(+)), glycylsarcosine and amoxicillin (substrates of PEPT1), and sodium azide (Na(+)/K(+)-ATPase inhibitor) on the flux rate of NP-647 was determined. Molecular docking and molecular dynamics simulation studies were carried out to investigate molecular interactions of NP-647 with transporter using homology model of human PEPT1. The permeability coefficient (P(appCaco-2)) of NP-647 (32.5 × 10(-6) cm/s) was found to be four times higher than that of TRH. Results indicate that NP-647 is transported into Caco-2 cells by means of a carrier-mediated, proton-dependent mechanism that is inhibited by Gly-Sar and amoxicillin. In turn, NP-647 also inhibits the uptake of Gly-Sar into Caco-2 cells and, together, this evidence suggests that PEPT1 is involved in the process. Docking and molecular dynamics simulation studies indicate high affinity of NP-647 toward PEPT1 binding site as compared to TRH. High permeability of NP-647 over TRH is attributed to its increased hydrophobicity which increases its affinity toward PEPT1 by interacting with the hydrophobic pocket of the transporter through hydrophobic forces.

Discovery of Novel and Orally Bioavailable Inhibitors of PI3 Kinase Based on Indazole Substituted Morpholino-Triazines.

A new class of potent PI3Kα inhibitors is identified based on aryl substituted morpholino-triazine scaffold. The identified compounds showed not only a high level of enzymatic and cellular potency in nanomolar range but also high oral bioavailability. The three lead molecules (based on their in vitro potency) when evaluated further for in vitro metabolic stability as well as pharmacokinetic profile led to the identification of 26, as a candidate for further development. The IC50 and EC50 value of 26 is 60 and 500 nM, respectively, for PI3Kα enzyme inhibitory activity and ovarian cancer (A2780) cell line. The identified lead also showed a high level of microsomal stability and minimal inhibition activity for CYP3A4, CYP2C19, and CYP2D6 at 10 µM concentrations. The lead compound 26, demonstrated excellent oral bioavailability with an AUC of 5.2 µM at a dose of 3 mpk in mice and found to be well tolerated in mice when dosed at 30 mpk BID for 5 days.

A case of Hallervorden-Spatz disease presenting as catatonic schizophrenia.

Hallervorden-Spatz disease belongs to a group of disorders characterized by predominant involvement of basal ganglia. These cases may present to the psychiatrist with symptoms of depression, nervousness and rarely other psychotic symptoms. Very few cases of this disease have been reported from India. We report a case of Hallervorden-Spatz disease that presented to the psychiatry outpatient department with catatonia. This case highlights how presentation of Hallervorden-Spatz disease may overlap with catatonic symptoms and hence a high index of suspicion is required to make an accurate diagnosis.

Phase behavior and oral bioavailability of amorphous Curcumin.

Amorphous form has been used as a means to improve aqueous solubility and oral bioavailability of poorly water soluble drugs. The objective of present study was to characterize thermodynamic and kinetic parameters of amorphous form of Curcumin (CRM-A). CRM-A was found to be a good glass former with glass transition temperature (T(g)) of 342.64K and critical cooling rate below 1K/min. CRM-A had a moderate tendency of crystallization and exhibited Kauzmann temperature (T(KS)) of 294.23 K. CRM-A was found to be fragile in nature as determined by T(m)/T(g) (1.32), C(p)(1 iq):C(p)(glass) (1.22), strength parameter (D<10), fragility index (m>75), T(K)/T(g) (0.85), and T(g)-T(K) (48.41). Theoretically predicted aqueous solubility advantage of 43.15-folds, was reduced to 17-folds under practical conditions. This reduction in solubility was attributed to water induced devitrification, as evident through PXRD and SEM analysis. Further, oral bioavailability study of CRM-A was undertaken to investigate bioavailability benefits, if any. C(max) was improved by 1.97-folds (statistically significant difference over control). However, oral bioavailability (AUC(0-)(∞)) was improved by 1.45-folds (statistically non significant difference over control). These observations pointed towards role of rapid devitrification of CRM-A in GIT milieu, thus limiting its oral bioavailability advantage.

Bioavailability of a lipidic formulation of curcumin in healthy human volunteers.

Numerous publications have reported the significant pharmacodynamic activity of Curcumin (CRM) despite low or undetectable levels in plasma. The objective of the present study was to perform a detailed pharmacokinetic evaluation of CRM after the oral administration of a highly bioavailable lipidic formulation of CRM (CRM-LF) in human subjects. Cmax, Tmax and AUC0-¥ were found to be 183.35 ± 37.54 ng/mL, 0.60 ± 0.05 h and 321.12 ± 25.55 ng/mL respectively, at a dose of 750 mg. The plasma profile clearly showed three distinct phases, viz., absorption, distribution and elimination. A close evaluation of the primary pharmacokinetic parameters provided valuable insight into the behavior of the CRM after absorption by CRM-LF. CRM-LF showed a lag time (Tlag) of 0.18 h (around 12 min). Pharmacokinetic modeling revealed that CRM-LF followed a two-compartment model with first order absorption, lag time and first order elimination. A high absorption rate constant (K01, 4.51/h) signifies that CRM-LF ensured rapid absorption of the CRM into the central compartment. This was followed by the distribution of CRM from the central to peripheral compartment (K12, 2.69/h). The rate of CRM transfer from the peripheral to central compartment (K21, 0.15/h) was slow. This encourages higher tissue levels of CRM as compared with plasma levels. The study provides an explanation of the therapeutic efficacy of CRM, despite very low/undetectable levels in the plasma.

Novel lipid based oral formulation of curcumin: development and optimization by design of experiments approach.

The clinical utility of curcumin (CRM) is limited due to its poor oral bioavailability. Lipid based oral formulations (LBOFs) are emerging as useful oral drug delivery systems for 'difficult to deliver' molecules like CRM. In present study, we report novel Type IV LBOF for CRM using Gelucire 44/14, Labrasol, Vit. E TPGS and PEG 400 with superior CRM loading and enhanced oral bioavailability. The optimization of LBOF for CRM loading and post dilution droplet size was carried out by design of experiments (DoE) approach with Box-Behnken design. Oral bioavailability of optimized LBOF (O-LBOF) was evaluated in male Sprague-Dawley (SD) rats at a dose of 250 mg/kg. Raw CRM (control) showed C(max) and AUC(0-∞) of 32.29 ng/ml and 38.07 ng h/ml, respectively. O-LBOF improved C(max) and AUC(0-∞) by 11.6 and 35.8 folds respectively over control.

Identification of permeability-related hurdles in oral delivery of curcumin using the Caco-2 cell model.

Curcumin a poly-phenolic compound possesses diverse pharmacologic activities; however, its development as a drug has been severely impeded by extremely poor oral bioavailability. Poor aqueous solubility and extensive metabolism have been implicated for this but the role of membrane permeability has not been investigated. In the present study, permeability of curcumin was assessed using the Caco-2 cell line. Curcumin was poorly permeable with a P(app) (A → B) value of 2.93 ± 0.94 × 10(-6)cm/s. P(app) value in (B → A) study was found out to be 2.55 ± 0.02 × 10(-6)cm/s, thus ruling out the role of efflux pathways in poor oral bioavailability of curcumin. Studies using verapamil, a P-gp inhibitor, further confirmed this finding. Detailed mass balance studies showed loss of curcumin during transport. Further experiments using lysed cells revealed that 11.78% of curcumin was metabolized during transport. Studies using itraconazole, a CYP3A4 inhibitor, established its role in curcumin metabolism. Curcumin was also found to accumulate in cells as revealed by CLSM studies. Sorption and desorption kinetic studies further confirmed accumulation of curcumin inside the cells. Amount accumulated was quantitated by HPLC and found to be >20%. Thus, intestinal first-pass metabolism and intracellular accumulation played a role in poor permeability of curcumin. Based on its poor aqueous solubility and intestinal permeability, curcumin can be classified as a BCS Class IV molecule. This information can facilitate designing of drug delivery systems for enhancement of oral bioavailability of curcumin.

Comparative oral bioavailability advantage from curcumin formulations.

The aim of the present study was to study the oral bioavailability of seven different formulations of curcumin (CRM). CRM formulations viz. aqueous suspension, micronized suspension, nanosuspension, amorphous solid dispersion, hydroxypropyl-ß-cyclodextrin (HP-ß-CD) inclusion complex, combination with piperine, and spray-dried CRM-milk composite were compared for oral bioavailability in male Sprague-Dawley rats at a CRM dose of 250 mg/kg body weight using a validated high-performance liquid chromatography method. Aqueous suspension provided a C max and AUC(0 - t) of 28.9 ng/ml and 26.9 ng h/ml, respectively. In comparison, statistically significant increase in the oral bioavailability was obtained with the nanosuspension, HP-ß-CD inclusion complex, and amorphous solid dispersion with 251%, 567%, and 446% increase in terms of AUC(0 - t) and 405%, 415%, and 270% in terms of C max. However, no significant increase in AUC(0 - t) and C max was observed with piperine and micronized suspension. The milk composite reduced the oral bioavailability of CRM (10% and 37% in terms of AUC(0 - t) and C max). A statistically significant increase in the T max was observed with piperine and in HP-ß-CD complex, while the T max was reduced for nanosuspension. The results provide interesting insights into the role of solubility enhancement and metabolism inhibition, for improving the oral bioavailability of CRM.