Changes in major catechins,caffeine, and antioxidant activity during CTC processing of black tea from North East India

Tea (Camellia sinensis L.) leaves undergo complex chemical transformations during black tea processing. However, the dynamic chemical changes during tea processing have not been explored in popular cultivars of North East India. In this study, changes in catechins, caffeine, total polyphenol (TP) and formation of theaflavins were examined throughout the different stages of CTC (curl, tear and crush) black tea processing based on UPLC metabolomic analysis along with antioxidant activity for eight cultivars viz. S.3A/3, TV1, TV7, TV9, TV17, TV22, TV23 and TV25. The results demonstrated that the most prolific changes were observed after complete maceration of tea leaves. The total catechin, (−)-epigallocatechin gallate and (−)-epicatechin gallate levels decreased by 96, 97 and 89%, respectively as the processing progressed from fresh leaves to black tea. The TP level decreased by 26 to 37% throughout the processing path. The caffeine content increased by 18% during processing. The total theaflavin reached the highest level at 20 min of fermentation and then decreased by 13 to 36% at 40 min. Cultivar TV23 and S.3A/3 had a high content of total theaflavin with 17.9 and 16.9 mg g⁻¹, respectively. The antioxidant activity was observed to be decreased by 31% for the black tea as compared to fresh leaves. It is also observed that the total phenolic content exerted a greater effect on antioxidant activity rather than catechins and theaflavins. This study provides an insightful observation of black tea processing which will immensely help in improving the quality of processed tea.

Changes in catechins, caffeine, total polyphenol, theaflavins, and antioxidant activity during CTC processing of black tea from North East India cultivar were studied. Total polyphenol decreased up to 37% with the formation of theaflavins up to 1.8%.     

Initial non-opioid based anesthesia in a parturient having severe aortic stenosis undergoing cesarean section with aortic valve replacement

Pregnancy in presence of severe aortic stenosis (AS) causes worsening of symptoms needing further intervention. In the advanced stages of pregnancy, some patients may even require aortic valve replacement (AVR) and cesarean delivery in the same sitting. Opioid based general anesthesia for combined lower segment cesarean section (LSCS) with AVR has been described. However, the use of opioid may lead to fetal morbidity and need of respiratory support for the baby. We describe successful anesthetic management for LSCS with AVR in a >33 week gravida with severe AS and congestive heart failure. We avoided opioids till delivery of the baby AVR; the delivered neonate showed a normal APGAR score.     

Haemangioma of Cheek Different Presentation and Management

Though haemangioma of cheek is not a very uncommon entity, here we are presenting a case series of four such cases of haemangioma cheek of completely different presentation. One of which is classical maxillary haemangioma and the rest of the others have different and unusual presentations. They all have different radiological features and were managed successfully by different surgical approaches without any recurrence.     

A high methionine,low folate and vitamin B_6/B_(12) containing diet can be associated with memory loss by epigenetic silencing of netrin-1

Memory-epigenetics which is the loss of memory due to epigenetic modifications can be due to the silencing of genes involved in cognitive functions and this is the basis of the current study.We hypothesize that a diet containing high methionine and low vitamins can lead to memory impairment by increasing global DNA methylation and therefore,silencing the netrin-1 gene,which encodes the glycoprotein involved in neurogenesis,axonal guidance and maintenance of the synaptic plasticity.Wild type(C57 BL/6 J) mice were fed with a diet containing excess methionine(1.2%),low-folate(0.08 mg/kg),vitamin B_6(0.01 mg/kg),and B_(12)(10.4 mg/kg) for 6 weeks.Mice were examined weekly for the long-term memory function,using a passive avoidance test,which determined loss of fear-motivated long-term memory starting from the fourth week of diet.Similarly,an increase in brain %5-methyl cytosine was observed starting from the 4 th week of diet in mice.Mice fed with a high methionine,low folate and vitamins containing diet showed a decrease in netrin-1 protein expression and an increase in netrin-1 gene promotor methylation,as determined by methylation-sensitive restriction enzyme-polymerase chain reaction analysis.The increase in methylation of netrin-1 gene was validated by high-resolution melting and sequencing analysis.Furthermore,the association of netrin-1 with memory was established by administering netrin that considerably restored long-term fear motivated memory.Taken together,these results suggest that a diet rich in methionine and lacking in folate and vitamin B_6/B_(12) can induce defects in learning and memory.Furthermore,the data indicates that decrease in netrin-1 expression due to hyper-methylation of its gene can be associated with memory loss.The animal procedures were approved by the Institutional Animal Care and Use Committee,University of Louisville,USA(No.A3586-01) on February 2,2018.     

CDKN2A-p53 mediated antitumor effect of Lupeol in head and neck cancer

Purpose

The tumor suppressor protein p53 is known to control cell cycle arrest and apoptosis. Lupeol is a phytochemical that has been found to induce apoptosis in different cancer types through the extrinsic pathway. As yet, however, its role in the induction of cell cycle arrest and apoptosis through the intrinsic pathway in head and neck cancer has not been investigated. Here, we aimed at understanding the mechanism underlying the antitumor effect of Lupeol in head and neck cancer.

Methods

The antitumor effect of Lupeol on oral and laryngeal carcinomas was assessed using two in vitro 2D cell line models (HEp-2, UPCI:SCC-131) and, subsequently, an ex vivo 3D tumor explant culture platform that maintains key features of the native tumor microenvironment. The mechanism underlying Lupeol-mediated antitumor responses was delineated using MTT, colony formation, flow cytometry, immunofluorescence, Western blotting and immunohistochemistry assays.

Results

We found that Lupeol induced an enhanced expression of p53 in both cell line models tested and, subsequently, cell cycle arrest at the G1 phase. In addition we found that, following Lupeol treatment, p53 induced Bax expression and activated the intrinsic apoptotic pathway (as measured by Caspase-3 cleavage). Interestingly, Lupeol was also found to trigger G1 cell cycle arrest through up-regulation of the expression of CDKN2A, but not p21, resulting in inhibition of CyclinD1. In an ex vivo platform Lupeol was found to impart a potent antitumor response as defined by inhibition of Ki67 expression, decreased cell viability and concomitant activation (cleavage) of Caspase-3. Finally, we found that Lupeol can re-sensitize primary head and neck squamous cell carcinoma (HNSCC) tumor samples that had clinically progressed under a Cisplatin treatment regimen.

Conclusion

Together, our data indicate that Lupeol may orchestrate a bifurcated regulation of neoplastic growth and apoptosis in head and neck cancers and may serve as a promising agent for the management of tumors that have progressed on a platinum-based treatment regimen.

     

Hydrophilic prodrug approach for reduced pigment binding and enhanced transscleral retinal delivery of celecoxib

Transscleral retinal delivery of celecoxib, an anti-inflammatory and anti-VEGF agent, is restricted by its poor solubility and binding to the melanin pigment in choroid-RPE. The purpose of this study was to develop soluble prodrugs of celecoxib with reduced pigment binding and enhanced retinal delivery. Three hydrophilic amide prodrugs of celecoxib, celecoxib succinamidic acid (CSA), celecoxib maleamidic acid (CMA), and celecoxib acetamide (CAA) were synthesized and characterized for solubility and lipophilicity. In vitro melanin binding to natural melanin (Sepia officinalis) was estimated for all three prodrugs. In vitro transport studies across isolated bovine sclera and sclera-choroid-RPE (SCRPE) were performed. Prodrug with the highest permeability across SCRPE was characterized for metabolism and cytotoxicity and its in vivo transscleral delivery in pigmented rats. Aqueous solubilities of CSA, CMA, and CAA were 300-, 182-, and 76-fold higher, respectively, than celecoxib. Melanin binding affinity and capacity were significantly lower than for celecoxib for all three prodrugs. Rank order for the % in vitro transport across bovine sclera and SCRPE was CSA > CMA ~ CAA ~ celecoxib, with the transport being 8-fold higher for CSA than celecoxib. CSA was further assessed for its metabolic stability and in vivo delivery. CSA showed optimum metabolic stability in all eye tissues with only 10-20% conversion to parent celecoxib in 30 min. Metabolic enzymes responsible for bioconversion included amidases, esterase, and cytochrome P-450. In vivo delivery in pigmented BN rats showed that CSA had 4.7-, 1.4-, 3.3-, 6.0-, and 4.5-fold higher delivery to sclera, choroid-RPE, retina, vitreous, and lens than celecoxib. CSA has no cytotoxicity in ARPE-19 cells in the concentration range of 0.1 to 1000 μM. Celecoxib succinamidic acid, a soluble prodrug of celecoxib with reduced melanin binding, enhances transscleral retinal delivery of celecoxib.