Design,synthesis, and biological evaluation of selective and potent Carbazole-based butyrylcholinesterase inhibitors

Alzheimer’s disease (AD) is the most common form of dementia. Inhibition of BChE might be a useful therapeutic target for AD. A new series of Carbazole-Benzyl Pyridine derivatives were designed synthesized and evaluated as butyrylcholinesterase (BChE) inhibitors. In vitro assay revealed that all of the derivatives had selective and potent anti- BChE activities. 3-((9H-Carbazol-9-yl)methyl)-1-(4-chlorobenzyl)pyridin-1-ium chloride (compound 8f) had the most potent anti-BChE activity (IC₅₀ value?=?0.073?μM), the highest BChE selectivity and mixed-type inhibition. Docking study revealed that 8f interacted with the peripheral site, the choline binding site, catalytic site and the acyl pocket of BChE. Physicochemical properties were accurate to Lipinski's rule. In addition, compound 8f demonstrated neuroprotective activity at 10?µM. This compound could also inhibit AChE-induced and self-induced Aβ peptide aggregation at concentration of 100?µM and 10?µM respectively. The in-vivo study showed that compound 8f in 10?mg/kg increased the time spent in target quadrant in the probe day and decreased mean training period scape latency in rats. All results suggest that new sets of potent selective inhibitors of BChE have a therapeutic potential for the treatment of AD.     

Design,synthesis and molecular modeling of new 4-phenylcoumarin derivatives as tubulin polymerization inhibitors targeting MCF-7 breast cancer cells

A new set of 4-phenylcoumarin derivatives was designed and synthesized aiming to introduce new tubulin polymerization inhibitors as anti-breast cancer candidates. All the target compounds were evaluated for their cytotoxic effects against MCF-7 cell line, where compounds 2f, 3a, 3b, 3f, 7a and 7b, showed higher cytotoxic effect (IC₅₀?=?4.3–21.2?μg/mL) than the reference drug doxorubicin (IC₅₀?=?26.1?μg/mL), additionally, compounds 1 and 6b exhibited the same potency as doxorubicin (IC₅₀?=?25.2 and 28.0?μg/mL, respectively). The thiazolidinone derivatives 3a, 3b and 3f with potent and selective anticancer effects towards MCF-7 cells (IC₅₀?=?11.1, 16.7 and 21.2?μg/mL) were further assessed for tubulin polymerization inhibition effects which showed that the three compounds were potent tubulin polymerization suppressors with IC₅₀ values of 9.37, 2.89 and 6.13?μM, respectively, compared to the reference drug colchicine (IC₅₀?=?6.93?μM). The mechanistic effects on cell cycle progression and induction of apoptosis in MCF-7 cells were determined for compound 3a due to its potent and selective cytotoxic effects in addition to its promising tubulin polymerization inhibition potency. The results revealed that compound 3a induced cell cycle cessation at G2/M phase and accumulation of cells in pre-G1 phase and prevented its mitotic cycle, in addition to its activation of caspase-7 mediating apoptosis of MCF-7 cells. Molecular modeling studies for compounds 3a, 3b and 3f were carried out on tubulin crystallography, the results indicated that the compounds showed binding mode similar to the co-crystalized ligand; colchicine. Moreover, pharmacophore constructed models and docking studies revealed that thiazolidinone, acetamide and coumarin moieties are crucial for the activity. Molecular dynamics (MD) studies were carried out for the three compounds over 100?ps. MD results of compound 3a showed that it reached the stable state after 30?ps which was in agreement with the calculated potential and kinetic energy of compound 3a.     

Ameliorating Effect of Osteopontin on H<Subscript>2</Subscript>O<Subscript>2</Subscript>-Induced Apoptosis of Human Oligodendrocyte Progenitor Cells

Recently our group used oligodendrocyte progenitor cells (OPCs) as appropriate model cells to pinpoint the mechanism of the progress of neurodegenerative disorders. In the present study, we focused on the therapeutic role of osteopontin (OPN), a secreted glycosylated phosphoprotein, involved in a number of physiological events including bone formation and remodeling, immune responses, and tumor progression. Protective role of OPN, as a negative regulator of tumorigenesis, has already been clarified. Human embryonic stem cell-derived OPCs were pretreated with OPN before induction of apoptosis by H₂O₂. Data indicated that OPN prohibited cell death and enhanced OPC viability. This effect is achieved through reduction of apoptosis and induction of anti-apoptosis markers. In addition OPN induces expression of several integrin subunits, responsible for OPN interaction. Notably, our findings showed that expression of αV β1/β3/β5 and β8 integrins increased in response to OPN, while treatment with H₂O₂ down-regulated αV β1/β5 and β8 integrins expression significantly. In conclusion, OPN may act via αV integrin signaling and trigger suppression of P53-dependent apoptotic cascades. Therefore OPN therapy may be considered as a feasible process to prevent progress of neurodegenerative diseases in human.     

Sensitivity to house dust mite allergens and prevalence of allergy-causing house dust mite species in Pothwar,Pakistan

This study is the first report on the epidemiological status of house dust mite (HDM) allergy in Pothwar, Pakistan. Allergy data of 2087 symptomatic patients were obtained, of whom 1706 (81.7%) patients were skin-prick-test positive for HDM allergens. This percentage was significantly higher than for pollen and food allergens. In the results of this study Dermatophagoides farinae (61%) and D. pteronyssinus (29%) were the predominant species in the study area. Besides these pyroglyphids, predatory Cheyletus sp. (10%) and an oribatid mite sp. (1%) were also observed. Random and patients’ houses showed 87.4 and 87.1% positive mite infestation, respectively. Mean (±?SEM) D. farinae counts per g of dust in random samples was 235.4 ± 7.93 compared to 274.7 ± 10.78 from patients’ homes. Mean D. pteronyssinus counts from random houses compared to patients’ houses were 115.0 ± 4.57 and 124.6 ± 5.76, respectively. Mite counts depicted seasonal variation, with peaks during monsoon season. ELISA results of dust samples demonstrated that of the dust samples with?>?10 µg/g of dust, the threshold value described as a risk factor for developing asthma, 57.6% had Der f1 and 20% Der p1 allergen load. Mean Der f1 burden was significantly higher than Der p1, with maximum levels during monsoon and autumn seasons. This research established a better awareness about the epidemiological status of HDM allergy and prevalence of allergy causing HDM species in Pakistan.     

Comparison of effects of verapamil, low calcium diet and betamethasone on duodenal calcium absorption efficiency in the chick

The results indicate that oral administration of verapamil for 2 weeks to the chick is followed by an increase in the efficiency of the duodenal absorption of calcium. In these chicks both a decrease in serum calcium level and an increase in the activity of renal 1 alpha-hydroxylase were observed. The increased calcium absorption following prolonged treatment with verapamil resembles that induced by a low calcium diet. The mechanism of both responses presumably involves an increased production of 1,25-dihydroxyvitamin D3. Both verapamil- and low calcium diet-induced adaptations are capable of overcoming the inhibitory action of betamethasone on intestinal calcium absorption. No effects on calcium absorption were noted if verapamil was administered intraperitoneally which suggests that verapamil exerts its action directly on the intestinal mucosa.     

The role of antigen-presenting B cells in T cell priming in vivo. Studies of B cell-deficient mice

Mice rendered B cell deficient by treatment with rabbit anti-mouse IgM (anti-mu) antibodies from birth fail to respond when primed with soluble protein antigens in CFA, as measured by T cell proliferation when challenged with antigen in vitro. The role of B cells in T cell priming in vivo was examined by adoptively transferring hapten-specific B cells into anti-mu mice, followed by immunization with haptenated Ag in CFA. The T cell proliferative response to OVA of anti-mu BALB/c mice was partially restored by the administration of TNP or FITC-specific B cells and immunization with TNP-OVA or FITC-OVA, respectively. This reconstitution was Ag-specific, inasmuch as hapten-binding B cells restored the T cell responses to OVA in mice immunized with the same hapten coupled to OVA. The mechanism of B cell reconstitution of T cell priming in anti-mu mice was addressed using parental to F1 B cell transfers. The Ia restriction pattern of the activated T cells from these mice indicated that both direct presentation of Ag by transferred B cells and antibody-mediated enhancement of Ag presentation by non-B, host Ag-presenting cells occurred. Thus, Ag-specific B lymphocytes play a critical role in priming of T cells in vivo.     

Effect of tortilla-preparation process on aflatoxins B1 and B2 in corn

Naturally contaminated corn containing 450 and 54 ppb aflatoxins Bi and B2, respectively was treated with Ca(OH)₂ for making tortillas. The cleaned corn and tortillas were analyzed for aflatoxins B1 and B2 by high performance liquid chromatography (HPLC) and confirmed by thin layer chromatography (TLC). The average concentrations of aflatoxins B1 and B2 in the final products (tortillas) were only 40% and 28% lower than that in starting materials (corn kernels), respectively. Aflatoxins G1 and G2 were not detected in either corn or tortilla samples.     

Population dynamics of the phytophagous lady beetle,Epilachna vigintioctopunctata,in an eggplant field in Sumatra

From December, 1981 to December 1982, the population dynamics of the phytophagous lady beetle Epilachna vigintioctopunctata (Fabricius ) (Evp) was studied by mark-recapture of adults and the construction of a life table in an eggplant field in Padang, Sumatra, Indonesia.

1. After planting of the host plants, adults of Evp soon colonized and oviposited massively, resulting in a rapid population growth for 1–2 months; thereafter, the population increase slowed due to defoliation. Three–four months thereafter the host plants recovered their leaves, but leaf quality was less suitable for Evp and, as a result, the population remained at a low level during the rest of the study period. Adult population size fluctuated 7–8 fold during the study period.
2. Adult Evp showed a 1∶1 sex ratio.
3. The daily rate of residence, ψ_i, derived by theJolly-Seber formula fluctuated from 0.9 to 1.0.
4. The estimated mean length of residence of adults was 16.5 days (male) and 15.2 (female), but this was probably much shorter than the actual longevity, because the adults were so active that they flew away or dropped off the plants when they were approached or were slightly disturbed.
5. Adults showed a rich variation in elytral spot patterns. The average number of non-persistent spots per elytron was 0.52 in males and 1.08 in females; 23.3% of males and 24.6% of females had confluence(s).
6. The life table shows that parasitism by wasps, which killed 9.7% of eggs and 35.0% of pupae, and starvation by overcrowding contributed most to the total mortality from egg to adult emergence (>98%).
7. The high dispersal power of adults, coupled with their prolonged l_x−m_x schedules was advantageous for exploiting food plants which were variable in space and time.