Eunüs S. Ali

Steatosis inhibits liver cell store-operated Ca2+ entry and reduces ER Ca2+ through a protein kinase C-dependent mechanism

Lipid accumulation in hepatocytes can lead to non-alcoholic fatty liver disease (NAFLD), which can progress to non-alcoholic steatohepatitis (NASH) and Type 2 diabetes (T2D). Hormone-initiated release of Ca²⁺ from the endoplasmic reticulum (ER) stores and subsequent replenishment of these stores by Ca²⁺ entry through SOCs (store-operated Ca²⁺ channels; SOCE) plays a critical role in the regulation of liver metabolism. ER Ca²⁺ homoeostasis is known to be altered in steatotic hepatocytes. Whether store-operated Ca²⁺ entry is altered in steatotic hepatocytes and the mechanisms involved were investigated. Lipid accumulation in vitro was induced in cultured liver cells by amiodarone or palmitate and in vivo in hepatocytes isolated from obese Zucker rats. Rates of Ca²⁺ entry and release were substantially reduced in lipid-loaded cells. Inhibition of Ca²⁺ entry was associated with reduced hormone-initiated intracellular Ca²⁺ signalling and enhanced lipid accumulation. Impaired Ca²⁺ entry was not associated with altered expression of stromal interaction molecule 1 (STIM1) or Orai1. Inhibition of protein kinase C (PKC) reversed the impairment of Ca²⁺ entry in lipid-loaded cells. It is concluded that steatosis leads to a substantial inhibition of SOCE through a PKC-dependent mechanism. This enhances lipid accumulation by positive feedback and may contribute to the development of NASH and insulin resistance.

Assessment of chemotherapy on various biochemical markers in breast cancer patients

Chemotherapy is a standard treatment method for the patients with locally advanced breast cancer. Lately, cyclophosphamide (CYP) and doxorubicin (DOX) are used as the major chemotherapeutic agents especially for the treatment of breast cancer. Till date, no serum biomarker has been able to provide an early diagnosis of breast cancer. This study aimed to assess inflammatory, cardiac, renal and hematological markers in 56 breast cancer patients (BCP) before, during and after termination of chemotherapy with CYP and DOX. Blood samples were collected from the patients at the each treatment stages mentioned above. These samples were assessed for interleukin 6 (IL‐6), interleukin 10 (IL‐10), lactate dehydrogenase (LDH), creatine kinase (CK), creatinine, hemoglobin (Hb), leukocyte, platelet and Na+/K+‐ATPase levels either by ELISA or colorimetric methods. The results suggest a significant increase in IL‐6 level at all the stages in BCP as compared to control group. On the other hand, IL‐10, CK and Na+/K+‐ATPase levels were found to be significantly declined during all the stages. Moreover, the majority of hematological parameters remained unchanged throughout the treatment period with the exception of creatinine and Hb which showed slight modulation in their level at different stages. Based on the results, we conclude that breast cancer and co‐treatment with CYP and DOX, interfere arious biological markers, thereby, showing the physiological imbalance.

The glucagon-like peptide-1 analogue exendin-4 reverses impaired intracellular Ca(2+) signalling in steatotic hepatocytes.

The release of Ca(2+) from the endoplasmic reticulum (ER) and subsequent replenishment of ER Ca(2+) by Ca(2+) entry through store-operated Ca(2+) channels (SOCE) play critical roles in the regulation of liver metabolism by adrenaline, glucagon and other hormones. Both ER Ca(2+) release and Ca(2+) entry are severely inhibited in steatotic hepatocytes. Exendin-4, a slowly-metabolised glucagon-like peptide-1 (GLP-1) analogue, is known to reduce liver glucose output and liver lipid, but the mechanisms involved are not well understood. The aim of this study was to determine whether exendin-4 alters intracellular Ca(2+) homeostasis in steatotic hepatocytes, and to evaluate the mechanisms involved. Exendin-4 completely reversed lipid-induced inhibition of SOCE in steatotic liver cells, but did not reverse lipid-induced inhibition of ER Ca(2+) release. The action of exendin-4 on Ca(2+) entry was rapid in onset and was mimicked by GLP-1 or dibutyryl cyclic AMP. In steatotic liver cells, exendin-4 caused a rapid decrease in lipid (half time 6.5min), inhibited the accumulation of lipid in liver cells incubated in the presence of palmitate plus the SOCE inhibitor BTP-2, and enhanced the formation of cyclic AMP. Hormone-stimulated accumulation of extracellular glucose in glycogen replete steatotic liver cells was inhibited compared to that in non-steatotic cells, and this effect of lipid was reversed by exendin-4. It is concluded that, in steatotic hepatocytes, exendin-4 reverses the lipid-induced inhibition of SOCE leading to restoration of hormone-regulated cytoplasmic Ca(2+) signalling. The mechanism may involve GLP-1 receptors, cyclic AMP, lipolysis, decreased diacylglycerol and decreased activity of protein kinase C.

Correlations between Risk Factors for Breast Cancer and Genetic Instability in Cancer Patients- A Clinical Perspective Study

Molecular epidemiological studies have identified several risk factors linking to the genes and external factors in the pathogenesis of breast cancer. In this sense, genetic instability caused by DNA damage and DNA repair inefficiencies are important molecular events for the diagnosis and prognosis of therapies. Therefore, the objective of this study was to analyze correlation between sociocultural, occupational, and lifestyle risk factors with levels of genetic instability in non-neoplastic cells of breast cancer patients. Total 150 individuals were included in the study that included 50 breast cancer patients submitted to chemotherapy (QT), 50 breast cancer patients submitted to radiotherapy (RT), and 50 healthy women without any cancer. Cytogenetic biomarkers for apoptosis and DNA damage were evaluated in samples of buccal epithelial and peripheral blood cells through micronuclei and comet assay tests. Elder age patients (61–80 years) had higher levels of apoptosis (catriolysis by karyolysis) and DNA damage at the diagnosis (baseline damage) with increased cell damage during QT and especially during RT. We also reported the increased frequencies of cytogenetic biomarkers in patients who were exposed to ionizing radiation as well as for alcoholism and smoking. QT and RT induced high levels of fragmentation (karyorrhexis) and nuclear dissolution (karyolysis) and DNA damage. Correlations were observed between age and karyorrhexis at diagnosis; smoking and karyolysis during RT; and radiation and karyolysis during QT. These correlations indicate that risk factors may also influence the genetic instability in non-neoplastic cells caused to the patients during cancer therapies.

A comprehensive review on biological properties of citrinin

Citrinin (CIT) is a mycotoxin which causes contamination in the food and is associated with different toxic effects. A web search on CIT has been conducted covering the timespan since 1946. The accumulated data indicate that CIT is produced by several fungal strains belonging to Penicillium, Aspergillus and Monascus genera, and is usually found together with another nephrotoxic mycotoxin, ochratoxin A. Although, it is evident that CIT exposure can exert toxic effects on the heart, liver, kidney, as well as reproductive system, the mechanism of CIT-induced toxicity remains largely elusive. It is still controversial what are the genotoxic and mutagenic effects of CIT. Until now, its toxic effect has been linked to the CIT-mediated oxidative stress and mitochondrial dysfunction in biological systems. However, the toxicity strongly depends on its concentration, route, frequency and time of exposure, as well as from the used test systems. Besides the toxic effects, CIT is also reported to possess a broad spectrum of bioactivities, including antibacterial, antifungal, and potential anticancer and neuro-protective effects in vitro. This systematic review presents the current state of CIT research with emphasis on its bioactivity profile.

ANTIDIARRHEAL AND CYTOTOXIC ACTIVITIES OF ALSTONIA SCHOLARIS BARK

Alstonia scholaris (Apoc ynaceae) is an evergreen and tropical tree native to the Indian subcontinent and South - east Asia . It is a well known medicinal plant and commonly known as ‘ Chhatim ’ in Bangladesh . Traditionally the bark is used to treat anemia , menstrual disorders, colic, diarrhea , dysentery and acute arthritis. In the present study, the ethanolic extract of bark was investigated for phytochemical properties as well as anti diarrh eal and cytotoxic activities. In antidiarrheal activity test (castor oil induced diarrhea), the extra ct was taken as a dose of 250mg /kg body w eigh t orally in Swiss albino mice and t he standard drug l operamide, at a dose of 50mg/kg. The cytotoxic test was performed on brine shrimp ( Artemia salina ) . T he ethanolic extract contains alkaloid, reducing sug ar, saponin and t annin . It significantly increased mean latent period (1.09 hr) and decreased the frequency of defecation , which w ere comparable to the standard drug ( P <0.0 1) . In case of c ytotoxic test , the LC 50 & LC 90 were found as 22. 25 & 95.28 µg/ml , res pectively . The findings suggest that Alstonia scholaris possesses antidiarrh eal and cytotoxic activities.

Protective and therapeutic potential of ginger (Zingiber officinale) extract and [6]-gingerol in cancer: A comprehensive review: Ginger extract and [6]-gingerol as anticancer agents

Natural dietary agents have attracted considerable attention due to their role in promoting health and reducing the risk of diseases including cancer. Ginger, one of the most ancient known spices, contains bioactive compounds with several health benefits. [6]‐Gingerol constitutes the most pharmacologically active among such compounds. The aim of the present work was to review the literature pertaining to the use of ginger extract and [6]‐gingerol against tumorigenic and oxidative and inflammatory processes associated with cancer, along with the underlying mechanisms of action involved in signaling pathways. This will shed some light on the protective or therapeutic role of ginger derivatives in oxidative and inflammatory regulations during metabolic disturbance and on the antiproliferative and anticancer properties. Data collected from experimental (in vitro or in vivo) and clinical studies discussed in this review indicate that ginger extract and [6]‐gingerol exert their action through important mediators and pathways of cell signaling, including Bax/Bcl2, p38/MAPK, Nrf2, p65/NF‐κB, TNF‐α, ERK1/2, SAPK/JNK, ROS/NF‐κB/COX‐2, caspases‐3, ‐9, and p53. This suggests that ginger derivatives, in the form of an extract or isolated compounds, exhibit relevant antiproliferative, antitumor, invasive, and anti‐inflammatory activities.

A systematic review on the neuroprotective perspectives of beta-caryophyllene: Neurobiological effects of β-caryophyllene

Beta (β)‐caryophyllene (BCAR) is a major sesquiterpene of various plant essential oils reported for several important pharmacological activities, including antioxidant, anti‐inflammatory, anticancer, cardioprotective, hepatoprotective, gastroprotective, nephroprotective, antimicrobial, and immune‐modulatory activity. Recent studies suggest that it also possesses neuroprotective effect. This study reviews published reports pertaining to the neuropharmacological activities of BCAR. Databases such as PubMed, Scopus, MedLine Plus, and Google Scholar with keywords “beta (β)‐caryophyllene” and other neurological keywords were searched. Data were extracted by referring to articles with information about the dose or concentration/route of administration, test system, results and discussion, and proposed mechanism of action. A total of 545 research articles were recorded, and 41 experimental studies were included in this review, after application of exclusion criterion. Search results suggest that BCAR exhibits a protective role in a number of nervous system‐related disorders including pain, anxiety, spasm, convulsion, depression, alcoholism, and Alzheimers disease. Additionally, BCAR has local anesthetic‐like activity, which could protect the nervous system from oxidative stress and inflammation and can act as an immunomodulatory agent. Most neurological activities of this natural product have been linked with the cannabinoid receptors (CBRs), especially the CB2R. This review suggests a possible application of BCAR as a neuroprotective agent.

Analgesic Activity, Chemical Profiling and Computational Study on Chrysopogon aciculatus

Present study was undertaken to evaluate the analgesic activity of the ethanol extract of Chrysopogon aciculatus. In addition to bioassays in mice, chemical profiling was done by LC-MS and GC-MS to identify phytochemicals, which were further docked on the catalytic site of COX-2 enzymes with a view to suggest the possible role of such phytoconstituents in the observed analgesic activity. Analgesic activity of C. aciculatus was evaluated by acetic acid induced writhing reflex method and hot plate technique. Phytochemical profiling was conducted using liquid chromatography mass spectrometry (LC-MS) and gas chromatography mass spectrometry (GC-MS). In docking studies, homology model of human COX-2 enzyme was prepared using Easy Modeler 4.0 and the identified phytoconstituents were docked using Autodock Vina. Preliminary acute toxicity test of the ethanol extract of C. aciculatus showed no sign of mortality at the highest dose of 4,000 mg/kg. The whole plant extract significantly (p < 0.05) inhibited acetic acid induced writhing in mice at the doses of 500 and 750 mg/kg. The extract delayed the response time in hot plate test in a dose dependent manner. LC-MS analysis of the plant extract revealed the presence of aciculatin, nudaphantin and 5α,8α-epidioxyergosta-6,22-diene-3β-ol. Three compounds namely citronellylisobutyrate; 2,4-dihydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one and nudaphantin were identified in the n-hexane fraction by GC-MS. Among these compounds, six were found to be interacting with the binding site for arachidonic acid in COX-2 enzyme. Present study strongly supports the traditional use of C. aciculatus in the management of pain. In conclusion, compounds (tricin, campesterol, gamma oryzanol, and citronellyl isobutyrate) showing promising binding affinity in docking studies, along with previously known anti-inflammatory compound aciculatin can be held responsible for the observed activity.

Phytol: A review of biomedical activities

Phytol (PYT) is a diterpene member of the long-chain unsaturated acyclic alcohols. PYT and some of its derivatives, including phytanic acid (PA), exert a wide range of biological effects. PYT is a valuable essential oil (EO) used as a fragrance and a potential candidate for a broad range of applications in the pharmaceutical and biotechnological industry. There is ample evidence that PA may play a crucial role in the development of pathophysiological states. Focusing on PYT and some of its most relevant derivatives, here we present a systematic review of reported biological activities, along with their underlying mechanism of action. Recent investigations with PYT demonstrated anxiolytic, metabolism-modulating, cytotoxic, antioxidant, autophagy- and apoptosis-inducing, antinociceptive, anti-inflammatory, immune-modulating, and antimicrobial effects. PPARs- and NF-κB-mediated activities are also discussed as mechanisms responsible for some of the bioactivities of PYT. The overall goal of this review is to discuss recent findings pertaining to PYT biological activities and its possible applications.