Seong Lin Teoh

The effect of topical extract of Momordica charantia (bitter gourd) on wound healing in nondiabetic rats and in rats with diabetes induced by streptozotocin

Background.  Momordica charantia (MC; bitter gourd) is a traditional herb commonly used for its antidiabetic, antioxidant, contraceptive and antibacterial properties. It is also used for the rapid healing of wounds.

Oxidative Stress in Oral Diseases: Understanding Its Relation with Other Systemic Diseases

Oxidative stress occurs in diabetes, various cancers, liver diseases, stroke, rheumatoid arthritis, chronic inflammation, and other degenerative diseases related to the nervous system. The free radicals have deleterious effect on various organs of the body. This is due to lipid peroxidation and irreversible protein modification that leads to cellular apoptosis or programmed cell death. During recent years, there is a rise in the oral diseases related to oxidative stress. Oxidative stress in oral disease is related to other systemic diseases in the body such as periodontitis, cardiovascular, pancreatic, gastric, and liver diseases. In the present review, we discuss the various pathways that mediate oxidative cellular damage. Numerous pathways mediate oxidative cellular damage and these include caspase pathway, PERK/NRF2 pathway, NADPH oxidase 4 pathways and JNK/mitogen-activated protein (MAP) kinase pathway. We also discuss the role of inflammatory markers, lipid peroxidation, and role of oxygen species linked to oxidative stress. Knowledge of different pathways, role of inflammatory markers, and importance of low-density lipoprotein, fibrinogen, creatinine, nitric oxide, nitrates, and highly sensitive C-reactive proteins may be helpful in understanding the pathogenesis and plan better treatment for oral diseases which involve oxidative stress.

Tumour biology of obesity-related cancers: understanding the molecular concept for better diagnosis and treatment.

Obesity continues to be a major global problem. Various cancers are related to obesity and proper understanding of their aetiology, especially their molecular tumour biology is important for early diagnosis and better treatment. Genes play an important role in the development of obesity. Few genes such as leptin, leptin receptor encoded by the db (diabetes), pro-opiomelanocortin, AgRP and NPY and melanocortin-4 receptors and insulin-induced gene 2 were linked to obesity. MicroRNAs control gene expression via mRNA degradation and protein translation inhibition and influence cell differentiation, cell growth and cell death. Overexpression of miR-143 inhibits tumour growth by suppressing B cell lymphoma 2, extracellular signal-regulated kinase-5 activities and KRAS oncogene. Cancers of the breast, uterus, renal, thyroid and liver are also related to obesity. Any disturbance in the production of sex hormones and insulin, leads to distortion in the balance between cell proliferation, differentiation and apoptosis. The possible mechanism linking obesity to cancer involves alteration in the level of adipokines and sex hormones. These mediators act as biomarkers for cancer progression and act as targets for cancer therapy and prevention. Interestingly, many anti-cancerous drugs are also beneficial in treating obesity and vice versa. We also reviewed the possible link in the mechanism of few drugs which act both on cancer and obesity. The present review may be important for molecular biologists, oncologists and clinicians treating cancers and also pave the way for better therapeutic options.

The Role of MicroRNAs in Diagnosis, Prognosis, Metastasis and Resistant Cases in Breast Cancer.

The incidence and mortality due to breast cancer is increasing worldwide. There is a constant quest to know the underlying molecular biology of breast cancer in order to arrive at diagnosis and plan better treatment options. MicroRNAs (miRNAs) are small non-coding and single stranded RNAs which influence the gene expression and physiological condition in any tumor. The miRNAs may act on different pathways in various cancers. Recently, there are research reports on various miRNAs being linked to breast cancers. The important miRNAs associated with breast cancers include miR-21, miR-155, miR-27a, miR-205, miR-145 and miR-320a. In the present review we discuss the role of miRNAs in breast cancer, its importance as diagnostic markers, prognosis and metastasis markers. We also highlight the role of miRNAs with regard to resistance to few anticancerous drugs such as Tamoxifen and Trastuzumab. The role of miRNA in resistance to treatment is one of the core issues discussed in the present review. Much information on the miRNA roles is available particularly in the neoadjuvant chemotherapy setting, because this protocol allows the rapid association of miRNA expression with the treatment response. This review opens the door for designing better therapeutic options in drug resistance cases in breast cancer.

MicroRNA dysregulation in Alzheimer’s disease

BACKGROUND AND OBJECTIVE Alzheimers disease (AD) is arguably the largest healthcare issue of our time. AD is thought to be principally the result of an inter-play between the β-amyloid peptide and Tau, and it is driven by several genetic and environmental risk factors. Recent studies have shown that small non-protein-coding microRNA (miRNA) and the associated post-transcriptional gene regulation are important regulators of many neurodegenerative diseases, including AD. We reviewed recent studies identifying various miRNA dysregulated in AD. These miRNAs could play a significant role in the pathophysiology of AD, in both β-amyloid peptide and Tau toxicity. CONCLUSION The identification of dysregulated miRNAs pattern can serve as specific AD biomarkers which may provide the basis for new and effective diagnostic approach. In addition, these miRNAs may represent new targets for pharmaceutical development.

Phytochemicals and their effective role in the treatment of diabetes mellitus: a short review

There is a global increase in the incidence of diabetes mellitus (DM). Hyperglycemia is one of the prevailing conditions which gives rise to various diabetic complications. The major complications include diabetic nephropathy, retinopathy, neuropathy, delayed wound healing, heart attack, peripheral vascular disturbances and diabetic ketoacidosis. Treatment of complications due to DM always poses a challenge to the attending clinician. Alongsideallopathic medicines, DM and its complications were reported to be effectively treated with various natural products. In the present review, we discuss the role of different phytochemicals which were reported to be beneficial in the treatment of hyperglycemic conditions in DM. Most medicinal plants contain micronutrients, amino acids and proteins, mucilages, essential oils, sterols and triterpenoids, saponins, carotenoids, alkaloids, flavonoids, phenolic acids, tannins, bitter principles and coumarins. We discuss the effective role of these phytochemicals with an emphasis on secondary metabolites which mimic the action of insulin, and highlight their importance as future antidiabetic agents.

Role of MicroRNA in proliferation phase of wound healing

Wound healing is a complex biological process that is generally composed of four phases: hemostasis, inflammation, proliferation, and remodeling. The proliferation phase is crucial for effective healing compared to other phases. Many critical events occur during this phase, i.e., migration of fibroblasts, re-epithelialization, angiogenesis and wound contraction. Chronic wounds are common and are considered a major public health problem. Therefore, there is the increasing need to discover new therapeutic strategies. MicroRNA (miRNA) research in the field of wound healing is in its early phase, but the knowledge of the recent discoveries is essential for developing effective therapies for the treatment of chronic wounds. In this review, we focused on recently discovered miRNAs which are involved in the proliferation phase of wound healing in the past few years and their role in wound healing.

The Emerging Role of the Hippo Pathway in Lung Cancers: Clinical Implications

BACKGROUND The incidence of lung cancers has increased globally. Increased exposure to tobacco, passive smoking, less consumption of vegetables and fruits and occupational exposure to asbestos, arsenic and chromium are the main risk factors. The pathophysiology of lung cancer is complex and not well understood. Various microRNAs, genes and pathways are associated with lung cancers. The genes involved in lung cancers produce proteins involved in cell growth, differentiation, different cell cycles, apoptosis, immune modulation, tumor spread and progression. The Hippo pathway (also known as the Salvador-Warts-Hippo pathway) is the latest emerging concept in cancers. The Hippo pathway plays an important role in controlling the size of the tissue and organ by virtue of its action on cell proliferation and apoptosis. OBJECTIVE In the present review, we highlight the mammalian Hippo pathway, role of its core members, its upstream regulators, downstream effectors and the resistance cases in lung cancers. RESULTS Specific interaction of Mer with cell surface hyaluronan receptor CD44 is vital in cell contact inhibition, thereby activating Hippo pathway. Both transcription co-activators YAP and TAZ (also known as WWTR1, being homologs of Drosophila Yki) are important regulators of proliferation and apoptosis, and serve as major downstream effectors of the Hippo pathway. Mutation of NF2, the upstream regulator of Hippo pathway is linked to the cancers. CONCLUSION Targeting YAP and TAZ may be important for future drug delivery and treatment.

Higher division of the tibial nerve in the leg: gross anatomical study with clinical implications.

BACKGROUND AND OBJECTIVES Tibial nerve is a branch of the sciatic nerve and it is the main nerve innervating the muscles of the back of the leg. The tibial nerve divides into medial and lateral plantar nerves. The level of division may be important for surgical purpose. The main aim of the present study was to observe the exact level of division of the tibial nerve and discuss its clinical implications. MATERIALS AND METHODS A total of 20 cadaveric limbs (irrespective of left or right side) were taken randomly. The posterior compartment of the thigh and leg was dissected to trace the tibial nerve and its branches. The specimens were subjected to measurements with respect to an arbitrary horizontal line passing through tip of medial malleolus and the calcaneum. All the specimens were photographed. RESULTS In 5 cases (25%), the tibial nerve divided deep to the flexor retinaculum. In 15 cases (75%) cases, the tibial nerve divided at a distance of 3.5 cm - 6.5 cm (average 5 cm) above the medial malleolus. CONCLUSION The tibial nerve and its divisions are important for performing successful nerve blocks and insertion of plates while treating fractures. Variations may account for the various discrepancies between the electromyographic tests and clinical tests.

Dietary Acrylamide and the Risks of Developing Cancer: Facts to Ponder

Acrylamide (AA) is a water soluble white crystalline solid commonly used in industries. It was listed as an industrial chemical with potential carcinogenic properties. However to date, AA was used to produce polyacrylamide polymer, which was widely used as a coagulant in water treatment; additives during papermaking; grouting material for dams, tunnels, and other underground building constructions. AA in food could be formed during high-temperature cooking via several mechanisms, i.e., formation via acrylic acid which may be derived from the degradation of lipid, carbohydrates, or free amino acids; formation via the dehydration/decarboxylation of organic acids (malic acid, lactic acid, and citric acid); and direct formation from amino acids. The big debate is whether this compound is toxic to human beings or not. In the present review, we discuss the formation of AA in food products, its consumption, and possible link to the development of any cancers. We discuss the body enzymatic influence on AA and mechanism of action of AA on hormone, calcium signaling pathways, and cytoskeletal filaments. We also highlight the deleterious effects of AA on nervous system, reproductive system, immune system, and the liver. The present and future mitigation strategies are also discussed. The present review on AA may be beneficial for researchers, food industry, and also medical personnel.