Chronic complications of DM are caused largely by HG-induced cellular and molecular impairment of neural and vascular structure and function. HG-induced oxidative stress is a major contributor in the development of long-term complications of DM. DM-induced neuropathy and angiopathy, in turn, may lead to the dysfunction of cells, tissues and organ systems.

The passage of hydrophilic drugs, such as oxime acetylcholinesterase reactivators, into the central nervous system is restricted by the blood-brain and the blood-cerebrospinal fluid barriers. The present review summarizes morphological and functional properties of the blood-brain barrier, blood-cerebrospinal fluid barrier and cerebrospinal fluid-brain interface and reviews the existing data on brain entry of oximes. Due to the virtual absence of transcytosis, lack of fenestrations and unique properties of tight junctions in brain endothelial cells, the blood-brain barrier only allows free diffusion of small lipophilic molecules. Various carriers transport hydrophilic compounds and extrude potentially toxic xenobiotics. The blood-cerebrospinal fluid barrier is formed by the choroid plexus epithelium, whose tight junctions are more permeable than those of brain endothelial cells. The major function of plexus epithelium cells is active transport of ions for the production of the cerebrospinal fluid. The cerebrospinal fluid-brain interface is not a biological barrier and allows free diffusion. However, in contrast to passage via the blood-brain barrier or the blood-cerebrospinal fluid barrier, direct penetration from the cerebrospinal fluid into the brain is very slow, since much longer distances have to be covered. A bulk flow of brain interstitial fluid and cerebrospinal fluid speeds up exchange between these two fluid compartments. Oximes, by reactivating acetylcholinesterase, are important adjunct therapeutics in organophosphate poisoning. They are very hydrophilic and therefore cannot diffuse freely into the central nervous system. Changes in brain acetylcholinesterase activity, oxime concentration and some biological effects elicited by oxime administration in the periphery indicate, however, that oximes can gain access to the brain to a certain degree, probably by carrier-mediated transport, reaching in the brain about 4-10% of their respective plasma levels. The clinical relevance of this effect is hotly debated. Possible strategies to improve brain penetration of oximes are discussed.

Diabetes mellitus (DM) is one of the oldest known human disease currently affecting more than 200 million people worldwide. Diabetes mellitus is derived from two Greek words meaning siphon and sugar. In DM, patients have high blood level of glucose and this passes out with urine. This is because the endocrine pancreas does not produce either or not enough insulin or the insulin which is produced is not exerting its biochemical effect (or insulin resistance) effectively. Insulin is a major metabolic hormone which has numerous functions in the body and one main role is to stimulate glucose uptake into body’s cells where it is utilized to provide energy. The disease is classified into type 1 and type 2 DM. Type 1 DM develops when the insulin producing β cells have been destroyed and are unable to produce insulin. This is very common in children and is treated with insulin. Type 2 DM (T2DM) develops when the body is unable to produce an adequate amount of insulin or the insulin which is provided does not work efficiently. This is due to life style habits including unhealthy diet, obesity, lack of exercise and hereditary and environmental factors. Some symptoms of DM include excess urination, constant thirst, lethargy, weight loss, itching, decreased digestive enzyme secretion, slow wound healing and other related symptoms. If left untreated, DM can result in severe long-term complications such as kidney and heart failure, stroke, blindness, nerve damage, exocrine glands insufficiency and other forms of complications. T2DM can be treated and controlled by prescribed drugs, regular exercise, diet (including some plant-based food) and general change in life style habits. This review is concerned with the role of plant-based medicine to treat DM. One such plant is Momordica charantia which is grown in tropical countries worldwide and it has been used as a traditional herbal medicine for thousands of years although its origin in unknown. This review examines the medicinal chemistry and use(s) of M. charantia and its various extracts and compounds, their biochemical properties and how they act as anti-diabetic (hypoglycemic) drugs and the various mechanisms by which they exert their beneficial effects in controlling and treating DM.

Introduction: Currently, 424 million people aged between 20-79 years worldwide are diabetic. More than 25% of adults aged over 65 years in North America have Type 2 diabetes mellitus (DM). Diabetes-induced osteoporosis (DM-OS) is caused by chronic hyperglycemia, advanced glycated end products and oxidative stress. The increase in the prevalence of DM-OS has prompted researchers to develop new biological therapies for the management of DM-OS. Areas covered: This review covered the current and novel biological agents used in the management of DM-OS. Data were retrieved from PubMed, Scopus, American Diabetes Association and International Osteoporosis Foundation websites, and ClinicalTrials.gov. The keywords for the search included: DM, osteoporosis, and management. Expert opinion: Several biological molecules have been examined in order to find efficient drugs for the treatment of DM-OS. These biological agents include anti-osteoporosis drugs: net anabolics (parathyroid hormone/analogues, androgens, calcilytics, anti-sclerostin antibody), net anti-resorptive osteoporosis drugs (calcitonin, estrogen, selective estrogen receptor modulators, bisphosphonates, RANKL antibody) and anti-diabetic drugs (alpha glucosidase inhibitors, sulfonylureas, biguanides, meglitinides, thiazolidinediones, GLP-1 receptor agonists, dipeptidylpeptidase-4 inhibitors, sodium glucose co-transporter-2 inhibitors, insulin). Biological A c c e p t e d M a n u s c r i p t Information Classification: General medications that effectively decrease hyperglycemia and, at the same time, maintain bone health would be an ideal drug/drug combination for the treatment of DM-OS.

An overview is given on the analysis, formation, role and occurrence of formaldehyde in living organisms. Various methods have been used for the determination of formaldehyde in tissues and body fluids. Gas chromatography, thin-layer chromatography and HPLC were employed for the analysis of formaldehyde, mainly after derivatization. The formaldehyde level of human blood and urine was found at the low ppm level. The formaldehyde level could be increased upto several ten micro g/mL(-1) following special dietary supply. Biochemical pathway of both the formaldehyde production and demethylation/methylation processes is generally connected to the methionine - homocysteine cycles. Another important way of demethylation generated formaldehyde production is given by microsomal cytochrome P-450 dependent oxidation of xenobiotics, such as various drugs prescribed by doctors. Semicarbazide sensitive amine oxidase also produces formaldehyde. Increased level of formaldehyde may be the indication of either patho-physiological processes, or environmental contamination, or malnutrition. The formaldehyde-related methylation and demethylation procedures are also detailed. DNA methylation may have an important role in the pathogenesis of certain diseases.