Juvenile diabetes mellitus and serum lipids and lipoprotein levels

Antidiabetic and antiulcerative potential of Garcinia lanceifolia Roxb. bark

Background

Garcinia lanceifoliaRoxb. has been used by many ethnic communities of Northeast India to mitigate various disorders like dyspepsia, ulcers, diabetes, etc. However, a robust scientific study on its antidiabetic and antiulcer potential is unavailable till date. The aim of this present study is to scientifically validate if the antidiabetic and antiulcer effects reported by the ethnic tribes of Assam has any scientific value or not. The effects were tested in adult Wistar albino rats using approved animal models for preclinical testing of pharmacological activities.

Results

The hydroalcoholic extract of the bark ofGarcinia lanceifoliaRoxb. was prepared and its LD50was calculated. The LD50was determined to be greater than 5000 mg/kg body weight. The extract at doses of 250 mg/kg body weight and 500 mg/kg body weight was found to exhibit a very potent dose-dependent antidiabetic activity. The results were backed by a battery of test including analysis of serum levels of blood glucose, lipid profiles, in vivo antioxidant enzymes, and histopathological studies. Evidence of dose-dependent antiulcer activity of the extract was backed by robust scientific data. It was found that HAEGL induced a significant dose-dependent increase in the ulcer index in both alcohol-induced and acetic acid-induced ulcer models, which was evident from the macroscopic observation of the inner lining of the gastric mucosa and the histological evaluation of the extracted stomach.

Conclusion

The results suggested that the bark ofGarcinia lanceifolia(Roxb.) has significant antidiabetic and antiulcer potential. Further studies with respect to the development herbal dosage forms and its safety evaluation are required.

Antidiabetic activity of Chandraprabha vati - A classical Ayurvedic formulation

BACKGROUND

Chandraprabha vati is a classical Ayurvedic formulation, markedly used for mitigation of Prameha, which correlates in many ways with obesity, metabolic syndrome and diabetes mellitus.

OBJECTIVE

The present study was aimed to investigate effect of Chandraprabha vati in experimentally-induced hyperglycemia and lipid profile alterations.

MATERIALS AND METHODS

Antidiabetic effect of Chandraprabha vati was studied in fifty five Wistar rats. Graded doses of Chandraprabha vati (50, 100 and 200 mg/kg) were administered orally for 7 days to normal and alloxan-hyperglycemic rats (65 mg/kg, intravenously), and to glucose loaded normal rats for oral glucose tolerance test (OGTT). Fasting plasma glucose levels were assessed on different time intervals along with plasma cholesterol and triglycerides. Metformin (500 mg/kg, orally) was used as standard drug.

RESULTS

Chandraprabha vati did not cause any significant reduction in plasma glucose levels of normal rats (p > 0.05) but normalized the impaired glucose tolerance at 60 and 120 min (p < 0.05-p < 0.001) in OGTT when compared to vehicle control. In alloxan-hyperglycemic rats, administration of Chandraprabha vati (200 mg/kg) significantly reduced plasma glucose at 3 h, 12 h, 3rd day and 7th day (p < 0.01-p < 0.001) along with reduction in cholesterol and triglycerides levels (p < 0.01-p < 0.001) when compared to diabetic control group. The effects were comparable with metformin.

CONCLUSIONS

Chandraprabha vati exhibited anti-hyperglycemic effect and attenuated alterations in lipid profile. The results support the use of Chandraprabha vati for correction of Prameha in clinical practice.

Anti-diabetic activity of traditional Indian gold containing preparation: Shadguna Balijarita Makaradhwaja on streptozotocin induced diabetic rats

Background:

Makaradhwaja a gold containing mercurial preparation used for diabetes mellitus in indigenous system of medicine. It is a popular aphrodisiac and rejuvenator traditional medicine. It is prepared by using processed gold, mercury and sulfur in different ratios by applying intermittent heating pattern in Valuka Yantra.

Objectives:

The aim of the study was to evaluate anti-diabetic effect of Shadguna Balijarita Makaradhwaja (SBM) on streptozotocin (STZ) induced diabetic rats.

Materials and Methods:

Diabetes was induced to normal rats by injecting STZ in dose 40 mg/kg. Powdered SBM and dried extract of Tinospora cordifolia were mixed with honey and administered orally for 20 days at dose 2.63 mg/kg and 42.34 mg/kg body weight, respectively. The effects of treatment on body weight changes and blood glucose levels were quantified on day 1, 5, 10, 15 and 21 of the experiments. On the 21^st day, animals were sacrificed and gross histopathological changes in liver, kidney and pancreas were illustrated. Blood sugar level, glyacated hemoglobin, blood urea, serum cholesterol, serum creatinine, serum triglyceride and serum protein were estimated with standard methods. The study was conducted in the year 2011.

Results:

Test drug observed significant decrease (P < 0.001) in glyacated hemoglobin level compared to diabetic control rats. Blood sugar level of test drug group shown a significant decrease (279.11 ± 57.95) compared with diabetic rats.

Conclusion:

The present study demonstrates that SBM and dried extract of T. cordifolia with honey significantly reduces the blood glucose level and shows anti-diabetic effect.

Chromatographic analysis of the effects of fatty acids and glycation on binding by probes for Sudlow sites I and II to human serum albumin

The primary endogenous ligands of human serum albumin (HSA) are non-esterified fatty acids, with 0.1-2mol of fatty acids normally being bound to HSA. In type II diabetes, fatty acid levels in serum are often elevated, and the presence of high glucose results in an increase in the non-enzymatic glycation of HSA. High-performance affinity chromatography (HPAC) was used to examine the combined effects of glycation and the presence of long chain fatty acids on the binding of HSA with R-warfarin and l-tryptophan (i.e., probes for Sudlow sites I and II, the major sites for drugs on this protein). Zonal elution competition studies were used to examine the interactions of myristic acid, palmitic acid and stearic acid with these probes on HSA. It was found that all these fatty acids had direct competition with R-warfarin at Sudlow site I of normal HSA and glycated HSA, with the glycated HSA typically having stronger binding for the fatty acids at this site. At Sudlow site II, direct competition was observed for all the fatty acids with l-tryptophan when using normal HSA, while glycated HSA gave no competition or positive allosteric interactions between these fatty acids and l-tryptophan. These data indicated that glycation can alter the interactions of drugs and fatty acids at specific binding sites on HSA. The results of this study should lead to a better understanding of how these interactions may change during diabetes and demonstrate how HPAC can be used to examine drug/solute-protein interactions in complex systems.

Effects of Fatty Acids and Glycation on Drug Interactions with Human Serum Albumin

The presence of elevated glucose concentrations in diabetes is a metabolic change that leads to an increase in the amount of non-enzymatic glycation that occurs for serum proteins. One protein that is affected by this process is the main serum protein, human serum albumin (HSA), which is also an important carrier agent for many drugs and fatty acids in the circulatory system. Sulfonylureas drugs, used to treat type 2 diabetes, are known to have significant binding to HSA. This study employed ultrafiltration and high-performance affinity chromatography to examine the effects of HSA glycation on the interactions of several sulfonylurea drugs (i.e., acetohexamide, tolbutamide and gliclazide) with fatty acids, whose concentrations in serum are also affected by diabetes. Similar overall changes in binding were noted for these drugs with normal HSA or glycated HSA and in the presence of the fatty acids. For most of the tested drugs, the addition of physiological levels of the fatty acids to normal HSA and glycated HSA produced weaker binding. At low fatty acid concentrations, many of these systems followed a direct competition model while others involved a mixed-mode interaction. In some cases, there was a change in the interaction mechanism between normal HSA and glycated HSA, as seen with linoleic acid. Systems with only direct competition also gave notable changes in the affinities of fatty acids at their sites of drug competition when comparing normal HSA and glycated HSA. This research demonstrated the importance of considering how changes in the concentrations and types of metabolites (e.g., in this case, glucose and fatty acids) can alter the function of a protein such as HSA and its ability to interact with drugs or other agents.

Review: Glycation of human serum albumin

Glycation involves the non-enzymatic addition of reducing sugars and/or their reactive degradation products to amine groups on proteins. This process is promoted by the presence of elevated blood glucose concentrations in diabetes and occurs with various proteins that include human serum albumin (HSA). This review examines work that has been conducted in the study and analysis of glycated HSA. The general structure and properties of HSA are discussed, along with the reactions that can lead to modification of this protein during glycation. The use of glycated HSA as a short-to-intermediate term marker for glycemic control in diabetes is examined, and approaches that have been utilized for measuring glycated HSA are summarized. Structural studies of glycated HSA are reviewed, as acquired for both in vivo and in vitro glycated HSA, along with data that have been obtained on the rate and thermodynamics of HSA glycation. In addition, this review considers various studies that have investigated the effects of glycation on the binding of HSA with drugs, fatty acids and other solutes and the potential clinical significance of these effects.

Effect of diabetes mellitus on pharmacokinetic and pharmacodynamic properties of drugs

The effects of diabetes mellitus on the pharmacokinetics and pharmacodynamics of drugs have been well described in experimental animal models; however, only minimal data exist for humans and the current knowledge regarding the effects of diabetes on these properties remains unclear. Nevertheless, it has been observed that the pharmacokinetics and pharmacodynamics of drugs are changed in subjects with diabetes. It has been reported that diabetes may affect the pharmacokinetics of various drugs by affecting (i) absorption, due to changes in subcutaneous adipose blood flow, muscle blood flow and gastric emptying; (ii) distribution, due to non-enzymatic glycation of albumin; (iii) biotransformation, due to regulation of enzymes/transporters involved in drug biotransformation; and (iv) excretion, due to nephropathy. Previously published data also suggest that diabetes-mediated changes in the pharmacokinetics of a particular drug cannot be translated to others. Although clinical studies exploring the effect of diabetes on pharmacodynamics are still very limited, there is evidence that disease-mediated effects are not limited only to pharmacokinetics but also alter pharmacodynamics. However, for many drugs it remains unclear whether these influences reflect diabetes-mediated changes in pharmacokinetics rather than pharmacodynamics. In addition, even though diabetes-mediated pharmacokinetics and pharmacodynamics might be anticipated, it is important to study the effect on each drug and not generalize from observed data. The available data indicate that there is a significant variability in drug response in diabetic subjects. The discrepancies between individual clinical studies as well as between ex vivo and clinical studies are probably due to (i) the restricted and focused population of subjects in clinical studies; (ii) failure to consider type, severity and duration of the disease; (iii) histopathological characteristics generally being missing; and (iv) other factors such as varying medication use, dietary protein intake, age, sex and obesity. The obesity epidemic in the developed world has also inadvertently influenced the directions of pharmacological research. This review attempts to map new information gained since Gwilt published his paper in Clinical Pharmacokinetics in 1991. Although a large body of research has been conducted and significant progress has been made, we still have to conclude that the available information regarding the effect of diabetes on pharmacokinetics and pharmacodynamics remains unclear and further clinical studies are required before we can understand the clinical significance of the effect. An understanding of diabetes-mediated changes as well as of the source of the variability should lead to the improvement of the medical management and clinical outcomes in patients with this widespread disease.

Circulating lipids and glycaemic control in insulin dependent diabetic children

The prevalence of dyslipidaemia in children with insulin dependent diabetes mellitus (IDDM) and its relation to glycaemic control was studied in a group of 51 diabetic children and a control population of 132 schoolchildren. The prevalence of dyslipidaemia in the fasting state was increased in the diabetic group (39%) compared with control subjects (17%). Serum cholesterol concentration alone was raised in 25% of diabetic subjects while serum cholesterol and triglycerides were raised in 14%, compared with 16% and 0.7% respectively in control subjects. Serum total cholesterol (5.1 v 4.5 mmol/l), low density lipoprotein cholesterol (3.2 v 2.6 mmol/l), non-esterified fatty acids (0.91 v 0.50 mmol/l), and triglycerides (0.94 v 0.76 mmol/l) were higher in diabetic children. Serum total cholesterol, triglycerides, and apolipoprotein (apo)B concentrations increased with worsening control, while serum high density lipoprotein cholesterol and apoA-I concentrations were unaltered. There were also positive correlations between glycated haemoglobin and total cholesterol, triglycerides, and apoB in diabetic children. Thus, abnormalities in circulating lipids are common in young subjects with IDDM but largely disappear if blood glucose concentrations are reasonably controlled.

Atherogenic profiles in insulin-dependent diabetic patients and their treatment

Longitudinal studies have shown a large excess of cardiovascular mortality in insulin-dependent diabetic patients (IDDM) as compared to non-diabetic controls. Although diabetes appears to be an independent cardiovascular risk factor, increases in total and LDL-cholesterol together with a decrease of HDL-cholesterol are more pronounced in diabetics with cardiovascular disease. The general opinion, however, derived from a large number of cross-sectional studies, is that in well-controlled IDDM lipoprotein abnormalities are modest and only slightly different from matched non-diabetic controls. Most of the studies, however, used absolute criteria based on consensus statements and do not take the internal relations of the lipoproteins into account. When atherogenic indices (such as the relationship between total cholesterol and HDL-cholesterol or the Apo A1/apo B quotient) are used, 20 to 30% of an IDDM population considered to be in clinically acceptable control have to be considered pathological. This observation is even more important since the recent Diabetes Control and Complications Trial has shown that, especially in the younger group of patients, significantly higher total cholesterol and triglycerides and lower HDL-cholesterol were observed. Especially in these patients can diet and drug intervention be the most useful in the prevention of cardiovascular disease. These data are consistent with the fact that more sophisticated techniques have previously shown atherogenic changes in the composition of the VLDL-particles and lipoprotein enrichment in apo B. Since these techniques are not easily available in the clinic one has to refer to more classical techniques and the use of above mentioned atherogenic profiles to decide treatment.

The effects of diabetes mellitus on pharmacokinetics and pharmacodynamics in humans

The article reviews the effect of diabetes on the pharmacokinetics and pharmacodynamics of drugs in humans. For most drugs which cross the gastrointestinal wall by passive diffusion, oral absorption is unlikely to be affected by diabetes, although a delay in the absorption of tolazamide and a decrease in the extent of absorption of ampicillin have been reported. Subcutaneous absorption of insulin is more rapid in diabetic patients, whereas the intramuscular absorption of several drugs is slower. The binding of a number of drugs in the blood is reduced in diabetes, which may be due to glycosylation of plasma proteins or displacement by plasma free fatty acids, the level of which is increased in diabetic patients. Plasma concentrations of albumin and alpha 1-acid glycoprotein do not appear to be changed by the disease. The distribution of drugs with little or no binding in the blood is generally not altered, although the volume of distribution of phenazone (antipyrine) is reduced by 20% in insulin-dependent diabetes mellitus (IDDM). In contrast to animal studies, the metabolic clearance of most drugs in humans appears to be unaffected or slightly reduced by the disease. The presence of fatty liver in non-insulin-dependent diabetes mellitus (NIDDM) may contribute to a reduced hepatic clearance, whereas decreased binding in the blood may cause an increase in clearance. The effect of diabetes on hepatic blood flow in humans appears to be unknown. Diabetes affects kidney function in a significant number of diabetic patients. During the first 10 years after the onset of the disease, glomerular filtration is elevated in these patients. Thus, the renal clearance of a number of antibiotics has been shown to be increased in diabetic children. As the disease progresses, renal function is impaired and glomerular function declines from the initial elevated state. In diabetic adults the renal clearance of drugs either is comparable with that found in nondiabetic individuals or is reduced. A limited number of studies have been conducted comparing the dose-response of cardiovascular drugs in diabetic patients with that in nondiabetic controls. Decreased, increased and unchanged responses have been reported. It is apparent that in some cases an altered response may be observed for a drug when administered to a diabetic patient compared with a similar nondiabetic individual. At the present time, it is not possible to ascertain whether these studies reflect true pharmacodynamic changes or merely alterations in pharmacokinetics.(ABSTRACT TRUNCATED AT 400 WORDS)

High density lipoprotein cholesterol in insulin-dependent diabetic children

Thirty-one insulin-dependent diabetic children were studied (11 boys and 20 girls; 22 whites, 6 mulattoes and 3 Negroes; age-range: 8-14 years; mean age 11.7 years). According to the quality of their metabolic control the children were divided into 3 groups: Group 1, children in good metabolic control; Group 2, children in poor metabolic control but without ketosis; Group 3, children in severe ketoacidosis; 15 normal children (Group 4) served as controls. No hypercholesterolemia was found. As to blood sugar and serum triglyceride levels, significant differences were found between the control group and the diabetic groups as well as between the diabetic groups. When evaluating the result of HDL-cholesterol determinations we found a significant difference between the control group and Groups 2 and 3, as well as between diabetics in good control (Group 1) compared to Groups 2 and 3. We also found a correlation in diabetics in good control between blood sugar values and high HDL-cholesterol levels, and in diabetics in poor control between high blood sugar values and low HDL-cholesterol levels. No correlation was found between HDL-cholesterol and triglycerides in diabetes in poor metabolic control. In view of these findings the importance of reaching an optimal metabolic control in insulin-dependent children is emphasized, and the role of normoglycemia in the prevention of atherosclerosis is stressed.

The effect of diabetes on mevalonate metabolism in the rat

Previous studies have demonstrated a major difference in mevalonate metabolism by male and female rats by both the shunt and sterol pathways. This important sex difference was shown to be related to the presence of oestrogens and/or progesterone. In the present study we have investigated the effects of streptozotocin-induced diabetes on mevalonate metabolism. Firstly, insulin deficiency decreased the ability of the rats to oxidize mevalonate to carbon dioxide by the shunt pathway both in vivo and in vitro. This decrease was reversed by insulin treatment both in the intact animals as well as in tissue slices. Secondly, diabetes caused a marked increase in hepatic sterologenesis in the intact animal. This is the first demonstration that insulin plays significant regulatory role in both the shunt and sterol pathways of mevalonate metabolism.

Misleading plasma electrolytes in diabetic children with severe hyperlipidaemia

Severe abnormalities of plasma electrolyte concentrations were observed in 4 children who had massive hyperlipidaemia secondary to poorly-controlled, insulin-dependent diabetes mellitus. These electrolyte values were fallacious and invoked problems of clinical management, particularly with regard to fluid replacement. Each case is described and the interpretation of plasma elecytolyte values in hyperlipidaemia is discussed.