Pathophysiology of food intake : Obesity.& Biotechnological approaches in cure

GAURAV KUMAR PANDITSCHOOL OF LIFE SCIENCE

UNIVERSITY OF HYDERABADgauravbiologist@uohyd.ac.in

Pathophysiologyanorexia nervosaObesityCancer anorexia

neuroendocrine regulation of food intake central regulation of food intake –hypothalamus, neurohormones short- and long-term peripheral regulation of satiation and

energy balance - GIT hormones (ghrelin) - Adipose tissue hormones (leptin) - Pancreatic hormones (insulin)

The physiological regulation of food intake is a complex homeostatic process that is

regulated by many factor such as endocrine factor metabolic factors & combination with

visual, olfactory, emotions,

taste sensation, and the life conditions

Our prehistorical progenitors clearly did not have the opportunity to suffer either from obesity or anorexia nervosa

2.5 milion of years 50 years

The progression of mankind development

Obesity is classified by Body Mass Index (BMI)

Weight (kg) Height (m2)

WHO, 1998

Classification BMI (kg/m2) Metabolic c.

Normal weight 18.524.9 average

Overweight 2529.9 increasedObesity I 30.034.9 middleObesity II 35.039.9 highObesity III 40.0 V e ry high

BMI =

Complications of obesityMechanical

joint illness, dyspnoe, sleeping apnoe, heart hypetrophy,…..

Metabolic diabetes, hypertension,

hyperlipoproteinemia, ischemic heart disease, ictus, tumours, sterility,

depression,….. = Reaven metabolic syndrome

Leptin and obesity

Leptin deficiency is not epidemiologically significant cause of obesity (3 cases of leptin-gene mutation in humans accompanied by morbid obesity)

Most of obese patients have hyperleptinemia i.e. circulating leptin levels correlate with body fat content

Body weight loss induces decrease in circulating leptin levels

Why hyperleptinemia does not suppress food intake in patients

with obesity?Resistance to leptin effects: either on the

levels of leptin transport across the blood-brain barrier or on the postreceptor level

Primary leptin function is not to suppress food intake, but to trigger complex adaptive reaction of human body to starvation.

Obesity is accompanied by local inflammatory response in adipose

tissue

Obesity and GIT hormones

Decreased satiety perception represents an important risk factor for the development of obesity

Alterations in hormonal responses to food intake contribute to decrease satiety in obese .

Food fails to suppress ghrelin in obese

English et al. 2002

Postprandial ghrelin response in obese is (in contrast to healthy subjects) independent of caloric content and macronutrient composition of a mealContribution to resistance to weight loss in some of obese patients.

People come in all weights and sizes. Some eat but never gain a pound and others seem to gain weight by looking at a piece of pizza. So what causes some people to be overweight?

Obesity is on the rise worldwide. Every year, nearly 3 million people die of causes related to being overweight, victims of the lengthy lists of complications that can come with being obese—heart disease, stroke, and diabetes among them. Data on obesity from around the world are worrisome, but a number of new treatments are already helping patients control their weight..

Gene for Obesity

Two new papers in the journal Nature describe the results of New genes identified in obesity.

Study identified four new Genetic marker severe childhood obesity.

How much of weight is Genetics?

The ideal anti-obesity drug would produce sustained weight loss with minimal side effects. The mechanisms that regulate energy balance have substantial built-in redundancy, overlap considerably with other physiological functions,

A Question about Leptin Researchers have found that some obese individuals have high levels of leptin, while some other obese individuals have low levels of leptin. Based on what you know about this protein, how do you think both of these situations could result in obesity? An Internet or literature search can help you find additional answers.

Biotechnological approach.

Bioengineering Healthier Food Fish are rich in omega-3 fatty acids, which are increasingly recognized as a “superfood” that appears to boost everything from heart health to mood.

Unfortunately, many of the fish rich in omega-3s are either quickly disappearing from the oceans or contain worrisome levels of mercury, or both.

.C. elegans. The Caenorhabditis elegans

nematode worm is a soil-dwelling bisexual organism. One of its enzymes can help mammals produce healthful omega-3 fatty acids.

insert a gene for an enzyme found in C. elegans into mammalian cells that lack the enzyme to convert omega-6 fatty acids into omega-3 fatty acids

Biotechnological approach

More slim and more fit means more success and beauty……..

……….. but sometimes this motto of modern societies leads to death

Anorexia Nervosa (AN) Severe psychiatric disorder of unclear

etiology associated with significant morbidity and mortality .

Prevalence 0.3% of young girls, mortalty of 6%/decade.

Irrational fear of becoming fat even if patient is of normal or usually underweight.

Phobic response to food, abnormal eating behavior, hyperactivity, weakness, muscle aches, sleep disturbances, GIT complications, mood disturances, alterations of wide variety of hormonal and metabolic systems.

Combination of cultural-social, psychological, biological factors.

THANK YOU

School of Life SciencesUniversity of Hyderabad