1. INTRODUCTION
Obesity has been variously described as an excess of body weight or the body weight that is 20% over the ideal. Excess or ideal can be better understood by defining BMI (body mass index). A crude population measure of obesity is the body mass index (BMI), a person’s weight (in kg) divided by the square of his or her height (in m). A person with a BMI of 30 or more is generally considered obese. A person with a BMI equal to or more than 25 is considered overweight1. Obesity is a major cause of morbidity and mortality2. The prevalence of obesity (BMI≥30) continues to be a health concern for adults, children and adolescents3. Approximately 1.2 billion people in the world are overweight and at least 300 million of them are obese. According to the World Health Organization, obesity is one of the 10 most preventable health risks4.
Obesity is one of the fastest-growing major diseases in many areas of the world including Europe, the United States and Japan. Obesity results from an imbalance between energy intake and expenditure. Obesity is closely associated with life-style-related diseases such as hyperlipidemia, hypertension, arteriosclerosis and non-insulin-dependent diabetes mellitus and with increased risk of coronary heart disease. It has been reported that variations in total energy intake and diet composition are important in the regulation of metabolic processes. Furthermore, it has been suggested that dietary fat promotes body fat storage more effectively than dietary carbohydrate. Thus, inhibition of the digestion and absorption of dietary fat is a key to treating obesity. Dietary fat is not directly absorbed from the small intestine unless it has been subjected to the action of pancreatic lipase5.
The use of herbs as medicine, for various medical ailments, dates back to the Aryan period. With onset of scientific research in herbals, it is becoming clearer that the medicinal herbs have a potential in today’s synthetic era, as numbers of medicines are becoming resistant. According to one estimate only 20% of the plant flora has been studied and 60% of synthetic medicines owe their origin to plants. Ancient knowledge coupled with scientific principles can come to the forefront and provide us with powerful remedies to eradicate the diseases. All over the world, today we are looking for a natural system of healing that is comprehensive and complete that is not merely some curious form of folk healing but a real and rational system of medicine that is sensitive to both nature and the Earth. The benefits of herbs are many and varied. Various herbs can be used to treat obesity depending on the physical constitution and food habits of an individual. The main advantage of herbs is that these can be taken on a long-term basis without a risk of serious side-effects6.
The herbs used in the treatment of obesity are: Guggul, Shilajit, Zinziber officinalis, Piper nigrum, Emblica officinalis, and Terminalia bellerica. Hence, in the present study we are interested to screen anti-obesity activity of Moringa oleifera seeds, which are used in the traditional medicine for the same purpose7.
2. NEED FOR THE STUDY:
Body fat is good for health. It protects internal organs, isolates the organism thermically and softens blows. However, obesity is harmful and excessive weight can provoke serious disorders and obese people have from double to triple the probability of dying prematurely, compared to people with normal weight. An obese person runs the risk of a range of diseases that are linked to obesity and are more probable when the obesity level is higher. These diseases are: diabetes, biliary calculosis, respiratory insufficiency, nocturnal apnoea, cardiovascular diseases, arterial hypertension, arthrosis of backbone and of lower limbs, fertility anomalies, and cancer. The obesity state is also a specific risk factor for anaesthetic accidents, while using general anesthesia to undergo a surgical operation8.
The social consequences of being overweight and obese are serious and pervasive. Overweight and obese individuals are often targets of bias and stigma, and they are vulnerable to negative attitudes in multiple domains of living including places of employment, educational institutions, medical facilities, the mass media, and interpersonal relationships. Weight stigma occurs in multiple settings by a range of individuals. For obese adults, research has documented that individuals who experience weight stigmatization have higher rates of depression, anxiety, social isolation, and poorer psychological adjustment. Some obese adults may react to weight stigma by internalizing and accepting negative attitudes against them, which may in turn increase their vulnerability to low self-esteem. Stigma also has implications for physical health in the context of avoidance of health care services due to bias in medical settings. It is not known whether, or to what degree, stigma exacerbates poor self-care behaviors or contributes to additional complications and co-morbidities of obesity9.
The economic cost for the treatment of obesity is high, but the cost in human suffering cannot be estimated. Obesity often interfere with normal functioning and cause pain and suffering not only to those who have a disorder, but also to those who care about them. It can destroy family life as well as the life of the obese person. The complexity and pervasiveness of the obesity in every aspect of people's lives make it a challenging and potentially very rewarding area for research. Work in this area is thus particularly important. The development of new therapies has the potential to provide patients with significant improvements in quality of life, as well as reduce the future economic burden on health care systems.
Only a few allopathic medications are available for the treatment of obesity. However, a large number of plants are known to possess anti-obesity effects. These are so far not scientifically evaluated. Hence, the present project has been undertaken for screening of Moringa oleifera seeds for anti-obesity activity in experimental animals, as Moringa oleifera has vast medicinal uses and extensive pharmacological studies had been done on this plant. Literature revealed hypolipidemic and anti-atherogenic properties of Moringa oleifera leaves and fruits. But no reports are available on anti-lipidemic or anti-obesity activity of Moringa oleifera seeds, despite of its uses in treatment of obesity in traditional medicine.
3. REVIEW OF LITERATURE
Moringa oleifera
Kingdom: Plantae
Order: Brassicales
Family: Moringaceae
Genus: Moringa
Species: M. oleifera
Binomial name: Moringa oleifera.
Other names for the Moringa include: Drumstick tree, Nuggekayee.10
Part used: Leaves,fruits, seeds, bark, pods, flowers and roots.
Chemical constituents:
Active Ingredient: Saponins 10% & Saponins 20%
Main chemical components are pterygospermin, moringine, moringinine spirochin, behenic acid, moringic acid, niazinin A & B, niazimicin, campesterol, stigmasterol, beta sitosterol, amino acids11, p-hydroxybenzaldehyde, and methyl p-hydroxybenzoate12.
Ethnomedical information: Moringa preparations are cited in the scientific literature as having antibiotic, antitrypanosomal, hypotensive, antispasmodic, antiulcer, anti-inflammatory, hypocholesterolemic, and hypoglycemic activities13.
It inhibits the growth of gram-positive and gram-negative bacteria.
In high concentration it inhibits the growth of fungus.
It acts as potent antitubercular and used to cure liver diseases.
It stimulates the sympathetic nerve endings.
It accerlates the heart beats and constrict the blood vessels.
It inhibits the tone and movements of involuntary movements of the gastrointestinal tract.
It is used to treat migraine, epilepsy, chronic depression and neuronal cell death.
It is used to treat Parkinson's and Alzheimer's disease.
It is useful in colic, flatulence, diarrhoea, vesical and renal calculi.
It is also used in fever, inflammations, amenorrhoea and dysmenorrhoea.
It is also used in cough, cold and eye diseases11.
Reported biological activities of Moringa oleifera seeds:
Inhibitory action of ethanolic extract of seeds of Moringa oleifera Lam. on systemic and local anaphylaxis.
Effect of Moringa oleifera Lam. seed extract on Toluene diisocyanate-induced immune mediated inflammatory responses in rats.
Protective effect of ethanolic extract of seeds of Moringa oleifera Lam. against inflammation associated with development of arthritis in rats
Effect of Moringa oleifera Lam. seed extract on ovalbumin-induced airway inflammation in guinea pigs.
Anti-fungal activity of crude extracts and essential oil of Moringa oleifera14.
4. OBJECTIVE OF THE STUDY
To evaluate anti-obesity activity of alcoholic extract of Moringa oleifera seeds in experimental animals.
5. MATERIALS AND METHODS
- Experimental animals
Mice and Rats of either sex will be housed in standard laboratory conditions and fed with animal standard diet and water ad libitum.
- Plant material:
Seeds of Moringa oleifera will be collected, shade dried and powdered with mechanical grinder. The powered seeds will be extracted using Soxhlet extraction apparatus. Extract will be evaporated to dryness, weighed and stored in a refrigerator for further use.
C. Selection of the dose
Based on the previous published studies, the doses selected are 100 mg/kg and 200 mg/kg given orally15.
D. Grouping of animals
Each group contains 6 animals
Group I – serves as control
Group II - given suitable dose of the standard (Sibutramine)
Group III – 100 mg/kg of the alcoholic extract
Group IV – 200 mg/kg of the alcoholic extract
E. Statistical analysis:
Statistical analysis will be done by using Students ‘t’ test or ANOVA.
Methods:
1) Estimation of body and parametrial adipose tissue weights, plasma triacylglycerol and total cholesterol in mice fed a high-fat diet for 9 weeks
Female Albino mice (3 weeks old) will be divided into four groups that will be matched for body weight, after 1 week of being fed laboratory pellet chow ad libitum. The control group continued will be fed laboratory pellet chow ad libitum. The mice consume the high-fat diet or the high-fat diet containing Moringa oleifera seeds extract and standard for 9 weeks. The body weight of each mouse will be measured once a week and the total amount food consumed will be recorded 3 times per week. After the mice have been fed these diets for 9 weeks, blood will be taken from each mouse by venous puncture under anesthesia with diethyl ether; the mice will be then killed with an overdose of diethyl ether. Experiments will be performed in a ventilated room. The plasma will be prepared and frozen at -80°C until analysis. The liver and parametrial adipose tissue will be dissected and weighed. Liver triacylglycerol and total cholesterol concentrations will be measured using Wako Triglyceride E-Test and Total Cholesterol E-Test kits5.
2) Fat excretion in feces of mice
Female Albino mice (3 weeks old) will be housed for 1 week in a room maintained at 25 ± 1°C with 60% relative humidity and given free access to standard laboratory pellet chow and water. The mice consumed the high-fat diet or the high-fat diet containing Moringa oleifera seeds extract and standard for 3 days. Wet weight and triacylglycerol content in the feces will be obtained during the last 24 h and measured using the Triglyceride E-Test kit5.
3) Plasma triacylglycerol levels after oral administration of lipid emulsions to rats:
Male Wistar rats will be housed for 1 week in the above same conditions. After rats had been deprived of food overnight, they will be orally administered 1 mL of a lipid emulsion consisting of corn oil (3 mL), cholic acid (40 mg) and cholesteryl oleate (1 g) plus physiological saline (3 mL), the lipid emulsion (1 mL) plus Moringa oleifera seeds extract or the lipid emulsion plus standard drug. Blood samples will be taken from the tail vein 0, 0.5, 1, 2, 3, 4 and 5 h after administration of the lipid emulsion with or without total saponins or orlistat using a capillary tube (heparinized), and centrifuged at 5500 × g for 5 min in a centrifuge to obtain the plasma. The plasma triacylglycerol concentration will be determined using a Triglyceride E-Test kit5.
6. EXPERIMENTAL DESIGN
Route of administration: Oral
Sl no / Group / Treatment / No. of animals / Parameters1 / Group I / Vehicle / 6 / Body weight
Liver weight
Adipose tissue weight
Plasma triacyl glycerol level
Total cholesterol content
Weight of the feces
Triacyl glycerol level in feces
Liver triacyl glycerol
2 / Group II / Standard (Sibutramine) / 6
3 / Group III / 100 mg/kg of alcoholic Extract / 6
4 / Group IV / 200 mg/kg of alcoholic Extract / 6
7. BIBILOGRAPHY:
- Pieter van Baal HM, Johan PJ, Ardine de WG, Rudolf HT, Talitha FL, et al., Lifetime medical costs of obesity: Prevention no cure for increasing health expenditure. PLoS Med 2008; 5:29.
- http://www.cdc.gov/nccdphp/dnpa/obesity/
- Colin W, Jacqueline B, Bill C, Travis H, Mssssselyn G,et al., Obesity: Prevalence, theories, medical consequences, management, and research directions. J Int Soc Sports Nutr 2005; 2: 4–31.
- Kun Han, Yi-Nan Z, Masayuki Y, Hiromichi O, Yoshiyuki K. Anti-obesity effects of chikusetsusaponins isolated from Panax japonicus rhizomes. BMC Complement Altern Med2005. 5:9.
- Faizi S, Siddiqui BS, Saleem R, Aftab K, Shaheen F, Gilani AH. Hypotensive constituents from the pods of Moringa oleifera. Planta Med 1998; 64: 225-228.
- Jed Fahey W. Moringa oleifera: A review of the medicinal evidence for its nutritional, therpeutic, and prophylactic properties. Trees Life J. 2005; 1: 5.
- http://www.ncbi.nlm.nih.gov/sites/entrez.
- Mahajan SG, Mali RG, Mehta AA. Protective effect of ethanolic extract of seeds of Moringa oleifera Lam. against inflammation associated with development of arthritis in rats. J Immunotoxicol. 2007; 4: 39-47.