Here is an essay on ‘Onion’ for class 8, 9, 10, 11 and 12. Find paragraphs, long and short essays on ‘Onion’ especially written for school and college students.
Essay on Onion
1. Essay on Onion (As an Anti-Carcinogenic):
In recent years, extensive research has focused on the anti-carcinogenic potential of onion and its organosulfur constituents. Phytochemical research has proved that onion is rich in flavonols and organosulfur compounds, which have exhibited tumor inhibitory properties in laboratory studies. In a French epidemiological study, higher onion intake was correlated with lower risk of breast cancer. Furthermore, many experimental studies have demonstrated that organosulfur compounds and onion extracts have inhibitory effects on carcinogenesis in animals.
Wang et al. (2012b) suggested that the apoptosis induced by ethyl acetate extract of onion (EEO) occurs via inhibition of fatty acid synthase (FAS). The authors found that EEO could suppress lipid accumulation during the differentiation of 3T3- L1 adipocytes, which was also related to its inhibition of intracellular FAS activity suggesting that onion might be useful for preventing obesity-related malignancy.
2. Essay on Onion (As an Anti-Cognitive Impairment):
Shri and Singh (2008) demonstrated that the pretreatment with methanolic extract of outer scales (100 mg/kg and 200 mg/kg) and edible portions (100 mg/kg and 200 mg/kg) of onion bulb markedly reduced cerebral infarct size and attenuated impairment in short-term memory and motor coordination along with a marked decrease in mitochondrial TBARS.
Hwang et al. (2009) also proved the neuro-protective effects of onion extract and its major component, quercetin, on ischemic damage in the gerbil hippocampus – related to memory function. On the basis of this observation, the authors suggest that repeated administration of onion extract and quercetin can protect against neuronal damage from transient cerebral ischemia.
Nishimura et al. (2006) demonstrated that 2-n-propyl trisulfide present in onion ameliorated memory impairment in SAMP8 mouse by its anti-oxidant effect.
3. Essay on Onion (As an Anti-Diabetic Foods):
There are a few sporadic studies on onion as a hypoglycemic agent. An oral dose of 50 g of onion juice significantly controlled post-prandial glucose levels in diabetic patients. A. cepa and A. sativum possess a high level of anti-oxidant activity, which is attributed to the flavonoids and organosulphur compounds and have been demonstrated to possess anti-diabetic potential. But Islam et al. (2008) observed that a high fat diet impaired the antidiabetic effect of freeze dried onion powder in diabetic rat model.
Administration of a sulfur containing amino acid from Allium cepa, S-methyl cysteine sulphoxide (SMCS) (200 mg/kg for 45 days) to alloxan induced diabetic rats significantly controlled blood glucose as well as lipids in serum and tissues and normalized the activities of enzymes involved in glucose metabolism, liver hexokinase, glucose 6-phosphatase and HMG Co A reductase. The hypo-glycemic and hypo-lipidaemic actions of A. cepa were associated with anti-oxidant activity, since superoxide dismutase activities decreased while lipid hydro peroxide and lipoperoxide concentrations did not increase in diabetic rats treated with A. cepa.
Onion peel extract (OPE) improved glucose response and insulin resistance associated with type 2 diabetes by alleviating metabolic dysregulation of free fatty acids, suppressing oxidative stress, up-regulating glucose uptake at peripheral tissues, and/or down-regulating inflammatory gene expression in liver. Moreover, in most cases, OPE showed greater potency than pure quercetin equivalent providing a basis for the use of onion peel to improve insulin insensitivity in type 2 diabetes.
4. Essay on Onion (As an Anti-Inflammatory Foods):
Onion peel extract lowered serum LDL-cholesterol and enhanced HDL- cholesterol through increasing low-density lipoprotein receptor and ATP-binding cassette transporter A1 genes. Supplementation with quercetin-rich onion peel extract was found to influence adipokine expressions, particularly from mesenteric fat, addressing the modulatory effect of this substance on obesity-induced inflammation.
Wang et al. (2013) reported that administration of an aqueous extract of Welsh onion green leaves (WOE) in the range of 0.25 – 1.0 g/Kg showed a concentration dependent inhibition on paw edema development after carrageenan treatment in mice. The anti-inflammatory effects of WOE were closely attributed to decreased levels of tissue NO and tumor necrosis factor-α (TNF-α) along with reduction in lipid oxidation and increase in antioxidant enzyme activities, including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPX) in vivo. In addition, there was a decrease in the number of acetic acid-induced writhing responses and formalin-induced pain in the late phase in mice.
5. Essay on Onion (As an Antimicrobial Foods):
Onion is an exceptionally strong antibiotic and antiseptic food. It was used to treat infections in wounded Russian soldiers during World War II. Latest researches have confirmed the bactericidal properties of onion. A significant growth inhibition was shown in most of the organisms, tested (Gram-positive organisms, Gram-negative organisms and fungi) at random by garlic and onion.
Cholera is a major public health problem in developing countries of the world. The spread of microbial drug resistance is a global public health challenge that results in increased illness and death rate. Bacterial resistance, lack of surveillance data and proper microbiological facilities are major problems regarding diagnosis of cholera.
Thirty-three clinical isolates of Vibrio cholerae tested were sensitive to onion (Allium cepa) extracts of two types (purple and yellow). Purple type of extract had MIC range of 19.2-21.6 mg/ml. The extract of yellow type onion had an MIC range of 66-68.4 mg/ml.