Table 4 Studies showing anti-diabetic properties of bitter gourd fruit and extracts
Sl No | Nature of study | Treatment given | Results obtained | Ref |
|---|---|---|---|---|
1 | In vivo trial in streptozotocin induced diabetic rats | Bitter gourd in powder form incorporated at 10% level at expense of equivalent amount of corn startch in AIN 76 basal diet for 45 days | Improved diabetic status by significant reduction in glomerular filtration rate | Shetty et al. 2005 |
2 | In vivo study in insulin resistant db/db mice | Administration of whole fruit powder, a lipid fraction, a saponin fraction or the hydrophilic residue of bitter gourd at a daily dosage of 150 mg/ kg body weight for 5 weeks | Lower glycated Hb level in all treatment groups Saponin and lipid fraction treated group shown reduced lipid peroxidation in adipose tissue Reduced protein tyrosine phosphate 1 B (PTB 1 B) activity in skeletal muscles (first study to demonstrate PTB 1 B regulation) | Klomann et al. 2010 |
3 | Multicentre, randomised, double blind, active control trial in newly diagnosed type 2 diabetes patients | Bitter melon capsule with 500 mg of dried powder of fruit pulp containing 0.04 – 0.05 (w/w) of charantin at the rate of 500/1000/2000 mg bittermelon per day and 1000 mg metformin per day for 4 weeks. | Modest hypoglycaemic effect and significant reduction in fructosamine levels from baseline in 2000 mg treated patients. But less effect than metformin 100 mg per day | Fuangchan et al. 2011 |
4 | Randomised clinical trial on diabetic patients | 45 ml of bitter gourd fermented beverage as a morning drink | Significant improvement in reducing symptoms of diabetes, reduced fasting and post prandial blood sugar | Devaki & Premavalli 2014 |
5 | In vivo rat model with induced diabetes with streptozotocin | Administration of fruit extract at the rate of 1.5 g /kg of rats for 28 days after induction of diabetes | Improved vascular compilation by decreasing blood pressure, serum total cholesterol, triglyceride levels, aortic tissue MDA level Increased aortic nitrous oxide level | Abas et al. 2015 |
6 | Preliminary clinical trial on non-insulin- dependent diabetes mellitus patients | Powdered bitter gourd made into a tablet having a polypeptide of 20 mg. Dose of 4 to 6 tablets per day half an hour before meals, t.d .s for 8 weeks | Effective oral adjunt hypoglycemic effect without no reportable clinical side effects | Salam et al. 2015 |
7 | In vitro alpha amylase and alpha glucosidase activities | Spectrophotometric assay of protein extracts from two varieties of bitter gourd | Inhibition of alpha amylase and alpha glucosidase activity on par with acarbose. | Poovitha & Parani 2016 |
8 | In vivo assay in streptozotocin induced diabetic rats | 10 mg/ kg body weight of protein extract from bitter gourd cultivars was fed to rats. Blood drawn after 10, 30,60 and 120 min of oral administration | Significant reduction in peak blood glucose and area under the curve | Poovitha & Parani, 2016 |
9 | In vivo study on diabetes induced mice by streptozotocin | Aqueous and ethanol extracts of bitter gourd at the rate of 200 mg / kg weight of mice for 3 weeks | Significant reduction in blood glucose level | Yousaf et al. 2016 |
10 | In vivo study in high sucrose diet induced diabetic rats | Skin, flesh and fruit powder at the rate of 150 and 300 mg / kg body weight for 56 days | Decrease in blood glucose level & increasing serum insulin level at the arte of 300 mg | Mahwish et al. 2018 |
11 | Randomized placebo controlled single blinded clinical trial with 52 individuals with prediabetics | Daily bitter gourd consumption of 2.5 g of powder over a course of 8 weeks: Cross over design, 8 weeks for each study period & 4 weeks wash out. | Lowered fasting plasma glucose | Krawinkel et al. 2018 |