Table 2.
Details regarding plant, its part used, mechanism reported and results observed in clinical trials during diabetes.
| Plant | Clinical trail | Part used | Sample size (n) | Intervention method in intervened groups | Period of treatment | Mechanism reported | Results |
| Aloe vera | A1 | Juice from gel | 72 | 1 tablespoonful aloe juice BID | 42 days | N/A | ↓Blood sugar and triglyceride levels[78] |
| A2 | Juice from gel | 72 | 1 tablespoonful aloe juice BID + 2 glibenclamide (5 mg) tablets | 42 days | N/A | ↓ Glucose and ↓ triglyceride[79] | |
| A3 | Leaves extracted gel powder | 67 | Aloe capsules (300 mg BID) | 2 months | ↓Insulin resistance | ↓HbA1c, LDL, and total cholesterol[80] | |
| A4 | Extract as tablet | 44 | Aloe extract tablets (1000 mg OD) | 2 months | N/A | No reduction in fasting blood sugar, HbA1c, total cholesterol, triglycerides, HDL/LDL[81] | |
| A5 | Powder of the leaves extracted gel | 90 | First intervention: Group 1: no treatment. Group 2: aloe powder (100 mg) Group 3: aloe powder (200 mg) | 3 months | ↑Effectiveness of insulin | ↓Fasting and post prandial blood glucose and lipid profile[82] | |
| Second intervention: nutrition to group 2 and 3. | 3 months | ||||||
| American ginseng | B1 | Opaque gelatin capsule | 39 | Konjac-glucomannan blend fiber (6g/day) + ginseng (3g/day) | 12 weeks with 4 weeks washout period (Crossover) | ↑insulin secretion | ↓ HbA1c and lipid panel[83] |
| B2 | Ginseng root extract | 74 | Capsules (total 3g/day) | 12 weeks | N/A | Safe in T2DM patient with CVS risk (Mucalo et al., 2014) | |
| B3 | Gelatin capsules | 19 | Ginseng capsules (3g) + oral glucose challenge (25g) in each visit | 4 visits (1 week interval between each visit) | ↓Digestion and ↑insulin secretion | Change in glycaemia[84] | |
| B4 | Root of American ginseng | 10 | Either placebo or ginseng 3, 6, or 9 g randomly/each visit | 16 visits with a 3 days interval | ↓Digestion and ↑insulin secretion | No effect on post prandial glycaemia[85] | |
| B5 | Dried whole root extract | 24 | Ginseng capsules (3g/day) | 8 weeks with 4 weeks washout period | ↑Insulin secretion | ↓HbA1c, fasting blood glucose[86] | |
| Bilberry | C1 | Fruit extract | 8 | 0·47 g of Mirtoselect (equal to 50 g of fresh bilberries) | Single dose with 2 weeks washout period | ↓Carbohydrate digestion or absorption | ↓Postprandial glycaemia and insulin[87] |
| Cinnamon | D1 | Capsule | 60 | Cinnamon capsules (500 mg BID) | 3 months | NA | No change in glucose and lipid profile[88] |
| D2 | Aqueous extract as capsule | 60 | 1, 3, 6 g cinnamon daily | 40 days | ↑Stimulation of insulin | ↓Serum glucose and lipid profile[89] | |
| D3 | Whole bark extract as capsule | 25 | Cinnamon 1500 mg/day | 6–7 weeks | ↑Insulin sensitivity | No improvement in glucose[90] | |
| D4 | Capsule | 109 | Cinnamon capsule (1g/day) | 90 days | N/A | ↓HbA1c[91] | |
| D5 | Aqueous cinnamon extract | 79 | Capsule (112 mg of aqueous cinnamon extract TID) | 4 months | N/A | ↓Fasting glucose[92] | |
| D6 | Capsule | 14 | Giving cinnamon capsule 1.5g/day | 30 days | NA | ↓Glucose, triglycerides and cholesterol[93] | |
| D7 | Bark extract as tablet | 66 | Placebo/cinnamon extract at 120 or 360 g/day. | 3 months | NA | ↓Fasting blood glucose and HbA1c[94] | |
| D8 | Capsule | 72 | Cinnamon (1 g/day) | 90 days | ↑Insulin stimulated tyrosine phosphorylation | No significant differences in glucose profile or number of hypoglycemic episodes[95] | |
| D9 | Bark extract as capsule | 44 | Cinnamon supplement (3g/day). | 8 weeks | ↑Insulin stimulated tyrosine phosphorylation | No significant difference in glycemic indicators between arms of the study[96] | |
| D10 | Bark powder as capsule | 58 | Cinnamon (2 g/day) | 12 weeks | ↑Glucose transporter (GLUT4) and receptor proteins | ↓HbA1c and blood pressure[97] | |
| Fenugreek | E1 | Seed extract (Fenfuro-TM) | 174 | Fenfuro capsule (500 mg BID) | 90 days | NA | ↓Post-prandial blood glucose and FBG[98] |
| E2 | Seeds soaked in hot water | 60 | Fenugreek seeds soaked in hot water (10g/day) | 6 months | ↑ Insulin release | ↓FBG levels and HbA1c[99] | |
| E3 | Dried ripe seed capsule | 69 | Fenugreek saponins 6 capsules (TFGs) TID (0.35g/cap) | 12 weeks | NA | ↓Glycemia and CSQS in the treated group[100] | |
| E4 | Seed powder | 24 | Powdered fenugreek seeds (10 g/day) yogurt or with hot water. | 8 weeks | ↑Insulin | ↓FBG[101] | |
| E5 | Hydro-alcoholic seeds extract | 25 | Hydro-alcoholic extract (1g/ day) | 2 months | ↑Insulin release | ↓HbA1c and insulin resistance[102] | |
| E6 | Seed powder | 80 | Fenugreek powder (25g/day) | 2 months | ↑ Insulin release | ↓FBS and HbA1c[103] | |
| E7 | Seed powder | 30 | Two sachet of Polyherbal formulation (PHF) containing fenugreek 2.5 g | 40 days | ↑Insulin | ↓FBG and HbA1c[104] | |
| Garlic | F1 | Aged garlic extract (Kyolic) | 26 | 1200 mg of Aged garlic extract daily | 4 weeks with 4 weeks washout | N/A | No extra benefit for adding aged garlic[105] |
| F2 | Aqueous extract capsule | 32 | Capsules (combination of 200 mg turmeric and 200 mg garlic). Three groups; group 1 (1.2g), group 2 (1.6g) and group 3 (2.4g) daily | 12 weeks | ↑ Insulin secretion | ↓Glucose profile[106] | |
| F3 | Garlic powder tablets (Allicor) | 60 | 300 mg Allicor/day | 4 weeks | ↑Insulin secretion | ↓Blood glucose[107] | |
| F4 | Bulb extract (Lasuna) capsule | 60 | Garlic capsules (250 mg BID) added to standard therapy | 12 weeks | ↑Insulin secretion and sensitivity | ↓Glycemic level[108] | |
| F5 | N/A | 96 | Capsules (50 mg/day) added to standard medication | 12 weeks | N/A | ↓Fasting blood glucose[109] | |
| F6 | Garlic (KWAI) tablet | 60 | Tablets (300 mg TID) | 24 weeks | ↑ Insulin secretion | ↓Fasting blood sugar[110] | |
| F7 | Garlic tablet | 210 | 5 groups received garlic (300, 600, 900, 1200, and 1500 mg/day), one took metformin and one was placebo. | 24 weeks | N/A | ↓FBS and HbA1c[111] | |
| F8 | Kyolic aged garlic extract | 48 | Extract (3g/day) | 3 months | ↑ Insulin secretion | No change in blood glucose[17] | |
| F9 | Bulb extract (Lasuna) capsules | 60 | Capsules (250 mg BID) + metformin. | 12 weeks | Sulfur containing metabolites i.e. allicin and its derivatives | Reduction in fasting blood glucose when used with metformin (250 mg)[112] | |
| Gymnema | G1 | Water-soluble leaves extract | 60 | 2 capsules daily (200 mg/cap) | 2–30 months | ↑Endogenous insulin | ↓Insulin requirements[14] |
| G2 | Water-soluble leaves extract | 47 | Capsule (400 mg/day) | 18–20 months | Beta cells regeneration | Reduced glucose and glycosylated Hgb[15] | |
| G3 | Beta Fast GXR (leaves extract) | 100 | Tablets (400 mg BID) | 90 days | ↑Insulin levels due to regeneration of the pancreatic beta cells | ↓Postprandial plasma glucose, HbA1c and pre-prandial plasma glucose concentrations[113] | |
| G4 | Om Santal Adivasi (OSA) | 11 | Capsules (1 g/day) | 6 days | ↑Insulin secretion | ↓Fasting glucose and ↑serum insulin[114] | |
| G5 | Leaves powder | 20 | Powder (6 g/day) | One month | N/A | ↓Blood glucose and postprandial blood glucose levels[115] | |
| Jambolan | H1 | Dried leaves tea | 27 | Group 1: Syzygium cumini leaves tea (2g/ day) + placebo tablets, Group 2: placebo tea + glyburide tablets (5 mg BID), Group3: placebo tea & tablet | 28 days | N/A | No hypoglycemic effect observed[116] |
| H2 | Dried leaves tea | 27 | Syzygium cumini leaves tea (2g/day) + placebo tablets, placebo tea + glyburide tablets (5 mg BID), placebo tea + placebo tablet | 28 days | N/A | ↓Hyperglycemic effect[117] | |
| Bitter Melon | I1 | Powdered whole karela fruit | 8 | Powder 50 mg/kg BID | 7 days | N/A | Enhanced glucose tolerance[118] |
| I2 | Dried powder of fruit pulp in capsule | 129 | Karela 0.5 g/day, 1 g/day, 2 g/day or metformin 1 g/day. | 4 weeks | N/A | ↓Fructosamine however, the hypoglycemic effect was less than metformin[119] | |
| I3 | Fresh whole fruit in tablet | 50 | Tablets (6 g/day) + standard medication | 4 weeks | N/A | No significant changes observed[120] | |
| I4 | Methanolic fruit soft extract | 15 | Extract (200 mg BID) + half dose metformin/glibenclamide | 7 days | N/A | ↑Hypoglycemic action[121] | |
| I5 | Dried fruit pulp capsule | 95 | Karela (2/4 g/day) or glibenclamide (5 mg/day) | 10 weeks | N/A | ↓HbA1c and plasma glucose[122] | |
| I6 | Extract of fruits/tissue cultures | 9 | Vegetable insulin doses (10/20/30 IU) | One day (single dose) | N/A | ↓Blood glucose[123] | |
| I7 | Dried fruit pulp capsule | 24 | Capsule (2000 mg/day) | 3 months | ↑Insulin secretion | ↓HA1c and insulin AUC[124] | |
| I8 | Charantia Ampalaya capsules | 40 | 2 capsule TID | 3 months | N/A | No significant effect observed[125] | |
| I9 | Fresh unripe fruit juice | 50 | Rosiglitazone (4 mg/day) or bitter melon juice (55 mL/24 h) | 6 months | N/A | No change in serum glucose[126] | |
| Maitake | J1 | Fruit bodies in caplets | Two | First participant; MMP caplet (500 mg TID) reduced to 2caplets/ day | 5 months | ↑Effect on insulin receptors | ↑Glycemic control[127] |
| Second participant; MMP caplet (500 mg TID) | 3 months | ||||||
| Neem | K1 | Powder leave aqueous extract | 400 | Neem extracts (5 mL/day) | 2 months | ↓Carbohydrate absorption from gut | ↓Fasting blood sugar level[18] |
| K2 | Powder leave aqueous extract | 90 | Capsules (2 g/day) of tulsi leaf powder, neem leaf powder or mixture of both | 3 months | N/A | ↓Diabetic symptoms[128] | |
| K3 | Seeds powder | 55 | Moringa oleifera (8g) or neem (6g) per day | 40 days | N/A | ↓Fasting and postprandial blood glucose[129] | |
| Nopal | L1 | N/A | Study 1: 7 | Meal containing 50 g carbohydrates from glucose or dehydrated nopal | 1 visit/each meal (1 week washout period | N/A | ↓Plasma glucose-dependent insulinotropic peptide peaks and serum insulin[130] |
| Study 2: 14 | High-carbohydrate breakfast or high-soy-protein breakfast, with/without 300 g of nopal | 4 visits (1 week washout period between meals) | |||||
| L2 | Fresh and tender stems | 32 | Group 1: broiled nopal stems (500 g), group 2: only water (400 mL), Group 3: nopal, water and broiled squash | Single dose, 1 week washout between each intervention. | ↑Insulin sensitivity is suggested | ↓Glucose and ↑hypoglycemia[131] | |
| L3 | Stems | 28 | 500 g of nopal | Single dose | N/A | ↓Serum glucose and insulin[132] | |
| L4 | Dehydrated extract, capsulated | 6 | 30 capsules of dehydrated nopal extract (10.1 g) | Single dose | N/A | No hypoglycemic effects observed[132] | |
| L5 | Heated blended crude stem | 8 | 5 interventions; 4 for nopal stems (entire broiled, blended broiled, blended crude, and heated blended) and 1 water as placebo. | 5 separate interventions (72 hs between them) | N/A | ↓Serum glucose[132] | |
| L6 | Dried, capsulated | 10 | 30 nopal capsules | Single dose | N/A | No hypoglycemic effect observed[132] | |
| 14 | 10 nopal capsules TID. | 1 week | |||||
| Onion | M1 | Fresh onion cut into slices | 84 | Crude fresh slices (100 g), standard diabetic treatment, or 15 ml of water. | Single dose | Improved and regenerated cells | ↓Blood glucose and FBG[133] |
| Psyllium | N1 | Psyllium pre-mixed in cookies | 77 | Cookies containing either flaxseed/psyllium/placebo (10 g/day) | 12 weeks | N/A | ↓FBG and HbA1c[134] |
| N2 | Psyllium pre-mixed in cookies | 51 | cookies containing either flaxseed/ psyllium/placebo (10g per day) | 12 weeks | N/A | ↓FBG and HbA1c[135] | |
| N3 | Fiber psyllium (Metamucil) | 37 | Psyllium (3.4 g BID), psyllium (6.8 g BID) or placebo. | 12 weeks | ↓Carbohydrate absorption | ↓FBG and HbA1c[136] | |
| N4 | Soluble fiber | 40 | Soluble fiber (10.5 g) daily | 8 weeks | ↓ CHO absorption/digestion | ↓Glucose level[137] | |
| N5 | Psyllium fiber | 18 | 6.8 g psyllium twice in the first visit and placebo in the crossover visits. | One day of treatment for each group (crossover) | ↓Access of glucose to the gut | ↓PBG and insulin concentrations[138] | |
| Siberian ginseng | O1 | Purified solution of extract | 75 | Extract of Siberian ginseng (480 mg/day), American ginseng (480 mg/day), or placebo | 3 months | ↑Glucose induced insulin secretion | ↓Fasting and post prandial blood sugar[139] |
| Turmeric | P1 | (Sina Curcumin) | 70 | Curcumin (80 mg/day) | 3 months | N/A | ↓HbA1c, FBG, TG, and BMI[140] |
| P2 | Capsule | 100 | Curcuminoids capsule (150 mg BID) | 3 months | ↓Serum A-FABP levels | ↓ Blood glucose with anti-diabetic effects[141] | |
| P3 | Rhizomes | 60 | 2 g turmeric + standard metformin therapy. | 4 weeks | ↑Beta cell stimulation | ↓Fasting plasma glucose[16] | |
| P4 | Extracts isolated from rhizome | 100 | Curcuminoids (300 mg/day) | 3 months | ↓BG and ↑insulin resistance | ↓Fasting blood glucose[142] |