In vivo antidiabetic effects of phenolic compounds of spinach, mustard, and cabbage leaves in mice

Abstract

Leafy vegetables are considered to have health-promoting potentials, mainly attributed to bioactive phenolic compounds. The antidiabetic effects of spinach, mustard, and cabbage were studied by feeding their phenolic-rich aqueous extracts to alloxan-induced diabetic mice. The antioxidant, biochemical, histopathological, and hematological indices of the control, diabetic, and treated mice were studied. Phenolic compounds present in the extracts were identified and quantified using HPLC-DAD. Results showed ten, nineteen, and eleven phenolic compounds in spinach, mustard, and cabbage leave aqueous extracts, respectively. The body weight, tissue total glutathione (GSH) contents, fasting blood sugar, liver function tests, renal function tests, and lipid profile of the mice were affected by diabetes and were significantly improved by the extract treatments. Likewise, hematological indices and tissues histological studies also showed recovery from diabetic stress in treated mice. The study's findings highlight that the selected leafy vegetables potentially mitigate diabetic complications. Among the studied vegetables, cabbage extract was comparatively more active in ameliorating diabetic stress.

Keywords: Antidiabetic potential; Cabbage; Diabetes; Mustard; Phenolic compounds; Spinach.

Fig. 1

HPLC-DAD chromatograms of the leaves extracts at 320 nm. (A) Spinach, (B) cabbage, and (C) mustard.

Fig. 2

Effect of spinach, mustard, and cabbage leaves extracts on the body weight of mice. Abbreviations: C (non-diabetic control group), D (diabetic control group), and G (fed with antidiabetic drug i.e., Glucophage with a dose of 8.32 mg/kg body weight), SP (fed with spinach extract), BR (fed with mustard extract), CB (fed with cabbage extract), and 1, 2, and 3 of SP, BR, and CB are different doses. Data are the mean of replicate measurements with standard deviation (n = 5). * = vs control (C) group, # = vs diabetic (D), * = 0.03, ** = 0.002, *** < 0.001, # = 0.03, ## = 0.002, ### < 0.001 using Dunnett’s multiple comparison test.

Fig. 3

Effect of spinach, mustard, and cabbage leaves extracts on the total glutathione levels (GSH) (A) liver, and (B) kidneys of mice. Abbreviations: C (non-diabetic control group), D (diabetic control group), and G (fed with antidiabetic drug i.e., Glucophage with a dose of 8.32 mg/kg body weight), SP (fed with spinach extract), BR (fed with mustard extract), CB (fed with cabbage extract), and 1, 2, and 3 of SP, BR, and CB are different doses. Data are the mean of triplicate measurements with standard deviation. * = vs control (C) group, # = vs diabetic (D), ** = 0.002, *** < 0.001, ## = 0.002, ### < 0.001 using Dunnett’s multiple comparison test.

Fig. 4

Effect of spinach, mustard, and cabbage leaves extracts on the liver of mice. (A) Control, (B) diabetic, (C) positive control, (D) Spinach extract, (E) mustard, and (F) cabbage. Abbreviations are CV, central vein; H, hepatocytes; K, Kupfer cells; and F, fats.

Fig. 5

Effect of spinach, mustard, and cabbage leaves extracts on the kidney of mice. (A) Control, (B) diabetic, (C) positive control, (D) Spinach extract, (E) mustard, and (F) cabbage. Abbreviations are GC, Glomerular corpuscle; Hy, hyalinization of kidney tubules; LP, lymphocytic proliferation; DCT, Distal convoluted tubules; PCT, Proximal convoluted tubules; and CV, central vein.