2β-hydroxybetulinic acid 3β-caprylate: an active principle from Euryale Ferox Salisb. seeds with antidiabetic, antioxidant, pancreas & hepatoprotective potential in streptozotocin induced diabetic rats

Abstract

The aim of the present study was to evaluate the glycemic control, antioxidant, pancreas and liver protective effect of 2β-hydroxybetulinic acid 3β-caprylate (HBAC) from Euryale ferox Salisb. seeds on streptozotocin induced diabetic rats. The active principle was isolated from Euryale ferox Salisb. seeds extract by utilizing chromatographic techniques. The rats were divided into seven experimental groups: Gp 1-normal; Gp2- normal + HBAC (60 mg/kg p.o.); Gp3- diabetic control; Gp 4- Diabetic + HBAC (20 mg/kg p.o.); Gp5- Diabetic + HBAC (40 mg/kg p.o.); Gp6- Diabetic + HBAC (60 mg/kg p.o.) and Gp 7- Diabetic + Glibenclamide (10 mg/kg p.o.). Biochemical estimation, free radical scavenging examination and histopathological study was performed at the end of experimentation i.e. on 28th day. The active principle isolated and identified with spectral data as 2β-hydroxybetulinic acid 3β-caprylate (HBAC). It was detected for the first time that HBAC has improvised the glycemic control in streptozotocin induced diabetic rats. Furthermore, it is remarkable to note that it exhibited excellent free radical scavenging property and pancreas and hepatoprotective property as well, supported by histopathological examination. One of the mechanisms of action of HBAC appears to be stimulating the release of insulin from pancreatic β-cells. HBAC improved the glycemic control, reduced the free radical activity along with corrected glycemic control, lipid profile, and enhanced level of insulin alongh with improvement in pancreas and hepatoprotective architecture. Considering the above results, HBAC shows potential to develop a medicine for diabetes as combinatorial or mono-therapy.

Keywords: Diabetes; Euryale ferox; HBAC; Seeds.

Fig. 1

Structure of 2β-hydroxybetulinic acid 3β-caprylate

Fig. 2

Effect of isolate HBAC on histological profile of pancreas in normal, STZ-induced diabetic untreated and STZ-induced diabetic treated wistar rats (original magnification 40×, DXIT 1200, Nikon, Japan). (i) NPAN Heamatoxylin and eosin (H/E) stained sections of pancreas of normal control rat portraying normal islet of langerhans shown by yellow arrows (ii) NPHBAC-60 Pancreatic section of normal rats received 60 mg/kg body wt. of HBAC showing normal islets, along with normal beta cells (iii) PSTZ Pancreatic section of streptozotocin induced diabetic rat showing no/destroyed islet of langerhans and beta cells depicted by red arrows. (iv) SPHBAC-20 Pancreatic section of STZ-induced diabetic rats treated with HBACat 20 mg/kg body wt. showing small number of islet of langerhans (green arrows). (v) SPHBAC-40 Section of pancreas of STZ-induced diabetic rats treated with HBAC at 40 mg/kg body wt. portraying increased number of islet of langerhans with small proportions of beta cells (green arrows). (vi) SPHBAC-60 Pancreas of diabetic rats treated with 60 mg/kg body wt. HBAC depicting nearly normal islet of langerhans (green arrows (vii) SPHBACGLIM Pancreatic section of diabetic rats treated with Glibenclamide showing normal pancreatic islet of langerhans with enhancement in the number of beta cells (dark yellow arrow)

Fig. 3

Effect of isolated HBAC on histological profile of liver in normal, STZ-induced diabetic untreated and STZ-induced diabetic treated wistar rats (original magnification 40×, DXIT 1200, Nikon, Japan). (i) NLIV Heamatoxylin and eosin (H/E) stained sections of liver of normal control rats showing normal portal triad along with normal hepatocytes with central vein (yellow arrows).(ii) LHBAC-60 Hepatic section of normal rat received 60 mg/kg body wt. of HBAC depicting normal portal triad and hepatocytes (yellow arrows) (iii) STZ-L Liver section of rats received streptozotocin depicting destructed portal trial, disarranged hepatocytes and central vein (red arrows).(iv) SLHBAC-20 Section of liver supplemented with 20 mg/kg body wt. of HBACportaying improvement in structure of portal triad (green arrows). (v) SLHBAC-40 Liver section of rats received 40 mg/kg body wt. of HBAC showing arranged hepatocytes (green arrows). (vi) SLHBAC-60 Section of liver or diabetic rats treated with 60 mg/kg body wt. of HBAC depicting arranged central vein (green arrows). (vii) LGLIM Liver section of rat administered with Glibenclamide showing normal microvasculature along with normal hepatocytes (dark yellow arrows)

Fig 4

Effect of isolate HBAC on histological profile of kidney in normal, STZ-induced diabetic untreated and STZ-induced diabetic treated wistar rats. (Original magnification 40×, DXIT 1200, Nikon, Japan). (i) NKID Heamatoxylin and eosin (H/E) stained sections of kidney of normal control rats showing normal glomeruli with normal baseline and tubules (yellow arrow). (iii) KHBAC-60 Section of kidney of normal rats received 60 mg/kg body wt. of HBAC showing normal glomeruli and tubules (yellow arrows) (ii) STZ-K Section of kidney of STZ-induced diabetic rats depicting destroyed glomeruli with fat deposition on baseline along with infiltration of lymphocytes (red arrows). (iv) SKHBAC-20 Kidney section of diabetic rats treated with HBAC at dose of 20 mg/kg body wt. portraying improved vasculature and glomeruli (green arrows). (iv) SKHBAC-40 Section of kidney of diabetic rats treated with 40 mg/kg body wt. of HBAC showing normal tubules along with virtually improved structure of glomeruli (green arrows). (v) SKHBAC-60 Kidney section of diabetic treated rats with 60 mg/kg body wt of HBAC depicting nearly normal glomeruli (green arrows). (vii) K-GLIM Section of kidney of the rat supplemented with Glibenclamide showing normal glomeruli with improved structure of tubules (dark yellow arrows)