Antidiabetic and antioxidant potential of Gardenia latifolia in type-2 diabetic rats fed with high-fat diet plus low-dose streptozotocin

Phytochemical profiling and anticancer potential of gardenia latifolia extracts against arsenic trioxide induced liver fibrosis in rat model

Introduction

Arsenic trioxide (As2O3) is an environmental contaminant that may cause hepatic injuries. As2O3-induced liver injuries are detected as an underlying cause of hepatocellular carcinoma (HCC) around the globe. The present study aimed to investigate the potential of Gardenia latifolia (GL) extracts against oxidative stress and apoptotic activity in HCC-induced rats and to explore in silico molecular docking analysis of phytocompounds of G. latifolia.

Methods

The present study was designed to investigate the hepato-protective effect of ethanol and n-hexane extract of G. latifolia. Phytochemical analysis was performed using gas-chromatography-mass spectrometry (GC-MS), and the identified metabolites were used for computational docking analysis. The binding potential and inhibitory effect of the identified metabolites against inflammatory markers were assessed. Fifty male albino rats were selected for the in vivo study and were randomly divided into five groups, with 10 rats in each group. Group I is the control group. Hepatotoxicity was induced in groups II, III, IV, and V with 350 mg/kg/day of As2O3. Group II was taken as positive control, Group III and IV were treated with ethanol and n-hexane extract of G. latifolia, respectively, and Group V was treated with cisplatin 3.0 mg/kg/day. At the end of treatment, different stress and liver biomarkers were also analyzed.

Results and Discussion

The quantitative phytochemical profiling revealed a high content of total flavonoid and tannins found at 5.731 ± 0.1856 mg quercetin equivalent (QE)/g and 86.31 ± 14.20 mg tannic acid equivalent (TAE)/g in G. latifolia n-hexane extract, while a significant concentration of TFC was 276.821 ± 2.19 mg gallic acid equivalent (GAE)/g, in ethanolic extract. GC-MS analysis resulted in the identification of 26 metabolites in ethanol extract while 32 metabolites in n-hexane extract, respectively. Both the extracts restored the abnormal levels of stress markers (p < 0.05) in Groups III and IV, and were comparable to the comparative control group V, which was given cisplatin as the standard drug. The histopathological examination revealed the regeneration of hepatocytes, dilated sinusoidal cells, necrosis, and distorted hepatic architecture observed in arsenic trioxide hepatotoxic liver. Among the top most identified metabolites from GC-MS analysis, stigmasterol exhibited -8.3 and -7.1 kcal/mol in silico binding affinities against cyclooxygenase-2 (COX-2), and interleukin (IL-6), respectively, while Dasycarpidan-1-methanol exhibited the best binding affinities of -6.8 and -7.2 kcal/mole against matrixmetalloprotinease (MMP)-3 and heat shock protein-90 (HSP-90), respectively. 6-AH-cAMP showed the best docking score of -7.5 kcal/mol for the vascular endothelial growth factor (VEGF) macromolecule. Metabolite Dasycarpidan-1-methanol, acetate represented drug like properties so it was further analyzed by MD simulation and stable dynamic nature of protein ligand complex was evaluated.

Conclusion

In conclusion, the effective therapeutic potential of G. latifolia extracts targeted oxidative stress, increasing antioxidant activities and inhibiting inflammation and liver complications at early stages. Further research on the molecular level may further explore the anticancer potential of this plant against various types of cancers.

Antidiabetic and antioxidant potential of Crocin in high-fat diet plus streptozotocin-induced type-2 diabetic rats

OBJECTIVES

Crocin, the principal water-soluble active constituent of saffron, possesses numerous pharmacological activities. The present investigation examined the potential antidiabetic and antioxidant characteristics of Crocin in rats with type-2 diabetes by administering it orally and intraperitoneally (i.p.).

METHODS

After 2 weeks of a high-fat diet, streptozotocin (STZ) (i.p., 40 mg/kg) was administered to male adult rats to induce type-2 diabetes mellitus. Body weight and fasting blood glucose (FBG) were measured on days zero, weeks 1, and 2. At the end of 2 weeks of drug administration in their respective groups, fasting insulin and glucose levels were estimated, and insulin resistance (HOMA-IR) was determined. Intraperitoneal glucose (IPGTT) and insulin tolerance tests (ITT) were carried out. Histopathological investigation and biochemical parameters were estimated in pancreatic tissues.

RESULTS

The Crocin (100 mg/kg) treatment has significantly improved body weight, abatement of FBG, fasting insulin, and HOMA-IR. Likewise, Crocin treatment significantly improved the glucose and insulin challenges. We observed a significantly marked elevation in endogenous antioxidant enzymes in Crocin-treated groups. Similarly, Crocin treatment reversed the histopathological changes and restored the normal integrity and function of the pancreas.

CONCLUSION

The overall finding indicates that intraperitoneal administration of Crocin demonstrated better control of glycemic level and body weight. Further, it has improved insulin levels in the serum and potentiated antioxidant properties.

Unraveling the Antioxidant Activity of 2R,3R-dihydroquercetin

It has been reported that in an oxidative environment, the flavonoid 2R,3R-dihydroquercetin (2R,3R-DHQ) oxidizes into a product that rearranges to form quercetin. As quercetin is a very potent antioxidant, much better than 2R,3R-DHQ, this would be an intriguing form of targeting the antioxidant quercetin. The aim of the present study is to further elaborate on this targeting. We can confirm the previous observation that 2R,3R-DHQ is oxidized by horseradish peroxidase (HRP), with H2O2 as the oxidant. However, HPLC analysis revealed that no quercetin was formed, but instead an unstable oxidation product. The inclusion of glutathione (GSH) during the oxidation process resulted in the formation of a 2R,3R-DHQ-GSH adduct, as was identified using HPLC with IT-TOF/MS detection. GSH adducts appeared on the B-ring of the 2R,3R-DHQ quinone, indicating that during oxidation, the B-ring is oxidized from a catechol to form a quinone group. Ascorbate could reduce the quinone back to 2R,3R-DHQ. No 2S,3R-DHQ was detected after the reduction by ascorbate, indicating that a possible epimerization of 2R,3R-DHQ quinone to 2S,3R-DHQ quinone does not occur. The fact that no epimerization of the oxidized product of 2R,3R-DHQ is observed, and that GSH adducts the oxidized product of 2R,3R-DHQ on the B-ring, led us to conclude that the redox-modulating activity of 2R,3R-DHQ quinone resides in its B-ring. This could be confirmed by chemical calculation. Apparently, the administration of 2R,3R-DHQ in an oxidative environment does not result in 'biotargeting' quercetin.

Effective Therapeutic Verification of Crocin I, Geniposide, and Gardenia (Gardenia jasminoides Ellis) on Type 2 Diabetes Mellitus In Vivo and In Vitro

For many centuries, Gardenia (Gardenia jasminoides Ellis) was highly valued as a food homologous Chinese herbal medicine with various bioactive compounds, including crocin I and geniposide. However, the functional mechanism underlying the hypoglycemic effect of gardenia is absent in the literature. To evaluate the effect of gardenia and its different extracts on type 2 diabetes mellitus (T2DM) in in vivo and in vitro experiments, the dried gardenia powder was extracted using 60% ethanol and eluted at different ethanol concentrations to obtain the corresponding purified fragments. After that, the active chemical compositions of the different purified gardenia fragments were analyzed using HPLC. Then, the hypoglycemic effects of the different purified gardenia fragments were compared using in vitro and in vivo experiments. Finally, the different extracts were characterized using UPLC-ESI-QTOF-MS/MS and the mass spectrometric fragmentation pathway of the two main compounds, geniposide and crocin I, were identified. The experimental results indicated that the inhibitory effect of the 40% EGJ (crocin I) on the α-glucosidase was better than the 20% EGJ (geniposide) in vitro. However, the inhibitory effect of geniposide on T2DM was better than crocin I in the animal experiments. The different results in vivo and in vitro presumed potentially different mechanisms between crocin I and geniposide on T2DM. This research demonstrated that the mechanism of hypoglycemia in vivo from geniposide is not only one target of the α-glucosidase but provides the experimental background for crocin I and the geniposide deep processing and utilization.