α-Amylase and α-Glucosidase inhibitory activity assessment of

Evaluation of Antidiabetic and Antioxidant Activities of Fruit Pulp Extracts of Cucurbita moschata Duchesne and Cucurbita maxima Duchesne

Objective

To evaluate and compare the antidiabetic and antioxidant activities of fruit pulp extracts from Cucurbita moschata (PCMOS) and Cucurbita maxima (PCMAX).

Methods

The antidiabetic activity was carried out in vivo by orally and daily giving the extracts at a dose of 500 mg/kg·b.w. to the streptozotocin-induced diabetic male albino Wistar rats for six weeks. After the period of administration, blood glucose levels, body weight, serum insulin, morphology of islets of Langerhans, biochemical parameters, and haematological values of the rats were determined. Meanwhile, the antioxidant activity was carried out in vitro by determination of total phenolic and flavonoid contents, DPPH radical scavenging activity, and ferric reducing antioxidant power.

Results

PCMAX significantly (p < 0.05) reduced blood glucose levels but increased the body weight, serum insulin levels, size and number of islets of Langerhans, and β-cell number of the treated diabetic rats more than PCMOS did. However, they did not alter biochemical parameters and haematological values of the treated diabetic rats. PCMAX possessed total phenolic and flavonoid contents and showed DPPH scavenging and FRAP reducing antioxidant power more significantly (p < 0.05) than PCMOS.

Conclusions

According to the obtained results, it is indicated that PCMOS and PCMAX possess antidiabetic and antioxidant activities. PCMAX possesses more potent antidiabetic and antioxidant activities than PCMOS. These are probably due to PCMAX providing polysaccharide and total phenolic and flavonoid contents more than PCMOS.

Selected Species of the Cucurbitaceae Family Used in Mexico for the Treatment of Diabetes Mellitus

In Mexico, Diabetes mellitus (DM) is a serious health problem, and although the current pharmacological treatments for DM such as insulin and oral hypoglycemics are available, the Mexican population continues to use medicinal plants in the treatment of DM. The antidiabetic properties of the plant species that belong to the Cucurbitaceae family has already been recognized worldwide. Since Mexico is one of the most important centers of diversity of Cucurbitaceae, the present work contributes to the review of the most used species of Cucurbitaceae in the treatment of DM in Mexico. The reviewed species (Cucurbita ficifolia, C. maxima, C. moschata, C. pepo, Ibervillea sonorae, Sechium edule, Citrullus lanatus, Cucumis melo, and C. sativus) revealed that the antidiabetic effects exerted are effective in a number of mechanisms involved in the complex pathogenesis of DM: hypoglycemic, antioxidant, anti-inflammatory, anti-obesity, protective effects on diverse organs and cells, as well as in the control of dyslipidemias; furthermore, the select species of the Cucurbitaceae family could also be essential components of diets for the control of DM in patients with the disease. Thus, the Cucurbitaceae species selected in the present work represent a source of antidiabetic agents that perhaps establish the bases for novel clinical treatments.

Phyto-constituents profiling of Luffa echinata and in vitro assessment of antioxidant, anti-diabetic, anticancer and anti-acetylcholine esterase activities

Luffa echinata Roxb. is one of the neglected medicinal plants. It is an important source of bioactive metabolites and used in several Ayurvedic formulations. In the present analysis, mature leaves and fruits were extracted with acetone, ethanol, acetonitrile, methanol and water. Phytochemicals like total phenolic (TPC), flavonoid (TFC), tannin (TTC), alkaloid (TAC) and terpenoid (TTEC) content were analysed. Further, antioxidant (AOX) activities like 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, 2,2'-azino-bis-(3-ethyl) benzothiazoline-6-sulfonic acid (ABTS) radical scavenging, metal chelating activity (MC), ferric reducing antioxidant power (FRAP) and phosphomolybdenum assay (PMA) were studied. Highest TPC and TFC (189.57 ± 1.9 mg TAE/g extract, 30.48 ± 0.7 mg CE/g extract, respectively) were reported from acetone extract of the leaves. Ethanolic fruit extract showed the highest TTC (13.79 ± 0.2 mg CE/g extract). Acetone and acetonitrile fruit extract revealed maximum TTEC (602.79 ± 3.5 mg UAE/g extract) and moderate TAC (19.96 ± 0.9 mg GE/g extract), respectively. In AOX, highest DPPH (50.52 ± 0.03 mg AAE/g extract) and ABTS (26.78 ± 0.03 mg TE/g extract) radical scavenging reported in methanolic extract of fruit; however, acetone extract of leaf showed highest FRAP (376.89 ± 1.95 mg Fe(II)/g extract) and PMA (326.54 ± 4.73 mg AAE/g extract). In contrast, aqueous extract of leaf and fruit revealed highest metal chelating activity (41.67 ± 0.49 mg EDTA/g extract). In anti-diabetic studies, acetonitrile extract of leaves and fruits exhibited appreciable inhibition of α-amylase (83.33%) and α-glycosidase (77.42%) enzymes. Similarly, acetyl cholinesterase (AChE) inhibition was highest in water (88.91%) and acetone (81.87%) extracts of leaf and fruits. Fruit extracts showed potent anticancer activity against breast (MCF-7) and colon (HT-29) cancer cell lines (LC50 329.36 and 385.17 µg/mL, respectively). RP-HPLC analysis revealed highest cucurbitacin B (CuB) (196.24 ± 1.4 mg/g DW), followed by cucurbitacin I (CuI) and cucurbitacin E (CuE) in the fruits (57.14 ± 4.9 and 2.03 ± 0.03 mg/g DW, respectively). RP-HPLC analysis of extracts revealed presence of gallic acid (GA), catechin (CA), vanillic acid (VA), chlorogenic acid (CHLA) and coumaric acid (COA), in which highest GA found in the fruits (1.26 ± 0.07 mg/g DW). Liquid chromatography and mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) analysis revealed presence of bioactive compounds from various groups. Based on the present findings, it was revealed that the fruit and leaf of L. echinata can be used as potent bioresource for natural antioxidants, anti-diabetic, and anticancer drug.

Evidence based study of antidiabetic potential of C. maxima seeds - In vivo

Objective

In vitro antidiabetic efficacy of Cucurbita maxima seed extract (CMSE) has already been studied in our previous findings. Thus, in order to validate these findings in biological system, in vivo antidiabetic activity of aqueous extract was investigated in normal as well as diabetic experimental models.

Methods

Variable doses of extract were administered orally to normal and STZ induced mild diabetic rats during fasting blood glucose (FBG) and glucose tolerance test (GTT) studies. In order to determine the extract's antidiabetic potential long-term FBG and post prandial glucose (PPG) studies were also carried out.

Results

Most effective dose of 200 mg kg⁻¹ of CMSE decreases the blood glucose level (BGL) in normal rats by 29.02% at 6 h during FBG studies and 23.23% at 3 h during GTT. However, the maximum reduction observed in BGL of mild diabetic rats during GTT the same interval of time was 26.15%. Moreover, in case of severely diabetic rats a significant reduction of 39.33% was observed in FBG levels whereas, in case of positive control, rats treated with 2.5 mg kg⁻¹ of glipizide, a fall of 42.9% in FBG levels was observed after 28 days. Results of PPG level also showed a fall of 33.20% in severely diabetic rats as compared to the positive control showing a fall of 44.2% at the end of the 28 days.

Conclusion

Thus, the present study validate the hypoglycemic and antidiabetic effect of CMSE and hence this extract could be explored further for developing as a novel antidiabetic agent.