Phytochemical screening and antidiabetic effects of fruit rind of Momordica dioica roxb. on streptozocin induced type 2 diabetic rats

Momordica dioica (M. dioica) is a gourd like blooming plant that is readily available in Bangladesh, requiring biological research to discover its therapeutic values. The goal of our research was to see if the ethanolic extract of this plant had any anti-hyperglycemic properties. Water, glibenclamide and M. dioica extracts were fed to Streptozocin induced type-2 diabetic rat models at a dose of 1.25 g/kg body weight (bw) for 28 days to see what kind of effects they had on serum glucose, insulin, liver glycogen and lipid contents. Except for the control group, all the groups followed a pattern of maintaining the body weight. The oral glucose tolerance test was observed to be improved in extract after 14 days of the experiment. When assessed with the control group, the M. dioica extract showed a significant (p = 0.0015) decrease in postprandial serum glucose level (M±SD, mmol/l, 13.23 ± 1.03 control Vs 11.47 ± 2.21 extract) at 120 min. The treatment of diabetic model rats with extract resulted in a 7% (p < 0.0001) reduction in serum cholesterol levels. While subsequent 28 days of treatment, insulin levels were found to be lowered in all groups (from 246.76 to 200.44 pg/dL; p < 0.0001 for standard and from 309.01 to 204.61 pg/dL; p < 0.0001 for sample). The results revealed that prolonged administration of M. dioica improved the glycemic and lipidemic state of type-2 diabetic rats, implying that more research is needed to identify the active ingredient (s).

α-globulin-rich rice cultivar, low glutelin content-1 (LGC-1), decreases serum cholesterol concentration in exogenously hypercholesterolemic rats

BACKGROUND

Rice α-globulin has been reported to have serum cholesterol-lowering activity in rats. However, it is still unclear whether α-globulin exerts this effect when taken as one of the dietary components. In the present study, we investigated the effect of two cultivars of rice, low glutelin content (LGC)-1 and LGC-Jun, on reducing serum cholesterol in exogenously hypercholesterolemic (ExHC) rats. LGC-1 is enriched in α-globulin (10.6 mg g^-1 rice flour, which is an approximately 1.5 times higher α-globulin content than in Koshihikari a predominant rice cultivar in Japan), whereas LGC-Jun is a globulin-negative cultivar.

METHODS

ExHC rats, the model strain of diet-induced hypercholesterolemia, were fed 50% LGC-1 or LGC-Jun and 0.5% cholesterol-containing diets for 2 weeks, followed by measurement of cholesterol metabolism parameters in serum and tissues.

RESULTS

Serum cholesterol and non-high-density lipoprotein cholesterol levels were significantly lower in the LGC-1 group compared to the LGC-Jun group. Cholesterol intestinal absorption markers, hepatic and serum levels of campesterol and β-sitosterol, and lymphatic cholesterol transport were not different between the two groups. Levels of 7α-hydroxycholesterol, an intermediate of bile acid synthesis, showed a downward trend in the livers of rats that were fed LGC-1 (P = 0.098). There was a significant decrease in the hepatic mRNA expression of Cyp7a1 (a synthetic enzyme for 7α-hydroxycholesterol) in the LGC-1 group compared to the LGC-Jun group.

CONCLUSION

Dietary LGC-1 significantly decreased serum cholesterol levels in ExHC rats. The possible mechanism for the cholesterol-lowering activity of LGC-1 is partial inhibition of bile acid and cholesterol synthesis in the liver. © 2021 Society of Chemical Industry.

Soyasaponin ameliorates obesity and reduces hepatic triacylglycerol accumulation by suppressing lipogenesis in high-fat diet-fed mice

Soyasaponins are triterpenoid glycosides found in soybean. We investigated whether soyasaponin ameliorates lipid metabolism and its possible mechanisms. In C57BL/6J mice fed a high-fat diet (HFD), soyasaponin (SAP) was orally administered for 9 weeks. Additionally, we evaluated the effect of soyasapogenols on 3T3-L1 adipocytes. In HFD-fed mice, the SAP significantly reduced body weight by 7% and relative adipose tissue weight by 35%. X-ray computed tomography demonstrated that the SAP reduced visceral and subcutaneous adipose tissue weights during week 3 of feeding. The SAP reduced sterol regulatory element-binding protein-1c (SREBP-1c) mRNA levels by 32% in the epididymal adipose tissue, significantly decreasing the triacylglycerol (TAG) content by 37% and SREBP-1c and fatty acid synthase mRNA levels by 52% and 61%, respectively, in the liver. In 3T3-L1 adipocytes, soyasapogenol B significantly decreased lipid droplets. The SAP containing soyasaponin A and B as conjugates demonstrate anti-obesity effects by suppressing adipocyte differentiation and lipogenesis, with a preventive effect on hepatic TAG accumulation by suppressing lipogenesis. PRACTICAL APPLICATION: Soyasaponin is one of the oleanane triterpenoids in soybeans. We have demonstrated that soyasaponin potently reduces body weight and white adipose tissue weight, and hepatic triacylglycerol accumulation in high-fat diet-fed mice. Thus, soyasaponin is a beneficial compound to prevent obesity and fatty liver.

Dietary egg white protein inhibits lymphatic lipid transport in thoracic lymph duct-cannulated rats

Dietary egg white protein (EWP) decreases serum cholesterol levels. We previously showed that EWP decreased cholesterol absorption in the intestine. Rats subjected to permanent lymph duct cannulation were used to investigate the effects of dietary EWP on lipid transport. They were fed diets with 20% EWP and casein, and their lymph was collected to quantify lymphatic lipid levels. Dietary EWP decreased lymphatic cholesterol transport compared with casein. It was previously shown that EWP excluded cholesterol from bile acid micelles. Therefore, pepsin-hydrolyzed EWP and casein were prepared. EWP was not completely digested. Ovalbumin, which is the most abundant protein in EWP, showed resistance to digestion by pepsin. This study investigated the effects of EWP pepsin hydrolysate (EWP-ph) on cholesterol micellar solubility, cholesterol transfer from the micellar to the oil phase, water-holding capacity (WHC), settling volume in water (SV), and relative viscosity and compared them with the effects of casein pepsin hydrolysate (C-ph). EWP-ph significantly decreased the micellar solubility and transfer rate and increased the WHC, SV, and relative viscosity compared with C-ph. Moreover, the pepsin hydrolysate of ovalbumin, a major protein in EWP, played a role in decreasing cholesterol micellar solubility, leading to the inhibition of cholesterol absorption. In conclusion, dietary EWP decreased cholesterol intestinal absorption by exerting combined effects of these physicochemical properties in the gut.

Phytochemical, Phytotherapeutical and Pharmacological Study of Momordica dioica

Momordica dioica is a perennial, dioecious, cucurbitaceous climbing creeper (commonly known as kakrol, spiny gourd or teasle gourd). It is native to Asia with extensive distribution in India and Bangladesh. It is used not only as preventive and curative agent for various diseases but also as vegetable with a significant nutritional value over thousands of years. This review aims to take an attempt to evaluate the phytochemical, ethnobotanical, phytotherapeutical and pharmacological properties of kakrol according to the view of traditional medicinal plant based treatment including ayurveda along with recent scientific observations. Kakrol is considered as an underutilized vegetable, although having significant presence of certain compounds containing higher nutritional value than many frequently consumed vegetables. Moreover, as a traditional medicinal plant, it is still potential for its phytochemical components that increase the demand of further extensive evaluation to justify its other therapeutical roles. Therefore, this effort will be helpful to researchers who interested to disclose the unjustified phytotherapeutical role of Momordica dioica.

Ezetimibe inhibits lymphatic transport of esterified cholesterol but not free cholesterol in thoracic lymph duct-cannulated rats

PURPOSE

Ezetimibe has been shown to inhibit dietary cholesterol absorption in animal models and humans, but studies on lymphatic lipid transport have not yet been performed. Rats subjected to permanent lymph duct cannulation were used to investigate the effects of ezetimibe on lipid transport.

METHODS

Rats were fed diets with and without ezetimibe (5.0 mg/kg), and their lymph was collected after feeding to quantify lymphatic lipid levels. Total cholesterol content in the intestinal mucosa was also measured.

RESULTS

Rats that consumed ezetimibe had significantly lower lymphatic total cholesterol transport with the reduction of esterified cholesterol transport. According to the calculation based on cholesterol consumption, ezetimibe reduced the total cholesterol lymphatic recovery rate by 54 %. We also determined that ezetimibe significantly reduced the total cholesterol content in the intestinal mucosa.

CONCLUSION

This is the first direct evidence that ezetimibe inhibits esterified but not free cholesterol lymphatic transport in thoracic duct-cannulated rats. The results also indicate that ezetimibe is not involved in the lymphatic transport of triacylglycerols, phospholipids, or α-tocopherol.

Anti-Allergic Effects of Kakrol (Momordica dioica Roxb.) Flesh Extract

We examined the inhibitory effect of the extract of kakrol extracted by 3 types of solvent (water, 50% and 100% ethanol) on histamine release in human basophilic KU812 cells. The water extract of kakrol flesh showed the strongest inhibitory effect on histamine release as compared with the other extracts. Therefore, we evaluated whether water extract of kakrol flesh had a suppressive effect on development of atopic dermatitis-like lesions in picryl chloride-treated NC/Nga mice. The dietary kakrol flesh water extract alleviated the development of skin lesions in ears accompanied by lower IgE levels and inflammatory cytokines levels in serum. These results indicate that the water extract of kakrol flesh might have therapeutic potential for allergic responses in vitro and in vivo.