Pharmacokinetic interaction of curcumin and glibenclamide in diabetic rats

Hypoglycemic and hypolipidemic activity of combined milk thistle and fenugreek seeds in alloxan-induced diabetic albino rats

BACKGROUND AND AIM

Despite the availability of antidiabetic drugs, they are not free from associated adverse side effects. This study aimed to evaluate the hypoglycemic and hypolipidemic effects of oral administration of seeds from two medicinal plants: (1) Milk thistle and (2) fenugreek.

MATERIALS AND METHODS

Plant seeds were washed in distilled water and ground with a coffee grinder. Alloxan was used to induce diabetes in 20 male albino rats. Diabetic rats were randomly divided into two groups: (1) Group 1 (n=10), diabetic rats fed with 0.5 g/kg milk thistle and 2 g/kg fenugreek seeds per day and (2) Group 2 (n=10), diabetic rats fed standard rodent food for 4 weeks.

RESULTS

Oral administration of milk thistle and fenugreek seeds for 2 weeks resulted in significant improvement in body weight, blood glucose, glycosylated hemoglobin (HbA1c), cholesterol, and triglyceride levels in alloxan-induced diabetic rats. After 4 weeks, this ameliorative effect was significantly elevated with respect to blood glucose (155.00±9.70 mg/dL vs. 427.50±5.70 mg/dL; p<0.001), HbA1c (5.5±0.19% vs. 13.65±1.77%; p<0.001), cholesterol (281.50±10.95 mg/dL vs. 334.30±6.80 mg/dL; p<0.001), triglyceride (239.60±6.87 mg/dL vs. 284.20±9.95 mg/dL; p<0.01), and body weight (265.30±8.10 g vs. 207.40±11.4 g; p<0.01) as compared with non-treated diabetic rats.

CONCLUSION

Milk thistle and fenugreek seeds possess hypoglycemic and hypolipidemic properties and could be used as natural compounds that are suitable as parent compounds for the development of new antidiabetic drugs.

Hypoglycemic and Toxic Effect of Morus mesozygia Leaf Extract on the Liver and Kidneys of Alloxan-Induced Hyperglycemic Wistar Rats

Purpose

We investigated the hypoglycemic and toxic effect of Morus mesozygia leaf extract on the liver and kidneys of alloxan-induced hyperglycemic wistar rats.

Method

Phytochemical analysis was done. Diabetes was induced by the use of alloxan monohydrate in six groups of rats, i.e., 200 mg/kg, 400 mg/kg, 800 mg/kg, glibenclamide, normal saline, and normal control group. Blood glucose was measured at the time of inoculation, then at 1, 2, 3, and 4 hours after. After 14 days, rats were killed under anesthesia; blood collected for measurement of total protein, albumin, TAGs, cholesterol, AST, ALT, urea, and creatinine; and whole tissue of liver and kidneys used for histological studies.

Results

The extract possessed antidiabetic effects between 400 mg/kg and 800 mg/kg doses, which we attributed to the presence of flavonoids, tannins, terpenoids, and amino acids. There was a drop in total protein and albumin with no statistical significance (P ≥ 0.05). The changes in levels of ALT, TAGs, cholesterol, AST, creatinine, and urea were not statistically different from the standard diabetic drug. The extract was protective against histological damage as there were no significant lesions suggestive of toxicities in the liver and kidneys at doses below 800 mg/kg.

Conclusion

We established credible evidence that Morus mesozygia leaf extract has hypoglycemic effects between 400 mg/kg and 800 mg/kg and that it is safe on the liver and kidneys of wistar rats at doses less than 800 mg/kg.

Preventive Effect of Curcumin Against Chemotherapy-Induced Side-Effects

Cancer is still a severe threat to the health of people worldwide. Chemotherapy is one of main therapeutic approaches to combat cancer. However, chemotherapy only has a limited success with severe side effects, especially causing damage to normal tissues such as bone marrow, gastrointestine, heart, liver, renal, neuron, and auditory tissues, etc. The side-effects limit clinical outcome of chemotherapy and lower patients’ quality of life, and even make many patients discontinue the chemotherapy. Thus, there is a need to explore effective adjuvant strategies to prevent and reduce the chemotherapy-induced side effects. Naturally occurring products provide a rich source for exploring effective adjuvant agents to prevent and reduce the side effects in anticancer chemotherapy. Curcumin is an active compound from natural plant Curcuma longa L., which is widely used as a coloring and flavoring agent in food industry and a herbal medicine in Asian countries for thousands of years to treat vomiting, headache, diarrhea, etc. Modern pharmacological studies have revealed that curcumin has strong antioxidative, anti-microbial, anti-inflammatory and anticancer activities. Growing evidence shows that curcumin is able to prevent carcinogenesis, sensitize cancer cells to chemotherapy, and protect normal cells from chemotherapy-induced damages. In the present article, we review the preventive effect of curcumin against chemotherapy-induced myelosuppression, gastrointestinal toxicity, cardiotoxicity, hepatotoxicity, nephrotoxicity, neurotoxicity, ototoxicity, and genotoxicity, and discuss its action mechanisms.

Evidence against the participation of a pharmacokinetic interaction in the protective effect of single-dose curcumin against gastrointestinal damage induced by indomethacin in rats

OBJECTIVE

To determine the role of a pharmacokinetic interaction in the protective effect of curcumin against the gastric damage induced by indomethacin administration as such or as its prodrug acemetacin.

METHODS

Wistar rats orally received single dose of indomethacin (30 mg/kg) with and without curcumin (30 mg/kg); gastric injury was evaluated by determining the total damaged area. Additional groups of rats received an oral single dose of indomethacin (30 mg/kg) or its prodrug acemetacin (34.86 mg/kg) in the presence or absence of curcumin (30 mg/kg). Indomethacin and acemetacin concentrations in plasma from blood draws were determined by high-performance liquid chromatography.Plasma concentration-against-time curves were constructed, and bioavailability parameters, maximal concentration (C_max) and area under the curve to the last sampling time (AUC_0-t) were estimated.

RESULTS

Concomitant administration of indomethacin and curcumin resulted in a significantly reduced gastric damage compared to indomethacin alone. However, co-administration of curcumin did not produce any significant alteration in the bioavailability parameters of indomethacin and acemetacin after administration of either the active compound or the prodrug.

CONCLUSION

Curcumin exhibits a protective effect against indomethacin-induced gastric damage, but does not produce a reduction of the bioavailability of this nonsteroidal anti-inflammatory drug, indomethacin. Data thus suggest that a pharmacokinetic mechanism of action is not involved in curcumin gastroprotection.