A Review of Traditional Chinese Medicine on Treatment of Diabetic Nephropathy and the Involved Mechanisms.

Diabetic nephropathy (DN) is a common microvascular complication of diabetes mellitus (DM), which can lead to renal failure in diabetic patients. At present, the first-line drugs for DN are mainly the renin-angiotensin system (RAS) inhibitors or angiotensin receptor blockers, and the latest approved aldosterone receptor antagonist finerenone, which delay the progression of DN to end-stage renal disease (ESRD), but the therapeutic effect is still not ideal. With a history of thousands of years, traditional Chinese medicine (TCM) has rich experience in the treatment of DN. Based on the theory of TCM, the clinical treatment of DN mainly focuses on generating fluid and nourishing blood, nourishing Qi and Yin, detoxifying and detumescent. In recently years, the therapeutic effects and mechanisms of TCM prescription, Chinese herbal medicine, and its active components on DN have received extensive attention in new drug development. This paper reviews the research progress of the mechanism of TCM on DN.

Binding effect of fluorescence labeled glycyrrhetinic acid with GA receptors in hepatocellular carcinoma cells.

Glycyrrhetinic acid (GA) is a natural active component from licorice, which is broadly used in traditional Chinese medicine. Lots of glycyrrhetinic acid receptors (GA-R) are proved to locate on the surface of liver cells. Many reports about the hepatocellular carcinoma (HCC) treatment were dependent on GA modified carriers. However, the reality of GA-R in HCC cells was not clear. In this paper, 18ß-glycyrrhetinic acid (18ß-GA) was labeled with fluorescence (FITC) by chemical synthesis. Together with the binding effect of fluorescence labeled glycyrrhetinic acid (FITC-GA), the competitive action of 18ß-GA with GA-R was investigated in HCC cells. The results showed that in HepG2 cells, 18ß-GA and FITC-GA presented similar cytotoxicity. The specific binding saturation of GA showed the dissociation constant (Kd) was 7.457±2.122pmol/L and the maximum binding counts (Bmax) was 2.385±0.175pmol/2.5×106 cells, respectively. FITC-GA bound to cytomembrane specifically and 18ß-GA competed to bind the sites significantly in HepG2 cells. Therefore, there is binding effect between fluorescence labeled GA and GA-R. The GA-R on HCC cells is confirmed as expected, which provides a useful reference of active target modified by GA and a novel approach for receptors and ligands study.

[Biological assay in quality control of animal medicines].

Animal medicine is a unique part of traditional Chinese medicine. They have strong effects, but their effective compounds are not entirely known. The efficiency and safety of animal medicines can't be effectively controlled by current quality assurance system and evaluation method, which has deeply influenced the development of animal medicines. Biological assay does not focus on efficacy of single component, but directly reflects the pharmacodynamics and safety of animal medicines by biological effect. With the development of biotechnology, many new technologies have emerged, such as biochip and high content analysis. Based on the related targets, pathways and key biochemical factors, the field of biological assay has been expanded. With advantages of pharmacology andoverall controllability, as well as the characteristics of in line with the quality control of Chinese Medicine, biological assay will become one of the important development directionsfor quality standardization of animal medicines.

Toxic effects caused by rhubarb (Rheum palmatum L.) are reversed on immature and aged rats.

AIM OF THE STUDY: Rhubarb is generally used to people of broad age, but diverse responses of people at different age to rhubarb have been little clarified. In this study, an attempt was made to access the safety of rhubarb to both immature and aged rats to provide some references for its clinical usage. MATERIALS AND METHODS: The total extract of rhubarb was administered intragastricly to both immature and aged rats once a day and lasted for 5 weeks. Then histopathologic and biochemical examinations were performed. RESULTS: No death was observed in immature rat groups, while 23.3% (21/90) subjects in aged rat groups died and most of the death cases were observed in the high-dosage (40 gkg(-1) of body weight per day od, counted on the quantity of crude material) group. The death rate between aged and immature rats was found of significantly statistical difference. Dosage-dependent histopathologic changes in kidney were observed in all the rhubarb-treated rats, principally involving the proximal tubules. Kidney changes in aged rats were severer than those observed in immature ones. Hepatic cells necrosis was occasionally observed in the middle- and high-dosage aged rat groups and minimal biliary hyperplasia was found in all the rhubarb-treated aged rats. Increased incidences of activated Kupffer cells and lymphocytic infiltration were found in all the rhubarb-treated rats. And dosage-dependent increase of interleukin 6 (IL-6) and notable increase of IL-8 was found in aged rat groups. CONCLUSIONS: The immature and aged rats showed reversed responses to the toxic potential of rhubarb extract. Elderly subjects were susceptible to the toxicity of high-dosage rhubarb, which drove rigorous consideration on rational use of rhubarb to aged people.

The diarrhoeogenic and antidiarrhoeal bidirectional effects of rhubarb and its potential mechanism.

AIM OF THE STUDY: The present study investigated the pharmacological effects of different extracts of rhubarb on intestinal function of mice, further to explore possible reasons for the adverse effects of long-term use of rhubarb as a purgative. MATERIALS AND METHODS: The total extract of rhubarb (TR) was extracted with 60% ethanol and the total anthraquinones extract (TA), total tannins extract (TT) and remaining components extract (RC) of rhubarb were separated from TR using macroporous resin. The pharmacological effects of each extract on the intestinal function of mice were evaluated by defecation test and the antidiarrhoeal activity of rhubarb tannins as well as its mechanism was studied by different animal models and histopathological examination. RESULTS: Both TR and TA produced purgative activities, but the purgative activity of TA was stronger than that of TR. Successive administration of TT produced an antidiarrhoeal activity in a time- and dose-dependent manner. Besides, successive administration of RC showed no significant effect on the intestinal function of mice. The antidiarrhoeal activity of rhubarb tannins was confirmed directly for the first time and its mechanism was probable that rhubarb tannins generated protein-precipitating reaction to the gastrointestinal mucosa due to its protein-precipitating action. CONCLUSIONS: The results confirmed that rhubarb had the diarrhoeogenic and antidiarrhoeal bidirectional effects due to the coexistence of anthraquinones and tannins. The bidirectional effects might be the reason or one of the reasons for the adverse effects of long-term use of rhubarb as a purgative.

Binding of berberine to bovine serum albumin: spectroscopic approach.

Fluorescence spectroscopy in combination with UV-vis absorption spectroscopy was employed to investigate the binding of an important traditional medicinal herb berberine to bovine serum albumin (BSA) under the physiological conditions. In the mechanism discussion, it was proved that the fluorescence quenching of BSA by berberine is a result of the formation of berberine-BSA complex. Fluorescence quenching constants were determined using the Stern-Volmer equation and Scatchard equation to provide a measure of the binding affinity between berberine and BSA. The results of thermodynamic parameters ΔG, ΔH, ΔS at different temperatures indicate that the electrostatic interactions play a major role for berberine-BSA association. Site marker competitive experiments indicated that the binding of berberine to BSA primarily took place in site II. Furthermore, the Effect of supramolecules to berberine-BSA system, and the distance r between donor (BSA) and acceptor (berberine) was obtained according to fluorescence resonance energy transfer (FRET).