Suppression of apoptosis in vascular endothelial cell, the promising way for natural medicines to treat atherosclerosis

Atherosclerosis, a chronic multifactorial disease, is closely related to the development of cardiovascular diseases and is one of the predominant causes of death worldwide. Normal vascular endothelial cells play an important role in maintaining vascular homeostasis and inhibiting atherosclerosis by regulating vascular tension, preventing thrombosis and regulating inflammation. Currently, accumulating evidence has revealed that endothelial cell apoptosis is the first step of atherosclerosis. Excess apoptosis of endothelial cells induced by risk factors for atherosclerosis is a preliminary event in atherosclerosis development and might be a target for preventing and treating atherosclerosis. Interestingly, accumulating evidence shows that natural medicines have great potential to treat atherosclerosis by inhibiting endothelial cell apoptosis. Therefore, this paper reviewed current studies on the inhibitory effect of natural medicines on endothelial cell apoptosis and summarized the risk factors that may induce endothelial cell apoptosis, including oxidized low-density lipoprotein (ox-LDL), reactive oxygen species (ROS), angiotensin II (Ang II), tumor necrosis factor-α (TNF-α), homocysteine (Hcy) and lipopolysaccharide (LPS). We expect this review to highlight the importance of natural medicines, including extracts and monomers, in the treatment of atherosclerosis by inhibiting endothelial cell apoptosis and provide a foundation for the development of potential antiatherosclerotic drugs from natural medicines.

Nose to brain drug delivery - A promising strategy for active components from herbal medicine for treating cerebral ischemia reperfusion

Cerebral ischemia reperfusion injury (CIRI), one of the major causes of death from stroke in the world, not only causes tremendous damage to human health, but also brings heavy economic burden to society. Current available treatments for CIRI, including mechanical therapies and drug therapies, are often accompanied by significant side-effects. Therefore, it is necessary to discovery new strategies for treating CIRI. Many studies have confirmed that the herbal medicine has the advantages of abundant resources, good curative effect and little side effects, which can be used as potential drug for treatment of CIRI through multiple targets. It's known that oral administration commonly has low bioavailability, and injection administration is inconvenient and unsafe. Many drugs can't delivery to brain through routine pathways due to the blood-brain-barrier (BBB). Interestingly, increasing evidences have suggested the nasal administration is a potential direct route to transport drug into brain avoiding the BBB and has the characteristics of high bioavailability for treating brain diseases. Therefore, intranasal administration can be treated as an alternative way to treat brain diseases. In the present review, effective methods to treat CIRI by using active ingredients derived from herbal medicine through nose to brain drug delivery (NBDD) are updated and discussed, and some related pharmacological mechanisms have also been emphasized. Our present study would be beneficial for the further drug development of natural agents from herbal medicines via NBDD.

Interactions of pharmacokinetic profile of different parts from Ginkgo biloba extract in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Extracts from Ginkgo biloba L. leaves confer their therapeutic effects through the synergistic actions of flavonoid and terpenoid components, but some non-flavonoid and non-terpenoid components also exist in this extract. In the study of this paper, an investigation was carried out to compare the pharmacokinetic parameters of fourteen compounds to clarify the influences of non-flavonoid and non-terpenoid fraction (WEF) on the pharmacokinetics profile of the flavonoid fraction (FF) and the terpene lactone fraction (TLF) from Ginkgo biloba extracts.

MATERIALS AND METHODS

A selective and sensitive UPLC-MS/MS method was established to determine the plasma concentrations of the fourteen compounds to compare the pharmacokinetic parameters after orally administration of FF, TLF, FF-WEF, FF-TLF, TLF-WEF and FF-TLF-WEF with approximately the same dose. At different time points, the concentration of rutin (1), isoquercitrin (2), quercetin 3-O-[4-O-(-β-D-glucosyl)-α-L-rhamnoside] (3), ginkgolide C (4), bilobalide (5), quercitrin (6), ginkgolide B (7), ginkgolide A (8), luteolin (9), quercetin (10), apigenin (11), kaempferol (12), isorhamnetin (13), genkwanin (14) in rat plasma were determined and main pharmacokinetic parameters including T1/2, Tmax, Cmax and AUC were calculated using the DAS 3.2 software package. The statistical analysis was performed using the Student׳s t-test with P<0.05 as the level of significance.

RESULTS

FF and WEF had no effect on the pharmacokinetic behaviors and parameters of the four terpene lactones, but the pharmacokinetic profiles and parameters of flavonoids changed while co-administered with non-flavonoid components. It was found that Cmax and AUC of six flavonoid aglycones in group FF-WEF, FF-TLF and FF-TLF-WEF had varying degrees of reduction in comparison with group FF, especially in group FF-TLF-WEF. On the contrary, the values of Cmax, Tmax and AUC of four flavonoid glycosides in group FF-TLF-WEF were significantly increased compared with those in group FF.

CONCLUSIONS

These results indicate that non-flavonoid components in Ginkgo biloba extracts could increase the absorption and improve the bioavailability of flavonoid glycosides but decrease the absorption and reduce the bioavailability of flavonoid aglycones.