Protective Effect of Ginsenoside R0 on Anoxic and Oxidative Damage In vitro

Neuroprotection and mechanisms of ginsenosides in nervous system diseases: Progress and perspectives

Ginsenosides are the primary component discernible from ginseng, including Rb1, Rb2, Rd, Rg1, Rg2, and compound K, and so forth. They have been shown to have multiple pharmacological activities. In recent years, more and more studies have been devoted to the neuroprotection of various ginsenosides against neurological diseases and their potential mechanisms. This paper comprehensively summarizes and reviews the neuroprotective effects of various ginsenosides on neurological diseases, especially acute and chronic neurodegenerative diseases, and their mechanisms, as well as their potential therapeutic applications to promote neuroprotection in disease prevention, treatment, and prognosis. Briefly, ginsenosides exert effective neuroprotective effects on neurological conditions, including stroke, Alzheimer's disease, Parkinson's disease, and brain/spinal cord injuries through a variety of molecular mechanisms, including anti-inflammatory, antioxidant, and anti-apoptotic. Among them, some signaling pathways play important roles in related processes, such as PI3K/Akt, TLR4/NF-κB, ROS/TXNIP/NLRP3, HO-1/Nrf2, Wnt/β-catenin, and Ca2+ pathway. In conclusion, the present study reviews the research progress on the neuroprotective effects of ginsenosides in the last decade, with the aim of furnishing essential theoretical underpinning and effective references for further research and exploration of the multiple medicinal values of Chinese herbal medicines and their small molecule compounds, including ginseng and panax ginseng. Because there is less evidence in the existing clinical studies, future research should be focused on clinical trials in order to truly reflect the clinical value of various ginsenosides for the benefit of patients.

Therapeutic mechanisms of ginseng in coronary heart disease

Coronary heart disease (CHD) is the most common clinical manifestation of cardiovascular disease. It is characterized by myocardial ischemia, which is caused by coronary atherosclerosis. CHD is a significant global health problem with increasing prevalence every year because of significant changes in the lifestyles and diets. Ginseng is a traditional Chinese medicinal herb that has been used in food preparations and traditional medicine for several centuries. Several studies have demonstrated that ginseng improved cardiac function by normalizing blood glucose levels and decreasing blood pressure, oxidative stress, platelet aggregation, and lipid dysregulation in vivo. This review describes the current understanding of the mechanisms by which ginseng alleviates CHD, and provides a reference for the clinical development and application of ginseng as an alternative therapy for CHD.

Identification of two UDP-glycosyltransferases involved in the main oleanane-type ginsenosides in Panax japonicus var. major

Two UDP-glycosyltransferases from Panax japonicus var. major were identified, and the biosynthetic pathways of three oleanane-type ginsenosides (chikusetsusaponin IVa, ginsenoside Ro, zingibroside R₁) were elucidated. Chikusetsusaponin IVa and ginsenoside Ro are primary active components formed by stepwise glycosylation of oleanolic acid in five medicinal plants of the genus Panax. However, the key UDP-glycosyltransferases (UGTs) in the biosynthetic pathway of chikusetsusaponin IVa and ginsenoside Ro are still unclear. In this study, two UGTs (PjmUGT1 and PjmUGT2) from Panax japonicus var. major involved in the biosynthesis of chikusetsusaponin IVa and ginsenoside Ro were identified based on bioinformatics analysis, heterologous expression and enzyme assays. The results show that PjmUGT1 can transfer a glucose moiety to the C-28 carboxyl groups of oleanolic acid 3-O-β-D-glucuronide and zingibroside R₁ to form chikusetsusaponin IVa and ginsenoside Ro, respectively. Meanwhile, PjmUGT2 can transfer a glucose moiety to oleanolic acid 3-O-β-D-glucuronide and chikusetsusaponin IVa to form zingibroside R₁ and ginsenoside Ro. This work uncovered the biosynthetic mechanism of chikusetsusaponin IVa and ginsenoside Ro, providing the rational production of valuable saponins through synthetic biology strategy.

Neuroprotective Effects of Ginsenosides against Cerebral Ischemia

Ginseng has been used worldwide as traditional medicine for thousands of years, and ginsenosides have been proved to be the main active components for their various pharmacological activities. Based on their structures, ginsenosides can be divided into ginseng diol-type A and ginseng triol-type B with different pharmacological effects. In this study, six ginsenosides, namely ginsenoside Rb1, Rh2, Rg3, Rg5 as diol-type ginseng saponins, and Rg1 and Re as triol-type ginseng saponins, which were reported to be effective for ischemia-reperfusion (I/R) treatment, were chosen to compare their protective effects on cerebral I/R injury, and their mechanisms were studied by in vitro and in vivo experiments. It was found that all ginsenosides could reduce reactive oxygen species (ROS), inhibit apoptosis and increase mitochondrial membrane potential in cobalt chloride-induced (CoCl₂-induced) PC12 cells injury model, and they could reduce cerebral infarction volume, brain neurological dysfunction of I/R rats in vivo. The results of immunohistochemistry and western blot showed that the expression of Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), silencing information regulator (SIRT1) and nuclear transcription factor P65 (NF-κB) in hippocampal CA1 region of some ginsenoside groups were also reduced. In general, the effect on cerebral ischemia of Rb1 and Rg3 was significantly improved compared with the control group, and was the strongest among all the ginsenosides. The effect on SIRT1 activation of ginsenoside Rb1 and the inhibition effect of TLR4/MyD88 protein expression of ginsenoside Rb1 and Rg3 were significantly stronger than that of other groups. The results indicated that ginsenoside Rg1, Rb1, Rh2, Rg3, Rg5 and Re were effective in protecting the brain against ischemic injury, and ginsenoside Rb1 and Rg3 have the strongest therapeutic activities in all the tested ginsenosides. Their neuroprotective mechanism is associated with TLR4/MyD88 and SIRT1 activation signaling pathways, and they can reduce cerebral ischemic injury by inhibiting NF-κB transcriptional activity and the expression of proinflammatory cytokines, including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6).

Therapeutic Effects of Cyathula officinalis Kuan and Its Active Fraction on Acute Blood Stasis Rat Model and Identification Constituents by HPLC-QTOF/MS/MS

BACKGROUND

Cyathula officinalis Kuan is widely used in the clinics for the treatment of blood stasis in China.

OBJECTIVE

To evaluate the improving blood rheology and anti-inflammatory properties of C. officinalis Kuan extract (CO) and its active fraction (ACO) on acute blood stasis model Wistar rats and characterize the correlative constituents.

MATERIALS AND METHODS

CO at 0.26, 0.53, and 1.04 g/kg and ACO at 0.38, 0.75, and 1.5 g/kg were administered to acute blood stasis model Wistar rats for 3 days. Whole blood viscosity, plasma viscosity, and the levels of interleukin-6 (IL-6), nitric oxide (NO), tumor necrosis factor alpha (TNF-α), and cyclooxygenase-2 (COX-2) in the plasma were measured. HPLC-QTOF/MS/MS method was used to identify the major constituents of ACO; the properties of two representative components (cyasterone and chikusetsusaponin IV) from ACO on thrombin-induced human umbilical vein endothelial cells damage model were also assessed by the levels of thromboxane A2 (TXA2), endothelin (ET), malondialdehyde (MDA), COX-2, endothelial nitric oxide synthase (eNOS), and superoxide dismutase (SOD).

RESULTS

CO and ACO significantly reduced whole blood viscosity, plasma viscosity, and levels of IL-6, NO, TNF-α, and COX-2 in vivo. Forty compounds were identified from ACO, mainly as phytoecdysteroids and saponins. Cyasterone and chikusetsusaponin IV could significantly inhibit levels of TXA2, ET, MDA, and COX-2 and promote the activities of eNOS and SOD in vitro.

CONCLUSION

CO and ACO possessed significant improving blood rheology and anti-inflammatory effects on acute blood stasis model rats and the representative components Cyasterone and chikusetsusaponin IV showed significant anti-inflammatory, antioxidant, and anticoagulant effects in vitro.

SUMMARY

Cyathula officinalis Kuan is widely used in the clinic for the treatment of blood stasis in ChinaThe C. officinalis Kuan extract and the active fraction of C. officinalis Kuan (ACO) possessed significant improving blood rheology and anti-inflammatory effects on acute blood stasis model ratsForty compounds were identified from ACO, mainly as phytoecdysteroids and saponins Abbreviations used: TCM: Traditional Chinese Medicine, CO: Cyathula officinalis Kuan extract, ACO: Active fraction of Cyathula officinalis Kuan, ROS: Reactive oxygen species, IL-6: Interleukin-6, TNF-α: Tumor necrosis factor alpha, NO: Nitric oxide, COX-2: Cyclooxygenase-2, TXA2: Thromboxane A2, ET: Endothelin, MDA: Malondialdehyde, eNOS: Endothelial nitric oxide synthase, SOD: Superoxide dismutase, ESI: Electronic spray ionization, ELISA: Enzyme-linked immunosorbent assay, HUVECs: Human umbilical vein endothelial cells, DMEM: Dulbecco's modified Eagle medium, MMP: Matrix metalloproteinase.

The beneficial effect of ginsenosides extracted by pulsed electric field against hydrogen peroxide-induced oxidative stress in HEK-293 cells

Background

Ginsenosides are the main pharmacological components of Panax ginseng root, which are thought to be primarily responsible for the suppressing effect on oxidative stress.

Methods

2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and oxygen radical absorption capacity were applied to evaluate the antioxidant activities of the ginsenosides. Human embryonic kidney 293 (HEK-293) cells were incubated with ginsenosides extracted by pulsed electric field (PEF) and solvent cold soak extraction (SCSE) for 24 h and then the injury was induced by 40μM H₂O₂. The cell viability and surface morphology of HEK-293 cells were studied using MTS assay and scanning electron microscopy, respectively. Dichloro-dihydro-fluorescein diacetate fluorescent probe assay was used to measure the level of intracellular reactive oxygen species. The intracellular antioxidant activities of ginsenosides were evaluated by cellular antioxidant activity assay in HepG2 cells.

Results

The PEF extracts displayed the higher 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and stronger oxygen radical absorption capacity (with an oxygen radical absorption capacity value of 14.48 ± 4.04μM TE per μg/mL). The HEK-293 cell model also suggested that the protective effect of PEF extracts was dose-dependently greater than SCSE extracts. Dichloro-dihydro-fluorescein diacetate assay further proved that PEF extracts are more active (8% higher than SCSE extracts) in reducing intracellular reactive oxygen species accumulation. In addition, scanning electron microscopy images showed that the HEK-293 cells, which were treated with PEF extracts, maintained more intact surface morphology. Cellular antioxidant activity values indicated that ginsenosides extracted by PEF had stronger cellular antioxidant activity than SCSE ginsenosides extracts.

Conclusion

The present study demonstrated the antioxidative effect of ginsenosides extracted by PEF in vitro. Furthermore, rather than SCSE, PEF may be more useful as an alternative extraction technique for the extraction of ginsenosides with enhanced antioxidant activity.

Effect of Korean Red Ginseng extraction conditions on antioxidant activity, extraction yield, and ginsenoside Rg1 and phenolic content: optimization using response surface methodology

Background

Extraction conditions greatly affect composition, as well as biological activity. Therefore, optimization is essential for maximum efficacy.

Methods

Korean Red Ginseng (KRG) was extracted under different conditions and antioxidant activity, extraction yield, and ginsenoside Rg1 and phenolic content evaluated. Optimized extraction conditions were suggested using response surface methodology for maximum antioxidant activity and extraction yield.

Results

Analysis of KRG extraction conditions using response surface methodology showed a good fit of experimental data as demonstrated by regression analysis. Among extraction factors, such as extraction solvent and extraction time and temperature, ethanol concentration greatly affected antioxidant activity, extraction yield, and ginsenoside Rg1 and phenolic content. The optimal conditions for maximum antioxidant activity and extraction yield were an ethanol concentration of 48.8%, an extraction time 73.3 min, and an extraction temperature of 90°C. The antioxidant activity and extraction yield under optimal conditions were 43.7% and 23.2% of dried KRG, respectively.

Conclusion

Ethanol concentration is an important extraction factor for KRG antioxidant activity and extraction yield. Optimized extraction conditions provide useful economic advantages in KRG development for functional products.