Radioprotective effects of dammarane sapogenins against 60 Co-induced myelosuppression in mice

Unraveling the pathogenesis of bone marrow hematopoietic injury and the therapeutic potential of natural products

Bone marrow hematopoietic injury encompasses a range of pathological conditions that disrupt the normal function of the hematopoietic system, primarily through the impaired production and differentiation of bone marrow hematopoietic cells. Key pathogenic mechanisms include aging, radiation damage, chemical induction, infection and inflammation, and cross-talk with non-hematopoietic diseases. These pathological factors often lead to myelosuppression and myeloid skewing. Furthermore, we explored the potential and application prospects of natural products in the treatment of bone marrow hematopoietic injury. Natural products, particularly those derived from Chinese herbal medicines and other natural sources, have emerged as promising therapeutic options due to their distinctive mechanisms and minimal side effects. A deeper understanding of the underlying mechanisms of bone marrow hematopoietic injury could illuminate how natural products exert their effects, thereby optimizing treatment strategies and offering safer, more effective options for patients. Future research should leverage emerging technologies to further elucidate the composition and interactions within the bone marrow microenvironment, as well as the specific pathways through which natural products modulate hematopoietic dysfunction.

Structural characterization of polysaccharides from Panax ginseng C. A. Meyer root and their triggered potential immunoregulatory and radioprotective activities

With people's increasing awareness of healthy diet, the diverse health-promoting functions of ginseng have been widely recognized. As one of the key functional components, ginseng polysaccharides have attracted increasing research interest. Here, three purified polysaccharide fractions, GPS-1a, GPS-1b, and GPS-2, were obtained from the root extract of Panax ginseng C. A. Meyer. Structurally, GPS-1a and GPS-1b were both linked in a → 6)-α-D-Glcp-(1 → pattern but composed of glucose and galactose in molar ratios of 9.76:0.24 and 9.81:0.19. In contrast, GPS-2 was composed of glucose, galactose, arabinose, rhamnose, and galacturonic acid in a molar ratio of 1.82:1.94:0.79:0.52:4.93. The main backbone consisted of →4)-α-D-GalpA-(1→, →4)-α-D-GalpA-6OMe-(1→, →3, 4)-α-D-GalpA-(1→, →3)-α-L-Rhap-(1 → linages, and its branches are composed of →5)-α-L-Araf-(1→, →4)-β-D-Galp-(1→, →2)-β-D-Glcp-(1→, α-D-GalAp-(1→. Benefitting from this structural variance, GPS-2 exhibited the most significant immunoregulatory and radioprotective efficacies. Specifically, GPS-2 promoted TLR2, NF-κB, and TRAF6 protein expression levels, thereby significantly improving macrophage phagocytosis, splenic lymphocyte proliferation, and stimulation of NO, IL-1β, IL-6, and TNF-α secretion, which activated RAW264.7 and splenic lymphocytes. The following radioprotection activity tests unveiled that GPS-2 increased the organ index, number of peripheral blood cells, cellularity of splenocytes, and bone marrow cell numbers in irradiated mice. This investigation revealed the contribution of polysaccharide structure characteristics to the bioactive expression and elucidated the potential utilization of GPS-2 as a radioprotective agent or immunomodulator.

Neuroprotective Effects of Dammarane Sapogenins Against lipopolysaccharide-induced Cognitive Impairment, Neuroinflammation and Synaptic Dysfunction

Neuroinflammation is a critical driver in the pathogenesis and progression of neurodegenerative disorders. Dammarane sapogenins (DS), a deglycosylated product of ginsenoside, possess a variety of potent biological activities. The present study aimed to explore the neuroprotective effects of DS in a rat model of neuroinflammation induced by intracerebroventricular injection of lipopolysaccharide (LPS). Our study revealed that DS pretreatment effectively improved LPS-induced associative learning and memory impairments in the active avoidance response test and spatial learning and memory in Morris water maze test. DS also remarkably inhibited LPS-induced neuroinflammation by suppressing microglia overactivation, pro-inflammatory cytok ine release (TNF-α and IL-1β) and reducing neuronal loss in the CA1 and DG regions of the hippocampus. Importantly, pretreatment with DS reversed LPS-induced upregulation of HMGB1 and TLR4 and inhibited their downstream NF-κB signaling activation, as evidenced by increased IκBα and decreased p-NF-κB p65 levels. Furthermore, DS ameliorated LPS-induced synaptic dysfunction by decreasing MMP-9 and increasing NMDAR1 expression in the hippocampus. Taken together, this study suggests that DS could be a promising treatment for preventing cognitive impairments caused by neuroinflammation.

Protection of the hematopoietic system against radiation-induced damage: drugs, mechanisms, and developments

Sometimes, people can be exposed to moderate or high doses of radiation accidentally or through the environment. Radiation can cause great harm to several systems within organisms, especially the hematopoietic system. Several types of drugs protect the hematopoietic system against radiation damage in different ways. They can be classified as "synthetic drugs" and "natural compounds." Their cellular mechanisms to protect organisms from radiation damage include free radical-scavenging, anti-oxidation, reducing genotoxicity and apoptosis, and alleviating suppression of the bone marrow. These topics have been reviewed to provide new ideas for the development and research of drugs alleviating radiation-induced damage to the hematopoietic system.

Histopathological Evaluation of Protective Effect of Telmisartan against Radiation-Induced Bone Marrow Injury

BACKGROUND

Radiation-induced hematopoietic suppression and myelotoxicity can occur due to the nuclear accidents, occupational irradiation and therapeutic interventions. Bone marrow dysfunction has always been one of the most important causes of morbidity and mortality after ionizing irradiation.

OBJECTIVE

This study aims to investigate the protective effect of telmisartan against radiation-induced bone marrow injuries in a Balb/c mouse model.

MATERIAL AND METHODS

In this experimental study, male Balb/c mice were divided into four groups as follow: group 1: mice received phosphate buffered saline (PBS) without irradiation, group 2: mice received a solution of telmisartan in PBS without irradiation, group 3: mice received PBS with irradiation, and group 4: mice received a solution of telmisartan in PBS with irradiation. A solution of telmisartan was prepared and administered orally at 12 mg/kg body weight for seven consecutive days prior to whole body exposing to a single sub-lethal dose of 5 Gy X-rays. Protection of bone marrow against radiation induced damage was investigated by Hematoxylin-Eosin (HE) staining assay at 3, 9, 15 and 30 days after irradiation.

RESULTS

Histopathological analysis indicated that administration of telmisartan reduced X-radiation-induced damage and improved bone marrow histology. The number of different cell types in bone marrow, including polymorphonuclear /mononuclear cells and megakaryocytes significantly increased in telmisartan treated group compared to the only irradiated group at all-time points.

CONCLUSION

The results of the present study demonstrated an efficient radioprotective effect of telmisartan in mouse bone marrow against sub-lethal X-irradiation.

Soy isoflavones protects against cognitive deficits induced by chronic sleep deprivation via alleviating oxidative stress and suppressing neuroinflammation

Mounting evidence suggests that there is a close association between chronic sleep deprivation (CSD) and cognitive deficits. The animal model of CSD-induced cognitive deficits is commonly used to seek potential treatments. Soy isoflavones (SI) have been reported to possess antioxidant, anti-inflammation, and neuroprotective effects. In the present study, the effects of SI on CSD-induced memory impairment were investigated. The mice were subjected to the sleep interruption apparatus and continuously sleep deprived for 2 weeks, while orally administrated with SI (10, 20, and 40 mg/kg) or Modafinil (MOD,100 mg/kg) during the CSD process. Immediately after the SD protocol, cognitive performance of mice was evaluated by the object location recognition (OLR) test, the novel object recognition (NOR) test, and the Morris water maze (MWM) task, as well as the hippocampus, was extracted for evaluation of oxidative stress parameters and inflammation levels through biochemical parameter assay and western blotting analysis. The results showed that SI administration remarkably improved the cognitive performance of CSD-treated mice in OLR, NOR, and MWM tests. In addition, SI significantly elevated total antioxidant capacity and superoxide dismutase enzyme activities, decreased malondialdehyde level, promoting antioxidant element nuclear erythroid-2-related factor 2, and its downstream targets, including heme oxygenase 1, and quinone oxidoreductase 1 protein expressions. Moreover, SI treatment significantly suppressed nuclear factor kappa B p65, nitric oxide synthase, and cyclooxygenase 2 activation, as well as the pro-inflammatory cytokines (Tumor necrosis factor-α [TNF-α], interleukin-6 [IL-6], and interleukin-1β [IL-1β]) release in the hippocampus of CSD-treated mice. In summary, the current study provides an insight into the potential of SI in treatment of cognitive deficits by CSD.

Ameliorative effects of ginsenosides on myelosuppression induced by chemotherapy or radiotherapy

BACKGROUND

and ethnopharmacological relevance: As the major side effect of radiotherapy or chemotherapy, myelosuppression usually leads to anemia, hemorrhage, immunosuppression, and even fatal infections, which may discontinue the process of cancer treatment. As a result, more and more attention is paid to the treatment of myelosuppression. Ginseng, root of Panax ginseng Meyer (Panax ginseng C. A. Mey), is considered as the king of herbs in the Orient, particularly in China, Korea and Japan. Ginsenosides, the most important active ingredients of ginseng, have been shown to have a variety of therapeutic effects, such as neuroprotective, anti-cancer and anti-diabetic properties. Considering that ginsenosides are closely associated with the pathogenesis of myelosuppression, researchers have carried out a few experiments on ginsenosides to attenuate myelosuppression induced by chemotherapy or radiotherapy in recent years.

AIM OF THE STUDY

To summarize previous studies about the effects of ginsenosides on alleviating myelosuppression and the mechanisms of action.

METHODS

Literatures in this review were searched in PubMed, China National Knowledge Infrastructure (CNKI), Web of Science, and ScienceDirect.

RESULTS

Ginsenosides play an important role in relieving myelosuppression predominantly by restoring hematopoiesis and immunity.

CONCLUSION

Ginsenosides might be potential candidates for the treatment of myelosuppression induced by chemotherapy or radiotherapy.

Dammarane sapogenins attenuates stress-induced anxiety-like behaviors by upregulating ERK/CREB/BDNF pathways

Dammarane sapogenins (DS), an extract derived from ginseng by alkaline hydrolysis of total ginsenosides, possesses high pharmacological activity and higher bioavailability than ginsenosides. The present study was designed to investigate the anxiolytic-like effects of DS in a mouse model of chronic social defeat stress (CSDS). DS (40 and 80 mg/kg) significantly ameliorated social avoidance and anxiety-like behavior in four test models of CSDS, showing increased time in the interaction zone in the social interaction test and in the center of the field in the open field test, an increased percentage of entries and open arm time in the elevated plus maze, and reduced latency to eat in the novelty-suppressed feeding test. Biochemical analyses showed that DS significantly reduced serum corticosterone levels and increased brain concentration of neurotransmitter 5-HT and noradrenaline in CSDS mice. Treatment with DS significantly upregulated BDNF (brain-derived neurotrophic factor), p-CREB/CREB and p-ERK1/2/ERK1/2 protein expression in the hippocampus and prefrontal cortex of CSDS mice. Collectively, these results suggest that DS exerts anxiolytic-like effects in CSDS model mice and the action is mediated, at least in part, by modulating the HPA (hypothalamic-pituitary-adrenal) axis and monoamine neurotransmitter levels, and via ERK/CREB/BDNF signaling pathway.

5-Androstenediol prevents radiation injury in mice by promoting NF-κB signaling and inhibiting AIM2 inflammasome activation

In the present study, the therapeutic effects of 5-androstenediol on radiation-induced myeloid suppression and tissue damage in mice and the possible mechanism were explored. The mice were subjected to whole-body irradiation, and 5-androstenediol was administered subcutaneously at different times and doses. The evaluation of the survival rate showed that the administration of 5-androstenediol every three days post-irradiation was the most effective in decreasing the death of the mice. Additionally, 5-androstenediol dose-dependently reduced the death caused by 9 Gy radiation. The pharmacological mechanism was investigated by blood analysis, western blot analysis, immunofluorescence and immunohistochemistry. 5-Androstenediol significantly ameliorated myeloid suppression, as demonstrated by elevated levels of total white blood cells, including neutrophils and platelets, in the peripheral blood. By H&E staining, we found that radiation-induced myeloid suppression in the bone marrow and spleen, as well as tissue damage in the lung and colon, was significantly ameliorated by treatment with 5-androstenediol. Immunohistochemistry showed elevated phosphorylation of p65 in the bone marrow and spleen, indicating the activation of NF-κB signaling. Moreover, 5-androstenediol markedly hampered the radiation-induced activation of caspase-1 and GSDMD in the colon by decreasing the interaction between AIM2 and ASC. Taken together, our results suggest that, by promoting NF-κB signaling and inhibiting inflammasome-mediated pyroptosis, 5-androstenediol can be used as a radioprotective drug.

Dammarane sapogenins alleviates depression-like behaviours induced by chronic social defeat stress in mice through the promotion of the BDNF signalling pathway and neurogenesis in the hippocampus

Chronic social defeat stress (CSDS) is a widely used behavioural paradigm of psychosocial stress that can be used to research the pathogenesis of depression and seek antidepressant drugs. Dammarane sapogenins (DS), the deglycosylated product of ginsenosides, has a wide range of biological activities, including immunomodulatory, antifatigue, antitumour and antidepressant activities. However, whether DS has antidepressant-like effects in a CSDS mouse model remains unknown. Therefore, the present study was conducted to evaluate the antidepressant properties of DS in CSDS mice and its underlying mechanisms. The results showed that the oral administration of DS (40 and 80 mg/kg) increased the time spent in the interaction zone in the social interaction test and the sucrose intake in the sucrose preference test, decreased the latency in the novelty-suppressed feeding test, and reduced the immobility time in both the tail suspension test and forced swimming test. Biochemical analyses of brain tissue and serum showed that DS treatment significantly decreased serum corticosterone levels and enhanced brain monoamine neurotransmitter levels in CSDS mice. In addition, an impairment in hippocampal neurogenesis that paralleled a reduced BDNF level in the hippocampus was observed in the mice that were subjected with CSDS for 3 weeks, while treatment with DS reversed these changes. Moreover, DS treatment significantly upregulated BDNF, pTrkB/TrkB, pAkt/Akt, pPI3K/PI3K, pCREB/CREB, pERK1/2/ERK1/2 and pmTOR/mTOR protein expression in the hippocampus. In conclusion, our results showed that DS exerts antidepressant-like effects in mice with CSDS-induced depression, that the effects may be mediated by the normalization of monoamine neurotransmitter levels, the prevention of HPA axis dysfunction and the impairment of hippocampal neurogenesis, and that this occurs partly through the ability of DS to enhance BDNF expression by increasing the TrkB/CREB/ERK pathway and the PI3K/AKT/mTOR pathway.

In Vitro/In Vivo Metabolism of Ginsenoside Rg5 in Rat Using Ultra-Performance Liquid Chromatography/Quadrupole-Time-of-Flight Mass Spectrometry

Background: Ginsenoside Rg5 has been proved to have a wide range of pharmacological activities. However, the in vitro and in vivo metabolism pathways of ginsenosides are still unclear, which impedes the understanding of their in vivo fate. In this paper, the possible metabolic process of Rg5 was studied and the metabolites are identified. Methods: Samples from rat liver microsomes (RLMs) in vitro and from rat urine, plasma and feces in vivo were collected for analysis after oral administration of Rg5. A rapid analysis technique using ultra-performance liquid chromatography (UPLC)/quadrupole-time-of-flight mass spectrometry (QTOF-MS) was applied for detecting metabolites of Rg5 both in vitro and in vivo. Results: A feasible metabolic pathway was proposed and described for ginsenoside Rg5. A total of 17 metabolic products were detected in biological samples, including the RLMs (four), rat urine (two), feces (13) and plasma (four). Fifteen of them have never been reported before. Oxidation, deglycosylation, deoxidation, glucuronidation, demethylation and dehydration were found to be the major metabolic reactions of Rg5. Conclusions: The present study utilized a reliable and quick analytical tool to explore the metabolism of Rg5 in rats and provided significant insights into the understanding of the metabolic pathways of Rg5 in vitro and in vivo. The results could be used to not only evaluate the efficacy and safety of Rg5, but also identify potential active drug candidates from the metabolites.