Icaritin Improves Memory and Learning Ability by Decreasing BACE-1 Expression and the Bax/Bcl-2 Ratio in Senescence-Accelerated Mouse Prone 8 (SAMP8) Mice

Icaritin greatly attenuates β-amyloid-induced toxicity in vivo

AIMS

The accumulation and deposition of β-amyloid (Aβ) has always been considered a major pathological feature of Alzheimer's disease (AD). The latest and mainstream amyloid cascade hypothesis indicates that all the main pathological changes in AD are attributed to the accumulation of soluble Aβ. However, the exploration of therapeutic drugs for Aβ toxicity has progressed slowly. This study aims to investigate the protective effects of Icaritin on the Aβ-induced Drosophila AD model and its possible mechanism.

METHODS

To identify the effects of Icaritin on AD, we constructed an excellent Drosophila AD model named Aβarc (arctic mutant Aβ42) Drosophila. Climbing ability, flight ability, and longevity were used to evaluate the effects of Icaritin on AD phenotypes. Aβarc was determined by immunostaining and ELISA. To identify the effects of Icaritin on oxidative stress, we performed the detection of ROS, hydrogen peroxide, MDA, SOD, catalase, GST, and Caspase-3. To identify the effects of Icaritin on energy metabolism, we performed the detection of ATP and lactate. Transcriptome analysis and qRT-PCR verifications were used to detect the genes directly involved in oxidative stress and energy metabolism. Mitochondrial structure and function were detected by an electron microscopy assay, a mitochondrial membrane potential assay, and a mitochondrial respiration assay.

RESULTS

We discovered that Icaritin almost completely rescues the climbing ability, flight ability, and longevity of Aβarc Drosophila. Aβarc was dramatically reduced by Icaritin treatment. We also found that Icaritin significantly reduces oxidative stress and greatly improves impaired energy metabolism. Importantly, transcriptome analysis and qRT-PCR verifications showed that many key genes, directly involved in oxidative stress and energy metabolism, are restored by Icaritin. Next, we found that Icaritin perfectly restores the integrity of mitochondrial structure and function damaged by Aβarc toxicity.

CONCLUSION

This study suggested that Icaritin is a potential drug to deal with the toxicity of Aβarc, at least partially realized by restoring the mitochondria/oxidative stress/energy metabolism axis, and holds potential for translation to human AD.

UHPLC-ESI-QE-Orbitrap-MS based metabolomics reveals the antioxidant mechanism of icaritin on mice with cerebral ischemic reperfusion

Background

Icaritin (ICT) has been previously demonstrated to display protective effects against cerebral ischemic reperfusion (I/R) by inhibiting oxidative stress, but the mechanism remains unclear. This study aimed to explore the mechanism from the perspective of metabolomics.

Methods

A mice cerebral artery occlusion/reperfusion (MCAO/R) model was explored to mimic cerebral ischemic reperfusion and protective effect of ICT was assessed by neurologic deficit scoring, infarct volume and brain water content. Ultra-high-performance liquid chromatography electrospray ionization orbitrap tandem mass spectrometry (UHPLC-ESI-QE-Orbitrap-MS) based metabolomic was performed to explore potential biomarkers. Brain tissue metabolic profiles were analyzed and metabolic biomarkers were identified through multivariate data analysis. The protein levels of Nrf2, HO-1 and HQO1 were assayed by western blot. The release of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) were detected using corresponding assay kits.

Results

The results showed that after ICT treatment, the neurological deficit, cerebral infarction area, brain edema and the level of MDA in brain tissue of MCAO/R mice were significantly reduced. Meanwhile, ICT enhanced the activity of SOD, CAT and GSH-Px. Western blot results confirmed that ICT up-regulated the protein levels of antioxidant-related protein including Nrf2, HO-1 and NQO1. According to the metabolomic profiling of brain tissues, clear separations were observed among the Sham, Model and ICT groups. A total of 44 biomarkers were identified, and the identified biomarkers were mainly related to linoleic acid metabolism, arachidonic acid metabolism, alanine, aspartate and glutamate metabolism, arginine biosynthesis, arginine and proline metabolism, D-glutamine and D-glutamate metabolism, taurine and hypotaurine metabolism and purine metabolism, respectively. At the same time, the inhibitory effect of ICT on arachidonic acid and linoleic acid in brain tissue, as well as the promoting effect on taurine, GABA, NAAG, may be the key factors for the anti-neurooxidative function of mice after MCAO/R injury.

Conclusion

Our results demonstrate that ICT has benefits for MCAO/R injury, which are partially related to the suppression of oxidative stress via stimulating the Nrf2 signaling and regulating the production of arachidonic acid, linoleic acid, taurine, GABA, NAAG in brain tissue.

Efficacy and safety of naotaifang capsules for hypertensive cerebral small vessel disease: Study protocol for a multicenter, randomized, double-blind, placebo-controlled clinical trial

Background: Hypertensive cerebral small vessel disease (HT-CSVD) is a cerebrovascular clinical, imaging and pathological syndrome caused by hypertension (HT). The condition manifests with lesions in various vessels including intracranial small/arterioles, capillaries, and small/venules. Hypertensive cerebral small vessel disease has complex and diverse clinical manifestations. For instance, it can present as an acute stroke which progresses to cause cognitive decline, affective disorder, unstable gait, dysphagia, or abnormal urination. Moreover, hypertensive cerebral small vessel disease causes 25-30% of all cases of ischemic strokes and more than 50% of all cases of single or mixed dementias. The 1-year recurrence rate of stroke in cerebral small vessel disease patients with hypertension is 14%. In the early stage of development, the symptoms of hypertensive cerebral small vessel disease are concealed and often ignored by patients and even clinicians. Patients with an advanced hypertensive cerebral small vessel disease manifest with severe physical and mental dysfunction. Therefore, this condition has a substantial economic burden on affected families and society. Naotaifang (NTF) is potentially effective in improving microcirculation and neurofunction in patients with ischemic stroke. In this regard, this multicenter randomized controlled trial (RCT) aims to furtherly evaluate the efficacy and safety of naotaifang capsules on hypertensive cerebral small vessel disease. Methods: This study is a multicenter, randomized, double-blind, placebo-controlled clinical trial. A total of 388 eligible subjects were recruited from the First Hospital of Hunan University of Chinese Medicine, Hunan Academy of Chinese Medicine Affiliated Hospital, the First Hospital of Shaoyang University, the First Traditional Chinese Medicine Hospital of Changde, and Jiangmen Wuyi Hospital of Traditional Chinese Medicine from July 2020 to April 2022. After a 4-week run-in period, all participants were divided into the intervention group (represented by Y-T, N-T) and control group (represented by Y-C, N-C); using a stratified block randomized method based on the presence or absence of brain damage symptoms in hypertensive cerebral small vessel disease (represented by Y and N). The Y-T and N-T groups were administered different doses of naotaifang capsules, whereas Y-C and N-C groups received placebo treatment. These four groups received the treatments for 6 months. The primary outcome included Fazekas scores and dilated Virchow-robin spaces (dVRS) grades on magnetic resonance imaging (MRI). The secondary outcomes included the number of lacunar infarctions (LI) and cerebral microbleeds (CMB) on magnetic resonance imaging, clinical blood pressure (BP) level, traditional Chinese medicine (TCM) syndrome scores, mini-mental state examination (MMSE) scale, and safety outcomes. Fazekas scores, dilated Virchow-robin spaces grades, and the number of lacunar infarctions and cerebral microbleeds on magnetic resonance imaging were tested before enrollment and after 6 months of treatment. The clinical blood pressure level, traditional Chinese medicine syndrome scores, mini-mental state examination scale and safety outcomes were tested before enrollment, after 3-month, 6-month treatment and 12th-month follow-up respectively. Conclusion: The protocol will comfirm whether naotaifang capsules reduce Fazekas scores, dilated Virchow-robin spaces grades, and the number of lacunar infarctions and cerebral microbleeds, clinical blood pressure, increase mini-mental state examination scores, traditional Chinese medicine syndrome scores of Qi deficiency and blood stasis (QDBS), and improve the quality of life of subjects. The consolidated evidence from this study will shed light on the benefits of Chinese herbs for hypertensive cerebral small vessel disease, such as nourishing qi, promoting blood circulation and removing blood stasis, and dredging collaterals. However, additional clinical trials with large samples and long intervention periods will be required for in-depth research. Clinical Trial registration: www.chictr.org.cn, identifier ChiCTR1900024524.

Therapeutic Effect of Icaritin on Cerebral Ischemia-Reperfusion-Induced Senescence and Apoptosis in an Acute Ischemic Stroke Mouse Model

An ischemic stroke is brain damage caused by interruption of blood supply to the brain that can cause death and long-term disability. New medical strategies or therapies are urgently needed for ischemic stroke. Icaritin (ICT) is a metabolite of icariin (ICA), which are two active flavonoid components extracted from Herba epimedii and considered neuroprotective agents in animal models of Alzheimer’s disease and ischemic stroke. The therapeutic effect of ICT on ischemic still remains to be clarified. The aim of this study was to investigate the therapeutic effect of ICT on cerebral ischemia-reperfusion-associated senescence and apoptosis in a middle cerebral artery occlusion (MCAO) mouse model (ischemia for 50 min and reperfusion for 24 h). Administration of ICT after ischemia significantly reduced MCAO-induced neurological damage, infarct volume, and histopathological changes in the brain of acute ischemic stroke mice. ICT treatment could also reduce neuronal apoptosis and senescence and reversed the expression of apoptosis- and senescence-related signaling proteins. These findings suggest that ICT may have therapeutic potential to ameliorate acute ischemic stroke.

Effect of icaritin on autophagy-related protein expression in TDP-43-transfected SH-SY5Y cells

Objective

To study the protective effect and mechanism of icaritin (ICT) in a SH-SY5Y cells with virus-loaded TAR DNA-binding domain protein 43(TDP-43) by examining the effect of ICT on the expression of autophagy-related proteins in TDP-43-infected SH-SY5Y cells.

Methods

A TDP-43-induced neuronal cell injury model was established by transfecting well-growing SH-SY5Y cells with virus loaded with the TDP-43 gene. The changes in cell viability were detected by the CCK-8 method. After successful transfection, the establishment of the model was verified by real-time quantitative PCR (qPCR) and Western blot methods. After the cells were subjected to drug intervention with ICT, the changes in the expression levels of TDP-43, cleaved Caspase-3, LC3 II/I, Beclin-1 and p62 were detected by Western blotting.

Results

After ICT intervention, it was found that compared with that of the TDP-43 group, the cell viability of the TDP-43+ICT group increased, the expression level of TDP-43 decreased, and the expression levels of the apoptotic protein cleaved Caspase-3, autophagy protein Beclin-1, and LC3-II/I decreased, while the expression level of the autophagy protein p62 increased.

Conclusion

ICT has a protective effect on the SH-SY5Y cell injury model transfected with TDP-43. This protective effect may be related to reducing the protein expression of TDP-43 and inhibiting autophagy.

Chinese Herbal Medicine for Primary Liver Cancer Therapy: Perspectives and Challenges

Primary liver cancer (PLC) is one of the most common solid malignancies. However, PLC drug development has been slow, and first-line treatments are still needed; thus, studies exploring and developing alternative strategies for effective PLC treatment are urgently needed. Chinese herbal medicine (CHM) has long been applied in the clinic due to its advantages of low toxicity and targeting of multiple factors and pathways, and it has great potential for the development of novel natural drugs against PLC.

Purpose: This review aims to provide an update on the pharmacological mechanisms of Chinese patent medicines (CPMs) and the latest CHM-derived compounds for the treatment of PLC and relevant clinical evaluations.

Materials and Methods: A systematic search of English literature databases, Chinese literature, the Clinical Trials Registry Platform, and the Chinese Clinical Trial Registry for studies of CHMs for PLC treatment was performed.

Results: In this review, we summarize the clinical trials and mechanisms of CPMs for PLC treatment that have entered the clinic with the approval of the Chinese medicine regulatory authority. These CPMs included Huaier granules, Ganfule granules, Fufang Banmao capsules, Jinlong capsules, Brucea javanica oil emulsions, and compound kushen injections. We also summarize the latest in vivo, in vitro, and clinical studies of CHM-derived compounds against PLC: icaritin and ginsenoside Rg3. Dilemmas facing the development of CHMs, such as drug toxicity and low oral availability, and future developments are also discussed.

Conclusion: This review provides a deeper the understanding of CHMs as PLC treatments and provides ideas for the development of new natural drugs against PLC.

Bioactive Flavonoids Icaritin and Icariin Protect against Cerebral Ischemia-Reperfusion-Associated Apoptosis and Extracellular Matrix Accumulation in an Ischemic Stroke Mouse Model

Stroke, which is the second leading cause of mortality in the world, is urgently needed to explore the medical strategies for ischemic stroke treatment. Both icariin (ICA) and icaritin (ICT) are the major active flavonoids extracted from Herba epimedii that have been regarded as the neuroprotective agents in disease models. In this study, we aimed to investigate and compare the neuroprotective effects of ICA and ICT in a middle cerebral artery occlusion (MCAO) mouse model. Male ICR mice were pretreated with both ICA and ICT, which ameliorated body weight loss, neurological injury, infarct volume, and pathological change in acute ischemic stroke mice. Furthermore, administration of both ICA and ICT could also protect against neuronal cell apoptotic death, oxidative and nitrosative stress, lipid peroxidation, and extracellular matrix (ECM) accumulation in the brains. The neuroprotective effects of ICT are slightly better than that of ICA in acute cerebral ischemic stroke mice. These results suggest that pretreatment with both ICA and ICT improves the neuronal cell apoptosis and responses of oxidative/nitrosative stress and counteracts the ECM accumulation in the brains of acute cerebral ischemic stroke mice. Both ICA and ICT treatment may serve as a useful therapeutic strategy for acute ischemic stroke.

Icaritin protects SH-SY5Y cells transfected with TDP-43 by alleviating mitochondrial damage and oxidative stress

Background

The aim of this study was to investigate the effect of icaritin (ICT) on TAR DNA-binding protein 43 (TDP-43)-induced neuroblastoma (SH-SY5Y) cell damage and to further explore its underlying mechanisms.

Methods

To investigate the possible mechanism, TDP-43 was used to induce SH-SY5Y cell injury. Cell viability was evaluated by the CCK-8 assay. The mitochondrial membrane potential (MMP) was determined with JC-1. The expression levels of TDP-43 and cytochrome C (CytC) were measuring by Western blotting. Changes in adenosine 5′-triphosphate (ATP) content, total antioxidative capacity (T-AOC), glutathione peroxidase (GSH-Px) activity, superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were detected with specific kits.

Results

The results showed that ICT reduced the cell damage induced by TDP-43. ICT reduced the expression level of TDP-43; increased ATP content and the MMP; decreased CytC expression; increased T-AOC and GSH-Px, total SOD (T-SOD), copper/zinc SOD (CuZn-SOD), and manganese SOD (Mn-SOD) activity; and decreased MDA content.

Conclusions

The results suggest that ICT has a protective effect on TDP-43-transfected SH-SY5Y cells that is related to reductions in TDP-43 expression and mitochondrial damage and alleviation of oxidative stress.