Gluco-obtusifolin and Its Aglycon, Obtusifolin, Attenuate Scopolamine-Induced Memory Impairment

Obtusifolin inhibits podocyte apoptosis by inactivating NF-κB signaling in acute kidney injury

Acute kidney injury (AKI) is a common clinical condition and is associated with unacceptable morbidity and mortality. Obtusifolin is an anthraquinone extracted from the seeds of Cassia obtusifolia with anti-inflammatory properties. This study focused on the role and mechanism of obtusifolin in AKI. The mouse podocyte cell line MPC5 was exposed to lipopolysaccharide (LPS) to establish a cell model of AKI. The viability of MPC5 cells treated with obtusifolin and/or LPS was detected by 3-(4, 5-Dimethylthiazol-2-yl)-2,5diphenyltetrazolium bromide assay. Cell apoptosis was analyzed by flow cytometry. The levels of podocyte injury- and apoptosis-related proteins as well as the nuclear factor-kappaB (NF-κB) signaling pathway was examined using western blotting analysis. The renal protective effects of obtusifolin were determined using an LPS-induced mouse model of AKI. Serum creatinine and blood urea nitrogen levels were measured. Hematoxylin-eosin staining of kidney sections was performed to evaluate renal histology. We found that MPC5 cells treated with LPS showed suppressed cell viability (p < 0.01) and increased cell apoptosis (p < 0.001). LPS reduced the protein expression of Bcl-2, nephrin, and synaptopodin as well as increased the protein levels of Bax and Cleaved Caspase-3 in podocytes in a concentration-dependent manner (p < 0.01). In addition, 10 μg/ml LPS-repressed cell viability was rescued by obtusifolin in a concentration-dependent manner (p < 0.01). Moreover, LPS-induced increase in MPC5 cell apoptosis was reversed by obtusifolin treatment (p < 0.01). Obtusifolin administration ameliorated LPS-induced kidney injury and reduced blood urea nitrogen and serum creatinine levels in mice (p < 0.001). Additionally, obtusifolin inhibited LPS-induced activation of NF-κB signaling in vitro and in vivo (p < 0.01). Overall, obtusifolin was effective in protecting renal function against LPS-induced AKI via inactivation of NF-κB signaling, which suggested that obtusifolin may act as a valuable agent for AKI therapy.

Simultaneous high-performance liquid chromatography analysis of anthraquinones in sicklepod sprouts with α-glucosidase inhibitory activity

INTRODUCTION

Sicklepod [Cassia obtusifolia L. syn Senna obtusifolia (L.) H.S. Irwin & Barneby, Fabaceae] sprouts are promising ingredients with health-promoting benefits. Notwithstanding, the pharmacologically active compounds in sicklepod sprouts have not been studied or analysed in detail.

OBJECTIVE

This study aimed to isolate and structurally identify phytochemicals showing α-glucosidase inhibitory activity in sicklepod sprouts and simultaneously quantify the compounds in the sprouts to determine the optimal cultivation method and germination time to maximise active compounds.

METHOD

A simultaneous high-performance liquid chromatography-ultraviolet (HPLC-UV) method with high sensitivity and accuracy was developed and used to analyse time-dependent changes in anthraquinone content during sicklepod germination.

RESULTS

Thirteen anthraquinones were isolated and identified, of which six-chrysoobtusin, emodin, 1-O-methyl-2-methoxychrysophanol, 7-O-methylobtusin, chrysophanol, and physcion-showed moderate α-glucosidase inhibitory activity. The maximum content of anthraquinones in a sprout was observed on Day 5 under both light and dark conditions.

CONCLUSION

The findings of this study revealed that sicklepod sprouts which are promising functional food materials contain a variety of anthraquinones.

Review of Pharmacotherapeutic Targets in Alzheimer's Disease and Its Management Using Traditional Medicinal Plants

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline, memory loss, and impaired daily functioning. While there is currently no cure for AD, several pharmacotherapeutic targets and management strategies have been explored. Additionally, traditional medicinal plants have gained attention for their potential role in AD management. Pharmacotherapeutic targets in AD include amyloid-beta (Aβ) aggregation, tau protein hyperphosphorylation, neuroinflammation, oxidative stress, and cholinergic dysfunction. Traditional medicinal plants, such as Ginkgo biloba, Huperzia serrata, Curcuma longa (turmeric), and Panax ginseng, have demonstrated the ability to modulate these targets through their bioactive compounds. Ginkgo biloba, for instance, contains flavonoids and terpenoids that exhibit neuroprotective effects by reducing Aβ deposition and enhancing cerebral blood flow. Huperzia serrata, a natural source of huperzine A, has acetylcholinesterase-inhibiting properties, thus improving cholinergic function. Curcuma longa, enriched with curcumin, exhibits anti-inflammatory and antioxidant effects, potentially mitigating neuroinflammation and oxidative stress. Panax ginseng's ginsenosides have shown neuroprotective and anti-amyloidogenic properties. The investigation of traditional medicinal plants as a complementary approach to AD management offers several advantages, including a lower risk of adverse effects and potential multi-target interactions. Furthermore, the cultural knowledge and utilization of these plants provide a rich source of information for the development of new therapies. However, further research is necessary to elucidate the precise mechanisms of action, standardize preparations, and assess the safety and efficacy of these natural remedies. Integrating traditional medicinal-plant-based therapies with modern pharmacotherapies may hold the key to a more comprehensive and effective approach to AD treatment. This review aims to explore the pharmacotherapeutic targets in AD and assess the potential of traditional medicinal plants in its management.

Neuroprotective potentials of Lead phytochemicals against Alzheimer's disease with focus on oxidative stress-mediated signaling pathways: Pharmacokinetic challenges, target specificity, clinical trials and future perspectives

BACKGROUND

Alzheimer's diseases (AD) and dementia are among the highly prevalent neurological disorders characterized by deposition of beta amyloid (Aβ) plaques, dense deposits of highly phosphorylated tau proteins, insufficiency of acetylcholine (ACh) and imbalance in glutamatergic system. Patients typically experience cognitive, behavioral alterations and are unable to perform their routine activities. Evidence also suggests that inflammatory processes including excessive microglia activation, high expression of inflammatory cytokines and release of free radicals. Thus, targeting inflammatory pathways beside other targets might be the key factors to control- disease symptoms and progression.

PURPOSE

This review is aimed to highlight the mechanisms and pathways involved in the neuroprotective potentials of lead phytochemicals. Further to provide updates regarding challenges associated with their use and their progress into clinical trials as potential lead compounds.

METHODS

Most recent scientific literature on pre-clinical and clinical data published in quality journals especially on the lead phytochemicals including curcumin, catechins, quercetin, resveratrol, genistein and apigenin was collected using SciFinder, PubMed, Google Scholar, Web of Science, JSTOR, EBSCO, Scopus and other related web sources.

RESULTS

Literature review indicated that the drug discovery against AD is insufficient and only few drugs are clinically approved which have limited efficacy. Among the therapeutic options, natural products have got tremendous attraction owing to their molecular diversity, their safety and efficacy. Research suggest that natural products can delay the disease onset, reduce its progression and regenerate the damage via their anti-amyloid, anti-inflammatory and antioxidant potentials. These agents regulate the pathways involved in the release of neurotrophins which are implicated in neuronal survival and function. Highly potential lead phytochemicals including curcumin, catechins, quercetin, resveratrol, genistein and apigenin regulate neuroprotective signaling pathways implicated in neurotrophins-mediated activation of tropomyosin receptor kinase (Trk) and p75 neurotrophins receptor (p75NTR) family receptors.

CONCLUSIONS

Phytochemicals especially phenolic compounds were identified as highly potential molecules which ameliorate oxidative stress induced neurodegeneration, reduce Aβ load and inhibit vital enzymes. Yet their clinical efficacy and bioavailability are the major challenges which need further interventions for more effective therapeutic outcomes.

Potent and Selective Inhibition of CYP1A2 Enzyme by Obtusifolin and Its Chemopreventive Effects

Obtusifolin, a major anthraquinone component present in the seeds of Cassia tora, exhibits several biological activities, including the amelioration of memory impairment, prevention of breast cancer metastasis, and reduction of cartilage damage in osteoarthritis. We aimed to evaluate the inhibitory effects of obtusifolin and its analogs on CYP1A enzymes, which are responsible for activating procarcinogens, and investigate its inhibitory mechanism and chemopreventive effects. P450-selective substrates were incubated with human liver microsomes (HLMs) or recombinant CYP1A1 and CYP1A2 in the presence of obtusifolin and its four analogs. After incubation, the samples were analyzed using liquid chromatography-tandem mass spectrometry. Molecular docking simulations were performed using the crystal structure of CYP1A2 to identify the critical interactions between anthraquinones and human CYP1A2. Obtusifolin potently and selectively inhibited CYP1A2-mediated phenacetin O-deethylation (POD) with a Ki value of 0.031 µM in a competitive inhibitory manner in HLMs, whereas it exhibited negligible inhibitory effect against other P450s (IC50 > 28.6 µM). Obtusifolin also inhibited CYP1A1- and CYP1A2-mediated POD and ethoxyresorufin O-deethylation with IC50 values of <0.57 µM when using recombinant enzymes. Our molecular docking models suggested that the high CYP1A2 inhibitory activity of obtusifolin may be attributed to the combination of hydrophobic interactions and hydrogen bonding. This is the first report of selective and potent inhibitory effects of obtusifolin against CYP1A, indicating their potential chemopreventive effects.

Phytochemistry, Ethnopharmacological Uses, Biological Activities, and Therapeutic Applications of Cassia obtusifolia L.: A Comprehensive Review

Cassia obtusifolia L., of the Leguminosae family, is used as a diuretic, laxative, tonic, purgative, and natural remedy for treating headache, dizziness, constipation, tophobia, and lacrimation and for improving eyesight. It is commonly used in tea in Korea. Various anthraquinone derivatives make up its main chemical constituents: emodin, chrysophanol, physcion, obtusifolin, obtusin, au rantio-obtusin, chryso-obtusin, alaternin, questin, aloe-emodin, gluco-aurantio-obtusin, gluco-obtusifolin, naphthopyrone glycosides, toralactone-9-β-gentiobioside, toralactone gentiobioside, and cassiaside. C. obtusifolia&nbsp;L. possesses a wide range of pharmacological properties (e.g., antidiabetic, antimicrobial, anti-inflammatory, hepatoprotective, and neuroprotective properties) and may be used to treat Alzheimer's disease, Parkinson's disease, and cancer. In addition, C. obtusifolia L. contributes to histamine release and antiplatelet aggregation. This review summarizes the botanical, phytochemical, and pharmacological features of C. obtusifolia and its therapeutic uses.

In vitro inhibitory effect of obtusofolin on the activity of CYP3A4, 2C9, and 2E1

Background

Obtusofolin is the major active ingredient of Catsia tora L., which possesses the activity of improving eyesight and protecting the optic nerve. Investigation on the interaction of obtusofolin with cytochrome P450 enzymes (CYP450s) could provide a reference for the clinical application of obtusofolin.

Methods

The effect of obtusofolin on the activity of CYP450s was investigated in the presence of 100 μM obtusofolin in pooled human liver microsomes (HLMs) and fitted with the Lineweaver–Burk plots to characterize the specific inhibition model and kinetic parameters.

Results

Obtusofolin was found to significantly inhibited the activity of CYP3A4, 2C9, and 2E1. In the presence of 0, 2.5, 5, 10, 25, 50, and 100 μM obtusofolin, the inhibition of these CYP450s showed a dose-dependent manner with the IC₅₀ values of 17.1 ± 0.25, 10.8 ± 0.13, and 15.5 ± 0.16 μM, respectively. The inhibition of CYP3A4 was best fitted with the non-competitive inhibition model with the K_i value of 8.82 μM. While the inhibition of CYP2C9 and 2E1 was competitive with the K_i values of 5.54 and 7.79 μM, respectively. After incubating for 0, 5, 10, 15, and 30 min, the inhibition of CYP3A4 was revealed to be time-dependent with the K_I value of 4.87 μM^− 1 and the K_inact value of 0.0515 min^− 1.

Conclusions

The in vitro inhibitory effect of obtusofolin implying the potential drug-drug interaction between obtusofolin and corresponding substrates, which needs further in vivo validations.

Obtusifolin, an Anthraquinone Extracted from Senna obtusifolia (L.) H.S.Irwin & Barneby, Reduces Inflammation in a Mouse Osteoarthritis Model

Osteoarthritis (OA) is an age-related degenerative disease that causes cartilage dysfunction and inflammation. Obtusifolin, an anthraquinone extracted from Senna obtusifolia (L.) H.S.Irwin & Barneby seeds, has anti-inflammatory functions; it could be used as a drug component to relieve OA symptoms. In this study, we investigated the effects of obtusifolin on OA inflammation. In vitro, interleukin (IL)-1β (1 ng/mL)-treated mouse chondrocytes were co-treated with obtusifolin at different concentrations. The expression of matrix metalloproteinase (Mmp) 3, Mmp13, cyclooxygenase 2 (Cox2), and signaling proteins was measured by polymerase chain reaction and Western blotting; collagenase activity and the PGE₂ level were also determined. In vivo, OA-induced C57BL/6 mice were administered obtusifolin, and their cartilage was stained with Safranin O to observe damage. Obtusifolin inhibited Mmp3, Mmp13, and Cox2 expression to levels similar to or more than those after treatment with celecoxib. Additionally, obtusifolin decreased collagenase activity and the PGE₂ level. Furthermore, obtusifolin regulated OA via the NF-κB signaling pathway. In surgically induced OA mouse models, the cartilage destruction decreased when obtusifolin was administered orally. Taken together, our results show that obtusifolin effectively reduces cartilage damage via the regulation of MMPs and Cox2 expression. Hence, we suggest that obtusifolin could be a component of another OA symptom reliever.

Pharmacokinetics and tissue distribution study of obtusifolin in rats by liquid chromatography-tandem mass spectrometry

This paper reports the validation of an assay for obtusifolin based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) and its application to a preclinical pharmacokinetic study in rats. After sample preparation of plasma and tissue homogenates by protein precipitation, the analyte and internal standard (IS) were separated by a reversed-phase chromatographic system in a run time of 5.0 min and detected by negative ion electrospray ionization followed by selected reaction monitoring of the precursor-to-product ion transitions at m/z 283.0-268.1 for obtusifolin and m/z 329.0-314.1 for IS. The assay was linear in the concentration range 1.0-500 ng/ml with the LLOQ of 1.0 ng/ml. In the pharmacokinetic study of an intragastric administration of 1.3 mg/kg obtusifolin, the maximum plasma concentration of obtusifolin was 152.5 ± 62.3 ng/ml, reached at 0.39 ± 0.17 h. The AUC_0-t and AUC_0-∞ were 491.8 ± 256.7 and 501.7 ± 256.7 ng × h/ml, respectively, with an elimination half-life of 3.1 ± 0.7 h. Obtusifolin was rapidly distributed into tissues, with the highest distribution in the liver and less in the brain. These results will give some insights for further pharmacological investigation of obtusifolin.

Traditional Ayurvedic and herbal remedies for Alzheimer's disease: from bench to bedside

INTRODUCTION

Alzheimer's disease (AD) is a progressive, neurodegenerative disorder prevalent worldwide among elderly populations. Owing to limited efficacy, side effects, and poor patient compliance for current rationally designed therapies, options are being searched from alternate therapies such as Indian (Ayurvedic), Chinese, or other traditional systems. Areas covered: Following a comprehensive literature search, the authors provide a review encompassing: (1) pathophysiological changes involved in AD, (2) Ayurvedic holistic approach and herbal medicines to manage dementia and AD, and (3) traditional plants and their phytoconstituents effective in AD with description of possible mechanism of action. Expert opinion: Traditional remedies could be adjunct therapeutic options to allay wide-ranging pathological cascades of AD. Ayurveda offers a holistic approach of treatment along with a list of nootropic herbs and formulations that are the rich sources of antioxidants, anti-amyloidogenic, neuroprotective, adaptogenic, anti-inflammatory, and immunomodulatory compounds that are found to modulate neuroendocrine-immune activities, enhance memory, intellect, rejuvenate brain functions, and improve quality of life. A strong knowledge base of traditional systems coupled with contemporary science may provide new functional leads for age-associated neurodegenerative disorders at preventive, promotive, and curative levels, and evolution of new drug therapies and development processes, though further research is needed.

Inhibitory activities of major anthraquinones and other constituents from Cassia obtusifolia against β-secretase and cholinesterases

ETHNOPHARMACOLOGICAL RELEVANCE

Semen Cassiae has been traditionally used as an herbal remedy for liver, eye, and acute inflammatory diseases. Recent pharmacological reports have indicated that Cassiae semen has neuroprotective effects, attributable to its anti-inflammatory actions, in ischemic stroke and Alzheimer's disease (AD) models.

AIM OF THE STUDY

The basic goal of this study was to evaluate the anti-AD activities of C. obtusifolia and its major constituents. Previously, the extract of C. obtusifolia seeds, was reported to have memory enhancing properties and anti-AD activity to ameliorate amyloid β-induced synaptic dysfunction. However, the responsible components of C. obtusifolia seeds in an AD are currently still unknown. In this study, we investigated the inhibitory effects of C. obtusifolia and its constituents against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1) enzyme activity.

MATERIALS AND METHODS

In vitro cholinesterase enzyme assays by using AChE, BChE, and BACE1 were performed. We also scrutinized the potentials of Cassiae semen active component as BACE1 inhibitors via enzyme kinetics and molecular docking simulation.

RESULTS

In vitro enzyme assays demonstrated that C. obtusifolia and its major constituents have promising inhibitory potential against AChE, BChE, and BACE1. All Cassiae semen constituents exhibited potent inhibitory activities against AChE and BACE1 with IC50 values of 6.29-109µg/mL and 0.94-190µg/mL, whereas alaternin, questin, and toralactone gentiobioside exhibited significant inhibitory activities against BChE with IC50 values of 113.10-137.74µg/mL. Kinetic study revealed that alaternin noncompetitively inhibited, whereas cassiaside and emodin showed mixed-type inhibition against BACE1. Furthermore, molecular docking simulation results demonstrated that hydroxyl group of alaternin and emodin tightly interacted with the active site residues of BACE1 and their relevant binding energies (-6.62 and -6.89kcal/mol), indicating a higher affinity and tighter binding capacity of these compounds for the active site of BACE1.

CONCLUSION

The findings of the present study suggest the potential of C. obtusifolia and its major constituents for use in the development of therapeutic or preventive agents for AD, especially through inhibition of AChE, BChE and BACE1 activities.

Effect of obtusifolin administration on retinal capillary cell death and the development of retinopathy in diabetic rats

Oxidative stress is increased in the retina in diabetes, and it is considered to play an important role in the development of retinopathy. Findings indicate that obtusifolin has antioxidant properties. The purpose of this study was to examine the effect of obtusifolin on retinal capillary cell apoptosis and the development of pathology in diabetes. Retina was used from streptozotocin-induced diabetic rats receiving diets supplemented with or without obtusifolin (100, 200, and 400 mg/kg) for 11 months of diabetes. Capillary cell apoptosis (by terminal transferase-mediated dUTP nick-end labeling) and formation of acellular capillaries were investigated in the trypsin-digested retinal microvessels. The effect of obtusifolin administration on retinal 8-hydroxy-2'deoxyguanosine (8-OHdG) and nitrotyrosine levels was determined by enzyme-linked immunosorbent assay. Obtusifolin administration for the entire duration of diabetes inhibited capillary cell apoptosis and the number of acellular capillaries in the retina, despite similar severity of hyperglycemia in the four diabetic groups (with and without obtusifolin). Retinal 8-OHdG and nitrotyrosine levels were significantly increased, respectively, in diabetes, and obtusifolin administration inhibited these increases. Our results demonstrate that the long-term administration of obtusifolin has beneficial effects on the development of diabetic retinopathy via inhibition of accumulation of oxidatively modified DNA and nitrotyrosine in the retina. Obtusifolin represents an achievable adjunct therapy to help prevent vision loss in diabetic patients.

The protective effect of Cassia obtusifolia on DSS-induced colitis

Cassia obtusifolia (CO) has been traditionally used in Korea to treat eye inflammation, photophobia, and lacrimation. However, the regulatory effect and molecular mechanism of CO in intestinal inflammation has not been understood. In this study, we investigate the protective effect of CO in dextran sulfate sodium (DSS)-induced colitis. CO reduced clinical signs of DSS-induced colitis, including body weight loss, shortened colon length, and increased disease activity index. The results show that CO significantly suppressed the levels of interleukin (IL)-6 and expression of cyclooxygenase-2 in DSS-treated colon tissues. Additionally, we observed that CO reduced the activation of transcription nuclear factor-κB p65 in DSS-treated colon tissues. Taken together, these findings suggest that CO has improving effects on DSS-induced ulcerative colitis, which may explain its beneficial effect in the regulation of chronic intestinal inflammation.

Traditional used Plants against Cognitive Decline and Alzheimer Disease

Alzheimer's disease (AD) is a neurodegenerative disorder characterized clinically by progressive memory deficits, impaired cognitive function, and altered and inappropriate behavior. Aging represents the most important risk factor for AD and the global trend in the phenomenon of population aging has dramatic consequences for public health, healthcare financing, and delivery systems in the word and, especially in developing countries. Mounting evidence obtained in in vitro and in vivo studies, suggests that various traditionally used plants in Asia, India, and Europe significantly affect key metabolic alterations culminating in AD-typical neurodegeneration. The present article aims to bring the reader up-to-date on the most recent studies and advances describing the direct and indirect activities of traditional used plants and its constituents possibly relieving features of AD. A variety of traditional used plants and its extracts exerted activities on AD related drug targets including AChE activity, antioxidative activity, modulation of Aβ-producing secretase activities, Aβ-degradation, heavy metal chelating, induction of neurotrophic factors, and cell death mechanisms. Although pre-clinical investigations identified promising drug candidates for AD, clinical evidences are still pending.