Beneficial effects of sennoside B on pentylenetetrazole-induced seizures in rats

BACKGROUND

Epilepsy is a common disorder affecting approximately 50 million people worldwide. Oxidative stress is known to play an important role in the pathophysiology of diseases, including epilepsy. In this study, we investigated the effects of sennoside B on PTZ-induced seizures in rats.

METHOD

The rats were grouped into Group Electroencephalography and Group Behavioral. Both Groups were divided into eight subgroups, and these subgroups were compared in terms of the time of first myoclonic jerk, Racine's Convulsion Scale, malondialdehyde levels, and brain superoxide dismutase activity. The experimental seizure model was performed with pentylenetetrazol.

RESULTS

The spike percentage was significantly lower in groups that received sennoside B, and this beneficial effect was shown to be associated with the dose of sennoside B received. The RCS score was lower and the FJM onset time was higher in the sennoside B-administered groups. Additionally, brain MDA and brain aquaporin-3 levels were lower and brain SOD activity was higher in the sennoside-administered groups.

CONCLUSIONS

The present study shows the beneficial effects of sennoside B on PTZ-induced convulsion in rats. It is considered that sennoside B which is a natural and safe product would be a good candidate for strengthening the management of epilepsy without serious side effects.

Response Surface Methodology (RSM)-Based Optimization of Ultrasound-Assisted Extraction of Sennoside A, Sennoside B, Aloe-Emodin, Emodin, and Chrysophanol from Senna alexandrina (Aerial Parts): HPLC-UV and Antioxidant Analysis

In this study, ultrasound-assisted extraction conditions were optimized to maximize the yields of sennoside A, sennoside B, aloe-emodin, emodin, and chrysophanol from S. alexandrina (aerial parts). The three UAE factors, extraction temperature (S₁), extraction time (S₂), and liquid to solid ratio (S₃), were optimized using response surface methodology (RSM). A Box–Behnken design was used for experimental design and phytoconstituent analysis was performed using high-performance liquid chromatography-UV. The optimal extraction conditions were found to be a 64.2 °C extraction temperature, 52.1 min extraction time, and 25.2 mL/g liquid to solid ratio. The experimental values of sennoside A, sennoside B, aloe-emodin, emodin, and chrysophanol (2.237, 12.792, 2.457, 0.261, and 1.529%, respectively) agreed with those predicted (2.152, 12.031, 2.331, 0.214, and 1.411%, respectively) by RSM models, thus demonstrating the appropriateness of the model used and the accomplishment of RSM in optimizing the extraction conditions. Excellent antioxidant properties were exhibited by S. alexandrina methanol extract obtained using the optimized extraction conditions with a DPPH assay (IC50 = 59.7 ± 1.93, µg/mL) and ABTS method (47.2 ± 1.40, µg/mL) compared to standard ascorbic acid.

A Novel Competitive Binding Screening Assay Reveals Sennoside B as a Potent Natural Product Inhibitor of TNF-α

Natural products (NPs) have played a significant role in drug discovery for diverse diseases, and numerous attempts have been made to discover promising NP inhibitors of tumor necrosis factor α (TNF-α), a major therapeutic target in autoimmune diseases. However, NP inhibitors of TNF-α, which have the potential to be developed as new drugs, have not been reported for over a decade. To facilitate the search for new promising inhibitors of TNF-α, we developed an efficient competitive binding screening assay based on analytical size exclusion chromatography coupled with liquid chromatography-tandem mass spectrometry. Application of this screening method to the NP library led to the discovery of a potent inhibitor of TNF-α, sennoside B, with an IC₅₀ value of 0.32 µM in TNF-α induced HeLa cell toxicity assays. Surprisingly, the potency of sennoside B was 5.7-fold higher than that of the synthetic TNF-α inhibitor SPD304. Molecular docking was performed to determine the binding mode of sennoside B to TNF-α. In conclusion, we successfully developed a novel competition binding screening method to discover small molecule TNF-α inhibitors and identified the natural compound sennoside B as having exceptional potency.

Repurposing of Some Natural Product Isolates as SARS-COV-2 Main Protease Inhibitors via In Vitro Cell Free and Cell-Based Antiviral Assessments and Molecular Modeling Approaches

The emergence of the SARS-CoV-2 pandemic has prompted scientists to search for an efficient antiviral medicine to overcome the rapid spread and the marked increase in the number of patients worldwide. In this regard natural products could be a potential source of substances active against coronavirus infections. A systematic computer-aided virtual screening approach was carried out using commercially available natural products found on the Zinc Database in addition to an in-house compound library to identify potential natural product inhibitors of SARS-CoV-2 main protease (MPRO). The top eighteen hits from the screening were selected for in vitro evaluation on the viral protease (SARS-CoV-2 MPRO). Five compounds (naringenin, 2,3',4,5',6-pentahydroxybenzophenone, apigenin-7-O-glucoside, sennoside B, and acetoside) displayed high activity against the viral protein. Acteoside showed similar activity to the positive control GC376. The most potent compounds were tested in vitro on SARS-CoV-2 Egyptian strain where only naringenin showed moderate anti-SARS-CoV-2 activity at non-cytotoxic micromolar concentrations in vitro with a significant selectivity index (CC50/IC50 = 178.748/28.347 = 6.3). Moreover; a common feature pharmacophore model was generated to explain the requirements for enzyme inhibition by this diverse group of active ligands. These results pave a path for future repurposing and development of natural products to aid in the battle against COVID-19.

[Determination of sennoside B, sennoside A and physcion in slimming health foods]

OBJECTIVE

To establish a quantitative analysis method for sennoside A, sennoside B and physcion by ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).

METHODS

The sample was extracted by methanol-2 mmol/L ammonium formate(9∶1) at 40 ℃ for 1 h. The separation was performed using Agilent Eclipse Plus C_(18 )(2. 1 mm × 50 mm, 1. 8 μm) column with gradient elution. The mobile phase was consisted of 0. 1% formic acid and methanol. Qualitative and quantitative analysis was conducted with an electrospray ionization source operated in the negative ionization(ESI~-) mode and multiple reaction monitoring(MRM) mode.

RESULTS

The linear range of three compounds were from 0. 1 to 10 μg/mL with the correlation coefficients(r) above 0. 995. The spiked recoveries were in the range of 81. 9% to 114. 5% at the concentrations of 0. 02, 0. 15 and 1. 60 mg/g with relative standard devisions(RSDs) ranged from 0. 30% to 3. 43%(n=6). The detection limits of sennoside A and sennoside B were 1. 2 μg/g. The detection limit of physcion was 2. 4 μg/g. Sennoside A, sennoside B or physcion were detected in 19 out of 40 batches of samples. The content of sennoside A ranged from 0. 184 to 6. 33 mg/g and the content of sennoside B ranged from 0. 202 to 7. 23 mg/g. The content of physcion ranged from 0. 042 to 0. 79 mg/g.

CONCLUSION

The method is simple, accurate and suitable for the determination of sennoside A, sennoside B and physcion.

Ellagic acid and Sennoside B inhibit osteosarcoma cell migration, invasion and growth by repressing the expression of c-Jun

Osteosarcoma is a mesenchymally derived, high-grade bone sarcoma that is the most frequently diagnosed primary malignant bone tumor. Today, chemoprevention is regarded as a promising and realistic approach in the prevention of human cancer. Previous studies have suggested ellagic acid (EA) and Sennoside B have potential in this regard. The aim of the present study was to elucidate the anti-osteosarcoma effects of EA and Sennoside B by using Saos-2 and MG63 osteosarcoma cells. It was identified that EA or Sennoside B treatment could inhibit the growth, migration and invasion of the cells, and induce G₁ cell cycle arrest by repressing the transcription of c-Jun. These results may provide a cellular basis for the application of EA or Sennoside B in the treatment of patients with osteosarcoma.

Experimental evaluation of radioiodinated sennoside B as a necrosis-avid tracer agent

Necrosis-avid agents are a class of compounds that selectively accumulate in the necrotic tissues after systemic administration, which can be used for in vivo necrosis imaging and targeted therapies. In order to search for a necrosis-avid tracer agent with improved drugability, we labelled iodine-131 on sennoside B (SB) as a naturally occurring median dianthrone compound. The necrosis targetability and clearance properties of (131)I-SB were evaluated in model rats with liver and muscle necrosis. On SPECT/CT images, a "hot spot" in the infarcted liver lobe and necrotic muscle was persistently observed at 24 h and 72 h post-injection (p.i.). Gamma counting of the tissues of interest revealed a radioactivity ratio of necrotic to viable liver at 4.6 and 3.4 and of necrotic to viable muscle at 7.0 and 8.8 at 24 h and 72 h p.i., respectively. The good match of autoradiographs and fluoromicroscopic images with corresponding histochemical staining suggested preferential uptake of (131)I-SB in necrotic tissue. Pharmacokinetic study revealed that (131)I-SB has an elimination half-life of 8.6 h. This study indicates that (131)I-SB shows not only prominent necrosis avidity but also favourable pharmacokinetics, which may serve as a potential necrosis-avid diagnostic agent for assessment of tissue viability.

An HPLC method to determine sennoside A and sennoside B in Sennae fructus and Sennae folium

INTRODUCTION

The current Ph. Eur. monographs for senna pods, senna leaf and senna leaf dry extract standardised describe a photometric assay based on the Bornträger reaction to determine hydroxyanthracene glycosides, calculated as sennoside B. The method is timeconsuming, unspecific for sennosides and the precision is not adequate for a modern assay.

AIM

The photometric method shall therefore be replaced by a modern HPLC method. About 70 % of the total anthrachinone content in herbal drugs of senna species is due to sennoside A and sennoside B. These substances are therefore suitable for the standardisation of Senna products. The Japanese Pharmacopoeia (JP) already describes an HPLC method to determine sennoside A and sennoside B in the monograph for senna leaf. It uses ion-pair chromatography with tetraheptylammoniumbromide. The procedure described in the monograph has a runtime of 70 min.

METHOD

The adapted and validated method described here uses solid-phase extraction (SPE) which allows a selective sample preparation by using an anion exchange phase. A conventional RP C18 column Tosh TSKgel ODS-80TS (4.6 mm × 150 mm), 5 μm, was used as stationary phase and acetonitrile for chromatography R, water R, phosphoric acid R (200:800:1 V/V/V) as mobile phase. The flow rate was 1.2 mL/min, the column temperature 40 °C, the detection wavelength 380 nm, and the injection volume 20 μL. The runtime is 10 min, the chromatogram shows 2 peaks due to sennoside A/B and 2 additional smaller compounds. One of them is rhein-8-O-glucoside.

RESULTS

The procedure has been successfully validated according to ICH guidelines. We analysed 6 batches of Senna. The pods (Senna angustifolia) showed a total content of sennoside A and B of 1.74-2.76 % m/m and the content of senna leaves was clearly lower with 1.07-1.19 % m/m, respectively.

CONCLUSION

The suggested method is considered to be suitable to determine sennoside A and sennoside B in senna leaves and senna pods. The consideration is based on the performed validation and on the results for the analysed samples. A short run time and better resolution are clear advantages of the suggested method, compared to other methods.