Tetrandrine, an alkaloid from S. tetrandra exhibits anti-hypertensive and sleep-enhancing effects in SHR via different mechanisms

Chronic Stress-Induced Elevation of Melanin-Concentrating Hormone in the Locus Coeruleus Inhibits Norepinephrine Production and Associated With Depression-Like Behaviors in Rats

BACKGROUND

Melanin-concentrating hormone (MCH) is a hypothalamic neuropeptide that projects throughout the central nervous system, including the noradrenergic locus coeruleus (LC). Our previous study suggested that MCH/MCH receptor 1 (MCHR1) in the LC may be involved in the regulation of depression. The present study investigated whether the role of MCH/MCHR1 in the LC in depression-like behaviors is associated with the regulation of norepinephrine.

METHOD

Chronic unpredictable stress (CUS) and an acute intra-LC microinjection of MCH induced depression-like behaviors in rats. The MCHR1 antagonist SNAP-94847 was also microinjected in the LC in rats that were suffering CUS or treated with MCH. The sucrose preference, forced swim, and locomotor tests were used for behavioral evaluation. Immunofluorescence staining, enzyme-linked immunosorbent assay, western blot, and high-performance liquid chromatography with electrochemical detection were used to explore the mechanism of MCH/MCHR1 in the regulation of depression-like behaviors.

RESULTS

CUS induced an abnormal elevation of MCH levels and downregulated MCHR1 in the LC, which was highly correlated with the formation of depression-like behaviors. SNAP-94847 exerted antidepressant effects in CUS-exposed rats by normalizing tyrosine hydroxylase, dopamine β hydroxylase, and norepinephrine in the LC. An acute microinjection of MCH induced depression-like behaviors through its action on MCHR1. MCHR1 antagonism in the LC significantly reversed the MCH-induced downregulation of norepinephrine production by normalizing MCHR1-medicated cAMP-PKA signaling.

CONCLUSIONS

Our study confirmed that the MCH/MCHR1 system in the LC may be involved in depression-like behaviors by downregulating norepinephrine production. These results improve our understanding of the pathogenesis of depression that is related to the MCH/MCHR1 system in the LC.

Suitability of Banana and Plantain Fruits in Modulating Neurodegenerative Diseases: Implicating the In Vitro and In Vivo Evidence from Neuroactive Narratives of Constituent Biomolecules

Active principles in plant-based foods, especially staple fruits, such as bananas and plantains, possess inter-related anti-inflammatory, anti-apoptotic, antioxidative, and neuromodulatory activities. Neurodegenerative diseases affect the functionality of the central and peripheral nervous system, with attendant cognitive deficits being hallmarks of these conditions. The dietary constitution of a wide range of bioactive compounds identified in this review further iterates the significance of the banana and plantain in compromising, halting, or preventing the pathological mechanisms of neurological disorders. The neuroprotective mechanisms of these biomolecules have been identified by using protein expression regulation and specific gene/pathway targeting, such as the nuclear and tumor necrosis factors, extracellular signal-regulated and mitogen-activated protein kinases, activator protein-1, and the glial fibrillary acidic protein. This review establishes the potential double-edged neuro-pharmacological fingerprints of banana and plantain fruits in their traditionally consumed pulp and less utilized peel component for human nutrition.

Alkaloids in genus stephania (Menispermaceae): A comprehensive review of its ethnopharmacology, phytochemistry, pharmacology and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Approximately 60 species of the genus Stephania (Menispermaceae) are distributed worldwide. Among these, 39 species are located in South and Southwest China; in particular, these plants are rich in alkaloids and were used in traditional Chinese medicine (TCM) against numerous ailments.

AIM OF THIS REVIEW

The purpose of this study was to provide organized information on the ethnopharmacological uses as well as the phytochemical, pharmacological, and toxicological evaluation of the alkaloids derived from plant species included in the genus Stephania. In addition, we aimed to provide comprehensive basic knowledge on the medicinal properties of these plants and establish meaningful guidelines for further research.

MATERIALS AND METHODS

Information related to the Stephania genus was collected from scientific databases, such as Web of Science, PubMed, Baidu Scholar, and China Academic Journals (CNKI), within the last 20 years on phytochemistry, pharmacology, and toxicology of the plants in genus Stephania. Furthermore, information was obtained from the Pharmacopoeia of the People's Republic of China. Chinese Pharmacopoeia and Flora of China.

RESULTS

Plant species belonging to the genus Stephania have been mentioned as traditional remedies and various alkaloidal compounds have been identified and isolated, including aporphine, proaporphine, morphinane, hasubanane, protoberberine, benzylisoquinoline, and bisbenzylisoquinoline and among others. The isolated alkaloidal compounds reportedly exhibited promising pharmacological properties, such as antimicrobial, antiviral, antitumor, antioxidant, antihyperglycemic, anti-inflammatory, antinociceptive, anti-multidrug resistance, neuroprotective, and cardioprotective activities.

CONCLUSIONS

The genus Stephania is widely used in TCM. The ethnopharmacological uses, phytochemistry, and pharmacology of the Stephania sp. Described in this review demonstrated that these plants contain numerous alkaloids and active constituents and display myriad pharmacological activities. Typically, research on the plants' pharmacological activity focuses on parts of the plants and the associated compounds. However, many Stephania species have rarely been studied, and the ethnomedicinal potential of those discovered has not been scientifically evaluated and needs to be further elucidated. Furthermore, quality control and toxicology studies are warranted in the future.

A Study on the Mechanism of the Sedative-hypnotic Effect of Cinnamomum camphora chvar. Borneol Essential Oil Based on Network Pharmacology

In this paper, we investigated the sedative-hypnotic effect of Cinnamomum camphora chvar. Borneol essential oil (BEO, 16.4% borneol), a by-product of steam distillation of Cinnamomum camphora chvar. Borneol, from which natural crystalline borneol (NCB, 98.4% borneol) is obtained. Using locomotor activity tests and pentobarbital sodium-induced sleep test, it was found that BEO significantly reduced locomotor activity (p < 0.05), shortened sleep latency (p < 0.0001), prolonged sleep duration (p < 0.05), and had a sedative-hypnotic effect. We constructed the "components-targets-signaling pathways" and "protein-protein interaction" (PPI) network of BEO using network pharmacology. The results show that the 24 active components of BEO acted on 17 targets, mainly through response to alkaloid and catecholamine transport, and neuroactive ligand-receptor interaction. The PPI network identified 12 key proteins, mainly dopamine receptor (DR)D2, opioid receptor mu 1 (OPRM1), and opioid receptor kappa 1 (OPRK1), and we further analyzed the active components and targets of BEO through molecular docking. The results showed that the active components and targets obtained by network pharmacology analyses had good binding activity, which reflected their multi-component, multi-target, multi-pathway action characteristics. This paper provides a theoretical basis for further study of the mechanism of action of BEO in the treatment of insomnia.

Tetrandrine Prevents Neomycin-Induced Ototoxicity by Promoting Steroid Biosynthesis

Aminoglycoside antibiotics are widely used for the treatment of serious acute infections, life-threatening sepsis, and tuberculosis, but all aminoglycosides cause side effects, especially irreversible ototoxicity. The mechanisms underlying the ototoxicity of aminoglycosides need further investigation, and there are no effective drugs in the clinic. Here we showed that tetrandrine (TET), a bioactive bisbenzylisoquinoline alkaloid derived from Stephania tetrandra, ameliorated neomycin-induced cochlear hair cell injury. In both in vitro and in vivo experiments we found that TET administration significantly improved auditory function and reduced hair cell damage after neomycin exposure. In addition, we observed that TET could significantly decrease oxidative stress and apoptosis in hair cells after neomycin exposure. Finally, RNA-seq analysis suggested that TET protected against neomycin-induced ototoxicity mainly by promoting steroid biosynthesis. Collectively, our results provide pharmacological evidence showing that TET may be a promising agent in preventing aminoglycosides-induced ototoxicity.

C19 Benzylisoquinoline Alkaloid with Unprecedented Architecture from Hypecoum erectum

Hyperectumine (1), the first C₁₉ benzylisoquinoline alkaloid with a complicated ring system, was isolated from Hypecoum erectum and structurally characterized. Its biosynthetic origin should involve a hybrid pattern of C₈ + C₈ + C₁ + C₂, from which a C₁₇ benzylisoquinoline alkaloid might be further attacked by a malonamic acid and undergo decarboxylation and cyclization to produce 1. Compound (-)-1 exhibited moderate anti-inflammatory activity via suppression of LPS-activated inflammatory mediators in RAW 264.7 macrophage cells.

Diversity in Chemical Structures and Biological Properties of Plant Alkaloids

Phytochemicals belonging to the group of alkaloids are signature specialized metabolites endowed with countless biological activities. Plants are armored with these naturally produced nitrogenous compounds to combat numerous challenging environmental stress conditions. Traditional and modern healthcare systems have harnessed the potential of these organic compounds for the treatment of many ailments. Various chemical entities (functional groups) attached to the central moiety are responsible for their diverse range of biological properties. The development of the characterization of these plant metabolites and the enzymes involved in their biosynthesis is of an utmost priority to deliver enhanced advantages in terms of biological properties and productivity. Further, the incorporation of whole/partial metabolic pathways in the heterologous system and/or the overexpression of biosynthetic steps in homologous systems have both become alternative and lucrative methods over chemical synthesis in recent times. Moreover, in-depth research on alkaloid biosynthetic pathways has revealed numerous chemical modifications that occur during alkaloidal conversions. These chemical reactions involve glycosylation, acylation, reduction, oxidation, and methylation steps, and they are usually responsible for conferring the biological activities possessed by alkaloids. In this review, we aim to discuss the alkaloidal group of plant specialized metabolites and their brief classification covering major categories. We also emphasize the diversity in the basic structures of plant alkaloids arising through enzymatically catalyzed structural modifications in certain plant species, as well as their emerging diverse biological activities. The role of alkaloids in plant defense and their mechanisms of action are also briefly discussed. Moreover, the commercial utilization of plant alkaloids in the marketplace displaying various applications has been enumerated.

An overview on the chemistry, pharmacology and anticancer properties of tetrandrine and fangchinoline (alkaloids) from Stephania tetrandra roots

Tetrandrine (TET) and fangchinoline (FAN) are dominant bisbenzylisoquinoline (BBIQ) alkaloids from the roots of Stephania tetrandra of the family Menispermaceae. BBIQ alkaloids comprise two benzylisoquinoline units linked by oxygen bridges. The molecular structures of TET and FAN are exactly the same, except that TET has a methoxy (-OCH₃) group, while FAN has a hydroxyl (-OH) group at C7. In this overview, the current knowledge on the chemistry, pharmacology and anticancer properties of TET and FAN have been updated. The focus is on colon and breast cancer cells, because they are most susceptible to TET and FAN, respectively. Against colon cancer cells, TET inhibits cell proliferation and tumor growth by inducing apoptosis and G1 cell cycle arrest, and suppresses adhesion, migration and invasion of cells. Against breast cancer cells, FAN inhibits cell proliferation by inducing apoptosis, G1-phase cell cycle arrest and inhibits cell migration. The processes involve various molecular mechanisms and signaling pathways. Some insights on the ability of TET and FAN to reverse multi-drug resistance in cancer cells and suggestions for future research are provided.

Bioguided isolation, identification and activity evaluation of antifungal compounds from Acorus tatarinowii Schott

ETHNOPHARMACOLOGY RELEVANCE

As a traditional folk medicine, Acorus tatarinowii Schott was used to treat digestive diseases, such as diarrhea, which may be related to Candida albicans infection; however according to literature surveys, there have been few studies of A. tatarinowii focusing on its antimicrobial activity, and almost all describe investigations using crude extracts or fractions.

AIM OF THE STUDY

The aims of the current study were to isolate and identify antifungal fractions of A. tatarinowii based on their antifungal activity, explore the preliminary mechanism of 60% ethanol elution (AT60) by metabonomics, and evaluate the antifungal activity of AT60 in vivo and in vitro, to provide natural resources against fungal infections.

MATERIALS AND METHODS

As a pilot evaluation of activity, A. tatarinowii fractions and compounds with antifungal bioactivity were isolated by bioactive-guided column chromatography, and identified by LC-QTOF-MS/MS and NMR spectroscopy. The antifungal effects of the active ingredients against resistant C. albicans were evaluated by in vivo and in vitro colony forming unit assays. The mechanism underlying the activity of AT60 against C. albicans was explored using an LC-QTOF-based metabonomics approach and fluorescence microscopy imaging.

RESULTS

AT60 showed better activity against C. albicans than the same dose of the first line antifungal drugs, fluconazole and itraconazole (positive control drugs). Subsequent phytochemical investigation of AT60 identified twenty-five known compounds, six of which were isolated: asaraldehyde (7), 1-(2,4,5-trimethoxyphenyl)-1,2-propanediol (12), α-asarone (14), β-asarone (15), γ-asarone (18), acotatarone C (19). Further, the compounds α-asarone (14) and acotatarone C (19) may be responsible for the antifungal activity, and exhibit synergistic effects. Metabonomics analysis indicated that AT60 can inhibit biofilm formation by regulating the C. albicans protein kinase C pathway.

CONCLUSIONS

Our results show that A. tatarinowii has potent bioactivity against C. albicans in vitro and in vivo, and can be considered an antifungal botanic agent.

History of uses, phytochemistry, pharmacological activities, quality control and toxicity of the root of Stephania tetrandra S. Moore: A review

ETHNOPHARMACOLOGICAL RELEVANCE

the root of Stephania tetrandra S. Moore, known as Fangji in China (Chinese: ), is a traditional Chinese medicine (TCM) with a long history of use. Fangji is a type of medicine used to treat various diseases, including rheumatism, arthralgia, edema and beriberi, unfavorable urination, and eczema.

AIM OF THIS REVIEW

There are many newly published reports on the history of uses, phytochemistry, pharmacological activity, quality control and toxicity of Fangji; however, no comprehensive systematic review exists. Therefore, the purpose of this review is to compile the latest and most comprehensive information on Fangji and provide a scientific basis for future research.

MATERIALS AND METHODS

A systematic literature search was conducted using multiple electronic databases, including SciFinder, Web of Science, PubMed, Science Direct, ACS Publications, J-stage, SpringerLink, Thieme, Wiley, and CNKI. Information was also collected from journals and Chinese Pharmacopoeia.

RESULT

Thus far, there were uses of Fangji against 20 different diseases/disorders, such as relieving edema and rheumatism pain, treating cough and asthma, treating enuresis, astringent urine and beriberi edema, purging blood and damp heat, and dispelling wind evil and dampness, etc. 48 compounds have been isolated from Fangji, belonging to alkaloids, flavonoids, and steroids, other compounds. The crude extracts and isolated compound of Fangji have shown a wide range of pharmacological activities, such as anti-tumor, anti-inflammatory, and neuroprotective activities, as well as role in reoxygenation, and antimicrobial effect, etc. Moreover, qualitative and quantitative analyses of quality control are reviewed, including qualitative analyses for the identification of compounds, as well as fingerprint and quantitative analyses by high performance liquid chromatography (HPLC) and capillary electrochromatography (CE). In the toxicity study, the hepatotoxicity, hepatorenal toxicity, nephrotoxicity, subacute and acute toxicities of the alcohol extract and water extract of Fangji, and tetrandrine were studied in-vitro and in-vivo experiments.

CONCLUSION

In the history of uses, Fangji can be used to treat a variety of diseases, most of which are manifested in removing wind and dampness. In recent years, the phytochemistry of Fangji has rarely been reported. The pharmacological activities of Fangji mainly focus on the compounds, tetrandrine and fangchinoline, and there are a few reports on the pharmacological studies of other compounds in Fangji. Moreover, the quality control of Fangji lacks a standard fingerprint to distinguish Fangji from other easily-confused medicinal materials. In the toxicity study, there is no report on the mechanism of toxicity research. Therefore, further studies on such mechanisms are needed.

A common neuronal mechanism of hypertension and sleep disturbances in spontaneously hypertensive rats: Role of orexinergic neurons

Epidemiologic studies have shown that sleep disorders are associated with the development of hypertension. The present study investigated dynamic changes in sleep patterns during the development of hypertension across the lifespan in spontaneously hypertensive rats (SHRs) and the neural mechanism that underlies these comorbidities, with a focus on the orexinergic system. Blood pressure in rats was measured using a noninvasive blood pressure tail cuff. Sleep was monitored by electroencephalographic and electromyographic recordings. Immunohistochemistry was used to detect the density and activity of orexinergic neurons in the perifornical nucleus. Hcrt2-SAP (400 or 800 ng) was microinjected in the lateral hypothalamus to lesion orexinergic neurons. Compared with Wistar-Kyoto rats, SHRs exhibited various patterns of sleep disturbances. In SHRs, dynamic changes in hypersomnia in the rats' active phase was not synchronized with the development of hypertension, but hyperarousal in the inactive phase and difficulties in falling asleep were observed concurrently with the development of hypertension. Furthermore, the density and activity of orexinergic neurons in the perifornical nucleus were significantly higher in SHRs than in age-matched Wistar-Kyoto rats. The reduction of orexinergic neurons in the lateral hypothalamus partially ameliorated the development of hypertension and prevented difficulties in falling asleep in SHRs. These results indicate that although the correlation between sleep disturbances and hypertension is very complex, common mechanisms may underlie these comorbidities in SHRs. Overactivity of the orexin system may be one such common mechanism.

Tetrandrine Suppresses Transient Receptor Potential Cation Channel Protein 6 Overexpression- Induced Podocyte Damage via Blockage of RhoA/ROCK1 Signaling

Objective

Podocyte damage is common in many renal diseases characterized by proteinuria. Transient receptor potential cation channel protein 6 (TRPC6) plays an important role in renal function through its regulation of intracellular Ca²⁺ influx and RhoA/ROCK pathways. Chinese herb Stephania tetrandra, with the main active component being tetrandrine, has been used for the treatment of various kidney diseases for several years and has shown a positive effect. This study aimed at investigating the effect and mechanism of tetrandrine in podocyte damage induced by high expression of TRPC6.

Methods

Immortalized, differentiated murine podocytes, MPC5 were treated with valsartan (0–800 μM) and tetrandrine (0–40 μM) for 48 h. The maximum safe concentrations of valsartan and tetrandrine were selected using a cell viability assay. MPC5 podocytes stably expressing TRPC6 were constructed using a lentivirus packaging system, followed by treatment with valsartan, tetrandrine, and Y-27632 for 48 h and U73122 (10 μM) for 10 min. The RhoA/ROCK pathway and podocyte-specific proteins (nephrin and synaptopodin) levels were quantified. Podocyte apoptosis and intracellular Ca²⁺ concentration were measured.

Results

Maximum safe concentrations of 100 μM valsartan and 10 μM tetrandrine showed no observable toxicity in podocytes. MPC5 podocytes stably expressing TRPC6 had higher intracellular Ca²⁺ influx, apoptotic percentages, and expression of RhoA/ROCK proteins, but lower expression of nephrin and synaptopodin proteins. U73122 treatment for 10 min did not inhibit TRPC6, but suppressed RhoA/ROCK protein. Y-27632 decreased ROCK1 expression, but did not influence the expression of TRPC6 protein. Both 100 μM valsartan and 10 μM tetrandrine for 48 h significantly inhibited intracellular Ca²⁺ influx, apoptosis, and RhoA/ROCK pathway, and increased nephrin and synaptopodin proteins in podocytes stably expressing TRPC6.

Conclusion

Elevated TRPC6 expression can lead to podocyte injury by inducing intracellular Ca²⁺ influx and apoptosis of podocytes, and this effect may be mediated by activation of the RhoA/ROCK1 pathway. Tetrandrine can alleviate podocyte injury induced by TRPC6 expression through inhibition of the RhoA/ROCK pathway, suggesting a protective role in podocyte damage.

A critical review: traditional uses, phytochemistry, pharmacology and toxicology of Stephania tetrandra S. Moore (Fen Fang Ji)

ABSTRACT

Stephania tetrandra S. Moore (S. tetrandra) is distributed widely in tropical and subtropical regions of Asia and Africa. The root of this plant is known in Chinese as "Fen Fang Ji". It is commonly used in traditional Chinese medicine to treat arthralgia caused by rheumatism, wet beriberi, dysuria, eczema and inflamed sores. Although promising reports have been published on the various chemical constituents and activities of S. tetrandra, no review comprehensively summarizes its traditional uses, phytochemistry, pharmacology and toxicology. Therefore, the review aims to provide a critical and comprehensive evaluation of the traditional use, phytochemistry, pharmacological properties, pharmacokinetics and toxicology of S. tetrandra in China, and meaningful guidelines for future investigations.

Exploring a New Natural Treating Agent for Primary Hypertension: Recent Findings and Forthcoming Perspectives

Primary hypertension describes abnormally-high systolic/diastolic blood pressure in a resting condition caused by various genetic or environmental risk factors. Remarkably, severe complications, such as ischemic cardiovascular disease, stroke, and chronic renal disease have led to primary hypertension becoming a huge burden for almost one-third of the total population. Medication is the major regimen for treating primary hypertension; however, recent medications may have adverse effects that attenuate energy levels. Hence, the search for new hypotensive agents from folk or traditional medicine may be fruitful in the discovery and development of new drugs. This review assembles recent findings for natural antihypertensive agents, extracts, or decoctions published in PubMed, and provides insights into the search for new hypotensive compounds based on blood-pressure regulating mechanisms, including the renin-angiotensin-aldosterone system and the sympathetic/adrenergic receptor/calcium channel system.

Tetrandrine inhibits proliferation of colon cancer cells by BMP9/ PTEN/ PI3K/AKT signaling

Despite advances in screening and treatment, colon cancer remains one of the leading causes of cancer-related death. Finding novel and useful drug treatment targets is also an urgent need for clinical applications. Tetrandrine (Tet) is extracted from the Chinese medicinal herbal medicine, which is a well-known calcium blocker with a variety of pharmacological activities, including anti-cancer. In this study, we recruited cell viability assay, flow cytometry analysis, cloning formation to confirm that Tet can inhibit the proliferation of SW620 cells, and induce apoptosis. Mechanically, we confirmed that Tet up-regulates the mRNA and protein level of BMP9 in SW620 cells. Over-expression BMP9 enhances the anti-cancer effects of Tet in SW620 cells, but these effects can be partly reversed by silencing BMP9. Also, Tet reduces phosphorylation of Aktl/2/3 in SW620 cells, which could be elevated by overexpressed BMP9 and impaired by silencing BMP9. Furthermore, we demonstrated that Tet reduces phosphorylated PTEN, which can be promoted by overexpressed BMP9, analogously also be attenuated through silencing BMP9. Finally, we introduced a xenograft tumor model to investigate the anti-proliferative effect of Tet, further to explore the effects of BMP9 and PTEN in SW620 cells. Our findings suggested that the anti-cancer activity of Tet in SW620 cells may be mediated partly by up-regulating BMP9, followed by inactivation PI3K/Akt through up-regulating PTEN at least.

Anticancer activity of tetrandrine by inducing pro-death apoptosis and autophagy in human gastric cancer cells

OBJECTIVES

To investigate the antitumour property of tetrandrine by inducing autophagy and apoptosis in human gastric cancer cells, and to explore the potential molecular mechanisms.

METHODS

The antitumour activity of tetrandrine was assessed through MTT assay. Apoptosis was measured by flow cytometry and microscopic examination of cellular morphology. The mitochondrial membrane potential was detected by staining with Rh-123. Induction of autophagy was monitored by transmission electron microscopy observation, using GFP-LC3 transfection.

KEY FINDINGS

The results revealed that tetrandrine exhibits significant antitumour activity against gastric human cancer cell and the antigastric tumour activity was depended on inducing autophagy and apoptosis through upregulating the apoptosis-related protein (cleaved PARP, cleaved caspase-3 and cleaved caspase-9) and autophagy-related protein (Beclin-1, LC3-II and p62), and decreasing the phosphorylation of AKT/mTOR, PS6K and P-4EBP1. Adding the inhibitor of autophagy, 3-MA or Baf-A1, increased the viability of tetrandrine-exposed gastric cancer cells, which confirmed the role of autophagy played in the gastric cancer cell death induced by tetrandrine.

CONCLUSIONS

These results demonstrated that the antitumour effects of tetrandrine by inducing autophagy and apoptosis involving Akt/mTOR pathway. Thus, tetrandrine may be a promising lead compound to be further developed in future for cancer therapy.

Effects of two bisbenzylisoquinoline alkaloids, Antioquine and Tetrandrine, compared to Verapamil in Rat Thoracic Aorta

The objective of this study was to compare two alkaloids (antioquine and tetrandrine) with verapamil; knowing that the smooth muscle respond to KCl and relationships with calcium. The effects of antioquine and tetrandrine, was studied in adults Wistar rat with modified methods used in the determination of aorta contractility and compared with verapamil effect in the same assays. The analysis of the effect of a drug or extract on aortic reactivity included maximal relaxation or maximal contraction (Cmax) (Phase 1). In our results, verapamil induced a blockade of 98.7 ± 0.7% (n = 6) in presence of endothelium and 97.9 ± 4.3% in ausence of endothelium, both in phase 1 and in phase 2 of 47.4 ± 4.1% (n = 6) in aortas in the presence of endothelium and 61.8 ± 1.1% in ausence of endothelium; Tetrandrine assays showed a phase 1 blocking effect of 63.4 ± 5.5 and 47.7 ± 2.9% (with and without endothelium, respectively) and phase 2 of 43.5 ± 6.2 and 28.5 ± 5.7%, (with and without endothelium, respectively). Antioquine presents in phase 1 and phase 2, a blockade that is not significant from the point of view of calcium antagonism. We can conclude that tetrandrine block the movement of calcium from both intracellular and extracellular deposits, with the greatest effect when aortas are in the presence of endothelium.

NMR, Novel Pharmacological and In Silico Docking Studies of Oxyacanthine and Tetrandrine: Bisbenzylisoquinoline Alkaloids Isolated from Berberis glaucocarpa Roots

Urease enzyme is responsible for gastric cancer, peptic ulcer, hepatic coma, and urinary stones in millions of people across the world. So, there is a strong need to develop new and safe antiurease drugs, particularly from natural sources. In search for new and effective drugs from natural sources bioassay-guided fractionation and isolation of Berberis glaucocarpa Stapf roots bark resulted in the isolation and characterization, on the basis of 1D and 2D NMR data, of two bisbenzylisoquinoline alkaloids, oxyacanthine (1) and tetrandrine (2), followed by urease inhibition studies. Crude extract, all the subfractions and the isolated compounds 1 and 2 displayed excellent urease enzyme inhibition properties in vitro. The antiurease nature and possible mode of action for compounds 1 and 2 were verified and explained through their molecular docking studies against jack-bean urease enzyme. Half-maximum inhibitory concentration (IC₅₀) was calculated for compounds 1 and 2. The IC₅₀ value was found to be 6.35 and 5.51 µg/mL for compounds 1 and 2, respectively. Both compounds 1 and 2 have minimal cytotoxicity against THP-1 monocytic cells.