Effects of strictosamide on mouse brain and kidney Na+, K+-ATPase and Mg2+-ATPase activities

Strategy for the quality control of herbal preparations made of Sarcocephalus latifolius: Development and validation of a UHPLC-PDA method for quantification of angustoline and strictosamide and chemical profiling using LC-QToF

INTRODUCTION

Sarcocephalus latifolius is one of the most used plants in West African traditional medicine to treat malaria.

OBJECTIVE

The aim is to establish a strategy to control the quality of herbal preparations made from S. latifolius.

METHOD

A UHPLC-PDA method was developed for the determination and quantification of the two main bioactive compounds (angustoline and strictosamide) in various parts of the plant. Additionally, an LC-QToF with electrospray ionization method is described for the identification and confirmation of compounds in samples of different parts of the plant.

RESULTS

With the UHPLC-PDA method, separation was achieved within 5 min using a C18 column stationary phase at a temperature of 45°C and a gradient system with a mobile phase of water and acetonitrile, both containing 0.1% formic acid. The method was validated for linearity, accuracy, precision (repeatability and intermediate precision), limit of detection (LOD), and limit of quantification (LOQ). The LOD and LOQ of angustoline were found to be 0.3 and 0.8 μg/ml, respectively, and those of strictosamide were found to be 0.1 and 0.3 μg/ml, respectively. Using the LC-QToF method, 90 secondary metabolites, including four isolated compounds from the plant's roots, were identified from leaf, bark, and root samples of S. latifolius.

CONCLUSION

This work is the first to propose a strategy to control the quality of herbal preparations made from S. latifolius. The developed method allows the quantification of the main bioactive compounds and the established chemical profile allows to distinguish the plant from any other species.

Nauclea officinalis: A Chinese medicinal herb with phytochemical, biological, and pharmacological effects

Nauclea officinalis (N. officinalis), a medicinal plant of the genus Nauclea in the family Rubiaceae, is used in the treatment of fever, pneumonia, pharyngolaryngitis, and enteritis in China. Extracts of N. officinalis include alkaloids, phenolic acids, pentacyclic triterpenoids, and flavonoids, which exert all kinds of pharmacological effects, for instance anti-inflammatory, anti-tumor, antibacterial, and antiviral and therefore show good effectiveness. To gain a comprehensive and deep understanding, the medicinal chemistry and chemical biology of N. officinalis are summarized in this review to provide a theoretical basis. The pharmacological effects were reviewed to provide evidence or insights into potential opportunities for further studies and medicinal exploitation of N. officinalis.

Total Synthesis of (-)-Strictosidine and Interception of Aryne Natural Product Derivatives "Strictosidyne" and "Strictosamidyne"

Monoterpene indole alkaloids are a large class of natural products derived from a single biosynthetic precursor, strictosidine. We describe a synthetic approach to strictosidine that relies on a key facially selective Diels-Alder reaction between a glucosyl-modified alkene and an enal to set the C15-C20-C21 stereotriad. DFT calculations were used to examine the origin of stereoselectivity in this key step, wherein two of 16 possible isomers are predominantly formed. These calculations suggest the presence of a glucosyl unit, also inherent in the strictosidine structure, guides diastereoselectivity, with the reactive conformation of the vinyl glycoside dienophile being controlled by an exo-anomeric effect. (-)-Strictosidine was subsequently accessed using late-stage synthetic manipulations and an enzymatic Pictet-Spengler reaction. Several new natural product analogs were also accessed, including precursors to two unusual aryne natural product derivatives termed "strictosidyne" and "strictosamidyne". These studies provide a strategy for accessing glycosylic natural products and a new platform to access monoterpene indole alkaloids and their derivatives.

Countrywide Survey of Plants Used for Liver Disease Management by Traditional Healers in Burkina Faso

Liver disease is highly prevalent in Africa, especially in the western African country Burkina Faso, due to the presence of multiple biological and chemical aggressors of the liver. Furthermore, diagnosis and appropriate care for liver disease are uneven and usually insufficient. This drives local communities to turn to folk medicine based on medicinal plants from healers. Small scale, ethnopharmacological studies on reputed hepatoprotective plants have been carried out in defined regions worldwide, but so far, no study has been carried out on a countrywide scale. Therefore, we have explored traditional healers’ practices in all thirteen regions of Burkina Faso. We interviewed 575 healers and we compiled a database with 2,006 plant entries. Here, we report results on liver nosology, liver pathologies, medicinal plants used for liver disease, and traditional practices through the lens of Burkinabe healers. Our goal was to give a full inventory of medicinal plants used to treat liver disease and to determine if there was consensus on the use of specific plants for specific symptoms. Analysis of the medicinal plants in use across the whole country provides local communities with a wider evidence base to determine which plants may be more effective in treating liver disease and could provide the scientific community, with a shortlist of plants suitable for chemical and pharmacological investigation to validate the plants’ therapeutic role.

Strictosamide alleviates the inflammation in an acute ulcerative colitis (UC) model

The ulcerative colitis (UC) is a typical inflammatory bowel disease (IBD) causing great damages, while strictosamide (STR) is a natural alkaloid that possesses strong anti-inflammatory property in infection and inflammation-related diseases. Our study is aimed at evaluating the anti-inflammatory activity of STR in the course of UC. Briefly, male Balb/c mice were treated with 3.5% dextran sulfate sodium (DSS) for 6 consecutive days to establish an acute model of UC, and the administration of gradient concentrations of STR was subsequently performed. Accordingly, colonic pathological alterations including the reduced ratio of colon weight/length, decreased disease activity index (DAI), and attenuated H&E damage were found in UC mice after STR treatment. Based on the analyses of real-time PCR and western blot, downregulation of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) was also determined in the colonic tissue of UC mice after the treatment of STR. ELISA and immunohistochemical staining further suggest the relief of inflammation in UC mice with decreased expressions of MPO and iNOS after STR treatment. In addition, STR was also validated to significantly inhibit NF-κB signaling in UC mice by western blot and Electrophoretic Mobility Shift Assay (EMSA). Meanwhile, restricted inflammation was also determined in STR-treated IEC6 and HT-29 cells. The utilization of PDTC, an inhibitor of NF-κB, further demonstrated that STR ameliorated the inflammation by inhibiting the NF-κB signaling in vitro. In summary, our study suggests that STR could be a potential candidate for IBD therapy.

Bioactivity and cytotoxicity profiling of vincosamide and strictosamide, anthelmintic epimers from Sarcocephalus latifolius (Smith) Bruce leaf

ETHNOPHARMACOLOGICAL RELEVANCE

The leaf of Sarcocephalus latifolius is known to be used traditionally by the Fulanis in Nigeria to deworm animals. As helminthosis remains a major constraint to profitable livestock production worldwide, a precarious situation aggravated by the advent of resistant parasites, the discovery of new anthelmintics is a priority, necessitating exploration of medicinal plants for their anthelmintic principles.

AIM OF THE STUDY

To identify and characterise compounds with anthelmintic activity from the leaf of Sarcocephalus latifolius.

MATERIALS AND METHODS

Powdered S. latifolius leaves were extracted by successive maceration with n-hexane, chloroform and acetone. The dried extracts were evaluated for anthelmintic activity against Haemonchus placei adult worms, and the most active extract was subjected to bioassay-guided chromatographic separations. The isolated compounds were evaluated for cytotoxicity against the mammalian HeLa and MC3T3-E1 cell lines, using alamar blue and CellTitreGlo^TM to quantify cell viability. LC₅₀ values were computed from the in vitro anthelmintic activity data by fitting to a non-linear regression equation (variable slope). Isolated compounds were characterized using spectroscopic and mass spectrometric analyses.

RESULTS

Anthelmintic activity LC₅₀ values for n-hexane, chloroform and acetone extracts were 47.85, 35.76 and 5.72 (mg/mL), respectively. Chromatographic separation of acetone extract afforded two bioactive epimers, identified as vincosamide (LC₅₀ 14.7 mg/mL) and strictosamide (LC₅₀ 12.8 mg/mL). Cytotoxicity evaluation showed that, below 200 μg/mL (400 μM), neither compound was toxic to the HeLa or MC3T3-E1 cells.

CONCLUSION

Vincosamide and strictosamide could serve as novel scaffolds for the development of anthelmintic derivatives with improved potency and helminth selectivity.

Berberine chloride ameliorated PI3K/Akt-p/SIRT-1/PTEN signaling pathway in insulin resistance syndrome induced in rats

The liver is the main organ involved in lipid metabolism process and it helps in drug detoxification. Insulin resistance is considered one of risk reasons which lead to several metabolic diseases. Currently, berberine (BER) occupies a huge challenge against multiple diseases with no toxic effect. The present work was aimed to identify, does BER-chloride has a poisonous influence on the liver? and investigating the outcome of BER-chloride on PI3K/Akt-p/SIRT-1/PTEN pathway during insulin resistance syndrome. The insulin resistance model was achieved in experimental female rats via high-fat diet (HFD). Glucose, insulin, lipid profiles, and hepatic oxidative stress parameters were assessed. PI3K, AKt-p, SIRT-1, and PTEN levels in hepatic tissue were determined at genome and protein levels. Further adiponectin concentration was performed in serum, hepatic, and white adipose tissues. Molecular study of fold alteration in insulin, insulin receptor, and retinol binding protein-4 (RBP4) in liver was done. PRACTICAL APPLICATIONS: Obesity syndrome causes multiple obstacles in modern years. The current results revealed elevation the body weight of rats, plasma glucose, homeostatic model assessment, glycated hemoglobin, insulin, and lipid profiles concentrations in a group of rats, which nourished HFD for 8 weeks and this rise, was diminished after 2 weeks from BER-chloride administration. Further, BER-chloride improved transaminases enzymes, pro-oxidant, and antioxidant defense system, PI3K, AKt-p, SIRT-1, and PTEN in the liver, with downregulation of hepatic RBP4. Hence, these data provide a crucial message that BER-chloride enhanced both hepatic function and insulin signaling pathways that might be of therapeutic importance to insulin resistance with no harmful effect on the liver. BER-chloride is predicted to be a drug of choice for obesity complications cure.

Traditional uses, phytochemistry and pharmacological properties of African Nauclea species: A review

ETHNOPHARMACOALOGICAL RELEVANCE

The genus Nauclea in Africa comprises seven species. Among them, N. latifolia, N. diderrichii and N. pobeguinii are widely used by the local population in traditional remedies. Preparation from various parts of plants (e.g. roots, bark, leaves) are indicated by traditional healers for a wide range of diseases including malaria, pain, digestive ailments or metabolic diseases.

MATERIALS AND METHODS

A literature search was conducted on African species of the genus Nauclea using scientific databases such as Google Scholar, Pubmed or SciFinder. Every document of ethnopharmacological, phytochemical or pharmacological relevance and written in English or French were analyzed.

RESULTS AND DISCUSSION

The Nauclea genus is used as ethnomedicine all along sub-Saharan Africa. Several local populations consider Nauclea species as a major source of remedies for malaria. In this regard, two improved traditional medicines are currently under development using extracts from N. latifolia and N. pobeguinii. Concerning the chemical composition of the Nauclea genus, indoloquinolizidines alkaloids could be considered as the major class of compounds as they are reported in every analyzed Nauclea species, with numerous structures identified. Based on traditional indications a considerable amount of pharmacological studies were conducted to ensure activity and attempt to link them to the presence of particular compounds in plant extracts.

CONCLUSION

Many experimental studies using plant extracts of the African species of the genus Nauclea validate traditional indications (e.g. malaria and pain). However, bioactive compounds are rarely identified and therefore, there is a clear need for further evaluations as well as for toxicity experiments. The sustainability of these plants, especially of N. diderrichii, a threatened species, should be kept in mind to adapt local uses and preparation modes of traditional remedies.

Phenolic-rich lychee (Litchi chinensis Sonn.) pulp extracts offer hepatoprotection against restraint stress-induced liver injury in mice by modulating mitochondrial dysfunction

The pulp from lychee, a tropical to subtropical fruit, contains large quantities of phenolic compounds and exhibits antioxidant activities both in vitro and in vivo. In the present study, we investigated the mechanisms underlying the hepatoprotective effects of lychee pulp phenolics (LPPs) against restraint stress-induced liver injury in mice. After 18 h of restraint stress, increased levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were observed. High levels of thiobarbituric acid reactive substances (TBARS) were also found. Restraint stress causes liver damage, which was protected against by LPP pretreatment at a dosage of 200 mg (kg d)(-1) for 21 consecutive days. This treatment remarkably decreased the serum ALT, AST and TBARS levels, elevated the liver glutathione (GSH) content, and the activities of glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT). Furthermore, respiratory chain complex and Na(+)-K(+)-ATPase activities were enhanced in liver mitochondria, while mitochondrial membrane potential levels and reactive oxygen species (ROS) production decreased. Thus, treatment with LPPs ameliorated restraint stress-induced liver mitochondrial dysfunction. These results suggest that LPPs protect the liver against restraint stress-induced damage by scavenging free radicals and modulating mitochondrial dysfunction. Thus, lychee pulp may be a functional biofactor to mitigate oxidative stress.

Modulatory Effects of Ferulic Acid on Cadmium-Induced Brain Damage

Studies have shown the pharmacological relevance of phenolics like ferulic acid (FA) in promoting health. This study sought to investigate the modulatory effects of FA on cadmium-induced brain damage in rats. Brain damage was induced in Wistar strain rats by oral administration of cadmium (5 mg/kg body weight) for 21 days. Assays for malondialdehyde (MDA) content, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), monoamine oxidase (MAO), and Na+/K+-ATPase activities were carried out. The study revealed significant ( P < .05) increases in the MDA content and all enzymes’ (AChE, BChE, MAO, and Na+/K+-ATPase) activity investigated following cadmium administration. However, rats administered FA (10 and 20 mg/kg body weight) alongside cadmium significantly ( P < .05) protected the brain by reversing the level of lipid peroxidation as measured by the MDA content as well as the enzymes’ activity. This study, therefore, substantiates the neuroprotective potentials of FA especially in the management of cadmium-induced toxicity.

Nauclea latifolia: biological activity and alkaloid phytochemistry of a West African tree

Covering up to 2016Nauclea latifolia (syn. Sarcocephalus latifolius, Rubiaceae), commonly called the African pincushion tree, is a plant widely used in folk medicine in different regions of Africa for treating a variety of illnesses, including malaria, epilepsy and pain. N. latifolia has not only drawn the interest of traditional healers but also of phytochemists, who have identified a range of bioactive indole alkaloids in its tissue. More recently, following up on the traditional use of extracts in pain management, a bio-guided purification from the roots of the tree led to the identification of the active ingredient as tramadol, available as a synthetic analgesic since the 1970s. The discovery of this compound as a natural phytochemical was highlighted worldwide. This review focuses on the correlation between extracted compounds and pharmacological activities, paying special attention to infectious diseases and neurologically-related disorders. A critical analysis of the data reported so far on the natural origin of tramadol and its proposed biosynthesis is also presented.

Therapeutic Potential of Spirooxindoles as Antiviral Agents

Antiviral therapeutics with profiles of high potency, low resistance, panserotype, and low toxicity remain challenging, and obtaining such agents continues to be an active area of therapeutic development. Due to their unique three-dimensional structural features, spirooxindoles have been identified as privileged chemotypes for antiviral drug development. Among them, spiro-pyrazolopyridone oxindoles have been recently reported as potent inhibitors of dengue virus NS4B, leading to the discovery of an orally bioavailable preclinical candidate (R)-44 with excellent in vivo efficacy in a dengue viremia mouse model. This review highlights recent advances in the development of biologically active spirooxindoles for their antiviral potential, primarily focusing on the structure-activity relationships (SARs) and modes of action, as well as future directions to achieve more potent analogues toward a viable antiviral therapy.

Medicinal plants of Guinea-Bissau: Therapeutic applications, ethnic diversity and knowledge transfer

ETHNOPHARMACOLOGICAL RELEVANCE

The rich flora of Guinea-Bissau, and the widespread use of medicinal plants for the treatment of various diseases, constitutes an important local healthcare resource with significant potential for research and development of phytomedicines. The goal of this study is to prepare a comprehensive documentation of Guinea-Bissau's medicinal plants, including their distribution, local vernacular names and their therapeutic and other applications, based upon local notions of disease and illness.

MATERIALS AND METHODS

Ethnobotanical data was collected by means of field research in Guinea-Bissau, study of herbarium specimens, and a comprehensive review of published works. Relevant data were included from open interviews conducted with healers and from observations in the field during the last two decades.

RESULTS

A total of 218 medicinal plants were documented, belonging to 63 families, of which 195 are native. Over half of these species are found in all regions of the country. The medicinal plants are used to treat 18 major diseases categories; the greatest number of species are used to treat intestinal disorders (67 species). More than thirty ethnic groups were identified within the Guinea-Bissau population; 40% of the medicinal plants have been recorded in the country's principal ethnic languages (i.e. Fula and Balanta).

CONCLUSIONS

This multi-disciplinary, country-wide study identifies a great diversity of plants used by indigenous communities as medicinal, which constitute an important common reservoir of botanical species and therapeutic knowledge. The regional overlap of many indigenous species, the consensual nature of disease groups based upon local perceptions of health conditions, and the relevance of local vernacular including Guinean Creole are key factors specific to the country which enhance the potential for the circulation and transmission of ethno-botanical and therapeutic knowledge.

Synthesis and Biological Evaluation of Strictosamide Derivatives with Improved Antiviral and Antiproliferative Activities

A series of novel derivatives of strictosamide were synthesized and biologically evaluated. Most of the new compounds exhibited improved activities than the parent compound strictosamide. Among them, compounds Ib and If possessed antiviral activities against influenza A virus (A/Jinan/15/90) with IC50 values of 4.12 and 12.35 μg/mL, respectively. Compound Ie possessed antiviral activity against respiratory syncytial virus (RSV) with an IC50 value of 9.58 μg/mL. Both compounds IIc and IId had moderate antiproliferative effects against five human cancer cell lines. The preliminary structure-activity relationships were also concluded. This study provides a promising new template with potential antiviral activity.

In vivo anti-inflammatory and analgesic activities of strictosamide from Nauclea officinalis

CONTEXT

Strictosamide is the main representative constituent of Nauclea officinalis Pierre ex Pitard (Rubiaceae), which has been used for a long time in China to treat diseases related to infection and inflammation, but its pharmacological activities are not well studied.

OBJECTIVE

This work evaluates the anti-inflammatory and analgesic activities of strictosamide by in vivo experiments.

MATERIALS AND METHODS

The anti-inflammatory activity was assessed in mice by models of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ear edema, acetic acid-elevated vascular permeability, and carboxymethylcellulose sodium (CMC-Na)-induced leukocyte migration. The analgesic activity was estimated in mice using acetic acid-induced writhing and hot-plate tests. Compound was injected to mice twice a day for 3 d at doses of 10, 20, and 40 mg/kg.

RESULTS

At 20 and 40 mg/kg, strictosamide obviously decreased the TPA-induced mice ear edema (24.7 and 28.1% inhibition, respectively), and significantly inhibited acetic acid-stimulated peritoneal vascular permeability in mice (23.3 and 33.4% inhibition, respectively). It also significantly decreased the leukocytes in the mice peritoneal cavity induced by CMC-Na at all the tested doses (46.0, 49.1, and 58.7% inhibition, respectively). To acetic acid-induced writhing test in mice, strictosamide markedly prolonged the pain latency at 20 and 40 mg/kg and decreased the writhing counts at 40 mg/kg (49.7% inhibition). However, it did not obviously improve the pain threshold of mice in hot-plate test.

DISCUSSION AND CONCLUSION

Strictosamide may have important effects on inflammation and inflammatory pain. The results provide scientific support for the role of strictosamide in the use of N. officinalis to treat inflammatory diseases.

Non-alcoholic fatty liver induces insulin resistance and metabolic disorders with development of brain damage and dysfunction

In the present study we investigated the effect of the non-alcoholic fatty liver disease (NAFLD) on the alterations in the activity of neurotransmitters catabolizing enzymes and energy catabolising enzymes, prooxidants, endogenous antioxidants and proinflammatory cytokines in brain tissue of NAFLD rats. Rats were intraperitonealy injected with CCl4 solution at a dose of (0.021 mole/Kg, 20 μL, body weight) three times weekly for four weeks. Acetylcholine esterase (AChE), monoamine oxidase (MAO), prooxidant/ antioxidants status, ATPase, lipid profile and glucose level were estimated spectrophotometrically while inflammatory markers; interleukin 6 and tumor necrosis factor alpha (IL6 and TNF-α) and insulin were assessed by ELISA technique. Our results showed that the induced NAFLD and insulin resistance (IR) were accompanied with hyperglycemia and hyperlipidemia and lowered brain glucose level with elevated ATPase activity, prooxidant status (TBARS level, xanthine oxidase and cytochrome 2E1 activities), and inflammatory markers. Through the induction period AChE activity was significantly increased compared to control in blood, liver and brain tissues. Also, MAO activity was significantly increased in both brain and liver tissue but decreased in serum compared with control. These biochemical data were supported with pathophysiological analysis that showed severe neurodegeneration, pyknosis acuolations and cavitations. These observations warrant the reassessment of the conventional concept that the NAFLD with IR progression may induce disturbances in activities of neurotransmitters catabolising enzymes and energy production accompanied with oxidative stress and metabolic disorders, acting as relative risk factors for brain dysfunction and damage with the development of age-associated neurodegenerative diseases such as Alzheimer's disease.