Antiedematogenic and free radical scavenging activity of swertiamarin isolated from Enicostemma axillare

Neuroprotective Effect of Swertiamarin in a Rotenone Model of Parkinson's Disease: Role of Neuroinflammation and Alpha-Synuclein Accumulation

Parkinson's disease (PD) is a progressive neurodegenerative disease with no permanent cure affecting around 1% of the population over 65. There is an urgency to search for a disease-modifying agent with fewer untoward effects. PD pathology involves the accumulation of toxic alpha-synuclein (α-syn) and neuronal inflammation leading to the degeneration of dopaminergic (DAergic) neurons. Swertiamarin (SWE), a well-studied natural product, possesses a strong anti-inflammatory effect. It is a secoiridoid glycoside isolated from Enicostemma littorale Blume. SWE showed a reversal effect on the α-syn accumulation in the 6-hydroxydopamine (6-OHDA)-induced Caenorhabditis elegans model of PD. However, there are no reports in the literature citing the effect of SWE as a neuroprotective agent in rodents. The present study aimed to evaluate the anti-inflammatory activity of SWE against lipopolysaccharide (LPS)-induced C6 glial cell activation and its neuroprotective effect in the intrastriatal rotenone mouse PD model. SWE treatment showed a significant reduction in interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) levels in LPS-induced C6 glial cell activation. Further, our studies demonstrated the suppression of microglial and astroglial activation in substantia nigra (SN) after administration of SWE (100 mg/kg, intraperitoneally) in a rotenone mouse model. Moreover, SWE alleviated the rotenone-induced α-syn overexpression in the striatum and SN. SWE ameliorated the motor impairment against rotenone-induced neurotoxicity and mitigated the loss of DAergic neurons in the nigrostriatal pathway. Therefore, SWE has the potential to develop as an adjunct therapy for PD, but it warrants further mechanistic studies.

Swertiamarin supplementation prevents obesity-related chronic inflammation and insulin resistance in mice fed a high-fat diet

Obesity is characterized by low-grade chronic inflammation, which underlies insulin resistance and non-alcoholic fatty liver disease (NAFLD). Swertiamarin is a secoiridoid glycoside that has been reported to ameliorate diabetes and NAFLD in animal models. However, the effects of swertiamarin on obesity-related inflammation and insulin resistance have not been fully elucidated. Thus, this study investigated the effects of swertiamarin on inflammation and insulin resistance in high-fat diet (HFD)-induced obese mice. C57BL/6 mice were fed a HFD or HFD containing swertiamarin for 8 weeks. Obesity-induced insulin resistance and inflammation were assessed in the epididymal white adipose tissue (eWAT) and livers of the mice. Swertiamarin attenuated HFD-induced weight gain, glucose intolerance, oxidative stress, and insulin resistance, and enhanced insulin signalling in mice. Compared to HFD-fed mice, the swertiamarin-treated mice exhibited increased lipolysis and reduced adipocyte hypertrophy and macrophage infiltration in eWAT. Moreover, swertiamarin alleviated HFD-mediated hepatic steatosis and inflammation by suppressing activation of the p38 MAPK and NF-κB pathways within the eWAT and liver of obese mice. In conclusion, supplementation with swertiamarin attenuated weight gain and hepatic steatosis, and alleviated obesity-associated inflammation and insulin resistance, in obese mice.

Chemistry, Pharmacology and Therapeutic Potential of Swertiamarin - A Promising Natural Lead for New Drug Discovery and Development

Swertiamarin, a seco-iridoid glycoside, is mainly found in Enicostemma littorale Blume (E. littorale) and exhibits therapeutic activities for various diseases. The present study aimed to provide a review of swertiamarin in terms of its phytochemistry, physicochemical properties, biosynthesis, pharmacology and therapeutic potential. Relevant literature was collected from several scientific databases, including PubMed, ScienceDirect, Scopus and Google Scholar, between 1990 and the present. This review included the distribution of swertiamarin in medicinal plants and its isolation, characterization, physicochemical properties and possible biosynthetic pathways. A comprehensive summary of the pharmacological activities, therapeutic potential and metabolic pathways of swertiamarin was also included after careful screening and tabulation. Based on the reported evidence, swertiamarin meets all five of Lipinski’s rules for drug-like properties. Thereafter, the physicochemical properties of swertiamarin were detailed and analyzed. A simple and rapid method for isolating swertiamarin from E. littorale has been described. The present review proposed that swertiamarin may be biosynthesized by the mevalonate or nonmevalonate pathways, followed by the seco-iridoid pathway. It has also been found that swertiamarin is a potent compound with diverse pharmacological activities, including hepatoprotective, analgesic, anti-inflammatory, antiarthritis, antidiabetic, antioxidant, neuroprotective and gastroprotective activities. The anticancer activity of swertiamarin against different cancer cell lines has been recently reported. The underlying mechanisms of all these pharmacological effects are diverse and seem to involve the regulation of different molecular targets, including growth factors, inflammatory cytokines, protein kinases, apoptosis-related proteins, receptors and enzymes. Swertiamarin also modulates the activity of several transcription factors, and their signaling pathways in various pathological conditions are also discussed. Moreover, we have highlighted the toxicity profile, pharmacokinetics and possible structural modifications of swertiamarin. The pharmacological activities and therapeutic potential of swertiamarin have been extensively investigated. However, more advanced studies are required including clinical trials and studies on the bioavailability, permeability and administration of safe doses to offer swertiamarin as a novel candidate for future drug development.

Swertiamarin from Enicostemma littorale, counteracts PD associated neurotoxicity via enhancement α-synuclein suppressive genes and SKN-1/NRF-2 activation through MAPK pathway

The elusive targets and the multifactorial etiology of Parkinson's disease (PD) have hampered the discovery of a potent drug for PD. Furthermore, the presently available medications provide only symptomatic relief and have failed to mitigate the pathogenesis associated with PD. Therefore, the current study was aimed to evaluate the prospective of swertiamarin (SW), a secoiridoid glycoside isolated from a traditional medicinal plant, Enicostemma littorale Blume to ameliorate the characteristic features of PD in Caenorhabditis elegans. SW (25 μM) administration decreased the α-synuclein (α-syn) deposition, inhibited apoptosis and increased dopamine level mediated through upregulating the expression of genes linked to ceramide synthesis, mitochondrial morphology and function regulation, fatty acid desaturase genes along with stress responsive MAPK (mitogen-activated protein kinase) pathway genes. The neuroprotective effect of SW was evident from the robust reduction of 6-hydroxydopamine (6-OHDA) induced dopaminergic neurodegeneration independent of dopamine transporter (dat-1). SW mediated translational regulation of MAPK pathway genes was observed through increase expression of SKN-1 and GST-4. Further, in-silico molecular docking analysis of SW with C. elegans MEK-1 showed a promising binding affinity affirming the in-vivo results. Overall, these novel finding supports that SW is a possible lead for drug development against the multi- factorial PD pathologies.

Synthesis, molecular docking and ADMET prediction of novel swertiamarin analogues for the restoration of type-2 diabetes: an enzyme inhibition assay

Swertiamarin is a lead, biologically active compound obtained from Enicostemma littorale Blume and known to be identified for the anti-diabetic activity. Present work comprises the synthesis and structural optimization of seven novel swertiamarin analogues and those were not being reported elsewhere till date. Swertiamarin was isolated, followed by modifications that have been accomplished amidst fluorinating, acetylating and oxidizing agents and also performed chromatographic purity and characterization of analogues. Furthermore, the swertiamarin analogues were screened for dipeptidyl peptidase IV (DPP-IV) enzyme inhibition with in silico studies. Besides, the pharmacokinetics and toxicity of analogues were predicted using ADMET software. In a nutshell, the compounds such as SNIPERSV-4 and SNIPERSV-7 have to pose good initial activity (∼48%) in comparison to standard DPP-IV inhibitor (Sitagliptin). The identified analogues were active against DPP-IV enzyme in preliminary screenings, and these findings would be beneficial for the new age researchers also for the therapy of diabetes.

Swertiamarin and quercetin combination ameliorates hyperglycemia, hyperlipidemia and oxidative stress in streptozotocin-induced type 2 diabetes mellitus in wistar rats

ETHNOPHARMACOLOGICAL RELEVANCE

Swertiamarin (Sw) and quercetin (Qu) have been isolated from different plants and are reported for their antidiabetic activities. The plants from which swertiamarin and quercetin were isolated are also traditionally used in the treatment of diabetes mellitus.

AIM OF THE STUDY

The present study is aimed to evaluate the synergistic effect of a combination of swertiamarin and quercetin (CSQ) on α-amylase in vitro and on streptozotocin (STZ) induced diabetes mellitus in vivo.

METHODS

Swertiamarin was isolated from the plant Enicostemma axillare and quercetin was procured in its pure form. Sw, Qu and CSQ were evaluated for in vitro α-amylase inhibitory activity. Based on the in vitro study results, CSQ was assessed for in vivo streptozotocin induced diabetes mellitus in Wistar rats. The effect of CSQ on blood glucose levels, body weight, serum biochemical parameters and antioxidant enzymes such as glutathione (GSH), superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx) and lipid peroxide levels were estimated. The histopathological observations of pancreatic tissues were also made.

RESULTS

The purity of swertiamarin was confirmed by HPLC. The results showed that CSQ was found to possess high percentage of inhibition in an in vitro α-amylase inhibitory study. In a STZ-induced type 2 diabetes mellitus (T2DM), body weight of rats in CSQ treated and control groups were unaltered. A marked reduction in the blood glucose levels was observed in the CSQ treated groups on 14th and 28th day. Decrease in the levels of low-density lipoprotein (LDL), triglycerides, total cholesterol and an increase in high-density lipoprotein (HDL) cholesterol level was observed in a dose dependant in CSQ treated groups. However, CSQ treated groups could significantly improve antioxidant protection by increasing the levels of serum GSH, SOD, Catalase and GPx and decreasing the levels of lipid peroxide (p < 0.05). In the histopathological study, the pancreatic islets of Langerhans and vacuolization have shown significant increase in both the treated groups.

CONCLUSIONS

The combination of swertiamarin and quercetin (CSQ) has proven a preventive and therapeutic effect against T2DM and suggests that this is a potential combination of phytoconstituents for excellent hypoglycemic activity in T2DM.

Swertiamarin, a secoiridoid glycoside modulates nAChR and AChE activity

The ailments related to a malfunction in cholinergic functioning currently employ the use of inhibitors for acetylcholinesterase (AChE) and N-methyl-d-aspartate (NMDA) receptors. The present study was designed to elucidate the potential of swertiamarin (SW), a secoiridoidal glycoside isolated from Enicostemma littorale in curtailing the cholinergic dysfunction. Using Caenorhabditis elegans as a model, SW was found to enhance neurotransmission by modulating AChE and nicotinic acetylcholine receptor (nAChR) activity; being orchestrated through up-regulation of unc-17 and unc-50. SW exhibited AChE inhibition both in vivo and cell-free system. The in silico molecular docking of SW and human AChE (hAChE) displayed good binding energy of -6.02. Interestingly, the increase in aldicarb and levamisole sensitivity post SW treatment was curtailed to a significant level in daf-16 and skn-1 mutants. SW raised the level of the endogenous antioxidant enzymes through up-regulation of sod-3 and gst-4 that act downstream to DAF-16 and SKN-1, imparting protection against neurodegeneration. The outcome of our study displays SW as a potential natural molecule for the amelioration of cholinergic dysfunction. Moreover, the study also indicates that SW elicits antioxidant response via up-modulation of daf-16 possibly through unc-17 upregulation. Further research on SW pertaining to the underlying mechanism and potential is expected to significantly advance the current understanding and design of possible ameliorative or near ameliorative regimens for cholinergic dysfunction.

Medicinal and edible plants used by the Lhoba people in Medog County, Tibet, China

ETHNOPHARMACOLOGICAL RELEVANCE

The Lhoba people are a small, ancient, tribal ethnic group from the Himalayas and are located in the Tibet Autonomous Region of China. Medog County is rich in biocultural diversity. For a long time, Medog has been almost isolated from the outside world. The Lhoba people, who live in Medog, have maintained a relatively unique lifestyle and have accumulated rich traditional knowledge (TK), especially about medicinal and edible plants. Currently, there is very little documentation of the plants traditionally used by the local Lhoba communities.

AIM OF THE STUDY

Our investigation aimed to (i) document the species of medicinal and food plants used by the Lhoba people in Medog County, Tibet, China; (ii) screen the most important plant taxa for specific medicines, and identify the aliments treated to further contribute to drug and food supplement research; and (iii) examine whether the ethnobotanical knowledge of the Lhoba is similar among different tribes and discuss traditional uses in the health practices and livelihoods of the local communities.

METHODS

Ethnobotanical data were recorded through semi-structured interviews, guided field trips, and quantitative analysis. The informant consensus factor (FIC) was used as a quantitative index.

RESULTS

Ninety-one informants (61 men and 30 women) were interviewed. A total of 75 species, including 37 medicinal plants for 14 categories of diseases and 57 edible plants from six types of food, were recorded. Among the usage types of medicinal plants, the highest FIC values were recorded for antidotes (FIC = 0.98), anthelmintics (FIC = 0.98), and treatments of gastrointestinal problems (FIC = 0.93). The FIC values for different types of edible plants were very similar. The most frequently used medicinal and food plants in the studied communities are Zanthoxylum motuoense, Crassocephalum crepidioides, and Swertia nervosa. According to the comparative study, few differences in the use of wild plants were found. There appeared to be more overlapping species between two Lhoba tribes in Medog, named Mixingba and Miguba, with 46 (61%) common species, compared with the Bo'gaer tribe in Milin, which had only two (2.7%) overlapping species. This might be due to the different geographical environments, vegetation types, and different influences of other ethnic cultures.

CONCLUSIONS

The Lhoba people in Medog County, Tibet, China, have rich TK about the uses of wild plants. However, the TK is seriously threatened due to environmental degradation and acculturation, and it showed signs of being forgotten and abandoned by the younger generation. Therefore, measures are urgently needed to document and protect the TK of the uses of the wild plant resources; and (i) the most frequently used medicinal and/or edible plants; (ii) the plants used to treat the most commonly mentioned diseases; and (iii) the endemic species that are widely used in Medog, which should be assessed for their potential future as food supplements and therapeutic products.

Molecular docking, antiproliferative and anticonvulsant activities of swertiamarin isolated from Enicostemma axillare

Present study aimed for molecular docking, antiproliferative and anticonvulsant activities of swertiamarin isolated from the successive methanol extract of Enicostemma axillare. Molecular docking of swertiamarin on telomerase targets (PDB ID: 5UGW, 3DU6 and 4ERD), followed by antiproliferative activity on HEp2 and HT-29 cells by MTT and SRB assays. Also tested for anticonvulsant activity by pentylenetetrazole (PTZ, 80 mg/kg bw) induced convulsant. Molecular docking study predicted good total score of the swertiamarin with the selected targets. Swertiamarin possesses antiproliferative activity on HEp-2 and HT-29 cells with lower CTC₅₀ values. It also served as significant anticonvulsant agent with prolonged onset and reduced duration of the seizures. These results confirm that swertiamarin exhibited potential antiproliferative and anticonvulsant activities.

Bioinformatics analysis of differentially expressed genes in hepatocellular carcinoma cells exposed to Swertiamarin

Aim: To explore gene expression profiling in hepatocellular carcinoma (HCC) cells exposed to swertiamarin.

Methods: Cell viability, apoptosis and invasion were examined in HepG2 cells after swertiamarin treatment. Tumor growth of SK-Hep-1 cells xenografted in nude mice was monitored after swertiamarin treatment. Total RNA was isolated from HepG2 cells treated with swertiamarin for microarray analysis. The data of microarray were analyzed by bioinformatics.

Results: Swertiamarin treatment decreased the viability and invasion while increased the apoptosis of HepG2 cells, and significantly inhibited the growth of SK-Hep-1 cells xenografted in nude mice. Pathway and biological process analysis of differentially expressed genes (DEGs) in swertiamarin treated HepG2 cells showed that PI3k-Akt was the most significant regulated pathway. 47 targets of swertiamarin were predicted by CGBVS while 21 targets were predicted by 3NN. Notably, 8 targets were predicted as the targets of swertiamarin by both programs, including two prominent targets JUN and STAT3. A large range of DEGs induced by swertiamarin could be regulated by JUN and STAT3.

Conclusion: Swertiamarin treatment led to significant changes in the expression of a variety of genes that modulate cell survival, cell cycle progression, apoptosis, and invasion. Moreover, most of these genes can be clustered into pathway networks such as PI3K, JUN, STAT3, which are predicted targets of swertiamarin. Further confirmation of these targets will reveal the anti-tumor mechanisms of swertiamarin and facilitate the development of swertiamarin as a novel agent for cancer prevention and treatment.

Swertiamarin decreases lipid accumulation dependent on 3-ketoacyl-coA thiolase

Natural compounds are important resources for drug discovery. Using Caenorhabditis elegans (C. elegans) models, we screened active natural compounds with lipid lowering effects. Swertiamarin was found as a potent candidate to reduce lipid content in C. elegans. Using RNAi screening, we were able to demonstrate that kat-1 (ketoacyl thiolase-1) is necessary for the lipid lowering effect of swertiamarin. Furthermore, the activity of swertiamarin was verified in high fat diet induced obese mice. Consistent with the results in C. elegans, swertiamarin ameliorated high fat diet induced lipid deposition and hyperlipidemia. These results indicate that swertiamarin exerts lipid-lowering effects through kat-1 regulation and could serve as a possible therapeutic option to improve hyperlipidemia induced comorbidities.

Monoterpenes modulating cytokines - A review

Inflammatory response can be driven by cytokine production and is a pivotal target in the management of inflammatory diseases. Monoterpenes have shown that promising profile as agents which reduce the inflammatory process and also modulate the key chemical mediators of inflammation, such as pro and anti-inflammatory cytokines. The main interest focused on monoterpenes were to develop the analgesic and anti-inflammatory drugs. In this review, we summarized current knowledge on monoterpenes that produce anti-inflammatory effects by modulating the release of cytokines, as well as suggesting that which monoterpenoid molecules may be most effective in the treatment of inflammatory disease. Several different inflammatory markers were evaluated as a target of monoterpenes. The proinflammatory and anti-inflammatory cytokines were found TNF-α, IL-1β, IL-2, IL-5, IL-4, IL-6, IL-8, IL-10, IL-12 IL-13, IL-17A, IFNγ, TGF-β1 and IFN-γ. Our review found evidence that NF-κB and MAPK signaling are important pathways for the anti-inflammatory action of monoterpenes. We found 24 monoterpenes that modulate the production of cytokines, which appears to be the major pharmacological mechanism these compounds possess in relation to the attenuation of inflammatory response. Despite the compelling evidence supporting the anti-inflammatory effect of monoterpenes, further studies are necessary to fully explore their potential as anti-inflammatory compounds.

Swertiamarin, a natural steroid, prevent bone erosion by modulating RANKL/RANK/OPG signaling

Bone erosion is a central feature of rheumatoid arthritis (RA) that is characterized by the infiltration of the synovial lining by osteoclasts and lymphocytes. In the present study, swertiamarin a major secoiridoid glycoside was evaluated for anti-osteoclastogenic property to prevent bone erosion in Freund's complete adjuvant (FCA) induced in-vivo model, in-vitro osteoblast and osteoclasts as well as in co-culture system and in-silico molecular docking analysis. The swertiamarin treatment decreased the expression of TRAP, RANKL, and RANK levels and increased the levels of OPG levels significantly in both in vitro and in vivo models. In in vitro, the compound treatment significantly increased the cell proliferation and ALP levels in osteoblast cells; the high proliferation (153.8600±5.23%) and ALP release (165.6033±4.13%) were observed at 50μg/ml concentration of swertiamarin treatment. At the same time the treatment decreased the TRAP positive cells in osteoclast cells; the high reductions of TRAP positive cells (39.32±3.19%) were observed at 50μg/ml of swertiamarin treatment. The treatment modulated the levels of pro-inflammatory cytokines, MMPs and NF-κB levels in osteoblast and osteoclast co-culture system. In in silico analysis swertiamarin had affinity towards the proteins RANK, RANKL and OPG residues with low binding energy -4.5, -3.92 and -5.77kcal/mol respectively. Thus, the results of this study revealed the anti-osteoclastogenic activity of swertiamarin on the prevention of bone destruction.

Anti-apoptotic and cytoprotective effect of Enicostemma littorale against oxidative stress in Islets of Langerhans

Context Oxidative stress induces apoptosis within Islets of Langerhans in diabetes mellitus (DM). Enicostemma littorale blume, herb of the Gentianaceae family is used as an anti-diabetic agent across rural India. Objective This report demonstrates potent anti-apoptotic and cyto-protective activity of Enicostemma littorale MeOH extract (EL MeOH ext.) against 50 μM H2O2 in isolated rat Islets. Materials and methods In this study, the whole plant methanolic extract of EL with doses 0.25-4 mg/mL each for the preincubation duration of 0.5-4 h against 50 μM H2O2 were tested for optimum protective dose and time by Trypan blue dye exclusion assay. Islet intracellular reactive oxygen species (ROS) was quantified by DCFDA staining and cell death using PS/PI & FDA/PI staining. Further, comet assay, biochemical assessment of caspase-3 and antioxidant enzyme activities along with immunoblotting of PARP-1, caspase-3, TNF-α activation and p-P38 MapK (stress kinase) induction was performed. Results The optimized dose of EL MeOH ext. 2 mg/mL for 2 h was used throughout the study, which significantly decreased total Intracellular ROS and cell death. Further, caspase-3 activity, PARP-1 cleavage, p-P38 MapK (stress kinase) activation and TNF-α levels, which had been significantly elevated, were normalized. Antioxidant enzymes like catalase, superoxide dismutase, reduced glutathione and glutathione peroxidase, along with Comet assay, demonstrated that pretreatment with EL MeOH ext. can augment antioxidant enzyme activities and protect from DNA damage. Discussion and conclusions Significant anti-apoptotic and cyto-protective effects were mediated by EL with Islets of Langerhans subjected to oxidative stress-induced cell death.

Evaluation and quantitative analysis of different growth periods of herb-arbor intercropping systems using HPLC and UV-vis methods coupled with chemometrics

As a result of the pressure from population explosion, agricultural land resources require further protecting and rationally utilizing. Intercropping technique has been widely applied for agricultural production to save cultivated area, improve crop quality, and promote agriculture economy. In this study, we employed high-performance liquid chromatography (HPLC) and ultraviolet-visible spectroscopy (UV-vis) combined with chemometrics for determination and qualitative evaluation of several kinds of intercropping system with Gentiana rigescens Franch. ex Hemsl. (GR), which is used as an hepatic protector in local communities in China. Results revealed that GR in a Camellia sinensis intercropping system contained most gentiopicroside, sweroside, and total active constituents (six chemical indicators), whose content reached 91.09 ± 3.54, 1.03 ± 0.06, and 104.05 ± 6.48 mg g(-1), respectively. The two applied quantitative and qualitative methods reciprocally verified that GR with 2 years of growth period performed better in terms of quality than 1 year, collectively.

Swertianlarin, an Herbal Agent Derived from Swertia mussotii Franch, Attenuates Liver Injury, Inflammation, and Cholestasis in Common Bile Duct-Ligated Rats

Swertianlarin is an herbal agent abundantly distributed in Swertia mussotii Franch, a Chinese traditional herb used for treatment of jaundice. To study the therapeutic effect of swertianlarin on cholestasis, liver injury, serum proinflammatory cytokines, and bile salt concentrations were measured by comparing rats treated with swertianlarin 100 mg/kg/d or saline for 3, 7, or 14 days after bile duct ligation (BDL). Serum alanine aminotransferase (ATL) and aspartate aminotransferase (AST) levels were significantly decreased in BDL rats treated with swertianlarin for 14 days (P < 0.05). The reduced liver injury in BDL rats by swertianlarin treatment for 14 days was further confirmed by liver histopathology. Levels of serum tumor necrosis factor alpha (TNFα) were decreased by swertianlarin in BDL rats for 3 and 7 days (P < 0.05). Moreover, reductions in serum interleukins IL-1β and IL-6 levels were also observed in BDL rats treated with swertianlarin (P < 0.05). In addition, most of serum toxic bile salt concentrations (e.g., chenodeoxycholic acid (CDCA) and deoxycholic acid (DCA)) in cholestatic rats were decreased by swertianlarin (P < 0.05). In conclusion, the data suggest that swertianlarin derived from Swertia mussotii Franch attenuates liver injury, inflammation, and cholestasis in bile duct-ligated rats.

Effect of cadmium stress on inductive enzymatic and nonenzymatic responses of ROS and sugar metabolism in multiple shoot cultures of Ashwagandha (Withania somnifera Dunal)

Withania somnifera is one of the most important medicinal plant and is credited with various pharmacological activities. In this study, in vitro multiple shoot cultures were exposed to different concentrations (5-300 μM) of cadmium (Cd) as cadmium sulphate to explore its ability to accumulate the heavy metal ion and its impact on the metabolic status and adaptive responses. The results showed that supplemental exposure to Cd interfered with N, P, and K uptake creating N, P, and K deficiency at higher doses of Cd that also caused stunting of growth, chlorosis, and necrosis. The study showed that in vitro shoots could markedly accumulate Cd in a concentration-dependent manner. Enzymatic activities and isozymic pattern of catalase, ascorbate peroxidase, guaiacol peroxidase, peroxidase, glutathione-S-transferase, glutathione peroxidase, monodehydroascorbate reductase, and dehydroascorbate reductase were altered substantially under Cd exposure. Sugar metabolism was also markedly modulated under Cd stress. Various other parameters including contents of photosynthetic pigments, phenolics, tocopherol, flavonoids, reduced glutathione, nonprotein thiol, ascorbate, and proline displayed major inductive responses reflecting their protective role. The results showed that interplay of enzymatic as well as nonenzymatic responses constituted a system endeavor of tolerance of Cd accumulation and an efficient scavenging strategy of its stress implications.

The screening research of anti-inflammatory bioactive markers from different flowering phases of Flos Lonicerae Japonicae

Flos Lonicerae Japonicae (FLJ) is an important cash crop in eastern Asia, and it is an anti-inflammatory Traditional Chinese Medicine. There are large variations in the quality of the marketed FLJ products. To find marker ingredients useful for quality control, a tandem technology integrating ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF), principal component analysis (PCA), heat map analysis and hierarchical cluster analysis coupled with a NF-κB luciferase reporter gene assay were used to identify the different ingredients from the green bud, white bud, flowering stage and leaf stages, as well as to screen the anti-inflammatory activity of FLJ compositions. As flowering progressed, the anti-inflammatory effects of FLJ gradually decreased; however, chlorogenic acid, swertiamarin and sweroside should be used to evaluate the quality of FLJ products.

Swertiamarin attenuates inflammation mediators via modulating NF-κB/I κB and JAK2/STAT3 transcription factors in adjuvant induced arthritis

Rheumatoid arthritis (RA) is an autoimmune and chronic inflammatory disease that leads to pannus formation followed by severe joint destruction, characterized by synovial hyperplasia, inflammation and angiogenesis. Swertiamarin is a secoiridoid glycoside that is used as an anti-inflammatory compound, mainly found in Enicostema axillare (Lam) A. Raynal, a medicinal plant used in Indian system of traditional medicine. In the present study, the effect of swertiamarin was evlauated in experimental adjuvant arthritis animal model by the estimation of biochemical (paw thickness, lysosomal enzymes, and urinary degradative products) parameters, proinflammatory cytokines and enzymes along with histopathological and radiographic observations. The proteins of phosphorylated NF-κB/IκB and JAK2/STAT3 transcription factors were also quantified from experimental animals as well as LPS induced RAW 264.7 macrophage cells. In in silico analysis, swertiamarin was docked with proinflammatory enzymes to confirm its potential. The administration of swertiamarin (2, 5, 10mg/kg bw) significantly (P⩽0.05) inhibited the levels of paw thickness, lysosomal enzymes and increased the body weight of experimental animals in a dose dependent manner. In molecular analysis, the treatment decreased the release of proinflammatory cytokines (IL1, TNF, IL-6) and proangiogenic enzymes (MMPs, iNOS, PGE2, PPARγ and COX-2); and also significantly (P⩽0.05) increased the levels of antiinflammatory proteins (IL-10, IL-4) when compared to the disease groups. The swertiamarin treatment significantly (P⩽0.05) inhibited the release of NF-κB p65, p-IκBα, p-JAK2 and p-STAT3 signaling proteins levels on both experimental animals and LPS induced cells. Histopathological and radiological analysis evidenced the curative effect of swertiamarin on bone destruction. The docking studies of swertiamarin on proinflammatory enzymes supported the results from the in vivo experiments. Thus the swertiamarin inhibited the development of arthritis by modulating NF-κB/IκB and JAK2/STAT3 signaling. These findings suggested that swertiamarin acted as an anti-rheumatic agent.

Comparative pharmacokinetics of swertiamarin in rats after oral administration of swertiamarin alone, Qing Ye Dan tablets and co-administration of swertiamarin and oleanolic acid

ETHNOPHARMACOLOGICAL RELEVANCE

Qing Ye Dan is a well-known herbal drug that is widely used to treat viral hepatitis in the Yi and Hani minority regions in the Yunnan province of China.

MATERIALS AND METHODS

An LC-MS/MS method was developed to determine the levels of swertiamarin in rat plasma. Swertiamarin and naringin (internal standard, IS) were extracted from rat plasma using solid-phase extraction (SPE) to purify the samples. The pharmacokinetics of the following different administration methods of swertiamarin in rats were studied: oral administration of swertiamarin alone, a Qing Ye Dan tablet (QYDT) and co-administration of swertiamarin and oleanolic acid, with each method delivering approximately 20mg/kg of swertiamarin. Non-compartmental pharmacokinetic profiles were constructed by using the software DAS (version 2.1.1), and the pharmacokinetic parameters were compared using an unpaired Student's t-test.

RESULTS

The results showed that the pharmacokinetic parameters Cmax, AUC0-∞, Vz/F and CLz/F were significantly different (P<0.05) among the three types of swertiamarin administration.

CONCLUSIONS

The data indicate that oleanolic acid and the other ingredients present in QYDT could affect the pharmacokinetic behaviour of swertiamarin in rats.

Cardioprotective and antihypertensive effects of Enicostemma littorale Blume extract in fructose-fed rats

We investigated the protective effects of Enicostemma littorale Blume (EL) extract on hypertension and insulin resistance along with its associated cardiovascular complications in high fructose (HF) fed rats. For this, rats were divided among 4 groups: (i) control, fed laboratory chow; (ii) fed with a high level of fructose; (iii) fed with a high level of fructose plus E. littorale extract; and (iv) fed with a high level of fructose plus rosiglitazone (Rg). EL and Rg treatments were given simultaneously with HF diet. The results show that untreated HF-fed rats showed altered oral glucose tolerance, increased fasting insulin, and increased fasting glucose. These rats also exhibited hypertriglyceridemia, moderate hypertension, platelet hyperaggregability, decreased prothrombin time, activated partial thromboplastin time, altered vascular reactivity, and increased serum levels of enzymes (creatine kinase, type muscle-brain (CK-MB), aspartate aminotransferase (SGOT), lactate dehydrogenase (LDH), and alanine aminotransferase (SGPT). This is the first demonstration of platelet hyperaggregation and prothrombotic alteration in HF-fed rats. HF-fed rats treated with EL showed improved insulin resistance, along with reduced hypertriglyceridemia, hypertension, platelet aggregability, blood coagulation, serum enzymes (CK-MB, SGOT, LDH and SGPT), and vascular reactivity. These effects of EL in HF-induced hypertensive rats might be associated with the suppression of hyperinsulinemia and hypertriglyceridemia, along with its antiatherogenic and antithrombogenic potential. These data indicate that the aqueous extract of EL has great therapeutic potential for the prevention and (or) management of insulin resistance and the associated hypertension.

Immunomodulatory potential of Enicostema axillare (Lam.) A. Raynal, a traditional medicinal plant

ETHNOPHARMACOLOGICAL RELEVANCE

Enicostema axillare (Lam.) A. Raynal., (Gentianaceae) has been used in traditional Indian system of medicine as depurative and for the treatment of psoriasis, intermittent fever and cancer. Ethnobotanical survey conducted in Theni District indicated a high consensus for this plant as blood purifier and to treat dermatopathy and venereal infections. The present study evaluated the immunomodulatory activity of the methanol extract of Enicostema axillare.

MATERIALS AND METHODS

In vivo immunomodulatory activity of Enicostema axillare methanol extract (100 and 200mg/kg b.w) was evaluated by assessing its effect on the total and differential leukocyte count, organ weight, hemaggultinating antibody titer, plaque forming cells, quantitative hemolysis of SRBC and delayed type hypersensitivity. Sheep red blood cells (SRBC, 5×10(8)cells/0.1mL) were used to immunize the animals. In vitro immunomodulatory potential of the extract was studied using peritoneal macrophages by evaluating its effects on NBT reduction, NO production and cytokine release.

RESULTS

The animals treated with Enicostema axillare methanol extract showed a significant (P≤0.05) increase in weight of the thymus and spleen. The total leukocyte and lymphocyte count was increased significantly (P<0.005) by the treatment. There was no significant alteration in neutrophil count. A dose dependent increase in antibody titer value was observed. A decreased response to DTH reaction induced by SRBC was recorded. A potential phagocytic response was seen on treatment with the extracts at 10 and 25μg/mL. The extract inhibited the release of pro-inflammatory cytokines and production of NO significantly in a dose dependent manner.

CONCLUSION

These findings suggested that the methanol extract of Enicostema axillare acted on both humoral and cell mediated immune functions and decreased the release of pro-inflammatory cytokines in the peritoneal macrophages.

Anti-inflammatory iridoids of botanical origin

Inflammation is a manifestation of a wide range of disorders which include; arthritis, atherosclerosis, Alzheimer's disease, inflammatory bowel syndrome, physical injury and infection amongst many others. Common treatment modalities are usually nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin, paracetamol, indomethacin and ibuprofen as well as corticosteroids such as prednisone. These however, may be associated with a host of side effects due to non-selectivity for cyclooxygenase (COX) enzymes involved in inflammation and those with selectivity may be highly priced. Thus, there is a continuing search for safe and effective antiinflammatory molecules from natural sources. Research has confirmed that iridoids exhibit promising anti-inflammatory activity which may be beneficial in the treatment of inflammation. Iridoids are secondary metabolites present in various plants, especially in species belonging to the Apocynaceae, Lamiaceae, Loganiaceae, Rubiaceae, Scrophulariaceae and Verbenaceae families. Many of these ethnobotanicals have an illustrious history of traditional use alluding to their use to treat inflammation. Although iridoids exhibit a wide range of pharmacological activities such as cardiovascular, hepatoprotection, hypoglycaemic, antimutagenic, antispasmodic, anti-tumour, antiviral, immunomodulation and purgative effects this review will acutely focus on their anti-inflammatory properties. The paper aims to present a summary for the most prominent iridoid-containing plants for which anti-inflammatory activity has been demonstrated in vitro and / or in vivo.

Evaluation of the irritating influence of carane derivatives and their antioxidant properties in a deoxyribose degradation test

Previous studies of the propranolol monoterpene derivative (-)-4-[2-hydroxy-3-(N-isopropylamino)-propoxyimino]-cis-carane hydrochloride (KP-23) and its diastereoisomers, KP-23R and KP-23S, demonstrated different effects on the cyclic AMP generating system as well as anti-inflammatory, analgesic, antihistaminic and antioxidant activity. The present study examined the influence of KP-23 and its diastereoisomers KP-23R and KP-23S on the skin-irritating activity and the mucous membrane-irritating activity as well as their influence on a late-type contact allergy in the in vivo tests. The hydroxyl radical scavenging potential of the three analogues was evaluated using their ability to inhibit Fe(II)/H2O2-induced oxidative degradation of 2-deoxyribose (2-DR) in the in vitro tests. The results obtained indicated that the hydroxyamine carane derivative did not evoke irritative changes and did not induce a late-type contact allergy in the guinea-pig. Diastereoisomers of KP-23 exhibit antioxidant properties in a dose-dependent manner and protected against OH-radicals generated from the Fenton reaction.

Two new secoiridoid glycosides from Verbena officinalis

Two new secoiridoid glycosides, verbenoside A (1) and verbenoside B (2), have been isolated from the ethanol extract of the aerial parts of Verbena officinalis L. Their structures were elucidated on the basis of spectroscopic evidences, especially 1D, 2D NMR, and MS experiments.