Therapeutic Potential of Hibiscus sabdariffa Linn. in Attenuating Cardiovascular Risk Factors

Cardiovascular diseases (CVDs) represent a broad spectrum of diseases afflicting the heart and blood vessels and remain a major cause of death and disability worldwide. CVD progression is strongly associated with risk factors, including hypertension, hyperglycemia, dyslipidemia, oxidative stress, inflammation, fibrosis, and apoptosis. These risk factors lead to oxidative damage that results in various cardiovascular complications including endothelial dysfunctions, alterations in vascular integrity, the formation of atherosclerosis, as well as incorrigible cardiac remodeling. The use of conventional pharmacological therapy is one of the current preventive measures to control the development of CVDs. However, as undesirable side effects from drug use have become a recent issue, alternative treatment from natural products is being sought in medicinal plants and is gaining interest. Roselle (Hibiscus sabdariffa Linn.) has been reported to contain various bioactive compounds that exert anti-hyperlipidemia, anti-hyperglycemia, anti-hypertension, antioxidative, anti-inflammation, and anti-fibrosis effects. These properties of roselle, especially from its calyx, have relevance to its therapeutic and cardiovascular protection effects in humans. This review summarizes the findings of recent preclinical and clinical studies on roselle as a prophylactic and therapeutic agent in attenuating cardiovascular risk factors and associated mechanisms.

Cardioprotective Properties of Kaempferol: A Review

Cardiac diseases, such as myocardial infarction and heart failure, have become a major clinical problem globally. The accumulating data demonstrate that bioactive compounds with antioxidant and anti-inflammatory properties have favorable effects on clinical problems. Kaempferol is a flavonoid found in various plants; it has demonstrated cardioprotective properties in numerous cardiac injury models. This review aims to collate updated information regarding the effects of kaempferol on cardiac injury. Kaempferol improves cardiac function by alleviating myocardial apoptosis, fibrosis, oxidative stress, and inflammation while preserving mitochondrial function and calcium homeostasis. However, the mechanisms of action of its cardioprotective properties remain unclear; therefore, elucidating its action could provide insight into directions for future studies.

Pharmacological activities and mechanisms of action of hypophyllanthin: A review

Hypophyllanthin is a major lignan present in various Phyllanthus species and has been used as one of the bioactive chemical markers for quality control purposes as it contributes to their diverse pharmacological activities. The objective of this study is to compile up-to-date data on the pharmacological actions and mechanisms of hypophyllanthin. This review also includes the extracts of Phyllanthus species whose pharmacological actions have been partially attributed to hypophyllanthin. The scientific findings on the compound are critically analyzed and its potential as a lead molecule for the discovery of drug candidates for the development of therapeutics to treat diverse diseases is highlighted. Data collection was mainly through the exploration of Ovid-MEDLINE, Scopus, Science Direct, and Elsevier databases. Studies conducted in vitro and in vivo showed that hypophyllanthin had potent immunomodulating properties as well as a variety of other pharmacological properties, including anti-inflammatory, hepatoprotective, anti-tumor, anti-allergic, anti-hypertensive, and phytoestrogenic properties. Several mechanisms of action on the effects of hypophyllanthin on the immune system, in cancer and other disease states, were presented to provide some insights into its pharmacological effects. Before being submitted to clinical investigations, additional animal studies utilising different animal models are necessary to analyse its bioavailability, pharmacokinetics, and pharmacodynamic properties, as well as its toxicity, to determine its efficacy and safety. Understanding its potential as a lead molecule for the discovery of therapeutic candidates, particularly for the development of therapies for inflammatory and immune-related disorders, requires an understanding of its pharmacological activities and mechanisms of action. An insight into its pharmacological activities and mechanisms of action will provide an understanding of its potential as a lead compound for the discovery of drug candidates, especially for the development of therapies for inflammatory and immune related diseases.

Parkia speciosa Hassk. Empty Pod Extract Prevents Cardiomyocyte Hypertrophy by Inhibiting MAPK and Calcineurin-NFATC3 Signaling Pathways

Cardiac hypertrophy is an early hallmark during the clinical course of heart failure. Therapeutic strategies aiming to alleviate cardiac hypertrophy via the mitogen-activated protein kinase (MAPK)/calcineurin-nuclear factor of activated T-cells (NFAT) signaling pathway may help prevent cardiac dysfunction. Previously, empty pod ethanol crude extract of Parkia speciosa Hassk was shown to demonstrate protective effects against cardiomyocyte hypertrophy. Therefore, the current study aimed to investigate the effects of various fractions of the plant ethanol extract on the MAPK/NFAT signaling pathway in angiotensin II (Ang II)-induced cardiomyocyte hypertrophy. Simultaneous treatment with ethyl acetate (EA) fraction produced the most potent antihypertrophic effect evidenced by the reduced release of B-type natriuretic peptide (BNP). Subsequently, treatment with the EA fraction (6.25, 12.5, and 25 μg/mL) prevented an Ang II-induced increase in cell surface area, hypertrophic factors (atrial natriuretic peptide and BNP), reactive oxygen species, protein content, and NADPH oxidase 4 expression in the cells. Furthermore, EA treatment attenuated the activation of the MAPK pathway and calcineurin-related pathway (GATA-binding protein 4 and NFATC3), which was similar to the effects of valsartan (positive control). Our findings indicate that the EA fraction prevents Ang II-induced cardiac hypertrophy by regulating the MAPK/calcineurin-NFAT signaling pathway.

Molecular mechanisms of sacubitril/valsartan in cardiac remodeling

Cardiovascular diseases have become a major clinical burden globally. Heart failure is one of the diseases that commonly emanates from progressive uncontrolled hypertension. This gives rise to the need for a new treatment for the disease. Sacubitril/valsartan is a new drug combination that has been approved for patients with heart failure. This review aims to detail the mechanism of action for sacubitril/valsartan in cardiac remodeling, a cellular and molecular process that occurs during the development of heart failure. Accumulating evidence has unveiled the cardioprotective effects of sacubitril/valsartan on cellular and molecular modulation in cardiac remodeling, with recent large-scale randomized clinical trials confirming its supremacy over other traditional heart failure treatments. However, its molecular mechanism of action in cardiac remodeling remains obscure. Therefore, comprehending the molecular mechanism of action of sacubitril/valsartan could help future research to study the drug’s potential therapy to reduce the severity of heart failure.

The Role of PKC-MAPK Signalling Pathways in the Development of Hyperglycemia-Induced Cardiovascular Complications

Cardiovascular disease is the most common cause of death among diabetic patients worldwide. Hence, cardiovascular wellbeing in diabetic patients requires utmost importance in disease management. Recent studies have demonstrated that protein kinase C activation plays a vital role in the development of cardiovascular complications via its activation of mitogen-activated protein kinase (MAPK) cascades, also known as PKC-MAPK pathways. In fact, persistent hyperglycaemia in diabetic conditions contribute to preserved PKC activation mediated by excessive production of diacylglycerol (DAG) and oxidative stress. PKC-MAPK pathways are involved in several cellular responses, including enhancing oxidative stress and activating signalling pathways that lead to uncontrolled cardiac and vascular remodelling and their subsequent dysfunction. In this review, we discuss the recent discovery on the role of PKC-MAPK pathways, the mechanisms involved in the development and progression of diabetic cardiovascular complications, and their potential as therapeutic targets for cardiovascular management in diabetic patients.

The Role of Polyphenol in Modulating Associated Genes in Diabetes-Induced Vascular Disorders

Diabetes-induced vascular disorder is considered one of the deadly risk factors among diabetic patients that are caused by persistent hyperglycemia that eventually leads to cardiovascular diseases. Elevated reactive oxygen species (ROS) due to high blood glucose levels activate signaling pathways such as AGE/RAGE, PKC, polyol, and hexosamine pathways. The activated signaling pathway triggers oxidative stress, inflammation, and apoptosis which later lead to vascular dysfunction induced by diabetes. Polyphenol is a bioactive compound that can be found abundantly in plants such as vegetables, fruits, whole grains, and nuts. This compound exerts therapeutic effects in alleviating diabetes-induced vascular disorder, mainly due to its potential as an anti-oxidative, anti-inflammatory, and anti-apoptotic agent. In this review, we sought to summarize the recent discovery of polyphenol treatments in modulating associated genes involved in the progression of diabetes-induced vascular disorder.

Anti-Inflammatory and Antioxidant Activity of Syzygium polyanthum (Wight) Walp

Syzygium polyanthum has been used as folk medicine to treat ailments related to oxidative stress and inflammation. In this study, the anti-inflammatory and antioxidant activity of stem bark and root bark of the plant were investigated. The experiments that have been carried out were estimation of total phenolic and total flavonoid in the methanol extracts and fractions of both parts, isolation and structure elucidation of chemical compounds, anti-inflammatory activity evaluation based on inhibition of prostaglandin E2 production in the LPS-induced human whole blood using radioimmunoassay technique as well as antioxidant activity based on assays by using free radical scavenging DPPH and FRAP. Results showed high amounts of phenolics and flavonoids in both parts of S. polyanthum. Seven compounds were succesfully isolated from the stem bark and identified as stigmasterol (1), 8-hydroxy-6-methoxy-3-pentylisocoumarin (2), 3,3’-di-O-methylellagic acid (3), methylgallate (4), asiatic acid (5), arjunolic acid (6), and daucosterol (7). The ethyl acetate fraction of the root bark showed potent inhibitory activity on the production of PGE2 (IC50 3.03 ± 0.83 μg/mL). The methanol extract of the stem bark displaying promising DPPH scavenging activity (SC50= 2.82 ± 0.1 μg/mL) and FRAP activity (7.02 ± 0.1 μg/μg of equivalent trolox amount). Compounds 1, 5, 6 and 7 showed pronounced inhibitory activity on the PGE2 production with IC50ranging from 0.052 to 1.25 μM. Meanwhile, compound 4 exhibited antioxidant activity toward DPPH (SC5010.60 μM) and FRAP (20.5 ± 1.0 μg/μg). The study concluded that S. polyanthum as a potential source for therapeutic agents with anti-inflammatory and antioxidant activities.

Extracts of Andrographis paniculata (Burm.f.) Nees Leaves Exert Anti-Gout Effects by Lowering Uric Acid Levels and Reducing Monosodium Urate Crystal-Induced Inflammation

Andrographis paniculata (Burm.f.) Nees has been found to have anti-inflammatory and immunostimulatory effects. This study was to investigate antihyperuricemic and anti-inflammatory effects of A. paniculata leaf extracts. Andrographolide, 14-deoxy-11,12-didehydroandrographolide, and neoandrographolide were quantified in 80% ethanol (EtOH80) and water extracts using High Performance Liquid Chromatography (HPLC) analysis. Antihyperuricemic activity was evaluated using a spectrophotometric in vitro inhibitory xanthine oxidase (XO) assay. The most active extract and andrographolide were further investigated in a hyperuricemic rat model induced by potassium oxonate to determine serum uric acid levels, liver XO activity, followed by Western blot analysis for renal urate transporter URAT1, GLUT9, and OAT1 to investigate the excretion of uric acid via kidney. Anti-inflammatory activity was assessed by in vitro interleukin assay for interleukin (IL-1α, IL-1β, IL-6, IL-8), and tumor necrosis factor (TNF-α) in monosodium urate (MSU) crystal-induced human fibroblast-like synoviocyte (HFLS) cells using ELISA-kits, followed by Western blot analysis for the expression of MyD88, NLRP3, NF-κB p65, and caspase-1 proteins to investigate the inflammation pathway. In vivo assay of the most active extract and andrographolide were performed based on the swelling rate and inhibition of pro-inflammatory mediator release from synovial fluid of a rat knee joint induced by MSU crystals. The results showed that the EtOH80 extract had a greater amount of andrographolide (11.34% w/w) than the water extract (1.38% w/w). In the XO inhibitory activity, none of the samples exhibited greater than 50% inhibition. However, in a rat model, EtOH80 extract (200 mg/kg/day) and andrographolide (30 mg/kg/day) decreased serum uric acid levels and reduced liver XO activity, reduced the protein expression levels of URAT1 and GLUT9, and restored the decrease in OAT1 levels. In the in vitro anti-inflammatory study, EtOH80 extract and andrographolide significantly decreased production of IL-1α, IL-1β, IL-6, and TNF-α, as well as inhibited the synthesis of MyD88, NLRP3, NF-κB p65, and caspase-1 in a concentration-dependent manner, almost comparable to dexamethasone. The EtOH80 extract (200 mg/kg/day) and andrographolide (30 mg/kg) significantly decreased swelling rate and IL-1α, IL-1β, IL-6, and TNF-α in the synovial fluid of rat models in a time-dependent manner, comparable to indomethacin (3 mg/kg/day). In conclusion, the findings show that EtOH80 extract has a substantial anti-gout effect by lowering uric acid levels and suppressing pro-inflammatory mediator production due to the andrographolide content, that might be beneficial in the treatment of gouty-inflammation.

Genistein: A Review on its Anti-Inflammatory Properties

Nowadays, non-resolving inflammation is becoming a major trigger in various diseases as it plays a significant role in the pathogenesis of atherosclerosis, asthma, cancer, obesity, inflammatory bowel disease, chronic obstructive pulmonary disease, neurodegenerative disease, multiple sclerosis, and rheumatoid arthritis. However, prolonged use of anti-inflammatory drugs is usually accompanied with undesirable effects and hence more patients tend to seek for natural compounds as alternative medicine. Considering the fact above, there is an urgency to discover and develop potential novel, safe and efficacious natural compounds as drug candidates for future anti-inflammatory therapy. Genistein belongs to the flavonoid family, in the subgroup of isoflavones. It is a phytoestrogen that is mainly derived from legumes. It is a naturally occurring chemical constituent with a similar chemical structure to mammalian estrogens. It is claimed to exert many beneficial effects on health, such as protection against osteoporosis, reduction in the risk of cardiovascular disease, alleviation of postmenopausal symptoms and anticancer properties. In the past, numerous in vitro and in vivo studies have been conducted to investigate the anti-inflammatory potential of genistein. Henceforth, this review aims to summarize the anti-inflammatory properties of genistein linking with the signaling pathways and mediators that are involved in the inflammatory response as well as its toxicity profile. The current outcomes are analysed to highlight the prospect as a lead compound for drug discovery. Data was collected using PubMed, ScienceDirect, SpringerLink and Scopus databases. Results showed that genistein possessed strong anti-inflammatory activities through inhibition of various signaling pathways such as nuclear factor kappa-B (NF-κB), prostaglandins (PGs), inducible nitric oxide synthase (iNOS), proinflammatory cytokines and reactive oxygen species (ROS). A comprehensive assessment of the mechanism of action in anti-inflammatory effects of genistein is included. However, evidence for the pharmacological effects is still lacking. Further studies using various animal models to assess pharmacological effects such as toxicity, pharmacokinetics, pharmacodynamics, and bioavailability studies are required before clinical studies can be conducted. This review will highlight the potential use of genistein as a lead compound for future drug development as an anti-inflammatory agent.

Molecular Modelling Simulations and Inhibitory Effects of Naturally Derived Flavonoids Targeting Platelet-Activating Factor Receptor (PAFR)

Background:

Platelet-activating factor (PAF) is an agonist mediator in the inflammatory process, which interacts with PAF receptor (PAFR) that eventually causes cancers, respiratory and neurodegenerative diseases. This interaction activates the mitogen-activated protein kinase (MAPK) pathway, leading to a pro-inflammatory cascade. The pathophysiological conditions due to activation of inflammatory cascade could be inhibited by PAF antagonists.

Objectives:

In this study, selected naturally derived flavonoids (flavone, biochanin A, and myricetin) with different functional groups were subjected to molecular modelling and experimental studies to investigate their potential as PAF antagonists.

Method:

Interactions of flavonoids and PAF were assessed via Autodock Vina for molecular docking and the AMBER program for molecular dynamic simulations. The experimentally antagonistic effects of the flavonoids were also conducted via PAF inhibitory assay to determine the IC50 values.

Results:

The findings of docking and dynamic simulations have revealed that all selected flavonoids interact with PAFR in the binding site with considerably good binding affinity up to - 9.8 kcal mol-1 as compared to cedrol (- 8.1 kcal mol-1) as a standard natural PAFR antagonist. The PAFR-flavonoid complexes exhibited four conserved active site residues, which included W73, F97, F174, and L279. The stability of all complexes was attained in a 30 ns simulation. The findings of in silico analyses were then compared to the experimental study on PAF inhibitory assay. Inhibitory effects of flavonoids against PAFR showed moderate activities, ranging from 27.8 – 30.8 μgM-1.

Conclusion:

All studied flavonoids could act as promising PAF antagonists with some enhancement in their structures to exhibit potent antagonistic activity. However, these naturally derived flavonoids demand further investigation at cellular and animal models to develop new PAF antagonist drug candidates for treating PAF-mediated diseases.

Parkia speciosa Hassk. Empty Pod Extract Alleviates Angiotensin II-Induced Cardiomyocyte Hypertrophy in H9c2 Cells by Modulating the Ang II/ROS/NO Axis and MAPK Pathway

Cardiac hypertrophy is characteristic of heart failure in patients who have experienced cardiac remodeling. Many medicinal plants, including Parkia speciosa Hassk., have documented cardioprotective effects against such pathologies. This study investigated the activity of P. speciosa empty pod extract against cardiomyocyte hypertrophy in H9c2 cardiomyocytes exposed to angiotensin II (Ang II). In particular, its role in modulating the Ang II/reactive oxygen species/nitric oxide (Ang II/ROS/NO) axis and mitogen-activated protein kinase (MAPK) pathway was examined. Treatment with the extract (12.5, 25, and 50 μg/ml) prevented Ang II-induced increases in cell size, NADPH oxidase activity, B-type natriuretic peptide levels, and reactive oxygen species and reductions in superoxide dismutase activity. These were comparable to the effects of the valsartan positive control. However, the extract did not significantly ameliorate the effects of Ang II on inducible nitric oxide synthase activity and nitric oxide levels, while valsartan did confer such protection. Although the extract decreased the levels of phosphorylated extracellular signal-related kinase, p38, and c-Jun N-terminal kinase, valsartan only decreased phosphorylated c-Jun N-terminal kinase expression. Phytochemical screening identified the flavonoids rutin (1) and quercetin (2) in the extract. These findings suggest that P. speciosa empty pod extract protects against Ang II-induced cardiomyocyte hypertrophy, possibly by modulating the Ang II/ROS/NO axis and MAPK signaling pathway via a mechanism distinct from valsartan.

Luteolin and apigenin derived glycosides from Alphonsea elliptica abrogate LPS-induced inflammatory responses in human plasma

ETHNOPHARMACOLOGICAL RELEVANCE

Numerous Alphonsea species including Alphonsea elliptica (mempisang) leaves and fruits are indigenously used in inflammatory conditions such as postpartum swelling and rheumatism in southeast Asian countries. In our previous in-vitro findings, A. elliptica methanol extract exhibited platelet-activating factor inhibition, suggesting the presence of phyto-constituents with anti-inflammatory potential.

AIM OF THE STUDY

However, so far there is no literature available on the anti-inflammatory activity of this species. Henceforth, based on the above background and our previous laboratory findings, we hypothesize that phytoconstituents of A. elliptica could possess anti-inflammatory potential against inflammatory mediators including prostaglandin-E₂ (PGE₂), cyclooxegenase-2 (COX-2) and cytokines (IL-1β and IL-6).

MATERIALS AND METHODS

Vacuum and column chromatography techniques were employed for the isolation of phytoconstituents. The structure elucidation was carried out using HRESI-MS, ¹H and ¹³C-NMR analysis and compared with the published literature. For cytotoxicity analysis, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed on peripheral blood mononuclear cells. In-vitro anti-inflammatory activities were evaluated against the levels of PGE₂, COX-2, IL-1β and IL-6 in lipopolysaccharide (LPS)-induced human plasma using enzyme-linked immunosorbent assay and radioimmunoassay.

RESULTS

Unprecedentedly, chromatographic purification of methanolic leaves extract afforded five flavones namely vitexin, isovitexin, orientin, isoorientin, schaftoside with three flavanols; kaempferol, myricetin and rutin from A elliptica. In cell viability analysis, isolates did not present cytotoxicity up to 50 μM. In anti-inflammatory evaluation, orientin and isoorientin exhibited strong (≥70%), while isovitexin and vitexin produced strong to moderate (50-69%) PGE₂, COX-2, IL-1β and IL-6 inhibition at 25 and 50 μM. Isoorientin, orientin, isovitexin, and vitexin showed significant (p < 0.05) and concentration-dependent PGE₂ inhibition with IC₅₀ values (μM) of 11.40, 14.71, 17.70 and 20.58 against indomethacin (8.80). Furthermore, isoorientin, orientin, isovitexin, and vitexin produced significant concentration-dependent inhibition with IC₅₀ values (μM) of COX-2: 7.13, 9.51, 12.81, 16.61; IL-1β 4.80, 6.20, 10.85, 14.51; IL-6: 4.01, 5.90, 11.51 and 14.88 as compared to dexamethasone: 5.29, 2.93, 3.72, respectively (p < 0.05).

CONCLUSION

Conclusively, isolated phytoconstituents are reported for the first time from the A. elliptica. Moreover, isovitexin, vitexin orientin and isoorientin abrogated LPS-induced inflammatory responses in human plasma at non-cytotoxic concentrations.

New Insights into Molecular Mechanism behind Anti-Cancer Activities of Lycopene

Lycopene is a well-known compound found commonly in tomatoes which brings wide range of health benefits against cardiovascular diseases and cancers. From an anti-cancer perspective, lycopene is often associated with reduced risk of prostate cancer and people often look for it as a dietary supplement which may help to prevent cancer. Previous scientific evidence exhibited that the anti-cancer activity of lycopene relies on its ability to suppress oncogene expressions and induce proapoptotic pathways. To further explore the real potential of lycopene in cancer prevention, this review discusses the new insights and perspectives on the anti-cancer activities of lycopene which could help to drive new direction for research. The relationship between inflammation and cancer is being highlighted, whereby lycopene suppresses cancer via resolution of inflammation are also discussed herein. The immune system was found to be a part of the anti-cancer system of lycopene as it modulates immune cells to suppress tumor growth and progression. Lycopene, which is under the family of carotenoids, was found to play special role in suppressing lung cancer.

Rutin Modulates MAPK Pathway Differently from Quercetin in Angiotensin II-Induced H9c2 Cardiomyocyte Hypertrophy

Rutin is a flavonoid with antioxidant property. It has been shown to exert cardioprotection against cardiomyocyte hypertrophy. However, studies regarding its antihypertrophic property are still lacking, whether it demonstrates similar antihypertrophic effect to its metabolite, quercetin. Hence, this study aimed to investigate the effects of both flavonoids on oxidative stress and mitogen-activated protein kinase (MAPK) pathway in H9c2 cardiomyocytes that were exposed to angiotensin II (Ang II) to induce hypertrophy. Cardiomyocytes were exposed to Ang II (600 nM) with or without quercetin (331 μM) or rutin (50 μM) for 24 h. A group given vehicle served as the control. The concentration of the flavonoids was chosen based on the reported effective concentration to reduce cell hypertrophy or cardiac injury in H9c2 cells. Exposure to Ang II increased cell surface area, intracellular superoxide anion level, NADPH oxidase and inducible nitric oxide synthase activities, and reduced cellular superoxide dismutase activity and nitrite level, which were similarly reversed by both rutin and quercetin. Rutin had no significant effects on phosphorylated proteins of extracellular signal-related kinases (ERK1/2) and p38 but downregulated phosphorylated c-Jun N-terminal kinases (JNK1/2), which were induced by Ang II. Quercetin, on the other hand, had significantly downregulated the phosphorylated proteins of ERK1/2, p38, and JNK1/2. The quercetin inhibitory effect on JNK1/2 was stronger than the rutin. In conclusion, both flavonoids afford similar protective effects against Ang II-induced cardiomyocyte hypertrophy, but they differently modulate MAPK pathway.

Anti-Allergic Rhinitis Effects of Medicinal Plants and Their Bioactive Metabolites via Suppression of the Immune System: A Mechanistic Review

Allergic rhinitis (AR) is a common inflammatory condition of the nasal mucosa and it is an immunoglobulin E-mediated disease. The incidence and prevalence of AR globally have been escalating over recent years. Antihistamines, intranasal corticosteroids, decongestants, intranasal anticholinergics, intranasal cromolyn, leukotriene receptor antagonists and immunotherapy have been used in the treatment of AR. However, there is a need to search for more effective and safer remedies as many of the current treatments have reported side effects. Medicinal plants have been used traditionally to relief symptoms of AR but their efficacy and safety have not been scientifically proven. In this review, up-to-date reports of studies on the anti-allergic rhinitis of several medicinal plants and their bioactive metabolites through suppression of the immune system are compiled and critically analyzed. The plant samples were reported to suppress the productions of immunoglobulin E, cytokines and eosinophils and inhibit histamine release. The suppression of cytokines production was found to be the main mechanistic effect of the plants to give symptomatic relief. The prospect of these medicinal plants as sources of lead molecules for development of therapeutic agents to treat AR is highlighted. Several bioactive metabolites of the plants including shikonin, okicamelliaside, warifteine, methylwarifteine, luteolin-7-O-rutinoside, tussilagone, petasin, and mangiferin have been identified as potential candidates for development into anti-allergic rhinitis agents. The data collection was mainly from English language articles published in journals, or studies from EBSCOHOST, Medline and Ovid, Scopus, Springer, and Google Scholar databases from the year 1985-2020. The terms or keywords used to find relevant studies were allergic rhinitis OR pollinosis OR hay fever, AND medicinal plant OR single plant OR single herb OR phytotherapy. This comprehensive review serves as a useful resource for medicinal plants with anti-allergic rhinitis potential, understanding the underlying mechanisms of action and for future exploration to find natural product candidates in the development of novel anti-allergic rhinitis agents.

Mechanistic Studies of the Antiallergic Activity of Phyllanthus amarus Schum. & Thonn. and Its Compounds

Phyllanthus amarus Schum. & Thonn. (Phyllanthaceae) is a medicinal plant that is commonly used to treat diseases such as asthma, diabetes, and anemia. This study aimed to examine the antiallergic activity of P. amarus extract and its compounds. The antiallergic activity was determined by measuring the concentration of allergy markers release from rat basophilic leukemia (RBL-2H3) cells with ketotifen fumarate as the positive control. As a result, P. amarus did not stabilize mast cell degranulation but exhibited antihistamine activity. The antihistamine activity was evaluated by conducting a competition radioligand binding assay on the histamine 1 receptor (H1R). Four compounds were identified from the high performance liquid chromatography (HPLC) analysis which were phyllanthin (1), hypophyllanthin (2), niranthin (3), and corilagin (4). To gain insights into the binding interactions of the most active compound hypophyllanthin (2), molecular docking was conducted and found that hypophyllanthin (2) exhibited favorable binding in the H1R binding site. In conclusion, P. amarus and hypophyllanthin (2) could potentially exhibit antiallergic activity by preventing the activation of the H1 receptor.

UPLC-MS-Based Metabolomics Profiling for α-Glucosidase Inhibiting Property of Parkia speciosa Pods

Parkia speciosa is a food plant that grows indigenously in Southeast Asia. A great deal of interest has been paid to this plant due to its traditional uses in the treatment of several diseases. The pods contain many beneficial secondary metabolites with potential applications in medicine and cosmetics. However, studies on their phytochemical properties are still lacking. Therefore, the present study was undertaken to profile the bioactive compounds of P. speciosa pods collected from six different regions of Malaysia through ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) and α-glucosidase inhibitory potential. This study applied metabolomics to elucidate the differences between P. speciosa populations found naturally in the different locations and to characterize potential α-glucosidase inhibitors from P. speciosa pods. P. speciosa collected from different regions of Malaysia showed good α-glucosidase inhibitory activity, with a median inhibitory concentration (IC₅₀) of 0.45–0.76 μg/mL. The samples from the northern and northeastern parts of Peninsular Malaysia showed the highest activity. Using UHPLC-QTOF-MS/MS analysis, 25 metabolites were identified in the pods of P. speciosa. The findings unveiled that the pods of P. speciosa collected from different locations exhibit different levels of α-glucosidase inhibitory activity. The pods are a natural source of potent antidiabetic bioactive compounds.

Sinensetin: An Insight on Its Pharmacological Activities, Mechanisms of Action and Toxicity

Sinensetin, a plant-derived polymethoxylated flavonoid found in Orthosiphon aristatus var. aristatus and several citrus fruits, has been found to possess strong anticancer activities and a variety of other pharmacological benefits and promising potency in intended activities with minimal toxicity. This review aims to compile an up-to-date reports of published scientific information on sinensetin pharmacological activities, mechanisms of action and toxicity. The present findings about the compound are critically analyzed and its prospect as a lead molecule for drug discovery is highlighted. The databases employed for data collection are mainly through Google Scholar, PubMed, Scopus and Science Direct. In-vitro and in-vivo studies showed that sinensetin possessed strong anticancer activities and a wide range of pharmacological activities such as anti-inflammatory, antioxidant, antimicrobial, anti-obesity, anti-dementia and vasorelaxant activities. The studies provided some insights on its several mechanisms of action in cancer and other disease states. However, more detail mechanistic studies are needed to understand its pharmacological effects. More in vivo studies in various animal models including toxicity, pharmacokinetic, pharmacodynamic and bioavailability studies are required to assess its efficacy and safety before submission to clinical studies. In this review, an insight on sinensetin pharmacological activities and mechanisms of action serves as a useful resource for a more thorough and comprehensive understanding of sinensetin as a potential lead candidate for drug discovery.

Genus Parkia: Phytochemical, Medicinal Uses, and Pharmacological Properties

The genus Parkia (Fabaceae, Subfamily, Mimosoideae) comprises about 34 species of mostly evergreen trees widely distributed across neotropics, Asia, and Africa. This review aims to provide an overview of the current status of the species from the genus Parkia in terms of its relationship between its phytochemistry and medical uses. Comprehensive information on Parkia species was retrieved from electronic databases, which were Web of Science, ScienceDirect, PubMed, and Google Scholar. This review identified nine species from genus Parkia with properties of medicinal use. They are used traditionally to treat several ailments, such as diabetes, diarrhea, wounds, hypertension, cough, chronic piles, conjunctivitis, and measles. The most common species studied are P. biglobosa, P. speciosa, P. javanica, P. bicolor, P. biglandulosa, P. filicoidea, and P. clappertoniana. A considerable number of secondary metabolites, such as terpenoids, phenolic acids, flavonoids (aglycone and glycosides), and numerous volatile compounds have been identified in this genus, which are responsible for their diverse pharmacological activities. Their extracts, pure compounds and seed lectins have been reported for their anticancer, antimicrobial, antihypertensive, antiulcer, antidiabetic, anti-inflammatory, antioxidant, antimalarial, hepatoprotective, and antidiarrheal activities. The information gathered in this review might be of help for future studies in terms of the current knowledge on the link between the phytochemical components and medicinal uses. This could facilitate more discoveries on its potentials particularly in the pharmacological characteristics and potential to be developed into modern medicines.

Xanthine oxidase inhibitory activity of a new isocoumarin obtained from Marantodes pumilum var. pumila leaves

BACKGROUND

In traditional Malay medicine, Marantodes pumilum (Blume) Kuntze (family Primulaceae) is commonly used by women to treat parturition, flatulence, dysentery, dysmenorrhea, gonorrhea, and bone diseases. Preliminary screening of some Primulaceae species showed that they possess xanthine oxidase inhibitory activity. Thus, this study aimed to investigate the xanthine oxidase inhibitory activity of three varieties of M. pumilum and their phytochemical compounds.

METHOD

Dichloromethane, methanol, and water extracts of the leaves and roots of M. pumilum var. alata, M. pumilum var. pumila, and M. pumilum var. lanceolata were tested using an in vitro xanthine oxidase inhibitory assay. Bioassay-guided fractionation and isolation were carried out on the most active extract using chromatographic techniques. The structures of the isolated compounds were determined using spectroscopic techniques.

RESULTS

The most active dichloromethane extract of M. pumilum var. pumila leaves (IC50 = 161.6 μg/mL) yielded one new compound, 3,7-dihydroxy-5-methoxy-4,8-dimethyl-isocoumarin (1), and five known compounds, viz. ardisiaquinone A (2), maesanin (3), stigmasterol (4), tetracosane (5), and margaric acid (6). The new compound was found to be the most active xanthine oxidase inhibitor with an IC50 value of 0.66 ± 0.01 μg/mL, which was not significantly different (p > 0.05) from that of the positive control, allopurinol (IC50 = 0.24 ± 0.00 μg/mL).

CONCLUSION

This study suggests that the new compound 3,7-dihydroxy-5-methoxy-4,8-dimethyl-isocoumarin (1), which was isolated from the dichloromethane extract of M. pumilum var. pumila leaves, could be a potential xanthine oxidase inhibitor.

Anti-hyperuricemic and Anti-inflammatory Effects of Marantodes pumilum as Potential Treatment for Gout

Marantodes pumilum (Primulaceae) has been used in Malaysian folk medicine to help women regain strength after delivery and for “sickness in the bones.” It was previously revealed that its extracts inhibited xanthine oxidase (XO) activity in vitro. The leaves and roots of M. pumilum var. alata (MPA), var. pumila (MPP), and var. lanceolata (MPL) were individually extracted in ethanol (80%). The anti-hyperuricemic activity was initially assessed by XO inhibition with a spectrophotometric in vitro assay. The most active extract was further investigated on hyperuricemic rat model induced by potassium oxonate to determine serum uric acid levels and liver XO effect. The in vitro anti-inflammatory activity was carried out on monosodium urate (MSU) crystal-induced pro-inflammatory cytokines (i.e., interleukin (IL)1α, IL-1β, IL-6, IL-8, and tumor necrosis factor (TNF)-α) secretion using human peripheral blood mononuclear cells and ELISA technique, and prostaglandin E₂ (PGE₂)secretion using radioimmunoassay. The active extract was then investigated on gout-induced inflammation with MSU crystals to determine pro-inflammatory cytokines and PGE₂ secretion levels in the synovial fluid of rat knee joint. Quantitative analysis using validated HPLC was performed on the extracts to determine presence of bioactive flavonoids. The findings revealed that extract of MPP leaves gave the highest inhibitory activity on XO (IC₅₀ 130.5 μg/mL) compared to other extracts tested. However, all extracts possessed significantly lower activity compared to allopurinol (IC₅₀ 0.13 μg/mL). Oral administration of MPP leaf extract (200 mg/kg) significantly reduced serum uric acid level in hyperuricemic rats in time-dependent manner to the baseline level and it was as effective as allopurinol (5 mg/kg). The extract also inhibited liver XO activity (25%) compared to allopurinol (45%). In vitro anti-inflammatory assay showed that extract of MPP roots inhibited MSU crystals-induced secretion of IL-1α, IL-1β, IL-8, TNF-α, and PGE₂ with IC₅₀ values of 36, 25, 38, 18, and 46 μg/mL, respectively. Oral administration of the MPP root extract (200 mg/kg) significantly decreased IL-1α, IL-1β, IL-6, TNF-α, and PGE₂ levels in rat’s synovial fluid as effective as indomethacin. There were no significant body weight changes of all experimental animals. MPP extracts showed presence of myricetin, quercetin and kaempferol. Myricetin was detected with values of 0.2 and 0.6 mg/g for root and leaf extracts, respectively. The anti-hyperuricemic of MPP leaf and anti-inflammatory of MPP root indicated that MPP may be promising for complementary therapy of gout.

P4421Increased circulating levels of VCAM-1 correlate with left atrial remodeling in highly trained athletes

Introduction

Reports have shown increased risk of atrial fibrillation (AF) in athletes. Vascular cell adhesion molecule-1 (VCAM1) is associated with new onset AF in general population. VCAM1 and its relation with left atrial (LA) remodeling have not been investigated in athletes.

Purpose

To study VCAM1 and LA remodeling in marathon runners.

Methods

Study of 36 male marathon runners in the training period previous to race (42 km) and 18 sedentary controls with no risk factors. Athletes were divided in two groups according to highest training intensity reached (group 1, >100 km/week; group 2, 50–100 km/week). Previous to race in all subjects, VCAM1 serum levels were measured by ELISA and an echocardiogram was performed. In athletes, VCAM1 was measured immediately post-race. Wilcoxon and Spearman were used.

Results

See table. Group 1 showed a significant increment in VCAM1 post-race (651±350 to 905±373 ng/mL; p=0.002) as compared to group 2 with no increment (533±133 to 651±138 ng/mL; p=0.117). In athletes, a moderate correlation between LA volume and VCAM1 was found (rho: 0.483; p=0.007).

Baseline characteristics Group 1 (n=18) Group 2 (n=18) Controls (n=18) p value Age (years) 37±6 38±5 36±4 0.373 Heart rate (bpm) 53±8 57±7 69±6 * 0.001 Body surface area (m2) 1.8±0.1 1.8±0.1 1.9±0.1 0.075 LV diastolic diameter (mm) 49±5 48±5 46±4 0.404 LV systolic diameter (mm) 29±5 30±5 30±4 0.879 Septal wall (mm) 9.1±1.2† 8.2±1.1 8.1±0.8 0.005 Posterior wall (mm) 9.3±2.1† 8.5±1.2 7.6±0.8 0.001 Ejection fraction (%) 55±3 55±6 57±4 0.110 LV mass index (g/m2) 106±27† 78±18 58±11 0.001 LA volume (mL/m2) 42±8† 30±11 25±9 0.001 E wave (cm/sec) 78±13 84±12 77±15 0.217 A wave (cm/sec) 50±12 53±10 48±16 0.438 DT (msec) 233±65 229±65 221±66 0.184 VCAM1 (ng/mL) 651±350† 533±133 440±98 0.022 Mean ± SD. *p<0.05 vs group 1 and 2 post Kruskall-Wallis; †p<0.05 vs other groups post Kruskall-Wallis. LV, left ventricle; LA, left atrium; DT, deceleration time.

Conclusions

Most trained athletes had increased levels of VCAM1 as compared to controls and less trained athletes. They also showed an increment post-effort. VCAM1 is related to LA remodeling in athletes. VCAM1 could be a potential biomarker of AF in athletes which should be confirmed.

Acknowledgement/Funding

FONDECYT 1170963 (LG); FONDAP 15130011 (LG,SL)

The medicinal uses, toxicities and anti-inflammatory activity of Polyalthia species (Annonaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Polyalthia is one of the largest and notable genera in Annonaceae family. Polyalthia species have been widely used in folklore medicine for the treatment of rheumatic fever, gastrointestinal ulcer and generalized body pain. Numerous in vitro and in vivo studies on Polyalthia Species have also corroborated the significant anti-inflammatory potential of its extracts and secondary metabolites.

AIM OF THE STUDY

This review is an attempt to assess the anti-inflammatory activity of Polyalthia species by giving critical appraisal and establishing evidences of their traditional uses. Moreover this review will highlight the lead compounds for future drug development that can serve as a potential anti-inflammatory drug with comparative efficacy and minimum side effects.

MATERIALS AND METHODS

An extensive literature review, focusing the anti-inflammatory potential of Polyalthia species was conducted using the following databases:PubMed, ScienceDirect, SpringerLink, Ovid, Scopus and ProQuest, as well as the locally available books, journals and relevant documents. The reference lists of retrieved papers were also searched for additional studies.

RESULTS

The Polyalthia species have shown significant anti-inflammatory activity through various mechanism of action. The most significant anti-inflammatory mechanism includes the inhibition of nuclear factor kappa B (NF-κB), prostaglandins (PGs), pro-inflammatory cytokines, inducible nitric oxide synthase (iNOS) and reactive oxygen species (ROS). The data suggests that hydroxycleroda-3,13-dien-15,16-olide and 16-oxocleroda-3,13-dien-15-oic acid, quercetin, rutin, spinasterol, α-spinasterol, goniothalamin and (-)-5-hydroxygoniothalamin are the most potent anti-inflammatory compounds from Polyalthia species with comparable IC₅₀ with positive controls.

CONCLUSIONS

Numerous pharmacological studies have supported the use of Polyalthia species against pain, rheumatic fever, haemorrhages and inflammation in traditional medicine. Flavonoids, diterpenoids, sterols and styrylpyrones from genus Polyalthia are the most significant class of compounds with potent anti-inflammatory activity. Secondary metabolites from these classes should be brought into further research to fill the gaps of knowledge in pharmacokinetics, pharmacodynamics, bioavailability, and toxicity in order to convert the pre-clinical results into clinical data for further investigation.

Parkia speciosa empty pod extract exerts anti-inflammatory properties by modulating NFκB and MAPK pathways in cardiomyocytes exposed to tumor necrosis factor-α

Parkia speciosa Hassk is a plant found abundantly in the Southeast Asia region. Its seeds, with or without pods, have been used in traditional medicine locally to treat cardiovascular problems. The pathogenesis of cardiovascular diseases involves inflammation and oxidative stress. Based on this information, we sought to investigate the potential protective effects of Parkia speciosa empty pod extract (PSE) on inflammation in cardiomyocytes exposed to tumor necrosis factor-α (TNF-α). H9c2 cardiomyocytes were divided into four groups; negative control, TNF-α, PSE + TNF-α and quercetin + TNF-α. Groups 3 and 4 were pretreated with PSE ethyl acetate fraction of ethanol extract (500 µg/mL) or quercetin (1000 µM, positive control) for 1 h before inflammatory induction with TNF-α (12 ng/mL) for 24 h. TNF-α increased protein expression of nuclear factor kappa B cell (NFκB) p65, p38 mitogen-activated protein kinase (p38 MAPK), inducible nitric oxide synthase, cyclooxygenase-2 and vascular cell adhesion molecule-1 when compared to the negative control (p < 0.05). It also elevated iNOS activity, nitric oxide and reactive oxygen species levels. These increases were significantly reduced with PSE and quercetin pretreatments. The effects of PSE were comparable to that of quercetin. PSE exhibited anti-inflammatory properties against TNF-α-induced inflammation in H9c2 cardiomyocytes by modulating the NFκB and p38 MAPK pathways.

Raging the War Against Inflammation With Natural Products

Over the last few decade Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) are the drugs of choice for treating numerous inflammatory diseases including rheumatoid arthritis. The NSAIDs produces anti-inflammatory activity via inhibiting cyclooxygenase enzyme, responsible for the conversation of arachidonic acid to prostaglandins. Likewise, cyclooxegenase-2 inhibitors (COX-2) selectively inhibit the COX-2 enzyme and produces significant anti-inflammatory, analgesic, and anti-pyretic activity without producing COX-1 associated gastrointestinal and renal side effects. In last two decades numerous selective COX-2 inhibitors (COXIBs) have been developed and approved for various inflammatory conditions. However, data from clinical trials have suggested that the prolong use of COX-2 inhibitors are also associated with life threatening cardiovascular side effects including ischemic heart failure and myocardial infection. In these scenario secondary metabolites from natural product offers a great hope for the development of novel anti-inflammatory compounds. Although majority of the natural product based compounds exhibit more selectively toward COX-1. However, the data suggest that slight structural modification can be helpful in developing COX-2 selective secondary metabolites with comparative efficacy and limited side effects. This review is an effort to highlight the secondary metabolites from terrestrial and marine source with significant COX-2 and COX-2 mediated PGE2 inhibitory activity, since it is anticipated that isolates with ability to inhibit COX-2 mediated PGE2 production would be useful in suppressing the inflammation and its classical sign and symptoms. Moreover, this review has highlighted the potential lead compounds including berberine, kaurenoic acid, α-cyperone, curcumin, and zedoarondiol for further development with the help of structure-activity relationship (SAR) studies and their current status.

Isolation, Purification, and Characterization of Five Active Diketopiperazine Derivatives from Endophytic Streptomyces SUK 25 with Antimicrobial and Cytotoxic Activities

In our search for new sources of bioactive secondary metabolites from Streptomyces sp., the ethyl acetate extracts from endophytic Streptomyces SUK 25 afforded five active diketopiperazine (DKP) compounds. The aim of this study was to characterize the bioactive compounds isolated from endophytic Streptomyces SUK 25 and evaluate their bioactivity against multiple drug resistance (MDR) bacteria such as Enterococcus raffinosus, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, and Enterobacter spp., and their cytotoxic activities against the human hepatoma (HepaRG) cell line. The production of secondary metabolites by this strain was optimized through Thornton's medium. Isolation, purification, and identification of the bioactive compounds were carried out using high-performance liquid chromatography, high-resolution mass liquid chromatography-mass spectrometry, Fourier transform infrared spectroscopy, and nuclear magnetic resonance, and cryopreserved HepaRG cells were selected to test the cytotoxicity. The results showed that endophytic Streptomyces SUK 25 produces four active DKP compounds and an acetamide derivative, which were elucidated as cyclo-(_L-Val-_L-Pro), cyclo-(_L-Leu-_L-Pro), cyclo-(_L-Phe-_L-Pro), cyclo-(_L-Val-_L-Phe), and N-(7-hydroxy-6-methyl-octyl)-acetamide. These active compounds exhibited activity against methicillin-resistant S. aureus ATCC 43300 and Enterococcus raffinosus, with low toxicity against human hepatoma HepaRG cells. Endophytic Streptomyces SUK 25 has the ability to produce DKP derivatives biologically active against some MDR bacteria with relatively low toxicity against HepaRG cells line.

Development and formulation of Moringa oleifera standardised leaf extract film dressing for wound healing application

ETHNOPHARMACOLOGICAL RELEVANCE

M.oleifera is a medicinal plant traditionally used for skin sores, sore throat and eye infections. Recently, the wound healing property of the leaves of M. oleifera was has been well demonstrated experimentally in both in vivo and in vitro models. However, there is a lack of research which focuses on formulating M.oleifera into a functional wound dressing. In this study, the M.oleifera leaf standardized aqueous extract with highest potency in vitro migration was formulated into a film for wound healing application.

MATERIALS AND METHODS

Firstly, M. oleifera leaf were extracted in various solvents (aqueous, 50%, 70% and 100% ethanolic extracts) and standardized by reference standards using UHPLC technique. The extracts were then tested for cell migration and proliferation using HDF and HEK cell lines. M. oleifera leaf aqueous extract was then incorporated into alginate-pectin (SA-PC) based film dressing. The film dressings were characterized for the physicochemical properties and the bioactives release from the M. oleifera leaf extract loaded film dressing was also investigated using Franz diffusion cells.

RESULTS

All extracts were found to contain vicenin-2, chlorogenic acid, gallic acid, quercetin, kaempferol, rosmarinic acid and rutin. Among all M. oleifera extracts, aqueous standardized leaf extracts showed the highest human dermal fibroblast and human keratinocytes cells proliferation and migration properties. Among the film formulations, SA-PC (3% w/v) composite film dressing containing M. oleifera aqueous leaf extract was found to possess optimal physicochemical properties as wound dressing.

CONCLUSION

A potentially applicable wound dressing formulated as an alginate-pectin film containing aqueous extracts of M. oleifera has been developed. The dressing would be suitable for wounds with moderate exudates.

Erratum to: Isolation, Purification, and Characterization of Five Active Diketopiperazine Derivatives from Endophytic Streptomyces SUK 25 with Antimicrobial and Cytotoxic Activities

This erratum is being published to correct the 2nd author's name of above manuscript by Alshaibani et al. that was published in Journal of Microbiology and Biotechnology (2017, 27: 1249-1256). The 2nd author name(Noraziah MohamadZin) should appear as 'Noraziah Mohamad Zin'.

Marantodes pumilum (Blume) Kuntze Inhibited Secretion of Lipopolysaccharide- and Monosodium Urate Crystal-stimulated Cytokines and Plasma Prostaglandin E2

Background

Marantodes pumilum is traditionally used for dysentery, gonorrhea, and sickness in the bones. Previous studies revealed its antibacterial and xanthine oxidase inhibitory activities.

Objective

To evaluate the inhibitory effects of three M. pumilum varieties on the secretion of lipopolysaccharide (LPS)- and monosodium urate crystal (MSU)-induced cytokines and plasma prostaglandin E₂ (PGE₂) in vitro.

Materials and Methods

The leaves and roots of M. pumilum var. alata (MPA), M. pumilum var. pumila (MPP), and M. pumilum var. lanceolata (MPL) were successively extracted with dichloromethane (DCM), methanol, and water. Human peripheral blood mononuclear cells and ELISA technique were used for the cytokine assay, whereas human plasma and radioimmunoassay technique were used in the PGE₂ assay. Flavonoids content was determined using a reversed-phase high-performance liquid chromatography.

Results

DCM extract of MPL roots showed the highest inhibition of LPS-stimulated cytokine secretion with IC₅₀ values of 29.87, 7.62, 5.84, 25.33, and 5.40 μg/mL for interleukin (IL)-1α, IL-1β, IL-6, IL-8, and tumor necrosis factor (TNF)-α, respectively; while that of plasma PGE₂ secretion was given by DCM extract of MPP roots (IC₅₀ 31.10 μg/mL). Similarly, the DCM extract of MPL roots demonstrated the highest inhibition against MSU-stimulated IL-1α, IL-1β, IL-6, IL-8, TNF-α, and PGE₂ secretion with IC₅₀ values of 11.2, 8.92, 12.29, 49.51, 9.60, and 31.58 μg/mL, respectively. Apigenin in DCM extracts of MPL (0.051 mg/g) and MPP (0.064 mg/g) roots could be responsible for the strong inhibitory activity against IL-1β, IL-6, TNF-α, and PGE₂.

Conclusion

The results suggested that DCM extracts of MPL and MPP roots are potential anti-inflammatory agents by inhibiting the secretion of LPS- and MSU-stimulated pro-inflammatory cytokines and PGE₂.

SUMMARY

Amongst 18 tested extracts, DCM extracts of MPL and MPP roots remarkably inhibited LPS- and MSU-stimulated pro-inflammatory cytokines and PGE₂ secretionPhytochemical analysis was performed for the active extracts using RP-HPLC systemThe presence of flavonoids particularly apigenin could be responsible for the anti-inflammatory activity. Abbreviations used: BSA: Bovine serum albumin, COX-2: Cyclooxygenase-2, CPM: Count per minute, DAMP: Danger-associated molecular pattern, DCM: Dichloromethane, DMSO: Dimethyl sulfoxide, ELISA: Enzyme-linked immunosorbent assay, FBS: Fetal bovine serum, H₂O: Water, HEPES: 4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid, HMC-1: Human mast cell-1, HMGB1: High-mobility group box 1, ICAM: Intercellular adhesion molecule, IFN: Interferon, IgG: Immunoglobulin G, IKK: IkB kinase, IL: Interleukin, iNOS: Inducible nitric oxide synthase, LPS: Lipopolysaccharide, MeOH: Methanol, MPA: Marantodes pumilum var. alata, MPL: Marantodes pumilum var. lanceolata, MPP: Marantodes pumilum var. pumila, MSU: Monosodium urate, MTT: Methylthiazole tetrazolium, NF-κB: Nuclear factor-kappa B, NLR: NOD-like receptor, NLRP3: NLR family pyrin domain containing protein 3, NO: Nitric oxide, NOD: Nucleotide-binding oligomerization domain, NSAID: Nonsteroidal anti-inflammatory drug, PAMP: Pathogen-associated molecular pattern, PBMC: Peripheral blood mononuclear cell, PBS: Phosphate buffered saline, PGE₂: Prostaglandin E_2, PMACI: Phorbol-12-myristate 13-acetate and calcium ionosphere A23187, PRR: Pathogen recognition receptor, PTFE: Polytetrafluoroethylene, RIA: Radioimmunoassay, RIG: Retinoic acid-inducible gene I, RLR: RIG I-like receptor, RP-HPLC: Reversed-phase high-performance liquid chromatography, RPMI-1640: Roswell Park Memorial Institute-1640, TLR: Toll-like receptor, TNF: Tumor necrosis factor, VCAM: Vascular cell adhesion molecule.

Annonaceae: Breaking the Wall of Inflammation

Inventories of tropical forests have listed Annonaceae as one of the most diverse plant families. For centuries, it is employed in traditional medicines to cure various pathological conditions including snakebite, analgesic, astringent, diarrhea, dysentery, arthritis pain, rheumatism, neuralgia, and weight loss etc. Phytochemical analysis of Annonaceae family have reported the occurrence of alkaloids, flavonoids, triterpenes, diterpenes and diterpene flavone glycosides, sterols, lignans, and annonaceous acetogenin characteristically affiliated with Annonaceae sp. Numerous past studies have underlined the pleotropic pharmacological activities of the crude extracts and isolated compounds from Annonaceae species. This review is an effort to abridge the ethnobotany, morphology, phytochemistry, toxicity, and particularly focusing on the anti-inflammatory activity of the Annonaceae species.

Medicinal uses, chemistry and pharmacology of Dillenia species (Dilleniaceae)

The genus Dillenia is comprised of about 100 species of evergreen and deciduous trees or shrubs of disjunct distribution in the seasonal tropics of Madagascar through South and South East Asia, Malaysia, North Australia, and Fiji. Species from this genus have been widely used in medicinal folklore to treat cancers, wounds, jaundice, fever, cough, diabetes mellitus, and diarrhea as well as hair tonics. The plants of the genus also produce edible fruits and are cultivated as ornamental plants. Flavonoids, triterpenoids, and miscellaneous compounds have been identified in the genus. Their extracts and pure compounds have been reported for their antimicrobial, anti-inflammatory, cytotoxic, antidiabetes, antioxidant, antidiarrheal, and antiprotozoal activities. Mucilage from their fruits is used in drug formulations.

Flavonoids from the Bark of Artocarpus integer var. silvestris and their Anti-inflammatory Properties

A new pyranoflavone, methoxycyclocommunol (1) together with four known flavonoids, artonin F (2), heteroflavanone A (3), cudraflavone C (4) and cyclocommunol (5) were isolated from the bark of Artocarpus integer var. silvestris Corner. Their structures were elucidated through extensive spectroscopic techniques (UV, IR, MS, 1D-NMR and 2D-NMR) and by comparison with literature data. All the pure compounds were tested for their anti-inflammatory activities by using screening kit and radioimmunoassay methods. In a 15-lipoxygenase (15-LOX) inhibitory assay, compounds 1, 2, 4 and 5 gave weak percentages of inhibition, 16.5, 18.3, 17.6, 10.2%, respectively at the concentration of 100 μM. Compounds 1, 3 and 4, however, showed strong dose-dependent inhibition towards prostaglandin E2 (PGE2) production in lipopolysaccharide-induced human whole blood using a radioimmunoassay method with IC50 values of 4.3, 0.8, and 0.07 μM, respectively suggesting that they strongly exhibited cyclooxygenase-2 (COX-2) activity.

Flavonoids from the Bark of Artocarpus integer var. silvestris and their Anti-inflammatory Properties

A new pyranoflavone, methoxycyclocommunol (1) together with four known flavonoids, artonin F (2), heteroflavanone A (3), cudraflavone C (4) and cyclocommunol (5) were isolated from the bark of Artocarpus integer var. silvestris Corner. Their structures were elucidated through extensive spectroscopic- techniques (UV, IR, MS, 1D-NMR and 2D-NMR) and by comparison with literature data. All the pure compounds were tested for their anti-inflammatory activities by using screening kit and radioimmunoassay methods. In a 15-lipoxygenase (15-LOX) inhibitory assay, compounds 1, 2, 4 and 5 gave weak percentages of inhibition, 16.5, 18.3, 17.6, 10.2%, respectively at the concentration of 100 μM. Compounds 1, 3 and 4, however, showed strong dose- dependent inhibition towards prostaglandin E₂ (PGE₂) production in lipopolysaccharide-induced human whole blood using a radioimmunoassay method with IC₅₀ values of 4.3, 0.8, and 0.07 μM, respectively suggesting that they strongly exhibited cyclooxygenase-2 (COX-2) activity.

Effects of Labisia pumila var alata extracts on the lipid profile, serum antioxidant status and abdominal aorta of high-cholesterol diet rats

BACKGROUND

Previous studies on Labisia pumila var. alata (LPva) have showed that it could inhibit low-density lipoprotein (LDL) oxidation and provide protection on myocardial infarction in rats.

HYPOTHESIS/PURPOSE

We hypothesized that LPva extracts can modulate the lipid profiles and serum antioxidant status of hypercholesterolemic rats. In the present study, we investigated the effects of aqueous and 80% ethanol extracts of LPva on atherogenic and serum antioxidant parameters as well as changes in abdominal aorta of high-cholesterol diet rats.

METHODS

The major components of the extracts, gallic acid, flavonoids and alkyl resorcinols were analyzed by using a validated reversed phase HPLC method. The rats were induced to hypercholesterolemic status with daily intake of 2% cholesterol for a duration of 8 weeks. Three different doses (100, 200 and 400mg/kg) of the extracts were administered daily on the 4th week onwards. The rats were then sacrificed and the blood was collected via abdominal aorta and serum was separated by centrifugation for biochemical analysis. Part of the aorta tissues were excised immediately for histopathological examination.

RESULTS

The serum of LPva treated rats showed significant reduction in serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) levels and the abdominal aorta showed a significant decrease of atheroma lesions in treated rats. Serum lipid profiles of treated rats showed a decrease in total cholesterol, total triglycerides and low-density lipoprotein (LDL) levels as compared to control group. The atherogenic indices in treated rats were significantly improved along with an increasing level of serum high-density lipoprotein (HDL). The extracts also exhibited significant increase of antioxidant enzymes and decrease of MDA as a product of lipid peroxidation.

CONCLUSION

LPva extracts can reduce the risk of dyslipidemia by improving the serum lipid profiles and modulating serum antioxidants.

Isolation and characterization of cyclo-(tryptophanyl-prolyl) and chloramphenicol from Streptomyces sp. SUK 25 with antimethicillin-resistant Staphylococcus aureus activity

Background

Zingiber spectabile, commonly known as Beehive Ginger, is used as an ethnobotanical plant in many countries as an appetizer or to treat stomachache, toothache, muscle sprain, and as a cure for swelling, sores and cuts. This is the first report of isolation of Streptomyces strain from the root of this plant. Strain Universiti Kebangsaan 25 (SUK 25) has a very high activity to produce secondary metabolites against methicillin-resistant Staphylococcus aureus (MRSA), which is associated with high morbidity and mortality rates due to acquired multidrug resistance genes and causes medication failure in some clinical cases worldwide. Phylogenetic analysis based on the 16S ribosomal RNA gene sequence exhibited that the most closely related strain was Streptomyces omiyaensis NBRC 13449T (99.0% similarity).

Aim

This study was conducted to carry out the extraction, identification, and biological evaluation of active metabolites isolated from SUK 25 against three MRSA strains, namely, MRSA ATCC 43300, MRSA ATCC 33591, and MRSA ATCC 49476.

Materials and methods

The production of secondary metabolites by this strain was optimized through Thronton’s media. Isolation, purification, and identification of the bioactive compounds were carried out using reversed-phase high-performance liquid chromatography, high-resolution mass spectrometry, Fourier transform infrared, and one-dimensional and two-dimensional nuclear magnetic resonance.

Results

During screening procedure, SUK 25 exhibited good antimicrobial potential against several strains of MRSA. The best biological activity was shown from fraction number VII and its subfractions F2 and F3 with minimum inhibitory concentration values at 16 µg/mL and 8 µg/mL, respectively. These two subfractions were identified as diketopiperazine cyclo-(tryptophanyl-prolyl) and chloramphenicol.

Conclusion

On the basis of obtained results, SUK 25 isolated from Z. spectabile can be regarded as a new valuable source to produce secondary metabolites against bacteria, especially MRSA.

Platelet-activating factor (PAF) antagonistic activity of a new biflavonoid from Garcinia nervosa var. pubescens King

The methanol extract of the leaves of Garcinia nervosa var. pubescens King, which showed strong inhibitory effects on platelet-activating factor (PAF) receptor binding, was subjected to bioassay-guided isolation to obtain a new biflavonoid, II-3,I-5, II-5,II-7,I-4',II-4'-hexahydroxy-(I-3,II-8)-flavonylflavanonol together with two known flavonoids, 6-methyl-4'-methoxyflavone and acacetin. The structures of the compounds were elucidated by spectroscopic methods. The compounds were evaluated for their ability to inhibit PAF receptor binding to rabbit platelets using ³H-PAF as a ligand. The biflavonoid and acacetin showed strong inhibition with IC₅₀ values of 28.0 and 20.4 µM, respectively. The results suggest that these compounds could be responsible for the strong PAF antagonistic activity of the plant.