Bioinformatics Study of Flavonoids From Genus Erythrina As Ace2 inhibitor Candidates For Covid-19 Treatment

Purpose

This study aimed to screen potential drug candidates from the flavonoids of the genus Erythrina for the Corona Virus Disease 2019 (COVID-19) treatment.

Patients and Methods

A comprehensive screening was conducted on the structures of 473 flavonoids derived from the genus Erythrina, focusing on their potential toxicity and pharmacokinetic profiles. Subsequently, flavonoids that were non-toxic and possessed favorable pharmacokinetic properties underwent further analysis to explore their interactions with the angiotensin-converting enzyme 2 (ACE2) receptor, employing molecular docking and molecular dynamics simulations.

Results

Among 473 flavonoids, 104 were predicted to be safe from being mutagenic, hepatotoxic, and inhibitors of the human ether-a-go-go-related gene (hERG). Among these 104 flavonoids, 18 compounds were predicted not to be substrates of P-glycoprotein (P-gp). Among these 18 flavonoids, gangetinin (471) and erybraedin D (310) exhibit low binding affinities and root mean square deviation (RMSD) values, indicating stable binding to the ACE2 receptor. The physicochemical attributes of compounds 310 and 471 suggest that they possess drug-like properties.

Conclusion

Gangetinin (471) and erybraedin D (310) may serve as promising candidates for COVID-19 treatment due to their potential to inhibit the ACE2-RBD interaction. This warrants further investigation into their inhibitory effects on ACE2-RBD binding through in vitro experiments.

Fractionation and characterisation of sialylated-mucin glycoprotein from edible birds' nest hydrolysates through anion exchange chromatography

Edible bird's nest (EBN) is made up of sialylated-mucin glycoprotein with various health benefits due to its high antioxidative activity. However, as a macromolecule with distinct charged sialic acid and amino acids, fractions with different charges would have varied physicochemical properties and antioxidant activity, which have not been studied. Therefore, this study aimed to fractionate and purify the enzymatic hydrolysed of cleaned EBN (EBNhc) and EBN by-product (EBNhbyp) through anion exchange chromatography (AEC), and determine their molecular weights, physicochemical properties, and antioxidative activities. Overall, 26 fractionates were collected from enzymatic hydrolysate by AEC, which were classified into 5 fractions. It was found that the positively charged fraction of EBNhc (CF 1) and EBNhbyp (DF 1) showed the significantly highest (p < 0.05) soluble protein contents (22.86 and 18.40 mg/g), total peptide contents (511.13 and 800.47 mg/g) and ferric reducing antioxidant power (17.44 and 6.96 mg/g) among the fractionates. In conclusion, a positively charged fraction (CF 1 and DF 1) showed more desired physicochemical properties and antioxidative activities. This research suggests the potential of AEC fractionation as a technology to purify EBN and produce positively charged EBN fractionates with antioxidative potential that could be applied as food components to provide health benefits.

Virtual Screening and ADMET Prediction to Uncover the Potency of Flavonoids from Genus Erythrina as Antibacterial Agent through Inhibition of Bacterial ATPase DNA Gyrase B

The emergence of antimicrobial resistance due to the widespread and inappropriate use of antibiotics has now become the global health challenge. Flavonoids have long been reported to be a potent antimicrobial agent against a wide range of pathogenic microorganisms in vitro. Therefore, new antibiotics development based on flavonoid structures could be a potential strategy to fight against antibiotic-resistant infections. This research aims to screen the potency of flavonoids of the genus Erythrina as an inhibitor of bacterial ATPase DNA gyrase B. From the 378 flavonoids being screened, 49 flavonoids show potential as an inhibitor of ATPase DNA gyrase B due to their lower binding affinity compared to the inhibitor and ATP. Further screening for their toxicity, we identified 6 flavonoids from these 49 flavonoids, which are predicted to have low toxicity. Among these flavonoids, erystagallin B (334) is predicted to have the best pharmacokinetic properties, and therefore, could be further developed as new antibacterial agent.

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.

Curcumin and Its Derivatives as Potential Antimalarial and Anti-Inflammatory Agents: A Review on Structure-Activity Relationship and Mechanism of Action

Curcumin, one of the major ingredients of turmeric (Curcuma longa), has been widely reported for its diverse bioactivities, including against malaria and inflammatory-related diseases. However, curcumin's low bioavailability limits its potential as an antimalarial and anti-inflammatory agent. Therefore, research on the design and synthesis of novel curcumin derivatives is being actively pursued to improve the pharmacokinetic profile and efficacy of curcumin. This review discusses the antimalarial and anti-inflammatory activities and the structure-activity relationship (SAR), as well as the mechanisms of action of curcumin and its derivatives in malarial treatment. This review provides information on the identification of the methoxy phenyl group responsible for the antimalarial activity and the potential sites and functional groups of curcumin for structural modification to improve its antimalarial and anti-inflammatory actions, as well as potential molecular targets of curcumin derivatives in the context of malaria and inflammation.

Role of Terpenophenolics in Modulating Inflammation and Apoptosis in Cardiovascular Diseases: A Review

One in every three deaths worldwide is caused by cardiovascular diseases (CVDs), estimating a total of 17.9 million deaths annually. By 2030, it is expected that more than 24 million people will die from CVDs related complications. The most common CVDs are coronary heart disease, myocardial infarction, stroke, and hypertension. A plethora of studies has shown inflammation causing both short-term and long-term damage to the tissues in many organ systems, including the cardiovascular system. In parallel to inflammation processes, it has been discovered that apoptosis, a mode of programmed cell death, may also contribute to CVD development due to the loss of cardiomyocytes. Terpenophenolic compounds are comprised of terpenes and natural phenols as secondary metabolites by plants and are commonly found in the genus Humulus and Cannabis. A growing body of evidence has shown that terpenophenolic compounds exhibit protective properties against inflammation and apoptosis within the cardiovascular system. This review highlights the current evidence elucidating the molecular actions of terpenophenolic compounds in protecting the cardiovascular system, i.e., bakuchiol, ferruginol, carnosic acid, carnosol, carvacrol, thymol and hinokitiol. The potential of these compounds is discussed as the new nutraceutical drugs that may help to decrease the burden of cardiovascular disorders.

Steroids from Diplazium esculentum: Antiplasmodial activity and molecular docking studies to investigate their binding modes

Diplazium esculentum is an edible fern commonly consumed by the local community in Malaysia either as food or medicine. Isolation work on the ethyl acetate extract of the stem of D. esculentum resulted in the purification of two steroids, subsequently identified as stigmasterol (compound 1) and ergosterol5,8-endoperoxide (compound 2). Upon further testing, compound 2 displayed strong inhibitory activity against the Plasmodium falciparum 3D7 (chloroquine-sensitive) strain, with an IC₅₀ of 4.27±1.15 µM, while compound 1 was inactive. In silico data revealed that compound 2 showed good binding affinity to P. falciparum-Sarco endoplasmic reticulum calcium-dependent ATPase (PfATP6); however, compound 1 did not show an antiplasmodial effect due to the lack of a peroxide moiety in the chemical structure. Our data suggested that the antiplasmodial activity of compound 2 from D. esculentum might be due to the inhibition of PfATP6, which resulted in both in vitro and in silico inhibitory properties.

Pencirian Jangkitan Plasmodium berghei NK65 terhadap Mencit ICR sebagai Model Jangkitan Malaria Teruk

Malaria teruk atau ‘severe’ kebiasaannya disebabkan oleh jangkitan Plasmodium falciparum. Jangkitan Plasmodium falciparum pada manusia boleh menyebabkan kerosakan organ, anemia teruk, komplikasi serius, koma dan kematian. Bagi tujuan memahami patogenesis malaria teruk, model haiwan digunakan dalam kajian kali ini bagi mengenal pasti sama ada gabungan hos-parasit daripada mencit ICR dengan Plasmodium berghei NK65 boleh menyebabkan jangkitan malaria teruk pada hos. Pencirian jangkitan P. berghei ANKA pernah dilakukan sebelum ini terhadap mencit ICR; walau bagaimanapun, pencirian jangkitan P. berghei NK65 secara terperinci terhadap mencit ICR dalam kajian ini adalah pertama kali dilaporkan. Inokulasi sel darah merah (RBC) terjangkit-P. berghei NK65 (2 ´ 107 parasit RBC (pRBC)/mL) dilakukan terhadap mencit ICR dengan suntikan secara intraperitoneum. Pemantauan perubahan ciri fizikal seperti berat, suhu mencit, kematian mencit, pos mortem, histologi dan aras sitokin inflamasi yang terhasil selepas jangkitan direkod untuk analisis. Strain P. berghei NK65 menghasilkan jangkitan tahap teruk terhadap mencit ICR iaitu paras parasitemia melebihi 50% pada hari ke-10 selepas jangkitan diikuti kematian. Analisis histopatologi menunjukkan jangkitan ini menyebabkan perubahan pada tisu serebrum, perlekatan leukosit pada endotelium dan pensekuesteran pRBC dalam salur darah serebrum serta pendarahan intravaskular. Selepas jangkitan, pensekuesteran pRBC dan pengumpulan pigmen malaria turut dilihat pada organ utama mencit. Tambahan lagi, edema pulmonari, pembentukan membran hialin pada peparu dan pendarahan kortikal pada ginjal dilihat pada mencit terjangkit. Sitokin proinflamasi (TNF-α, IFN-γ, dan IL-18) dan sitokin antiinflamasi (IL-10 dan IL-4) juga meningkat dalam serum mencit terjangkit. Secara rumusannya, model jangkitan mencitICR-P. berghei NK65 yang digunakan dalam kajian ini menunjukkan ciri-ciri jangkitan malaria teruk. Hasil daripada kajian ini boleh digunakan sebagai asas untuk memahami patogenesis bagi malaria teruk pada manusia dan model jangkitan malaria haiwan pada masa akan datang.

Traditional Medicinal Uses, Phytochemistry, Biological Properties, and Health Applications of Vitex sp

The genus Vitex is also known as a chaste tree, in which it is a large shrub native to the tropical and subtropical regions of the world. A diverse range of species is distributed throughout Southern Europe, the Mediterranean, and Central Asia. The Vitex tree, including its leaves and fruits, has been used for herbal remedies in the form of pastes, decoctions, and dried fruits since ancient times. This article aimed to prepare a comprehensive review of traditional uses and secondary metabolites derived from Vitex sp., including the chemical compounds, biological activities, application of Vitex in human clinical trials, toxicology and safety, marketed products, and patents. The scientific findings were obtained using a number of search engines and databases, including Google Scholar, PMC, and ScienceDirect. Vitex species are well known in pharmacology to have medicinal values, such as anti-inflammatory, antibacterial, antifungal, antimicrobial, antioxidant, and anticancer properties. Previous studies reported that some species are proven to be effective in treating diseases, such as diabetes, and improving female health. A total of 161 compounds from different Vitex species are reported, covering the literature from 1982 to 2022. A chemical analysis report of various studies identified that Vitex exhibited a wide range of phytoconstituents, such as iridoid, diterpenoid, ecdysteroid, and flavonoid and phenolic compounds. Apart from that, the review will also discuss the application of Vitex in human clinical trials, toxicology and safety, marketed products, and patents of the genus. While the extracts of the genus have been made into many commercial products, including supplements and essential oils, most of them are made to be used by women to improve menstrual conditions and relieve premenstrual syndrome. Among the species, Vitex agnus-castus L. is the only one that has been reported to undergo clinical trials, mainly related to the use of the genus for the treatment of mastalgia, menstrual bleeding problems, amenorrhea, menorrhagia, luteal insufficiency, and premenstrual syndrome. Overall, the review addresses recent therapeutic breakthroughs and identifies research gaps that should be explored for prospective research work.

Electrochemical Oxidation of Different Therapeutic Classes of Pharmaceuticals Using Graphite-PVC Composite Electrode

This study reports electrochemical treatment of different therapeutic classes of pharmaceuticals (caffeine, prazosin, enalapril, carbamazepine, nifedipine, levonorgestrel, and simvastatin) in a mixture. The electrochemical process was investigated using graphite-PVC anode at different applied voltages (3, 5, and 12 V), initial concentrations of studied pharmaceuticals in aqueous solution (5 and 10 mg/L), and concentrations of sodium chloride (1 and 2 g/L). The % removal of pharmaceuticals increased with the applied voltage, and was found higher than 98% after 50 min of electrolysis at 5 V. Energy consumption ranged between 0.760 and 3.300 Wh/mg using 12 V being the highest value compared to 3 and 5 V. The formation of chlorinated by-products from four selected pharmaceuticals, simvastatin (C11H13Cl3O5, and C10H12Cl4O3), prazosin (C13H12Cl3N5O3 and C10H11Cl4N2O2), carbamazepine and caffeine (C15H11N2O2Cl and C8H9N4O2Cl) was identified and elucidated using liquid chromatography-time of flight mass spectrometry (LC-TOF/MS).

Therapeutic Approach of Flavonoid in Ameliorating Diabetic Cardiomyopathy by Targeting Mitochondrial-Induced Oxidative Stress

Diabetes cardiomyopathy is one of the key factors of mortality among diabetic patients around the globe. One of the prior contributors to the progression of diabetic cardiomyopathy is cardiac mitochondrial dysfunction. The cardiac mitochondrial dysfunction can induce oxidative stress in cardiomyocytes and was found to be the cause of majority of the heart morphological and dynamical changes in diabetic cardiomyopathy. To slow down the occurrence of diabetic cardiomyopathy, it is crucial to discover therapeutic agents that target mitochondrial-induced oxidative stress. Flavonoid is a plentiful phytochemical in plants that shows a wide range of biological actions against human diseases. Flavonoids have been extensively documented for their ability to protect the heart from diabetic cardiomyopathy. Flavonoids' ability to alleviate diabetic cardiomyopathy is primarily attributed to their antioxidant properties. In this review, we present the mechanisms involved in flavonoid therapies in ameliorating mitochondrial-induced oxidative stress in diabetic cardiomyopathy.

Alkaloid Caulerpin and Cytotoxic Activity against NCL-H460 Lung Cancer Cells Isolated along with β-sitosterol from the Halimeda cylindracea Decaisne

Alkaloid caulerpin (1), along with β-sitosterol (2), were isolated from the n-hexane extract of the macroalga Halimeda cylindracea Decaisne. The chemical structure was identified by a spectroscopic method including IR, MS, UV, NMR 1D, NMR 2D, and comparison with data of spectra previously reported. Compounds (1) and (2) were isolated for the first time from this macroalga. Compund (1) were evaluated for their cytotoxicity activity against NCL-H460 lung cancer cells in vitro and showed moderate activity with IC50 value of 20.05 µg/mL.

Review of sialic acid's biochemistry, sources, extraction and functions with special reference to edible bird's nest

Sialic acids are a group of nine-carbon α-keto acids. Sialic acid exists in more than 50 forms, with the natural types discovered as N-acetylneuraminic acid (Neu5Ac), deaminoneuraminic acid (2-keto-3-deoxy-nonulononic acid or Kdn), and N-glycolylneuraminic acid (Neu5Gc). Sialic acid level varies depending on the source, where edible bird's nest (EBN), predominantly Neu5Ac, is among the major sources of sialic acid. Due to its high nutritive value and complexity, sialic acid has been studied extensively through acid, aqueous, and enzymatic extraction. Although detection by chromatographic methods or mass spectrometry is common, the isolation and recovery work remained limited. Sialic acid is well-recognised for its bioactivities, including brain and cognition development, immune-enhancing, anti-hypertensive, anticancer, and skin whitening properties. Therefore, sialic acid can be used as a functional ingredient in the various industries. This paper reviews the current trend in the biochemistry, sources, extraction, and functions of sialic acids with special reference to EBN.

Bioactivity profile of three types of seaweed as an antioxidant, UV-protection as sunscreen and their correlation activity

Seaweed is one of the marine algae that have antioxidant sources because it contains bioactive compounds such as carotenoids, phenol compounds and their derivatives, polysaccharide sulfate, and vitamins. Algae consist of three major groups namely brown algae (phaeophyta), red algae (rhodophyta), and green algae (chlorophyta). The purpose of this study was to determine the bioactivity profile of seaweed extract Eucheuma cottoni, Sargassum polycystum and Caulerpa racemosa so that it could be developed as a cosmetic raw material. The three types of seaweed were extracted by maceration and bioactivity testing was carried out as an antioxidant using the ABTS radical reduction method and bioactivity testing as UV-protection with the parameters of the percentage transmission of erythema, pigmentation and Sun Protective Factor (SPF). The results showed that C. racemosa extract provided a very strong antioxidant activity and was able to protect the skin from UV exposure with an SPF value that was categorized as ultra-protection. Antioxidant activity of the three types of seaweed is positively correlated to the protective effect based on the SPF value.

S-allylcysteine improves ischemia/reperfusion alteration on cardiac function, antioxidant, and mitochondrial permeability

S-Allylcysteine (SAC) is an extensively studied natural product which has been proven to confer cardioprotection. This potentiates SAC into many clinical relevance possibilities, hence, the use of it ought to be optimally elucidated. To further confirm this, an ischemia/reperfusion model has been used to determine SAC at 10 mM and 50 mM on cardiac function, cardiac marker, and mitochondrial permeability. Using Langendorff setup, 24 adult male Wistar rats' hearts were isolated to be perfused with Kreb-Henseleit buffer throughout the ischemia/reperfusion method. After 20 min of stabilization, global ischemia was induced by turning off the perfusion for 35 min followed by 60 min of reperfusion with either Kreb-Henseleit buffer or SAC with the dose of 10 mM or 50 mM. The cardiac function was assessed and coronary effluent was collected at different timepoints throughout the experiment for lactate dehydrogenase (LDH) measurement. The harvested hearts were then used to measure glutathione while isolated mitochondria for mPTP analysis. SAC-reperfused hearts were shown to prevent the aggravation of cardiac function after I/R induction. It also dose-dependently upregulated glutathione reductase and glutathione level and these were also accompanied by significant reduction of LDH leakage and preserved mitochondrial permeability. Altogether, SAC dose-dependently was able to recover the post-ischemic cardiac function deterioration alongside with improvement of glutathione metabolism and mitochondrial preservation. These findings highly suggest that SAC when sufficiently supplied to the heart would be able to prevent the deleterious complications after the ischemic insult.

Data on antiplasmodial and stage-specific inhibitory effects of Aromatic (Ar)-Turmerone against Plasmodium falciparum 3D7

Aromatic (ar)-turmerone is one of the aromatic constituents abundant in turmeric essential oil from Curcuma longa. Ar-turmerone exhibited anti-inflammatory properties. So far, antiplasmodial data for ar-turmerone is still not reported. The data showed the in vitro antiplasmodial effect of ar-turmerone against Plasmodium falciparum 3D7 (chloroquine-sensitive) via Plasmodium lactate dehydrogenase assay (pLDH) and cytotoxic effect against Vero mammalian kidney cells using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) colourimetric assay. Selectivity indexes of ar-turmerone were calculated based on inhibition concentration at 50% of parasite growth (IC₅₀) from MTT and pLDH assays and the effects of ar-turmerone were compared to the antimalarial reference drug chloroquine diphosphate. The inhibitory effect of ar-turmerone at the intraerythrocytic stages of plasmodial lifecycles was evaluated via a stage-dependant susceptibility test. The antiplasmodial and cytotoxic activities of ar-turmerone revealed IC₅₀ values of 46.8 ± 2.4 μM and 820.4 ± 1.5 μM respectively. The selectivity index of ar-turmerone was 17.5. Ar-turmerone suppressed the ring-trophozoite transition stage of the intraerythrocytic life cycle of P. falciparum 3D7.

NMR and LCMS analytical platforms exhibited the nephroprotective effect of Clinacanthus nutans in cisplatin-induced nephrotoxicity in the in vitro condition

Background

Clinacanthus nutans (C. nutans) Lind. locally known as Belalai Gajah or Sabah snake grass is a medicinal plant belonging to Acanthaceae family. In Asia, this plant is traditionally used for treating skin rashes, insects and snake bites, diabetes mellitus, fever and for diuretic effect. C. nutans has been reported to possess biological activities including anti-oxidant, anti-inflammation, anti-cancer, anti-diabetic and anti-viral activities.

Methods

Proton Nuclear Magnetic Resonance (¹H NMR) and Liquid Chromatography Mass Spectroscopy (LCMS) coupled with multivariate data analysis were employed to characterize the metabolic variations of intracellular metabolites and the compositional changes of the corresponding culture media in rat renal proximal tubular cells (NRK-52E).

Results

NMR and LCMS analysis highlighted choline, creatine, phosphocholine, valine, acetic acid, phenylalanine, leucine, glutamic acid, threonine, uridine and proline as the main metabolites which differentiated the cisplatin-induced group of NRK-52E from control cells extract. The corresponding media exhibited lactic acid, glutamine, glutamic acid and glucose-1-phosphate as the varied metabolites. The altered pathways perturbed by cisplatin nephrotoxic on NRK-52E cells included changes in amino acid metabolism, lipid metabolism and glycolysis.

Conclusion

The C. nutans aqueous extract (1000 μg/mL) exhibited the most potential nephroprotective effect against cisplatin toxicity on NRK-52E cell lines at 89% of viability. The protective effect could be seen through the changes of the metabolites such as choline, alanine and valine in the C. nutans pre-treated samples with those of the cisplatin-induced group.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12906-020-03067-3.

Roselle attenuates cardiac hypertrophy after myocardial infarction in vivo and in vitro

Roselle (Hibiscus sabdariffa Linn) has been traditionally used as folk medicine for hypertension and maintaining cardiovascular health, with therapeutic potential in protecting against numerous cardiovascular diseases. However, it remains unclear whether roselle can be used for management of cardiac hypertrophy seen after myocardial infarction (MI). This study therefore investigated the effects of aqueous roselle extract on cardiac hypertrophy arising from myocardial infarction both in vivo and in vitro. For in vivo study, male Sprague-Dawley rats were divided into control or MI groups (receiving 85 mg/kg isoproterenol s.c. for 2 days) and were given roselle extract (100 mg/kg, p.o daily) for 28 days. Cardiac structure and functional changes were evaluated at study end-point using histology, Langendorff analysis and gene expression analysis. In vitro effects of roselle were also assessed on ANG II-induced cardiomyocytes hypertrophy using H9c2 cells, simulating cardiac hypertrophy evident after MI. Roselle significantly ameliorated MI-induced cardiac systolic and diastolic dysfunction, as seen across improvement in left ventricular developed pressure (LVDP) and its derivative (LVdP/dtmax) and isovolumic relaxation (Tau). Oxidative stress evident across elevated pro-oxidant markers (NOX2 subunit of NADPH oxidase and 8-isoprostane) as well as reduced antioxidant markers (superoxide dismutase and glutathione) were also significantly attenuated by roselle. Furthermore, roselle treatment markedly reduced markers of cardiac remodeling (cardiac hypertrophy and fibrosis) compared to the untreated MI rats. On in vitro analysis, roselle significantly attenuated ANG II-induced cardiomyoycte hypertrophy in dose-dependent manner. This study demonstrated that roselle attenuates cardiac hypertrophy and dysfunction seen after MI both in vivo and in vitro, and these effects are likely mediated by phenolic compounds found in roselle extract.

Piper sarmentosum Promotes Endothelial Nitric Oxide Production by Reducing Asymmetric Dimethylarginine in Tumor Necrosis Factor-α-Induced Human Umbilical Vein Endothelial Cells

Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of endothelial nitric oxide synthase (eNOS). ADMA is degraded by dimethylarginine dimethylaminohydrolase (DDAH). Elevated levels of ADMA lead to reduction in nitric oxide (NO) production, which is linked to endothelial dysfunction and atherosclerosis. Piper sarmentosum is an herb that has shown stimulation on endothelial NO production by increasing both expression and activity of eNOS. Thus, this study determined whether the positive effect of P. sarmentosum on NO production is related to its modulation on the DDAH-ADMA pathway in cultured human umbilical vein endothelial cells (HUVEC) exposed to tumor necrosis factor-α (TNF-α). HUVEC were divided into four groups: control, treatment with 250 µg/ml of aqueous extract of P. sarmentosum leaves (AEPS), treatment with 30 ng/ml of TNF-α, and concomitant treatment with AEPS and TNF-α for 24 h. After treatments, HUVEC were collected to measure DDAH1 messenger RNA (mRNA) expression using quantitative real-time polymerase chain reaction. DDAH1 protein level was measured using enzyme-linked immunosorbent assay (ELISA), and DDAH enzyme activity was measured using colorimetric assay. ADMA concentration was measured using ELISA, and NO level was measured using Griess assay. Compared to control, TNF-α-treated HUVEC showed reduction in DDAH1 mRNA expression (P < 0.05), DDAH1 protein level (P < 0.01), and DDAH activity (P < 0.05). Treatment with AEPS successfully increased DDAH1 mRNA expression (P < 0.05), DDAH1 protein level (P < 0.01), and DDAH activity (P < 0.05) in TNF-α-treated HUVEC. Treatment with TNF-α caused an increase in ADMA level (P < 0.01) and a decrease in endothelial NO production (P < 0.001). Whereas treatment with AEPS was able to reduce ADMA level (P < 0.01) and restore NO (P < 0.001) in TNF-α-treated HUVEC. The results suggested that AEPS promotes endothelial NO production by stimulating DDAH activity and thus reducing ADMA level in TNF-α-treated HUVEC.

Dexibuprofen amide derivatives as potential anticancer agents: synthesis, in silico docking, bioevaluation, and molecular dynamic simulation

BACKGROUND

The amide derivatives of nonsteroidal anti-inflammatory drugs have been reported to possess antitumor activity. The present work describes the synthesis of dexibuprofen amide analogues (4a-j) as potential anticancer agents.

METHODS

The title amides (4a-j) were obtained by simple nucleophilic substitution reaction of dexibuprofen acid chloride with substituted amines in good yield and chemical structures were confirmed by FTIR, 1H NMR, 13C NMR and mass spectral data.

RESULTS

The brine shrimp lethality assay results showed that all of the synthesized compounds are non-toxic to shrimp larvae. The inhibitory effects on tumor growth were evaluated and it was observed that N-(2,5-dichlorophenyl)-2-(4-isobutylphenyl) propionamide (4e) and N-(2-chlorophenyl)-2-(4-isobutylphenyl) propionamide (4g) exhibited excellent antitumor activity compared to all other derivatives. The compound 4e bearing 2,5-dichloro substituted phenyl ring and 4g possesses 2-chloro substituted phenyl ring exhibited 100% inhibition of the tumor growth. The anticancer activity was evaluated against breast carcinoma cell line (MCF-7) and it was observed that derivative 4e exhibited excellent growth inhibition of cancer cells with IC50 value of 0.01±0.002 µm, which is better than the standard drugs. The docking studies against breast cancer type 1 susceptibility protein BRCA1 (PDBID 3K0H) exhibited good binding affinities, which are in good agreement with the wet lab results. The compounds 4e and 4g showed the binding energy values of -6.39 and -6.34 Kcal/mol, respectively. The molecular dynamic (MD) simulation was also carried out to evaluate the residual flexibility of the best docking complexes of compounds 4e and 4g. The MD simulation analysis assured that the 4e formed a more stable complex with the target protein than the 4g. The synthesized amide derivatives exhibited were devoid of gastrointestinal side effects and no cytotoxic effects against human normal epithelial breast cell line (MCF-12A) were found.

CONCLUSION

Based upon our wet lab and dry lab findings we propose that dexibuprofen analogue 4e may serve as a lead structure for the design of more potent anticancer drugs.

Electro-transformation of mefenamic acid drug: a case study of kinetics, transformation products, and toxicity

Poor removal of many pharmaceuticals and personal care products in sewage treatment plants leads to their discharge into the receiving waters, where they may cause negative effects for aquatic environment and organisms. In this study, electrochemical removal process has been used as alternative method for removal of mefenamic acid (MEF). For our knowledge, removal of MEF using electrochemical process has not been reported yet. Effects of initial concentration of mefenamic acid, sodium chloride (NaCl), and applied voltage were evaluated for improvement of the efficiency of electrochemical treatment process and to understand how much electric energy was consumed in this process. Removal percentage (R%) was ranged between 44 and 97%, depending on the operating parameters except for 0.1 g NaCl which was 9.1%. Consumption energy was 0.224 Wh/mg after 50 min at 2 mg/L of mefenamic acid, 0.5 g NaCl, and 5 V. High consumption energy (0.433 Wh/mg) was observed using high applied voltage of 7 V. Investigation and elucidation of the transformation products were provided by Bruker software dataAnalysis using liquid chromatography-time of flight mass spectrometry. Seven chlorinated and two non-chlorinated transformation products were investigated after 20 min of electrochemical treatment. However, all transformation products (TPs) were eliminated after 140 min. For the assessment of the toxicity, it was impacted by the formation of transformation products especially between 20 and 60 min then the inhibition percentage of E. coli bacteria was decreased after 80 min to be the lowest value.

New Prenylated Dihydrostilbenes from Croton Laevifolius

Two prenylated dihydrostilbenes have been isolated from the methanol extract of the flower of Croton laevifolius. The structures of these compounds were assigned as 3,5,3′,4′-tetrahydroxy-2,6,2′-tris(3-methylbut-2-enyl)dihydrostilbene (laevifolin A) and 3,5,3′,4′-tetrahydroxy-2,6,5′-tris(3-methylbut-2-enyl)dihydrostilbene (laevifolin B) based on spectroscopic evidence, including UV, IR, 1D and 2D NMR, and mass spectra. The chemotaxonomic significance of the presence of these dihydrostilbene derivatives is briefly discussed.

The fate of prazosin and levonorgestrel after electrochemical degradation process: Monitoring by-products using LC-TOF/MS

Prazosin (PRZ) and levonorgestrel (LNG) are widely used as an anti-disease drugs due to their biological activity in the human body. The frequent detection of these compounds in water samples requires alternative technologies for the removal of both compounds. After electrochemical degradation of PRZ and LNG, the parent compounds could be completely removed after treatment, but the identification and characterization of by-products are necessary as well. In this study, the effects of NaCl concentration and applied voltage were investigated during the electrochemical degradation process. The results revealed that the increase of NaCl concentration and applied voltage could promote the generation of hypochlorite OCl^- and then enhance the degradation of PRZ and LNG. After initial study, 6V and 0.2g NaCl were selected for further experiments (96% and 99% removal of PRZ and LNG after 40min, respectively). Energy consumption was also evaluated and calculated for PRZ and LNG at 3, 6 and 8V. Solid phase extraction (SPE) method plays an important role in enhancing the detection limit of by-products. Furthermore, characterization and identification of chlorinated and non-chlorinated by-products were conducted using an accurate liquid chromatography-time of flight/mass spectrometry LC-TOF/MS instrument. The monitoring of products during the electrochemical degradation process was performed at 6V and 0.2g NaCl in a 50mL solution. The results indicated that two chlorinated products were formed during the electrochemical process. The toxicity of by-products toward E. coli bacteria was investigated at 37°C and 20hr incubation time.

Methylation and Acetylation Enhanced the Antidiabetic Activity of Some Selected Flavonoids: In Vitro, Molecular Modelling and Structure Activity Relationship-Based Study

Flavonoids have been reported to exert antihyperglycemic effects and have potential to enhance the current therapy options against type 2 diabetes mellitus. However, the structure activity relationships (SAR) studies of flavonoids against this disease have not been thoroughly comprehended. Hence, in the present study, 14 structurally related flavonoids viz. wogonin, techtochrysin, norwogonin, isoscutellarein, hypolaetin, kaempferol, quercetin, methyl ether of wogonin, acetate of wogonin, acetate of norwogonin, 8-hydroxy-7-methoxyflavone, chrysin, (+)-catechin and (-)-epicatechin were taken into account for in vitro antidiabetic evaluation. Cell viability of RIN-5F pancreatic cells and 3T3-L1 pre-adipocyte cells was initially tested, then an insulin secretion assay of RIN-5F as well as adipogenesis and glucose uptake measurements of adipocyte were investigated. Subsequently, protein expressions study through adipokines measurement (leptin, adiponectin, TNF-α, RBP-4) via enzyme-linked immunosorbent assay (ELISA) kit, Western blotting analysis against GLUT4 and C/EBP-α as well as molecular docking against GLUT1 were analyzed. The results from cell culture antidiabetic assays (insulin secretion, adipogenesis, and glucose uptake), protein expressions and molecular docking pointed that the methoxy group at position C-8 is responsible for antidiabetic property of selected flavonoids via glucose uptake mechanism indicated by up regulation of GLUT4 and C/EBP-α expressions. The mechanism could be enhanced by the addition of an acetate group at C-5 and C-7 of the flavone skeleton.

Flavonoids from Tetracera indica Merr. induce adipogenesis and exert glucose uptake activities in 3T3-L1 adipocyte cells

BACKGROUND

Tetracera indica Merr. (Family: Dilleniaceae), known to the Malay as 'Mempelas paya', is one of the medicinal plants used in the treatment of diabetes in Malaysia. However, no proper scientific study has been carried out to verify the traditional claim of T. indica as an antidiabetic agent. Hence, the aims of the present study were to determine the in vitro antidiabetic potential of the T. indica stems ethanol extract, subfractions and isolated compounds.

METHODS

The ethanol extract and its subfractions, and isolated compounds from T. indica stems were subjected to cytotoxicity test using MTT viability assay on 3T3-L1 pre-adipocytes. Then, the test groups were subjected to the in vitro antidiabetic investigation using 3T3-L1 pre-adipocytes and differentiated adipocytes to determine the insulin-like and insulin sensitizing activities. Rosiglitazone was used as a standard antidiabetic agent. All compounds were also subjected to fluorescence glucose (2-NBDG) uptake test on differentiated adipocytes. Test solutions were introduced to the cells in different safe concentrations as well as in different adipogenic cocktails, which were modified by the addition of compounds to be investigated and in the presence or absence of insulin. Isolation of bioactive compounds from the most effective subfraction (ethyl acetate) was performed through repeated silica gel and sephadex LH-20 column chromatographies and their structures were elucidated through 1H-and 13C-NMR spectroscopy.

RESULTS

Four monoflavonoids, namely, wogonin, norwogonin, quercetin and techtochrysin were isolated from the T. indica stems ethanol extract. Wogonin, norwogonin and techtochrysin induced significant (P < 0.05) adipogenesis like insulin and enhanced adipogenesis like rosiglitazone. Wogonin and norwogonin also exhibited significant (P < 0.05) glucose uptake activity.

CONCLUSION

The present study demonstrated that the flavonoids isolated from the T. indica stems possess antidiabetic potential revealing insulin-like and insulin-sensitizing effects which were significant among the compounds. This also rationalizes the traditional use of T. indica in the management of diabetes in Malaysia.

Potential Secondary Metabolites from Marine SpongeAaptos aaptosfor Atherosclerosis and Vibriosis Treatments

Natural products play a crucial role in drug discovery. In the last decade, the advent of marine natural product research has produced a remarkable number of compounds, particularly those isolated from marine sponges, with a broad range of activities for the treatment of human and animal diseases. In this study, five known alkaloids namely aaptamine (1), 9-demethylaaptamine (2), 4- N-methylaaptamine (3), 9-methoxyaaptamine (4), 9-demethyloxyaaptamine (5), an uncommon amide in sponge, 4-hydroxybenzamide (6) and 3 β,5α-cholesterol (7) were isolated from the butanol extract of Aaptos aaptos (Schmidt, 1864) by bioactivity-guided isolation. Their structures were determined based on a detailed analysis of their 1D and 2D spectroscopic NMR and EIMS spectral data as well as comparison with literature data. Cytotoxic activity and anti-atherosclerotic property of the compounds were determined based on their ability to increase the transcriptional activity of SRB1 promoter and PPRE in human liver HepG2 cell line. The results showed that compounds 4 and 7 exhibited cytotoxic effects and compounds 1–4 and 7 increased the transcriptional activity of SRB1 promoter and PPRE. This suggests that compounds isolated from A. aaptos may have potential as anti-cancer agents and to reduce the progression of atherosclerosis. In addition, the compounds 1–4 displayed antibacterial activity against shrimp pathogenic bacteria, Vibrio harveyi and Vibrio sp. This suggests that the compounds have potential as vibriosis treatment.

Gancidin W, a potential low-toxicity antimalarial agent isolated from an endophytic Streptomyces SUK10

Endophytic Streptomyces strains are potential sources for novel bioactive molecules. In this study, the diketopiperazine gancidin W (GW) was isolated from the endophytic actinobacterial genus Streptomyces, SUK10, obtained from the bark of Shorea ovalis tree, and it was tested in vivo against Plasmodium berghei PZZ1/100. GW exhibited an inhibition rate of nearly 80% at 6.25 and 3.125 μg kg-1 body weight on day four using the 4-day suppression test method on male ICR strain mice. Comparing GW at both concentrations with quinine hydrochloride and normal saline as positive and negative controls, respectively, 50% of the mice treated with 3.125 μg kg-1 body weight managed to survive for more than 11 months after infection, which almost reached the life span of normal mice. Biochemical tests of selected enzymes and proteins in blood samples of mice treated with GW were also within normal levels; in addition, no abnormalities or injuries were found on internal vital organs. These findings indicated that this isolated bioactive compound from Streptomyces SUK10 exhibits very low toxicity and is a good candidate for potential use as an antimalarial agent in an animal model.

Characterisation of fucoidan extracted from Malaysian Sargassum binderi

Fucoidan is a sulphated polysaccharide that consists mainly of fucose, normally found in brown seaweeds. In this study, fucoidan was extracted from Sargassum binderi (Fsar) from Malaysia and subsequently characterised. The chemical characteristics of Fsar were found to be different than those of commercial food grade fucoidan (Fysk) and those of previously studied fucoidans. NMR analysis proposed that the main structure of Fsar is →3)fuc-2-OSO3(-)(1→3)fuc(1→. The molecular weight (47.87kDa) and degree of sulphation (0.20) of Fsar were higher than those of Fysk, at 27.98kDa and 0.15, respectively. However, Fsar's polydispersity index (1.12) and fucose content (34.50%) were lower than those of Fysk, at 1.88 and 43.30%, respectively. Both Fsar and Fysk showed similar thermo-gravimetric properties with four mass losses, amorphous in nature and negative optical rotations. Results show that Fsar has fundamental characteristics of fucoidan with different structural conformation i.e. variation in glycosidic linkages and sulphate group orientation.

Biological Activities of Isolated Compounds from Three Edible Malaysian Red Seaweeds,Gracilaria changii, G. manilaensisandGracilariasp

Gracilaria species are red marine macroalgae that are found abundantly in Malaysia. Gracilaria changii from Morib, Selangor, G. manilaensis and Gracilaria sp. from Gelang Patah, Johor were used in this study. Five compounds were successfully isolated and identified as hexadecanoic acid (1), cholest-5-en-3-ol (2), 2-hydroxymyristic acid (3), cholesteryl myristate (4) and 1-(4'-methoxyphenyl)-3-(2”,4”,6”-trihydroxyphenyl)-3-hydroxypropanone (5) based on spectral data analysis (IR, UV, GC-MS,1H NMR,13C NMR, HMQC and HMBC). All compounds isolated were tested for cytotoxicity (MTT assay for HL-60 and MCF-7 cell lines), and antibacterial (disc diffusion method), antioxidant (DPPH free radical scavenging assay and xanthine oxidase inhibitory assay) and acetylcholinesterase inhibitory (AChE) activity (TLC bioautographic method). Compounds 1 and 3 exhibited strong cytotoxic activity against HL-60 and MCF-7 cell lines. Compound 5 showed high antioxidant activity in both the DPPH free radical scavenging and xanthine oxidase inhibition assays. Compound 1 showed positive activity for AChE inhibitory with a minimum inhibition dose of 0.625 μg sample. All compounds demonstrated antibacterial activity producing 8 to 14 mm inhibition zones. A positive control was applied to all bioassays and experiments were performed with three replicates. Results demonstrated that three edible red seaweeds are rich sources of bioactive compounds with potential application for pharmaceutical purposes.

Biological Activities of Isolated Compounds from Three Edible Malaysian Red Seaweeds, Gracilaria changii, G. manilaensis and Gracilaria sp

Gracilaria species are red marine macroalgae that are found abundantly in Malaysia. Gracilaria changii from Morib, Selangor, G. nanilaensis and Gracilaria sp. from Gelang Patah, Johor were used in this study. Five compounds were successfully isolated and identified as hexadecanoic acid (1), cholest-5-en-3-ol (2), 2-hydroxymyristic acid (3), cholesteryl myristate (4) and 1-(4'-methoxyphenyl)-3-(2",4",6"-trihydroxyphenyl)-3-hydroxypropanone (5) based on spectral data analysis (IR, UV, GC-MS, 'H NMR, "C NMR, HMQC and HMBC). All compounds isolated were tested for cytotoxicity (MTT assay for HL-60 and MCF-7 cell lines), and antibacterial (disc diffusion method), antioxidant (DPPH free radical scavenging assay and xanthine oxidase inhibitory assay) and acetylcholinesterase inhibitory (AChE) activity (TLC bioautographic method). Compounds I and 3 exhibited strong cytotoxic activity against HL-60 and MCF-7 cell lines. Compound 5 showed high antioxidant activity in both the DPPH free radical scavenging and xanthine oxidase inhibition assays. Compound I showed positive activity for AChE inhibitory with a minimum inhibition dose of 0.625 tg sample. All compounds demonstrated antibacterial activity producing 8 to 14 mm inhibition zones. A positive control was applied to all bioassays and experiments were performed with three replicates. Results demonstrated that three edible red seaweeds are rich sources of bioactive compounds with potential application for pharmaceutical purposes.

Chemical properties and toxicology studies of fucoidan extracted from Malaysian Sargassum binderi

Fucoidan is a sulfated polysaccharide that consists mainly of fucose and is found in brown seaweeds. In this study, fucoidan was extracted from Sargassum binderi (F_sar) from Malaysia and subsequently characterized in terms of composition, structure and toxicology. It was found that the molecular weight, polydispersity index, monosaccharide profile and degree of sulfation of F_sar differed from those of commercial food-grade fucoidan (F_ysk). NMR analysis suggested that the main structure of F_sar was →3)fuc-2-OSO₃ ^-(1→3)fuc-2-OSO₃ ^-(1→. A cytotoxicity study employing up to 200 mg/mL Sargassum binderi extract showed that cell inhibition was less than 50% (IC₅₀), while acute toxicity results classified S. binderi as category 5 (unclassified) according to the OECD Guideline 423, as no mortality was observed at the highest dosage (2,000 mg/kg). Both toxicity results showed that this material is safe to be consumed. The chemical characteristics and non-toxicity of F_sar demonstrate its potential in biological and food product applications.

In vivo antimalarial activity of the endophytic actinobacteria, Streptomyces SUK 10

Endophytic bacteria, such as Streptomyces, have the potential to act as a source for novel bioactive molecules with medicinal properties. The present study was aimed at assessing the antimalarial activity of crude extract isolated from various strains of actinobacteria living endophytically in some Malaysian medicinal plants. Using the four day suppression test method on male ICR strain mice, compounds produced from three strains of Streptomyces (SUK8, SUK10, and SUK27) were tested in vivo against Plasmodium berghei PZZ1/100 in an antimalarial screen using crude extracts at four different concentrations. One of these extracts, isolated from Streptomyces SUK10 obtained from the bark of Shorea ovalis tree, showed inhibition of the test organism and was further tested against P. berghei-infected mice for antimalarial activity at different concentrations. There was a positive relationship between the survival of the infected mouse group treated with 50 µg/kg body weight (bw) of ethyl acetate-SUK10 crude extract and the ability to inhibit the parasites growth. The parasite inhibition percentage for this group showed that 50% of the mice survived for more than 90 days after infection with the parasite. The nucleotide sequence and phylogenetic tree suggested that Streptomyces SUK10 may constitute a new species within the Streptomyces genus. As part of the drug discovery process, these promising finding may contribute to the medicinal and pharmaceutical field for malarial treatment.

A new symmetrical tetramer oligostilbenoid containing tetrahydrofuran ring from the stem bark of Dryobalanops lanceolata

A new tetramer oligostilbenoid possessing tetrahydrofuran ring, malaysianol C (1), was isolated from the acetone extract of the stem bark of Dryobalanops lanceolata, together with four known oligostilbenoids nepalensinol E (2), ϵ-viniferin (3), laevifonol (4), and ampelopsin F (5). The structures of isolated compounds were elucidated on the basis of spectral evidence. The antibacterial activity of the isolated compounds was evaluated using resazurin microtitre-plate assay, whereas the cytotoxic activity was tested using MTT assay. The plausible biogenetic routes of the isolated compounds are also discussed.

Cytotoxic Properties of Oligostilbenoids from the Tree Barks of Hopea dryobalanoides

A new modified stilbene dimer, diptoindonesin D (1), was isolated from the acetone extract of the tree bark of Hopea dryobalanoides, together with seven known compounds, parviflorol (2), (D)-balanocarpol (3), heimiol A (4), hopeafuran (5), (+)-α-viniferin (6), vaticanol B (7) and (D)-hopeaphenol (8). Cytotoxic properties of compounds 1-8 were evaluated against murine leukemia P-388 cells. Compound 8 was found to be the most active with IC50 of 5.7 μm

SDF7, a group of Scoparia dulcis Linn. derived flavonoid compounds, stimulates glucose uptake and regulates adipocytokines in 3T3-F442a adipocytes

ETHNOPHARMACOLOGY RELEVANCE

Adipocytes are major tissues involved in glucose uptake second to skeletal muscle and act as the main adipocytokines mediator that regulates glucose uptake mechanism and cellular differentiation. The objective of this study were to examine the effect of the SDF7, which is a fraction consists of four flavonoid compounds (quercetin: p-coumaric acid: luteolin: apigenin=8: 26: 1: 3) from Scoparia dulcis Linn., on stimulating the downstream components of insulin signalling and the adipocytokines expression on different cellular fractions of 3T3-F442a adipocytes.

MATERIAL AND METHODS

Morphology and lipid accumulation of differentiated 3T3-F442a adipocytes by 100 nM insulin treated with different concentrations of SDF7 and rosiglitazone were examined followed by the evaluation of glucose uptake activity expressions of insulin signalling downstream components (IRS-1, PI3-kinase, PKB, PKC, TC10 and GLUT4) from four cellular fractions (plasma membrane, cytosol, high density microsome and low density microsome). Next, the expression level of adipocytokines (TNF-α, adiponectin and leptin) and immunoblotting of treated 3T3-F442 adipocytes was determined at 30 min and 480 min. Glucose transporter 4 (GLUT4) translocation of 3T3-F442a adipocytes membrane was also determined. Lastly, mRNA expression of adiponectin and PPAR-γ of 3T3-F442a adipocytes were induced and compared with basal concentration.

RESULTS

It was found that SDF7 was able to induce adipocytes differentiation with great extends of morphological changes, lipid synthesis and lipid stimulation in vitro. SDF7 stimulation of glucose transport on 3T3-F442a adipocytes are found to be dose independent, time-dependent and plasma membrane GLUT4 expression-dependent. Moreover, SDF7 are observed to be able to suppress TNF-α and leptin expressions that were mediated by 3T3-F442a adipocytes, while stimulated adiponectin secretion on the cells. There was a significant expression (p<0.01) of protein kinase C and small G protein TC10 on 3T3-F442a adipocytes upon treatment with SDF7 as compared to the control. SDF7 was also found to be effective in stimulating adiponectin and PPAR-γ mRNA upregulation at 50 µg/ml.

CONCLUSION

SDF7 exhibited good lipogenesis, adiponectinesis and glucose uptake stimulatory properties on 3T3-F442a adipocytes.