Active compound from the leaves of Vitex negundo L. shows anti-inflammatory activity with evidence of inhibition for secretory Phospholipase A(2) through molecular docking

Phytochemical characterization and phospholipase A2 inhibitory effect of Vitex negundo L. root extracts

ETHNOPHARMACOLOGICAL RELEVANCE

Snake bites are a critical health issue in many parts of the world particularly in Asian countries lacking efficient health facilities in rural areas. Cobra is the most common snake type in Asia and is responsible for a large number of mortalities particularly in rural areas. Plants are usually considered the most effective and easy-to-approach treatment for snake bites in rural areas of various countries. Vitex negundo L. is an important medicinal plant traditionally used to treat snake bite envenomation in many countries of Asia.

AIM OF THE STUDY

From literature survey of plants traditionally used in the treatment of snake bites in Asian countries including India, Pakistan and Sri Lanka, roots of V. negundo were selected for the present study. Anti-snake venom potential of its roots was assessed through various in vitro assays targeting the phospholipase A2 enzyme.

MATERIALS AND METHODS

V. negundo roots were sequentially extracted in different organic solvents to get fractions and in methanol to get total extract. The extracts were evaluated for phospholipase A2 (PLA2) inhibitory potential through inhibition of venom-induced hemolysis, ADP-induced platelet aggregation, PLA2-induced fatty acid hydrolysis and anticoagulant effect of cobra venom. Antioxidant power was determined using DPPH and superoxide radical scavenging assays. GC-MS and HPLC analysis was performed for the total methanol extract.

RESULTS

Strong PLA2 inhibitory effect was observed for all the extracts. The ethyl acetate, acetone and methanol fractions significantly inhibited toxic effects of cobra venom under in vitro conditions. Radical scavenging potential of these fractions was also significantly high as compared to non-polar fractions in both DPPH and superoxide scavenging assays. Phytochemical analysis indicated high phenolic and flavonoid contents in these fractions. GC-MS and HPLC analysis of total methanol extract confirmed the presence of bis(2-ethylhexyl) phthalate, phenol, o-Guaiacol, palmitic acid-methyl ester, methyl stearate, quercetin and kaempferol in the plant.

CONCLUSION

The study concluded that the roots of V. negundo, particularly their polar extracts, have strong PLA2 inhibitory effect against cobra venom confirming their traditional use to manage snake bites. The roots of this plant can be further studied for isolation of plant-based antisera.

Evaluation of the anti-inflammatory and antioxidant properties and isolation and characterization of a new bioactive compound, 3,4,9-trimethyl-7-propyldecanoic acid from Vitex negundo

ETHNOPHARMACOLOGICAL RELEVANCE

Herbal medicines derived from plant extraction are affordable, more therapeutically effective, and have fewer side effects than contemporary medications. Vitex negundo L. (V. negundo). is a medicinal shrub, which contains numerous phytoconstituents. In ancient medicinal practices, V. negundo was primarily prescribed as an analgesic and anti-inflammatory drug.

AIM OF THE STUDY

This study aims to evaluate the anti-inflammatory and antioxidant characteristics of crude extracts from V. negundo leaves, including those derived from petroleum ether (P), methanol (M), and aqueous (A) solvents. Additionally, the research seeks to identify the specific bioactive compounds responsible for these observed properties.

MATERIALS AND METHODS

The nitric oxide scavenging study was performed to evaluate the V. negundo crude extract's ability to function as a nitric oxide scavenger. Protein denaturation and proteinase inhibition experiments were employed to study the ability of extracts to suppress proteolysis and inhibit the enzymes that cause tissue injury. The membrane-stabilizing potency of plant extracts were examined through the process of heat-induced hemolysis. The ability of the extracts to neutralize free radicals showed a dose-dependent response, and the aqueous extract exhibited substantially higher activity in both FRAP and DPPH. The GC-MS analysis of V. negundo extracts revealed a vast array of pharmacologically active metabolites. Based on this Bioassay-guided fractionation approach, the optimal extract was selected for the potent molecule isolation and characterization.

RESULTS

The findings demonstrated that the aqueous extract of V. negundo exhibited markedly superior radical scavenging and anti-inflammatory capabilities compared to the other two extracts. Furthermore, a new molecule, 3,4,9-trimethyl-7-propyldecanoic acid was isolated from this extract, and its chemical structure was successfully determined.

CONCLUSION

This study revealed that the aqueous extract of V. negundo demonstrated notably stronger in vitro anti-inflammatory and antioxidant properties in comparison to the methanol and petroleum ether extracts. The identified active compound, 3,4,9-trimethyl-7-propyldecanoic acid is likely responsible for the extract's free radical scavenging and anti-inflammatory effects. Furthermore, conducting both in vitro and in vivo studies is crucial to substantiate the potential of this active constituent for the development of an anti-inflammatory drug derived from V. negundo.

Potential efficacy and mechanism of eight mild-natured and bitter-flavored TCMs based on gut microbiota: A review

The mild-natured and bitter-flavored traditional Chinese medicines (MB-TCMs) are an important class of TCMs that have been widely used in clinical practice and recognized as safe long-term treatments for chronic diseases. However, as an important class of TCMs, the panorama of pharmacological effects and the mechanisms of MB-TCMs have not been systemically reviewed. Compelling studies have shown that gut microbiota can mediate the therapeutic activity of TCMs and help to elucidate the core principles of TCM medicinal theory. In this systematic review, we found that MB-TCMs commonly participated in the modulation of metabolic syndrome, intestinal inflammation, nervous system disease and cardiovascular system disease in association with promoting the growth of beneficial bacteria Bacteroides, Akkermansia, Lactobacillus, Bifidobacterium, Roseburia as well as inhibiting the proliferation of harmful bacteria Helicobacter, Enterococcus, Desulfovibrio and Escherichia-Shigella. These alterations, correspondingly, enhance the generation of protective metabolites, mainly including short-chain fatty acids (SCFAs), bile acid (BAs), 5-hydroxytryptamine (5-HT), indole and gamma-aminobutyric acid (GABA), and inhibit the generation of harmful metabolites, such as proinflammatory factors trimethylamine oxide (TAMO) and lipopolysaccharide (LPS), to further exert multiplicative effects for the maintenance of human health through several different signaling pathways. Altogether, this present review has attempted to comprehensively summarize the relationship between MB-TCMs and gut microbiota by establishing the TCMs-gut microbiota-metabolite-signaling pathway-diseases axis, which may provide new insight into the study of TCM medicinal theories and their clinical applications.

Cardioprotective Effects of Vitex negundo: A Review of Bioactive Extracts and Compounds

There has been accumulating interest in the application of medicinal plants as alternative medicine to treat various diseases and/or to develop modern medicines. Vitex negundo is one of such medicinal plants that has been of interest to many researchers and has been of use in traditional medicine. V. negundo is found in Sri Lanka, Madagascar, Malaysia, India, China, The Philippines and East Africa. Therapeutic properties of V. negundo have previously been reviewed. Different parts, preparations and bioactive components of V. negundo possess potential protective and therapeutic effects against cardiovascular disease and related conditions as demonstrated in previous studies. We review the present state of scientific knowledge on the potential use of V. negundo and some of its bioactive components in protecting against cardiovascular diseases and related pathologies. Previous studies in animal and non-animal experimental models, although limited in number and vary in design, seem to support the cardioprotective effect of V. negundo and some of its active components. However, there is need for further preclinical and clinical studies to validate the use of V. negundo and its active constituents in protection and treatment of cardiovascular diseases. Additionally, since only a few V. negundo compounds have been evaluated, specific cardioprotective effects or mechanisms and possible side effects of other V. negundo compounds need to be extensively evaluated.

Taxonomic and Metabolite Diversities of Moss-Associated Actinobacteria from Thailand

Actinobacteria are a group of ecologically important bacteria capable of producing diverse bioactive compounds. However, much remains unknown about the taxonomic and metabolic diversities of actinobacteria from many geographic regions and ecological niches. In this study, we report the isolation of actinobacteria from moss and moss-associated rhizosphere soils in Thailand. Among the 89 isolates analyzed for their bioactivities, 86 strains produced indole-3-acetic acid (IAA, ranging from 0.04 to 59.12 mg/L); 42 strains produced hydroxamate type of siderophore; 35 strains produced catecholate type of siderophore; 21 strains solubilized tricalcium phosphate; and many strains exhibited antagonistic activities against one to several of the seven selected plant, animal, and human pathogens. Overall, actinobacteria from the rhizosphere soil of mosses showed greater abilities to produce IAA and siderophores and to solubilize tricalcium phosphate than those from mosses. Among these 89 isolates, 37 were analyzed for their 16S rRNA gene sequences, which revealed their diverse phylogenetic distributions among seven genera, Streptomyces, Micromonospora, Nocardia, Actinoplanes, Saccharothrix, Streptosporangium, and Cryptosporangium. Furthermore, gas chromatography-mass spectrometry analyses of ethyl acetate crude extracts of three selected isolates with inhibitory effects against a methicillin-resistant Staphylococcus aureus strain revealed diverse metabolites with known antimicrobial activities. Together, our results demonstrate that actinobacteria from mosses in Thailand are taxonomically diverse and capable of producing a range of metabolites with plant-growth-promoting and microbial pathogen-inhibiting potentials.

Cliona varians-Derived Actinomycetes as Bioresources of Photoprotection-Related Bioactive End-Products

Sunscreen and sunblock are crucial skincare products to prevent photoaging and photocarcinogenesis through the addition of chemical filters to absorb or block ultraviolet (UV) radiation. However, several sunscreen and sunblock ingredients, mostly UV filters, have been associated with human and environmental safety concerns. Therefore, the exploration and discovery of promising novel sources of efficient and safer compounds with photoprotection-related activities are currently required. Marine invertebrates, particularly their associated microbiota, are promising providers of specialized metabolites with valuable biotechnological applications. Nevertheless, despite Actinobacteria members being a well-known source of bioactive metabolites, their photoprotective potential has been poorly explored so far. Hence, a set of methanolic extracts obtained from Cliona varians-derived actinomycetes was screened regarding their antioxidant and UV-absorbing capacities (i.e., photoprotection-related activities). The active extract-producing strains were identified and classified within genera Streptomyces, Micrococcus, Gordonia, and Promicromonospora. This is the first report of the isolation of these microorganisms from C. varians (an ecologically important Caribbean coral reef-boring sponge). The in vitro cytotoxicity on dermal fibroblasts of oxybenzone and the selected active extracts revealed that oxybenzone exerted a cytotoxic effect, whereas no cytotoxic effect of test extracts was observed. Accordingly, the most active (SPFi > 5, radical scavenging > 50%) and nontoxic (cell viability > 75%) extracts were obtained from Streptomyces strains. Finally, LC-MS-based characterization suggested a broad chemical space within the test strains and agreed with the reported streptomycetes' chemodiversity. The respective metabolite profiling exposed a strain-specific metabolite occurrence, leading to the recognition of potential hits. These findings suggest that marine Streptomyces produce photoprotectants ought to be further explored in skincare applications.

Discovery of a "Cocktail" of Potential SARS-COV-2 Main Protease Inhibitors through Virtual Screening of Known Chemical Components of Vitex negundo L. ("Lagundi")

AIM

The prevailing crisis caused by the COVID-19 pandemic demands the development of effective therapeutic agents that can be implemented with minimal to zero adverse effects.

BACKGROUND

Vitex negundo L. (VNL) is a medicinal plant with reported efficacy against respiratory diseases and some of the COVID-19 symptoms. Funded by the Department of Science and Technology (DOST), the University of the Philippines - Philippine General Hospital (UP-PGH) is currently conducting clinical trials of VNL and other medicinal plants as adjuvant therapeutic agents against mild cases of COVID-19. The basis for the clinical trials is primarily the pharmacological efficacy of the medicinal plants against respiratory disorders and associated COVID-19 symptoms.

OBJECTIVE

This study assessed the in silico potential of VNL components against SARS-CoV-2 main protease (Mpro), an enzyme that plays an important role in COVID-19, the disease caused by the SARS-CoV-2.

METHOD

Phytochemical mining of VNL components from the literature was conducted. A database consisting of 250 known compounds from different parts of VNL was created and screened against SARS-CoV-2 Mpro using the PyRx virtual screening tool. The most promising components were further subjected to in silico absorption, distribution, metabolism, excretion, and toxicity (ADMET) analyses using the SwissADME web server and Toxtree software.

RESULTS

Virtual screening revealed that 102 VNL components in the database had comparable to or better binding affinities toward SARS-COV-2 Mpro than known chemical inhibitors (e.g. N3 and carmofur). It was determined that the active site of SARS-CoV-2 Mpro receptor consists of multiple H-donor and acceptor sites; hence, the most stable receptor-ligand complexes are generally formed by VNL ligands that establish effective H-bonding with the SARS-CoV-2 Mpro. The promising components, representing a "cocktail" of potential inhibitors also revealed interesting ADMET properties.

CONCLUSION

This in silico study identified VNL as a potential single source of a cocktail of SARS-CoV-2 Mpro inhibitors and a promising adjuvant therapeutic agent against COVID-19 or its symptoms. Furthermore, the study offers a rationale on phytochemical mining from medicinal plants as a means that can be implemented in the early stage of a drug discovery and development program.

Contemporary advances of cyclic molecules proposed for inflammation

This review stretches insight about the advancement (2011-2021) of synthesized non-heterocyclic, heterocyclic and natural occurring cyclic molecules for inflammation. While inflammation is very significant in the abolition of pathogens and other causes of soreness, a protracted inflammatory procedure takes to outcomes in chronic disease that might finally affect in organ failure or damage. Thus, restraining the provocative process by the use of anti-inflammatory agents is chief in controlling this damage. It also reveals other pursuit along with their anti-inflammatory activity. Molecular docking studies represent most suitable PDB (Protein Data Bank) ID for the synthesized heterocyclic molecules with their selective inhibitor. It discusses the findings presented in recent research papers and provides understanding to researchers intended for the growth of newer combinations/molecules having littler side things.

Assessing Cu impacts on freshwater diatoms: biochemical and metabolomic responses of Tabellaria flocculosa (Roth) Kützing

Metals are a recognised threat to aquatic organisms but the impact of metals such as copper (Cu) on benthic freshwater diatoms is poorly understood, even if diatoms are commonly used as water quality indicators. Our study aimed to elucidate the cellular targets of Cu toxicity and the mechanisms cells resort to counteract toxicity and to increase tolerance to Cu. A concerted approach analysing the biochemical, physiological and metabolome alterations in diatom cells was conducted by exposing the freshwater diatom Tabellaria flocculosa to 0, 0.3, 6 and 10μgCu/L. Cu was already toxic to T. flocculosa at concentrations common in environments and which are not usually considered to be contaminated (0.3μgCu/L). Under Cu impact, the metabolome of T. flocculosa changed significantly, especially at high concentrations (6 and 10μgCu/L). Cu toxicity was counteracted by increasing extracellular immobilization (EPS, frustulins), antioxidant (SOD, CAT) and detoxifying (GSTs) enzymes activity and low molecular weight antioxidants (GSH). These mechanisms were fuelled by higher energy production (increased ETS activity). At the highest Cu concentration (10μg/L), these processes were specially enhanced in an attempt to restrain the oxidative stress generated by high intracellular Cu concentrations. However, these mechanisms were not able to fully protect cells, and damage in membranes and proteins increased. Moreover, the decrease of hydroxylamine and unsaturated fatty acids and the increase of saturated fatty acids, 2-palmitoylglycerol, glycerol and diterpenoid compounds should be tested as new specific markers of Cu toxicity in future studies. This information can support the prediction of diatom behaviour in different Cu contamination levels, including highly impacted environments, such as mining scenarios, and may assist in environmental risk assessment policies and restoration programs.

Anti-inflammatory activity of dimethyl octenol and oleanene tetrol isolated from Trianthema decandra L

Dimethyl octenol from chloroform extract and oleanene tetrol from water extract of Trianthema decandra (TD) were isolated and characterized by using HPLC, UV, FT-IR, NMR, LC-MS and CHNS, their structure were elucidated from their respective spectral data. The anti-inflammatory activity of chloroform extract, water extract, dimethyl octenol and oleanene tetrol of T. decandra were studied and underlying cellular and molecular mechanisms of action were investigated in vitro and in vivo using macrophage-like cell line (RAW264.7 cells) and type II collagen induced arthritis mice models. Nitric oxide production was inhibited and TNF-α secretion was supressed in stimulated RAW cells treated with the chloroform extract and dimethyl octenol of T. decandra. Further, the chloroform and water extract, dimethyl octenol and oleanene tetrol inhibited protein denaturation and stabilized HRBC membranes in vitro. Reduction in inflammation as a measure of paw diameter was recorded in all the treated animals when compared to control animals. Catalase, peroxidase and glutathione peroxidase levels significantly increased in the joint tissue of treated groups. The possible mechanism of action of these compounds was studied using in silico molecular docking methods with phospholipase A₂ (PLA₂), cycloxygenase-1 (COX-1) and cycloxygenase-2 (COX-2) as targets. Among the three target proteins, the inhibition of the inflammatory protein PLA₂ and COX-2 towards dimethyl octenol and oleanene tetrol respectively. Our results contribute towards confirmation of the traditional use of TD and its compounds for the therapy of rheumatoid arthritis and other inflammatory joint disorders.

The genus Vitex: A review

The review includes 161 references on the genus Vitex, and comprises ethnopharmacology, morphology and microscopy, phytoconstituents, pharmacological reports, clinical studies, and toxicology of the prominent species of Vitex. Essential oils, flavonoids, iridoid glycosides, diterpenoides and ligans constitute major classes of phytoconstituents of the genus. A few species of this genus have medicinal value, among these, leaves and fruits of V. agnus-castus Linn. (Verbenaceae) has been traditionally used in treatment of women complaints. V. agnus-castus has also been included in herbal remedies, which are in clinical use to regulate the menstrual cycle, reduce premenstrual symptom tension and anxiety, treat some menopausal symptoms as well as to treat hormonally induced acne. Despite a long tradition of use of some species, the genus has not been explored properly. In the concluding part, the future scope of Vitex species has been emphasized with a view to establish their multifarious biological activities and mode of action.

Antifungal activity of phenyl derivative of pyranocoumarin from Psoralea corylifolia L. seeds by inhibition of acetylation activity of trichothecene 3-o-acetyltransferase (Tri101)

Antifungal activity of petroleum ether extract of Psoralea corylifolia L. seed, tested against Fusarium sp. namely, Fusarium oxysporum, Fusarium moniliforme, and Fusarium graminearum, was evaluated by agar well diffusion assay. The chromatographic fractionation of the extract yielded a new phenyl derivative of pyranocoumarin (PDP). The structure of the PDP was confirmed using spectroscopic characterization (GC-MS, IR, and NMR), and a molecular mass of m/z 414 [M-2H]⁺ with molecular formula C₂₇H₂₈O₄ was obtained. The PDP had a potent antifungal activity with a minimum inhibitory concentration of 1 mg/mL against Fusarium sp. Molecular docking using Grid-Based Ligand Docking with Energetics (GLIDE, Schrodinger) was carried out with the Tri101, trichothecene 3-O-acetyltransferase, as target protein to propose a mechanism for the antifungal activity. The ligand PDP showed bifurcated hydrogen bond interaction with active site residues at TYR 413 and a single hydrogen bond interaction at ARG 402 with a docking score −7.19 and glide energy of −45.78 kcal/mol. This indicated a strong binding of the ligand with the trichothecene 3-O-acetyltransferase, preventing as a result the acetylation of the trichothecene mycotoxin and destruction of the “self-defense mechanism” of the Fusarium sp.