Antiplatelet aggregation and platelet activating factor (PAF) receptor antagonistic activities of the essential oils of five Goniothalamus species

Chemical Compositions and Antimicrobial and Mosquito Larvicidal Activities of the Leaf Essential Oils of Goniothalamus yunnanensis W.T.Wang and G. touranensis Ast: Experimental and In Silico Approaches

The current research describes a phytochemical analysis and antimicrobial activity of essential oils extracted from the leaves of two Vietnamese Annonaceae species Goniothalamus yunnanensis W.T.Wang and G. touranensis Ast. By the GC-FID/MS (gas chromatography-flame ionization detection/mass spectrometry) analyses, sesquiterpene hydrocarbons accounted for the highest percentage of 68.22 % in G. yunnanensis leaf essential oil with bicyclogermacrene (31.03 %) and (E)-caryophyllene (21.12 %) being the main compounds. G. touranensis leaf essential oil was dominated by monoterpene hydrocarbons (57.08 %) with p-cymene (19.95 %) and α-pinene (16.82 %) being the major compounds. By the microdilution broth susceptibility assay, two oil samples showed strong antibacterial effects on the Gram-positive bacteria Enterococcus faecalis ATCC51299, Staphylococcus aureus ATCC29213, and Bacillus cereus ATCC11778 with the MIC values of 16-64 μg/mL. They also inhibited the growth of the yeast Candida albicans ATCC 60193 with the same MIC value of 128 μg/mL. From the vector-based intervention approach, both oil samples showed strong mosquito larvicidal activity against four-instar larvae of Aedes aegypti and Ae. albopictus with the 24 h LC50 values of 16.75-27.60 μg/mL and 24 h LC90 values of 24.31-46.18 μg/mL. Docking results indicated that bicyclogermacrene and p-cymene exhibited the highest ΔG (binding affinity) values of -8.208 and -6.799 kcal/mol with the olfactory binding proteins (OBPs) of Ae. aegypti and Ae. albopictus, respectively.

The Anti-Inflammatory and Antithrombotic Properties of Bioactives from Orange, Sanguine and Clementine Juices and from Their Remaining By-Products

The anti-oxidant properties of vitamin C and of phenolic compounds of citrus fruits are well established. However, the evaluation of the anti-inflammatory and antithrombotic potential of both vitamin C and of the more amphiphilic and lipophilic components of citrus fruits needs further attention. In this study, the anti-inflammatory and antithrombotic properties of vitamin C and of freshly squeezed juices and their lipid bioactives from the Navalina and Sanguine orange varieties and the Clementine variety of mandarins, as well as from their remaining by-products, were evaluated against the inflammatory and thrombotic pathways of the platelet-activating factor (PAF) and thrombin in platelets, as well as against PAF-biosynthesis in leukocytes. The non-oxidized juices of these citrus fruits and a vitamin C supplement showed stronger anti-PAF and antithrombin effects than their oxidized versions through their general anti-oxidant effect in platelets. The total lipids (TLs) and the HPLC-derived fractions of phenolic compounds and of polar lipid bioactives from both juices and their peels’ by-products showed a more specific stronger inhibitory effect against the inflammatory and thrombotic pathways of PAF and thrombin in platelets, while these bioactives strongly inhibited also the specific enzyme activities of the main biosynthetic enzymes of PAF in leukocytes. The stronger bioactivity of the dietary bioactives found in the juices of these citrus fruits against specific biochemical pathways of inflammation and thrombosis seems to act with synergy with the anti-oxidant potential of their vitamin C content, which further supports the notion that these juices are functional foods with anti-inflammatory protective health benefits. In addition, the presence of these dietary bioactive phenolic compounds and polar lipid bioactives in the remaining peels’ wastes further enhance the valorization of such food industry by-products as potential sources of anti-inflammatory bioactives to be used as ingredients for novel functional products.

Potential clinical applications of phytopharmaceuticals for the in-patient management of coagulopathies in COVID-19

Thrombotic complications occur in many cardiovascular pathologies and have been demonstrated in COVID‐19. The currently used antithrombotic drugs are not free of adverse reactions, and COVID‐19 patients in particular, when treated with a therapeutic dose of an anticoagulant do not receive mortality benefits. The clinical management of COVID‐19 is one of the most difficult tasks for clinicians, and the search for safe, potent, and effective antithrombotic drugs may benefit from exploring naturally bioactive molecules from plant sources. This review describes recent advances in understanding the antithrombotic potential of herbal drug prototypes and points to their future clinical use as potent antithrombotic drugs. Although natural products are perceived to be safe, their clinical and therapeutic applications are not always apparent or accepted. More in‐depth studies are necessary to demonstrate the clinical usefulness of plant‐derived, bioactive compounds. In addition, holistic approaches in systematic investigations and the identification of antithrombotic mechanisms of the herbal bioactive molecule(s) need to be conducted in pre‐clinical studies. Moreover, rigorous studies are needed to compare the potency of herbal drugs to that of competitor chemical antithrombotic drugs, and to examine their interactions with Western antithrombotic medicines. We have also proposed a road map to improve the commercialization of phytopharmaceuticals.

Coagulation System Activation for Targeting of COVID-19: Insights into Anticoagulants, Vaccine-Loaded Nanoparticles, and Hypercoagulability in COVID-19 Vaccines

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as COVID-19, is currently developing into a rapidly disseminating and an overwhelming worldwide pandemic. In severe COVID-19 cases, hypercoagulability and inflammation are two crucial complications responsible for poor prognosis and mortality. In addition, coagulation system activation and inflammation overlap and produce life-threatening complications, including coagulopathy and cytokine storm, which are associated with overproduction of cytokines and activation of the immune system; they might be a lead cause of organ damage. However, patients with severe COVID-19 who received anticoagulant therapy had lower mortality, especially with elevated D-dimer or fibrin degradation products (FDP). In this regard, the discovery of natural products with anticoagulant potential may help mitigate the numerous side effects of the available synthetic drugs. This review sheds light on blood coagulation and its impact on the complication associated with COVID-19. Furthermore, the sources of natural anticoagulants, the role of nanoparticle formulation in this outbreak, and the prevalence of thrombosis with thrombocytopenia syndrome (TTS) after COVID-19 vaccines are also reviewed. These combined data provide many research ideas related to the possibility of using these anticoagulant agents as a treatment to relieve acute symptoms of COVID-19 infection.

Chemical characterization of Goniothalamus macrophyllus and Goniothalamus malayanus leaves' essential oils

This study was aimed to investigate the chemical compositions of the essential oils from Goniothalamus macrophyllus and Goniothalamus malayanus growing in Malaysia. The essential oils were obtained by hydrodistillation and fully characterized by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Analyses of the essential oils from G. macrophyllus and G. malayanus resulted in 93.6 and 95.4% of the total oils, respectively. The major components of G. macrophyllus oil were germacrene D (25.1%), bicyclogermacrene (11.6%), α-copaene (6.9%) and δ-cadinene (6.4%), whereas in G. malayanus oil bicyclogermacrene (43.9%), germacrene D (21.1%) and β-elemene (8.4%) were the most abundant components.

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.

Natural Products for Antithrombosis

Thrombosis is considered to be closely related to several diseases such as atherosclerosis, ischemic heart disease and stroke, as well as rheumatoid arthritis, hyperuricemia, and various inflammatory conditions. More and more studies have been focused on understanding the mechanism of molecular and cellular basis of thrombus formation as well as preventing thrombosis for the treatment of thrombotic diseases. In reality, there is considerable interest in the role of natural products and their bioactive components in the prevention and treatment of thrombosis related disorders. This paper briefly describes the mechanisms of thrombus formation on three aspects, including coagulation system, platelet activation, and aggregation, and change of blood flow conditions. Furthermore, the natural products for antithrombosis by anticoagulation, antiplatelet aggregation, and fibrinolysis were summarized, respectively.

A comparative analysis of essential oils of Goniothalamus macrocalyx Ban., Goniothalamus albiflorus Ban. and Goniothalamus tamirensis Pierre ex Fin. & Gagnep. from Vietnam

Essential oils hydrodistilled from the leaves and stem barks of Goniothalamus macrocalyx Ban., Goniothalamus albiflorus Ban. and Goniothalamus tamirensis Pierre ex Fin. & Gagnep. growing in Vietnam were analysed by gas chromatography (GC) and GC-coupled with mass spectrometry. α-Pinene (1.7-50.0%), β-pinene (tr-6.8%), β-myrcene (tr-1.5%), (E)-β-ocimene (tr-4.6%), β-caryophyllene (9.9-12.8%), aromadendrene (0.2-6.0%), α-humulene (1.7-6.9%), α-cadinol (1.2-14.5%), δ-cadinene (0.1-10.3%) and n-hexadecanoic acid (0.2-1.9%) were common to the oil samples. α-Pinene (50.0%) was the most abundant single constituent of the leaf oil of G. macrocalyx, whereas the major compounds of the stem were α-cadinol (14.5%), β-caryophyllene (10.3%) and octadecanoic acid (8.2%). Benzoic acid (18.4%), β-caryophyllene (12.4%) and α-pinene (10.3%) were present in the leaf of G. albiflorus, whereas limonene (21.2%), β-caryophyllene (12.8%) and α-phellandrene (9.3%) were identified in the stem. The leaf oil of G. tamirensis was characterised by abundance of α-pinene (33.4%), viridiflorol (18.5%) and β-caryophyllene (12.4%), whereas γ-gurjunene (11.2%), β-caryophyllene (10.9%) and δ-cadinene (10.3%) predominates in the stem oil.

Plant extracts inhibit ADP-induced platelet activation in humans: their potential therapeutic role as ADP antagonists

Adenosine diphosphate (ADP) plays a pivotal role in platelet activation. Platelet hyperactivity is associated with vascular disease and also has a key role in haemostasis and thrombosis. ADP activates platelets through three purinoceptor subtypes, the G(q)-coupled P2Y(1) receptor, G(i)-coupled P2Y(12) receptor and P2X(1) ligand-gated cation channel. Platelet ADP purinergic receptors are therefore suitable targets for antiplatelet drugs. Thienopyridines such as clopidogrel and ticlopidine, as well as other ADP receptor antagonists like prasugrel, ticagrelor, cangrelor and elinogrel have demonstrated clinical benefits via the inhibition of the selective purinergic ADP receptor, P2Y(12). However, they still have limitations in their mode of action and efficacy, like increased risk of bleeding. Thus, the ongoing pursuit to develop newer and more effective antiplatelet agents continues. There is a growing interest in the purinergic antiplatelet properties exhibited by plant extracts. This article considers the following: pomolic acid isolated from Licania pittieri, brazilin isolated from the heartwood of Caesalpinia sappan L, phylligenin isolated from the twigs of Muraltia vulpina, bark oil of Gonystylus velutinus, seed and bark extracts from Aesculus hippocastanum L. and red wine phenolics and catechins isolated from green tea. Moreover, the method used to investigate platelet purinergic receptors should be considered, since using a more sensitive, high-resolution platelet sizer can sometimes detect platelet variations when the light transmission method was not able to do so. The exact mechanisms by which these plant extracts work need further investigation. They all however inhibit ADP-induced activation in human platelets. This could explain, at least in part, the protective effect of plant extracts as antiplatelet agents.

Platelet-activating factor (PAF)-antagonists of natural origin

Presently herbal medicines are being used by about 80% of the world population for primary health care as they stood the test of time for their safety, efficacy, cultural acceptability and lesser side effects. The discovery of platelet activating factor antagonists (PAF antagonists) during these decades are going on with different framework, but the researchers led their efficiency in studying in vitro test models. Since it is assumed that PAF play a central role in etiology of many diseases in humans such as asthma, neuronal damage, migraine, cardiac diseases, inflammatory, headache etc. Present days instinctively occurring PAF antagonist exists as a specific grade of therapeutic agents for the humans against these and different diseases either laid hold of immunological or non-immunological types. Ginkgolide, cedrol and many other natural PAF antagonists such as andrographolide, α-bulnesene, cinchonine, piperine, kadsurenone, different Piper species' natural products and marine origin plants extracts or even crude drugs having PAF antagonist properties are being used currently against different inflammatory pathologies. This review is an attempt to summarize the data on PAF and action of natural PAF antagonists on it, which were evaluated by in vivo and in vitro assays.