Anti-inflammatory constituents from Psychotria prainii H. Lév

A Comprehensive Description of the Anatomy and Histochemistry of Psychotria capillacea (Müll. Arg.) Standl. and an Investigation into Its Anti-Inflammatory Effects in Mice and Role in Scopolamine-Induced Memory Impairment

Species of the genus Psychotria are used in popular medicine for pain, inflammatory symptoms, and mental disorders. Psychotria capillacea (Müll. Arg.) Standl. (Rubiaceae) is commonly known as coffee and some scientific studies have demonstrated its therapeutic potential. The goal of this study was to investigate the anti-inflammatory and neuroprotective effects, and acetylcholinesterase (AChE) inhibitory activity of a methanolic extract obtained from leaves of P. capillacea (MEPC), as well as the micromorphology and histochemistry of the leaves and stems of this plant. In addition, the MEPC was analyzed by UHPLC-MS/MS and the alkaloidal fraction (AF) obtained from the MEPC was tested in a mouse model of inflammation. MEPC contained three indole alkaloids, one sesquiterpene (megastigmane-type) and two terpene lactones. MEPC (3, 30 and 100 mg/kg) and AF (3 and 30 mg/kg) were evaluated in inflammation models and significantly inhibited edema at 2 h and 4 h, mechanical hyperalgesia after 4 h and the response to cold 3 h and 4 h after carrageenan injection. Scopolamine significantly increased the escape latency, and reduced the swimming time and number of crossings in the target quadrant and distance, while MEPC (3, 30 and 100 mg/kg), due to its neuroprotective actions, reversed these effects. AChE activity was significantly decreased in the cerebral cortex (52 ± 3%) and hippocampus (60 ± 3%), after MEPC administration. Moreover, micromorphological and histochemical information was presented, to aid in species identification and quality control of P. capillacea. The results of this study demonstrated that P. capillacea is an anti-inflammatory and antihyperalgesic agent that can treat acute disease and enhance memory functions in mouse models.

Therapeutic potentials of iridoids derived from Rubiaceae against in vitro and in vivo inflammation: A scoping review

Acute inflammation may develop into chronic, life-threatening inflammation-related diseases if left untreated or if there are persistent triggering factors. Cancer, diabetes mellitus, stroke, cardiovascular diseases, and neurodegenerative disorders are some of the inflammation-related diseases affecting millions of people worldwide. Despite that, conventional medical therapy such as non-steroidal anti-inflammatory drugs (NSAIDs) is associated with serious adverse effects; hence, there is an urgent need for a newer and safer therapeutic alternative from natural sources. Iridoids are naturally occurring heterocyclic monoterpenoids commonly found in Rubiaceae plants. Plant extracts from the Rubiaceae family were demonstrated to have medicinal benefits against neurodegeneration, inflammation, oxidative stress, hyperglycaemia, and cancer. However, the therapeutic effects of natural iridoids derived from Rubiaceae as well as their prospective impacts on inflammation in vitro and in vivo have not been thoroughly explored. The databases of PubMed, Scopus, and Web of Science were searched for pertinent articles in accordance with PRISMA-ScR guidelines. A total of 31 pertinent articles from in vitro and in vivo studies on the anti-inflammatory potentials of iridoids from Rubiaceae were identified. According to current research, genipin, geniposide, and monotropein are the most researched iridoids from Rubiaceae that reduce inflammation. These iridoids primarily act by attenuating inflammatory cytokines and mediators via inhibition of the NF-κB signalling pathway in various disease models. A comprehensive overview of the current research on the anti-inflammatory properties of iridoids from the Rubiaceae family is presented in this review, highlighting the characteristics of the experimental models used as well as the mechanisms of action of these iridoids. To develop an alternative therapeutic agent from iridoids, more studies are needed to elucidate the effects and mechanism of action of iridoids in a wide variety of experimental models as well as in clinical studies pertaining to inflammation-related diseases.

Exploration of essential oil from Psychotria poeppigiana as an anti-hyperalgesic and anti-acetylcholinesterase agent: Chemical composition, biological activity and molecular docking

ETHNOPHARMACOLOGICAL RELEVANCE

Leaves from Psychotria poeppigiana Müll. Arg. (accepted as Palicourea tomentosa (Aubl.) Borhidi), Rubiaceae, has traditionally been used in medicine for treatments of inflammation and pain; Synonymously, Cephaelis elata for the treatment of dementia; However, few scientific studies have been evidence demonstrating this activity.

AIM OF THE STUDY

The aim of this study was to investigate the chemical composition of P. poeppigiana essential oil obtained from leaves (EOPP) and its antioxidant, anti-inflammatory and acetylcholinesterase (AChE) activities. Molecular docking simulations were carried out with the main constituents.

MATERIALS AND METHODS

EOPP (hydrodistillation) was analysed by gas chromatography-mass spectrometry (GC-MS). The fractionation of EOPP afforded germacrene D and bicyclogermacrene. The antioxidant activity of EOPP was determined by MDA assay. The inflammatory parameters were evaluated using CFA model (with paw edema, mechanical, thermal hyperalgesia, MPO and NAG) in EOPP (30, 100 and 300 mg/kg), germacrene D and bicyclogermacrene (30 mg/kg). The AChE inhibition was evaluated in rat brain structures and molecular docking simulations were carried out using Autodock v.4.3.2.

RESULTS

GC-MS analysis identified 19 compounds, and the major compounds were germacrene D (29.38%) and bicyclogermacrene (25.21%). EOPP exhibited high antioxidant capacity (IC₅₀ = 12.78 ± 1.36 μg/mL). All the tested doses of EOPP and both major constituents significantly inhibited cold and mechanical hyperalgesia and significantly blocked the increase in MPO activity 24 h after the CFA injection. There was significant AChE inhibition by EOPP and germacrene D in the cerebral cortex and hippocampus (>50%). Enzyme-ligand molecular modelling showed that the major constituents of EOPP interacted differently with AChE.

CONCLUSIONS

The chemical compounds of the essential oil from the leaves of P. poeppigiana is based mainly on terpenes, the sesquiterpenes germacrene D (29.38%) and bicyclogermacrene (25.21%) being the major compounds. EOPP presented antioxidant, anti-inflammatory and anti-acetylcholinesterase (AChE) activities. Besides, enzyme-ligand molecular modelling showed the EOPP may act as an anti-hyperalgesic and AChE inhibitory agent. Taken together, these results might be in accordance with if folk use for pain- and inflammation-related symptoms.

Study on constituents of Scutellaria nepetifolia as a potent source of phytochemicals with NO inhibitory effect

Based on the long history of Scutellaria plants in east traditional medicines, several species of Scutellaria showed promising antioxidant, anti-inflammation and neuroprotection effects in pharmacological researches. Using bioassay-guided fractionation of various extract of Scutellaria nepetifolia, an endemic species that grows widely in Iran, based on on nitric oxide (NO) inhibitory activity against H₂O₂ induced NO production in PC12 pheochromocytoma cells led to the isolation of two iridoid compounds namely, as 6β-hydroxy 8-epiboshnaloside (1) and 1,5,9-epideoxy loganic acid (2) and Verbascoside (3). Finally, the interaction of isolated compounds with inducible nitric oxide synthase (iNOS) protein was simulated by molecular docking study. It is the first report of these two iridoid glycosides from Scutellaria spp. All three isolated compounds showed strong interaction with iNOS enzyme in molecular docking simulations. So, they possibly contributed in the NO inhibitory effect of S. nepetifolia.

Antimycobacterial and Nitric Oxide Production Inhibitory Activities of Triterpenes and Alkaloids from Psychotria nuda (Cham. & Schltdl.) Wawra

A phytochemical study of leaves and twigs of Psychotria nuda resulted in 19 compounds, including five indole alkaloids, N,N,N-trimethyltryptamine, lyaloside, strictosamide, strictosidine, and 5α-carboxystrictosidine; two flavonolignans, cinchonain Ia and cinchonain Ib; an iridoid, roseoside; a sugar, lawsofructose; a coumarin, scopoletin; a diterpene, phytol; three triterpenes, pomolic acid, spinosic acid, and rotungenic acid; and five steroids, sitosterol, stigmasterol, campesterol, β-sitosterol-3-O-β-d-glucoside, and β-stigmasterol-3-O-β-d-glucoside. Some compounds were evaluated for their in vitro activity against Mycobacterium tuberculosis and their ability to inhibit NO production by macrophages stimulated by lipopolysaccharide (LPS). The compounds pomolic acid, spinosic acid, strictosidine, and 5α-carboxystrictosidine displayed antimycobacterial activity with minimum inhibitory concentrations ranging from 7.1 to 19.2 µg/mL. These compounds showed promising inhibitory activity against NO production (IC₅₀ 3.22 to 25.5 μg/mL). 5α-carboxystrictosidine did not show cytotoxicity against macrophages RAW264.7 up to a concentration of 100 µg/mL. With the exception of strictosamide, this is the first report of the occurrence of these substances in P. nuda.

Applications of Algal Polysaccharides and Derivatives in Therapeutic and Agricultural Fields

BACKGROUND

Recently, researchers have given more and more consideration to natural polysaccharides thanks to their huge properties such as stability, biodegradability and biocompatibility for food and therapeutics applications.

METHODS

a number of enzymatic and chemical processes were performed to generate bioactive molecules, such as low molecular weight fractions and oligosaccharides derivatives from algal polysaccharides.

RESULTS

These considerable characteristics allow algal polysaccharides and their derivatives such as low molecular weight polymers and oligosaccharides structures to have great potential to be used in lots of domains, such as pharmaceutics and agriculture etc. Conclusion: The present review describes the mains polysaccharides structures from Algae and focuses on the currents agricultural (fertilizer, bio-elicitor, stimulators, signaling molecules and activators) and pharmaceutical (wound dressing, tissues engineering and drugs delivery) applications by using polysaccharides and/or their oligosaccharides derivatives obtained by chemical, physical and enzymatic processes.

Asperuloside and Asperulosidic Acid Exert an Anti-Inflammatory Effect via Suppression of the NF-κB and MAPK Signaling Pathways in LPS-Induced RAW 264.7 Macrophages

Hedyotis diffusa is a folk herb that is used for treating inflammation-related diseases in Asia. Previous studies have found that iridoids in H. diffusa play an important role in its anti-inflammatory activity. This study aimed to investigate the anti-inflammatory effect and potential mechanism of five iridoids (asperuloside (ASP), asperulosidic acid (ASPA), desacetyl asperulosidic acid (DAA), scandoside methyl ester (SME), and E-6-O-p-coumaroyl scandoside methyl ester (CSME)) that are presented in H. diffusa using lipopolysaccharide (LPS)-induced RAW 264.7 cells. ASP and ASPA significantly decreased the production of nitric oxide (NO), prostaglandin E₂ (PGE₂), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in parallel with the inhibition of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), TNF-α, and IL-6 mRNA expression in LPS-induced RAW 264.7 cells. ASP treatment suppressed the phosphorylation of the inhibitors of nuclear factor-kappaB alpha (IκB-α), p38, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK). The inhibitory effect of ASPA was similar to that of ASP, except for p38 phosphorylation. In summary, the anti-inflammatory effects of ASP and ASPA are related to the inhibition of inflammatory cytokines and mediators via suppression of the NF-κB and mitogen-activated protein kinase (MAPK) signaling pathways, which provides scientific evidence for the potential application of H. diffusa.