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

Research Progress on Sesquiterpene Compounds from Artabotrys Plants of Annonaceae

Artabotrys, a pivotal genus within the Annonaceae family, is renowned for its extensive biological significance and medicinal potential. The genus's sesquiterpene compounds have attracted considerable interest from the scientific community due to their structural complexity and diverse biological activities. These compounds exhibit a range of biological activities, including antimalarial, antibacterial, anti-inflammatory analgesic, and anti-tumor properties, positioning them as promising candidates for medical applications. This review aims to summarize the current knowledge on the variety, species, and structural characteristics of sesquiterpene compounds isolated from Artabotrys plants. Furthermore, it delves into their pharmacological activities and underlying mechanisms, offering a comprehensive foundation for future research.

Trinity of inflammation, innate immune cells and cross-talk of signalling pathways in tumour microenvironment

Unresolved inflammation is a pathological consequence of persistent inflammatory stimulus and perturbation in regulatory mechanisms. It increases the risk of tumour development and orchestrates all stages of tumorigenesis in selected organs. In certain cancers, inflammatory processes create the appropriate conditions for neoplastic transformation. While in other types, oncogenic changes pave the way for an inflammatory microenvironment that leads to tumour development. Of interest, hallmarks of tumour-promoting and cancer-associated inflammation are striking similar, sharing a complex network of stromal (fibroblasts and vascular cells) and inflammatory immune cells that collectively form the tumour microenvironment (TME). The cross-talks of signalling pathways initially developed to support homeostasis, change their role, and promote atypical proliferation, survival, angiogenesis, and subversion of adaptive immunity in TME. These transcriptional and regulatory pathways invariably contribute to cancer-promoting inflammation in chronic inflammatory disorders and foster "smouldering" inflammation in the microenvironment of various tumour types. Besides identifying common target sites of numerous cancer types, signalling programs and their cross-talks governing immune cells' plasticity and functional diversity can be used to develop new fate-mapping and lineage-tracing mechanisms. Here, we review the vital molecular mechanisms and pathways that establish the connection between inflammation and tumour development, progression, and metastasis. We also discussed the cross-talks between signalling pathways and devised strategies focusing on these interaction mechanisms to harness synthetic lethal drug combinations for targeted cancer therapy.

Design, synthesis and evaluation of novel pyrrole-hydroxybutenolide hybrids as promising antiplasmodial and anti-inflammatory agents

In the pursuance of novel scaffolds with promising antiplasmodial and anti-inflammatory activity, a series of twenty-one compounds embraced with most promising penta-substituted pyrrole and biodynamic hydroxybutenolide in single skeleton was designed and synthesized. These pyrrole-hydroxybutenolide hybrids were evaluated against Plasmodium falciparum parasite. Four hybrids 5b, 5d, 5t and 5u exhibited good activity with IC₅₀ of 0.60, 0.88, 0.97 and 0.96 μM for chloroquine sensitive (Pf3D7) strain and 3.92, 4.31, 4.21 and 1.67 μM for chloroquine resistant (PfK1) strain, respectively. In vivo efficacy of 5b, 5d, 5t and 5u was studied against the P. yoelii nigeriensis N67 (a chloroquine-resistant) parasite in Swiss mice at a dose of 100 mg/kg/day for 4 days via oral route. 5u was found to show maximum 100% parasite inhibition with considerably increased mean survival time. Simultaneously, the series of compounds was screened for anti-inflammatory potential. In preliminary assays, nine compounds showed more than 85% inhibition in hu-TNFα cytokine levels in LPS stimulated THP-1 monocytes and seven compounds showed more than 40% decrease in fold induction in reporter gene activity analyzed via Luciferase assay. 5p and 5t were found to be most promising amongst the series, thus were taken up for further in vivo studies. Wherein, mice pre-treated with them showed a dose dependent inhibition in carrageenan induced paw swelling. Moreover, the results of in vitro and in vivo pharmacokinetic parameters indicated that the synthesized pyrrole-hydroxybutenolide conjugates abide by the required criteria for the development of orally active drug and thus this scaffold can be used as pharmacologically active framework that should be considered for the development of potential antiplasmodial and anti-inflammatory agents.

Nephroprotective potential of Polyalthia longifolia roots against vancomycin-induced renal toxicity in experimental animals

This study was done to investigate the possible nephroprotective effect of an ethanolic root extract of Polyalthia Longifolia (PL) on vancomycin-induced nephrotoxicity using curative and protective models. Vancomycin (150 mg/kg, intravenous) was given to healthy Wistar albino rats in the curative model before the start of treatment, whereas the protective group received vancomycin at the conclusion of the 10-day treatment procedure. Animals were divided into six groups for both models; group I served as the normal control, while groups II, III, IV, V, and VI were kept as toxic control, standard (selenium, 6 mg/kg), LDPL (low dose of PL 200 mg/kg), HDPL (high dose of PL 400 mg/kg), and HDPL + selenium (interactive) groups, respectively. Renal biomarkers [(uric acid, creatinine, blood urea nitrogen (BUN), serum proteins], and blood electrolyte levels were measured for all tested groups. When compared to the vancomycin group, the HDPL significantly (p < 0.01) showed greater effectiveness in lowering the BUN, potassium, and calcium levels. Additionally, in the curative model, there was a significant (p < 0.05) decrease in the blood levels of uric acid, creatinine, BUN, potassium, and calcium in the animals who received the combination of selenium and HDPL. Both LDPL and HDPL did not provide any distinguishable effect in the protective model, but groups that received HDPL with selenium did provide detectable protection by significantly lowering their levels of uric acid, BUN, serum potassium, and total serum protein in comparison to the vancomycin control group. These findings indicate that, whether administered before or after renal damage is induced, the Polyalthia longifolia root extract provided only modest protection to nephrons, which require selenium support to prevent vancomycin-induced kidney damage.

Chemical Fingerprinting, Antioxidant, and Anti-Inflammatory Potential of Hydroethanolic Extract of Trigonella foenum-graecum

In the current study, the antioxidant and anti-inflammatory potential of hydroethanolic extract of T. foenum-graecum seeds was evaluated. Phenolic profiling of T. foenum-graecum was conducted through high-performance liquid chromatography-photodiode array (HPLC-PDA) as well as through the mass spectrometry technique to characterize compounds responsible for bioactivity, which confirmed almost 18 compounds, 13 of which were quantified through a chromatographic assay. In vitro antioxidant analysis of the extract exhibited substantial antioxidant activities with the lowest IC50 value of both DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid) inhibition assays. The extract was found to be non-toxic against human RBCs and murine macrophage RAW 264.7 cells. Moreover, the extract significantly (p < 0.001) reduced the lipopolysaccharide (LPS)-induced tumor necrosis factor alpha (TNF-α), intrlukin-6 (IL-6), prostaglandin E2 (PGE2), and nitric oxide (NO) in RAW 264.7 cells in a concentration-dependent manner. The hydroethanolic extract of T. foenum-graecum exhibited considerable anti-inflammatory potential by decreasing the cellular infiltration to the inflammatory site in both carrageenan-induced peritonitis and an air pouch model of inflammation. Pretreatment with T. foenum-graecum extract caused significant improvement in antioxidants such as superoxide dismutase (SOD), CAT (catalase), malondialdehyde (MDA), and myeloperoxidase (MPO) against oxidative stress induced by carrageenan. Based on our results of in vivo and in vitro experimentation, we concluded that hydroethanolic extract of T. foenum-graecum is a potential source of phenolic compounds with antioxidant and anti-inflammatory potential.

Synthesis and Evaluation of Bakuchiol Derivatives as Potent Anti-inflammatory Agents in Vitro and in Vivo

Bakuchiol, a prenylated phenolic monoterpene derived from the fruit of Psoralen corylifolia L. (Buguzhi), is widely used to treat tumors, viruses, inflammation, and bacterial infections. In this study, we designed and synthesized 30 bakuchiol derivatives to identify new anti-inflammatory drugs. The anti-inflammatory activities of the derivatives were screened using lipopolysaccharide-induced RAW264.7 cells. To evaluate the anti-inflammatory activity of the compounds, we measured nitric oxide (NO), interleukin-6, and tumor necrosis factor-α production. Based on the screening results, compound 7a displayed more pronounced activity than bakuchiol and celecoxib. Furthermore, the mechanistic studies indicated that 7a inhibited pro-inflammatory cytokine release, which was correlated with activation of the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 signaling pathway and blockade of the nuclear factor-κB/mitogen-activated protein kinase signaling pathway. The in vivo anti-inflammatory activity in zebrafish indicated that 7a inhibited NO and reactive oxygen species production in a dose-dependent manner. These results indicate that 7a is a potential candidate for development as an anti-inflammatory agent.

Polyphenol-Polysaccharide Complex: Preparation, Characterization and Potential Utilization in Food and Health

Polysaccharides and polyphenols coexist in many plant-based food products. Polyphenol-polysaccharide interactions may affect the physicochemical, functional, and physiological properties, such as digestibility, bioavailability, and stability, of plant-based foods. In this review, the interactions (physically or covalently linked) between the selected polysaccharides and polyphenols are summarized. The preparation and structural characterization of the polyphenol-polysaccharide conjugates, their structural-interaction relationships, and the effects of the interactions on functional and physiological properties of the polyphenol and polysaccharide molecules are reviewed. Moreover, potential applications of polyphenol-polysaccharide conjugates are discussed. This review aids in a comprehensive understanding of the synthetic strategy, beneficial bioactivity, and potential application of polyphenol-polysaccharide complexes. Expected final online publication date for the Annual Review of Food Science and Technology, Volume 13 is March 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Clerodane Diterpenoids Identified from Polyalthia longifolia Showing Antifungal Activity against Plant Pathogens

In the search for new natural resources showing plant disease control effects, we found that the methanol extract of Polyalthia longifolia suppressed fungal disease development in plants. To identify the bioactive substances, the methanol extract of P. longifolia was extracted by organic solvents, and consequently, four new 2-oxo-clerodane diterpenes (1-4), a new 4(3 → 2)-abeo-clerodane diterpene (5), together with ten known compounds (6-16) were isolated and identified from the extracts. Of the new compounds, compound 2 showed a broad spectrum of antifungal activity with moderated minimum inhibitory concentration (MIC) values in a range of 50-100 μg/mL against tested fungal pathogens. Considering with the known compounds, compound 6 showed the most potent antifungal activity with an MIC value in the range of 6.3-12.5 μg/mL. When compound 6 was evaluated for an in vivo antifungal activity against rice blast, tomato late blight, and pepper anthracnose, compound 6 reduced the plant disease by at least 60% compared to the untreated control at concentrations of 250 and 500 μg/mL. Together, our results suggested that the methanol extract of twigs and leaves of P. longifolia and its major compound 6 could be used as a source for the development of eco-friendly plant protection agents.

Phytochemicals from Polyalthia Species: Potential and Implication on Anti-Oxidant, Anti-Inflammatory, Anti-Cancer, and Chemoprevention Activities

Polyalthia belong to the Annonaceae family and are a type of evergreen tree distributed across many tropical and subtropical regions. Polyalthia species have been used long term as indigenous medicine to treat certain diseases, including fever, diabetes, infection, digestive disease, etc. Recent studies have demonstrated that not only crude extracts but also the isolated pure compounds exhibit various pharmacological activities, such as anti-oxidant, anti-microbial, anti-tumor, anti-cancer, etc. It is known that the initiation of cancer usually takes several years and is related to unhealthy lifestyle, as well as dietary and environmental factors, such as stress, toxins and smoking. In fact, natural or synthetic substances have been used as cancer chemoprevention to delay, impede, or even stop cancer growing. This review is an attempt to collect current available phytochemicals from Polyalthia species, which exhibit anti-cancer potentials for chemoprevention purposes, providing directions for further research on the interesting agents and possible clinical applications.

Anti-rheumatic effect of quercetin and recent developments in nano formulation

Quercetin is a potential anti-rheumatoid drug. Nano formulation strategies could improve its solubility and efficacy.

Modulation of inflammatory pathways, medicinal uses and toxicities of Uvaria species: potential role in the prevention and treatment of inflammation

The therapeutic efficacy of the contemporary anti-inflammatory drugs are well established; however, prolonged use of such can often lead to serious and life-threatening side effects. Natural product-based anti-inflammatory compounds with superior efficacy and minimum toxicity can serve as possible therapeutic alternatives in this scenario. Genus Uvaria is a part of Annonaceae family, while the majority of its species are widely distributed in tropical rain forest regions of South East Asia. Uvaria species have been used extensively used as traditional medicine for treating all sorts of inflammatory diseases including catarrhal inflammation, rheumatism, acute allergic reactions, hemorrhoids, inflammatory liver disease and inflamed joints. Phytochemical analysis of Uvaria species has revealed flavones, flavonoids, tannins, saponins, polyoxygenated cyclohexene and phenolic compounds as major phyto-constituents. This review is an attempt to highlight the anti-inflammatory activity of Uvaria species by conducting a critical appraisal of the published literature. The ethnopharmacological relevance of Uvaria species in the light of toxicological studies is also discussed herein. An extensive and relevant literature on anti-inflammatory activity of Uvaria species was collected from available books, journals and electronic databases including PubMed, ScienceDirect, Scopus, Proquest and Ovid. Extracts and isolates of Uvaria species exhibited significant anti-inflammatory activity through various mechanisms of action. 6,7-di-O-Methyl-baicalein, flexuvarol B, chrysin, (-)-zeylenol, 6-hydroxy-5,7-dimethoxy-flavone, and pinocembrin were the most potent anti-inflammatory compounds with comparable IC₅₀ with positive controls. Therefore, it is suggested that further research should be carried out to determine the pharmacokinetics, pharmacodynamics and toxicity of these therapeutically significant compounds, to convert the pre-clinical results into clinical data for drug development and design.

α-Glucosidase inhibitory and nitric oxide production inhibitory activities of alkaloids isolated from a twig extract of Polyalthia cinnamomea

The first phytochemical investigation of Polyalthia cinnamomea led to the isolation and identification of two new oxoprotoberberine alkaloids, (-)-(13aS)-polyalthiacinnamines A and B, together with eleven known compounds. The structures of the new compounds were elucidated by extensive spectroscopic methods. The absolute configuration of miliusacunine E and consanguine B was established by X-ray diffraction analysis using Cu Kα radiation and ECD spectra, whereas the absolute configurations of polyalthiacinnamines A and B were established by comparison of their ECD spectra and specific rotations with those of miliusacunine E and consanguine B. Compounds 1-4, 6, and 8 exhibited α-glucosidase inhibitory activities (IC₅₀ values ranging from 11.3 to 57.9 µM) better than a positive control (acarbose, IC₅₀ 83.5 μM). Compound 2 also exhibited NO production inhibitory activity with an IC₅₀ value of 24.4 μM (indomethacin, a positive control, IC₅₀ = 32.2 μM).

Clerodane Diterpene Ameliorates Inflammatory Bowel Disease and Potentiates Cell Apoptosis of Colorectal Cancer

Inflammatory bowel disease (IBD) is general term for ulcerative colitis and Crohn's disease, which is chronic intestinal and colorectal inflammation caused by microbial infiltration or immunocyte attack. IBD is not curable, and is highly susceptible to develop into colorectal cancer. Finding agents to alleviate these symptoms, as well as any progression of IBD, is a critical effort. This study evaluates the anti-inflammation and anti-tumor activity of 16-hydroxycleroda-3,13-dien-15,16-olide (HCD) in in vivo and in vitro assays. The result of an IBD mouse model induced using intraperitoneal chemical azoxymethane (AOM)/dextran sodium sulfate (DSS) injection showed that intraperitoneal HCD adminstration could ameliorate the inflammatory symptoms of IBD mice. In the in vitro assay, cytotoxic characteristics and retained signaling pathways of HCD treatment were analyzed by MTT assay, cell cycle analysis, and Western blotting. From cell viability determination, the IC₅₀ of HCD in Caco-2 was significantly lower in 2.30 μM at 48 h when compared to 5-fluorouracil (5-FU) (66.79 μM). By cell cycle and Western blotting analysis, the cell death characteristics of HCD treatment in Caco-2 exhibited the involvement of extrinsic and intrinsic pathways in cell death, for which intrinsic apoptosis was predominantly activated via the reduction in growth factor signaling. These potential treatments against colon cancer demonstrate that HCD could provide a promising adjuvant as an alternative medicine in combating colorectal cancer and IBD.