Anti-inflammatory effect of methoxyflavonoids from Chiliadenus montanus (Jasonia Montana) growing in Egypt

Mechanistic Insights into the Anticancer Potential of Methoxyflavones Analogs: A Review

2-phenylchromen-4-one, commonly known as flavone, plays multifaceted roles in biological response that can be abundantly present in natural sources. The methoxy group in naturally occurring flavones promotes cytotoxic activity in various cancer cell lines by targeting protein markers, in facilitating ligand-protein binding mechanisms and activating cascading downstream signaling pathways leading to cell death. However, the lipophilic nature of these analogs is a key concern as it impacts drug membrane transfer. While lipophilicity is crucial for drug efficacy, the excessive lipophilic effects in flavonoids can reduce water solubility and hinder drug transport to target sites. Recent in vitro studies suggest that the incorporation of polar hydroxyl groups which can form hydrogen bonds and stabilize free radicals may help overcome the challenges associated with methoxy groups while maintaining their essential lipophilic properties. Naturally coexisting with methoxyflavones, this review explores the synergistic role of hydroxy and methoxy moieties through hydrogen bonding capacity in maximizing cytotoxicity against cancer cell lines. The physicochemical analysis revealed the potential intramolecular interaction and favorable electron delocalization region between both moieties to improve cytotoxicity levels. Together, the analysis provides a useful strategy for the structure-activity relationship (SAR) of flavonoid analogs in distinct protein markers, suggesting optimal functional group positioning to achieve balanced lipophilicity, effective hydrogen bonding, and simultaneously minimized steric hindrance in targeting specific cancer cell types.

The Genus Chiliadenus: A Comprehensive Review of Taxonomic Aspects, Traditional Uses, Phytochemistry and Pharmacological Activities

The genus Chiliadenus (Asteraceae) has been traditionally used in Mediterranean medicine for its anti-inflammatory, antioxidant, and antimicrobial properties. However, scientific research on this genus remains limited, highlighting the need for a comprehensive review of its chemical composition and pharmacological characteristics. This review compiles existing knowledge on Chiliadenus species, focusing on their secondary metabolites, such as flavonoids, terpenes, and essential oils, as well as associated biological activities. The findings show that the traditional therapeutic properties of Chiliadenus are well supported by reported pharmacological activities in previous studies, emphasizing the potential of this genus for the development of new therapeutic agents. However, the lack of comparative studies among Chiliadenus species and the scarcity of in vivo studies and clinical trials hinder the full realization of its therapeutic potential. Specifically, comparative studies could be key to identifying species with unique chemical profiles and understanding how variations in secondary metabolite composition may influence their pharmacological activities. This work highlights the urgent need to expand research in these areas to validate the pharmacological properties of Chiliadenus species for their application in modern medicine.

Polyphenols of the Inuleae-Inulinae and Their Biological Activities: A Review

Polyphenols are ubiquitous plant metabolites that demonstrate biological activities essential to plant-environment interactions. They are of interest to plant food consumers, as well as to the food, pharmaceutical and cosmetic industry. The class of the plant metabolites comprises both widespread (chlorogenic acids, luteolin, quercetin) and unique compounds of diverse chemical structures but of the common biosynthetic origin. Polyphenols next to sesquiterpenoids are regarded as the major class of the Inuleae-Inulinae metabolites responsible for the pharmacological activity of medicinal plants from the subtribe (Blumea spp., Dittrichia spp., Inula spp., Pulicaria spp. and others). Recent decades have brought a rapid development of molecular and analytical techniques which resulted in better understanding of the taxonomic relationships within the Inuleae tribe and in a plethora of data concerning the chemical constituents of the Inuleae-Inulinae. The current taxonomical classification has introduced changes in the well-established botanical names and rearranged the genera based on molecular plant genetic studies. The newly created chemical data together with the earlier phytochemical studies may provide some complementary information on biochemical relationships within the subtribe. Moreover, they may at least partly explain pharmacological activities of the plant preparations traditionally used in therapy. The current review aimed to systematize the knowledge on the polyphenols of the Inulae-Inulinae.

Inhibition of Cysteine Proteases via Thiol-Michael Addition Explains the Anti-SARS-CoV-2 and Bioactive Properties of Arteannuin B

Artemisia annua is the plant that produces artemisinin, an endoperoxide-containing sesquiterpenoid used for the treatment of malaria. A. annua extracts, which contain other bioactive compounds, have been used to treat other diseases, including cancer and COVID-19, the disease caused by the virus SARS-CoV-2. In this study, a methyl ester derivative of arteannuin B was isolated when A. annua leaves were extracted with a 1:1 mixture of methanol and dichloromethane. This methyl ester was thought to be formed from the reaction between arteannuin B and the extracting solvent, which was supported by the fact that arteannuin B underwent 1,2-addition when it was dissolved in deuteromethanol. In contrast, in the presence of N-acetylcysteine methyl ester, a 1,4-addition (thiol-Michael reaction) occurred. Arteannuin B hindered the activity of the SARS CoV-2 main protease (nonstructural protein 5, NSP5), a cysteine protease, through time-dependent inhibition. The active site cysteine residue of NSP5 (cysteine-145) formed a covalent bond with arteannuin B as determined by mass spectrometry. In order to determine whether cysteine adduction by arteannuin B can inhibit the development of cancer cells, similar experiments were performed with caspase-8, the cysteine protease enzyme overexpressed in glioblastoma. Time-dependent inhibition and cysteine adduction assays suggested arteannuin B inhibits caspase-8 and adducts to the active site cysteine residue (cysteine-360), respectively. Overall, these results enhance our understanding of how A. annua possesses antiviral and cytotoxic activities.

Isolation of Various Flavonoids with TRAIL Resistance-Overcoming Activity from Blumea lacera

Eighteen compounds, including fourteen flavonoids (1-14), one steroid (15), two fatty acids (16,17), and one nitrogen-containing compound (18), were isolated from the methanol extract of the whole Blumea lacera plant collected in Thailand. Compounds 1-11 and 15-17 exhibited tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resistance-overcoming activity. Among them, bonanzin (2) and cirsilineol (7) had particularly strong TRAIL resistance-overcoming activity, where the IC₅₀ values against the human gastric adenocarcinoma cell line AGS in the presence of TRAIL (100 ng/mL) were 10.7 μM and 5.9 μM, respectively.

In vitro and in vivo antimalarial activity and chemical profiling of sugarcane leaves

Saccharum officinarum Linn. (sugarcane, Family-Poaceae) is employed in Ibibio traditional medicine for the treatment of various infections and diseases such as malaria. We This study aims to assess the antiplasmodial effect of the leaf extract and fractions on human malaria parasite (Plasmodium falciparum) in vitro, and rodent malaria parasite (P. berghei) in vivo, and analyse the bioactive components of the active fraction(s). The leaf extract and fractions of S. officinarum were prepared and their growth inhibitory effects tested against the chloroquine resistant P. falciparum strain (Dd2) and P. berghei infection in mice. An acute toxicity of the extract was determined. A combination of gas chromatography and liquid chromatography-mass spectrometry, and nuclear magnetic resonance spectroscopy was applied for metabolites profiling of crude extract and active fractions. The leaf extract and fractions demonstrated moderate activity against P. falciparum with the dichloromethane fraction producing the most potent activity (EC50 = 15.4 µg/mL). The leaf extract (170-510 mg/kg, p.o., LD50 = 1732 mg/kg) and fractions demonstrated significant (p < 0.05-0.001) effect on P. berghei infection in prophylactic  tests as well as in established infection with n-butanol fractions producing the highest effect. An unusual sulphur-containing compound, dilaurylthiodipropionate, fatty acids, phenolic acids, flavonoid and flavonoid glycoside were identified in the active fractions. These results give credence to the use of sugarcane leaves as malarial remedy locally by confirming the in vitro and in vivo antiplasmodial potential of leaf extract/fractions of S. officinarum.

In Vitro Cultures and Volatile Organic Compound Production in Chiliadenus montanus (Vhal.) Brullo

Callus and microshoot cultures were established for Chiliadenus montanus (Vhal.) Brullo. (Asteraceae), a medicinal plant known for producing volatile organic compounds (VOCs). Callus induction was achieved successfully by culturing leaf explants on full-strength Murashige and Skoog medium (MS) supplemented with 2.2 µM 2, 4-dichlorophenoxy acetic acid (2,4-D) and 6.9 µM kinetin (Kin). Successful direct shoot regeneration was achieved using nodal explants cultured onto half-strength MS media supplemented with 1.4 μM Gibberellic Acid (GA₃) and 4.4 μM 6-Benzylaminopurine (BAP). Indirect microshoots were successfully regenerated using callus cultured on MS media supplemented with 8.8 μM BAP, 2.2 μM Zeatin, and 1.4 μM GA₃ followed by culturing on MS media supplemented with 8.8 μM BAP and 0.5 μM naphthalene acetic acid (NAA). Using wild plant aerial parts, callus and microshoots samples, VOCs were extracted successfully using Headspace Solid-Phase Micro-Extraction (HS-SPME) and analyzed by gas chromatography-mass spectrometry (GC-MS). In wild plant extracts, sesquiterpene hydrocarbons were found to be predominant with the following principal components: Alloaromadendrene (11.92%), trans-Cadina-1(6),4-diene (7.54%), and α-caryophyllene (6.77%). The analysis of in vitro microshoots revealed high levels of oxygenated monoterpenes with cis-Myrtanol (16.62%), and β-Cyclocitral (14.3%) as the main components. Callus extract was dominated by monoterpene hydrocarbons and the main compounds identified were (Z)-β-Ocimene (22.27%), p-Cymene (15.13%), and α-pinene (13.78%). In conclusion, an efficient in vitro production system of VOCs in C. montanus was established that can be used in the future for boosting their production without endangering wild plants.

Targeting Mammalian 5-Lipoxygenase by Dietary Phenolics as an Anti-Inflammatory Mechanism: A Systematic Review

5-Lipoxygenase (5-LOX) plays a key role in inflammation through the biosynthesis of leukotrienes and other lipid mediators. Current evidence suggests that dietary (poly)phenols exert a beneficial impact on human health through anti-inflammatory activities. Their mechanisms of action have mostly been associated with the modulation of pro-inflammatory cytokines (TNF-α, IL-1β), prostaglandins (PGE2), and the interaction with NF-κB and cyclooxygenase 2 (COX-2) pathways. Much less is known about the 5-lipoxygenase (5-LOX) pathway as a target of dietary (poly)phenols. This systematic review aimed to summarize how dietary (poly)phenols target the 5-LOX pathway in preclinical and human studies. The number of studies identified is low (5, 24, and 127 human, animal, and cellular studies, respectively) compared to the thousands of studies focusing on the COX-2 pathway. Some (poly)phenolics such as caffeic acid, hydroxytyrosol, resveratrol, curcumin, nordihydroguaiaretic acid (NDGA), and quercetin have been reported to reduce the formation of 5-LOX eicosanoids in vitro. However, the in vivo evidence is inconclusive because of the low number of studies and the difficulty of attributing effects to (poly)phenols. Therefore, increasing the number of studies targeting the 5-LOX pathway would largely expand our knowledge on the anti-inflammatory mechanisms of (poly)phenols.

Oriental Hornet (Vespa orientalis) Larval Extracts Induce Antiproliferative, Antioxidant, Anti-Inflammatory, and Anti-Migratory Effects on MCF7 Cells

The use of insects as a feasible and useful natural product resource is a novel and promising option in alternative medicine. Several components from insects and their larvae have been found to inhibit molecular pathways in different stages of cancer. This study aimed to analyze the effect of aqueous and alcoholic extracts of Vespa orientalis larvae on breast cancer MCF7 cells and investigate the underlying mechanisms. Our results showed that individual treatment with 5% aqueous or alcoholic larval extract inhibited MCF7 proliferation but had no cytotoxic effect on normal Vero cells. The anticancer effect was mediated through (1) induction of apoptosis, as indicated by increased expression of apoptotic genes (Bax, caspase3, and p53) and decreased expression of the anti-apoptotic gene Bcl2; (2) suppression of intracellular reactive oxygen species; (3) elevation of antioxidant enzymes (CAT, SOD, and GPx) and upregulation of the antioxidant regulator Nrf2 and its downstream target HO-1; (4) inhibition of migration as revealed by in vitro wound healing assay and downregulation of the migration-related gene MMP9 and upregulation of the anti-migratory gene TIMP1; and (5) downregulation of inflammation-related genes (NFκB and IL8). The aqueous extract exhibited the best anticancer effect with higher antioxidant activities but lower anti-inflammatory properties than the alcoholic extract. HPLC analysis revealed the presence of several flavonoids and phenolic compounds with highest concentrations for resveratrol and naringenin in aqueous extract and rosmarinic acid in alcoholic extract. This is the first report to explain the intracellular pathway by which flavonoids and phenolic compounds-rich extracts of Vespa orientalis larvae could induce MCF7 cell viability loss through the initiation of apoptosis, activation of antioxidants, and inhibition of migration and inflammation. Therefore, these extracts could be used as adjuvants for anticancer drugs and as antioxidant and anti-inflammatory agents.