Trimethoxy Flavone Research Articles

Design, synthesis, and biological evaluation of novel 5,7,4′-trimethoxyflavone sulfonamide-based derivatives as highly potent inhibitors of LRPPRC/STAT3/CDK1

Leucine-rich pentatricopeptide repeat-containing protein (LRPPRC), signal transducer and activator of transcription 3 (STAT3), and cyclin-dependent kinase 1 (CDK1) are promising therapeutic targets for cancer treatment. However, there is a lack of effective inhibitors of LRPPRC, STAT3, and CDK1 in clinic. Our previous study has proved that 5,7,4′-Trimethoxyflavone (TMF) is a novel inhibitor of LRPPRC/STAT3/CDK1. However, the extraction rate of TMF from Tangerine Peel is quite low, and the doses of TMF in cells and mice are rather high. Herein, structural modifications of TMF have led to two series of TMF derivatives including sulfonamide substituted at 3′-position (7a–m) and 3′,8-position (11a–m). Among all compounds, 7e, 7k, 11e, and 11g exhibited as effective, broad-spectrum, and potent anticancer agents in vitro. Moreover, 7e, 7k, 11e, and 11g showed better antitumor effects than TMF and clinical used chemotherapy drug capecitabine in vivo with no obvious toxicity. Mechanism studies showed that 11g could bind to LRPPRC, STAT3, and CDK1 to disassociate the LRPPRC-JAK2-STAT3 and JAK2-STAT3-CDK1 complexes, resulting in suppression of JAK2/STAT3 signaling pathway. These findings suggest that 11g may serve as a leading compound for cancer therapy as a triple-target (LRPPRC, STAT3, and CDK1) inhibitor.

Ineffectiveness of 6,2',4'-trimethoxyflavone in mitigating cerebral ischemia/reperfusion injury after post-reperfusion administration in rats.

Pharmacological inhibition of aryl hydrocarbon receptor (AhR) activation after ischemia alleviates cerebral ischemia/reperfusion (IR) injury. To investigate whether AhR antagonist administration after reperfusion was also effective in attenuating cerebral IR injury. A total of 24 Sprague-Dawley rats were divided into the sham-operated group (no IR), control group (IR), and 6,2',4'-trimethoxyflavone (TMF) group (IR + TMF administration), with 10 rats assigned to each group. Cerebral IR injury was induced by 60 min of middle cerebral artery occlusion followed by reperfusion. TMF (5 mg/kg) was used as the AhR antagonist and was administered intraperitoneally immediately after reperfusion. Cerebral IR injury was observed using magnetic resonance imaging (MRI) and neurobehavioral assessments at baseline, immediately after ischemia, and at 3 days after ischemia. On MRI, the TMF group showed no significant differences in relative apparent diffusion coefficient (ADC), T2, and fractional anisotropy (FA) values; midline shift value; and infarct volume. In terms of neurobehavioral function, factors such as grip strength, contralateral forelimb use, time to touch, and time to remove adhesive tape from the forepaw, were also not significantly different between the control and TMF groups. This study demonstrated that AhR treatment after reperfusion had no noticeable effect on reducing cerebral IR injury in rats.

5,7,4′‐Trimethoxyflavone triggers cancer cell PD‐L1 ubiquitin–proteasome degradation and facilitates antitumor immunity by targeting HRD1

AbstractTargeting the programmed cell death 1/programmed cell death ligand 1 (PD‐1/PD‐L1) pathway has been identified as a successful approach for tumor immunotherapy. Here, we identified that the small molecule 5,7,4′‐trimethoxyflavone (TF) from Kaempferia parviflora Wall reduces PD‐L1 expression in colorectal cancer cells and enhances the killing of tumor cells by T cells. Mechanistically, TF targets and stabilizes the ubiquitin ligase HMG‐CoA reductase degradation protein 1 (HRD1), thereby increasing the ubiquitination of PD‐L1 and promoting its degradation through the proteasome pathway. In mouse MC38 xenograft tumors, TF can activate tumor‐infiltrating T‐cell immunity and reduce the immunosuppressive infiltration of myeloid‐derived suppressor cells and regulatory T cells, thus exerting antitumor effects. Moreover, TF synergistically exerts antitumor immunity with CTLA‐4 antibody. This study provides new insights into the antitumor mechanism of TF and suggests that it may be a promising small molecule immune checkpoint modulator for cancer therapy.

5,7-dihydroxy-3′,4′,5′-trimethoxyflavone mitigates lead induced neurotoxicity in rats via its chelating, antioxidant, anti-inflammatory and monoaminergic properties

Chronic exposure to lead (Pb) induces neurodegenerative changes in animals and humans. Drugs with strong antioxidant properties are effective against Pb-mediated neurotoxicity. In a prior study, we identified 5,7-dihydroxy-3′,4′,5′-trimethoxyflavone (TMF) from Ocimum basilicum L. leaves as a potent antioxidant and neuroprotective compound. This research explores TMF's neuroprotective effects against Pb-induced brain toxicity in rats to establish it as a therapeutic agent. Rats received lead acetate (100 mg/kg, orally, once daily) for 30 days to induce brain injury, followed by TMF treatment (5 and 10 mg/kg, oral, once daily) 30 min later. Cognitive and motor functions were assessed using Morris Water Maze and horizontal bar tests. Lead, monoamine oxidase (MAO) A and B enzymes, reduced glutathione (GSH), thiobarbituric acid reactive species (TBARS), Tumor necrosis factor-alpha (TNF-α), and IL-6 levels were measured in the hippocampus and cerebellum. Pb exposure impaired cognitive and motor functions, increased Pb, TBARS, TNF-α, and IL-6 levels, and compromised MAO A & B and GSH levels. TMF reversed Pb-induced memory and motor deficits and normalized biochemical anomalies. TMF's neuroprotective effects against lead involve chelating, antioxidant, anti-inflammatory, and monoaminergic properties, suggesting its potential as a treatment for metal-induced brain injury.

Isolation, Characterization, and Antiproliferative Activity of Polymethoxy Flavones from Mentha dumetorum

Background: Natural products have been used commonly in the pharmaceutical industry as well as traditional medicine due to their bioactive contents. Objective: The objective of this study is to isolate the polymethoxy flavones (PMFs) and evaluate the antiproliferative activity. Methods: The PMFs were extracted from Mentha dumetorum with boiling hot water and then partitioned with hexane and the extract was subjected to chromatographic techniques such as Sephadex LH-20, silica gel, and preparative TLC, and HPLC to isolate the compounds. The structures of isolated compounds were elucidated by spectroscopic techniques such as 1H-NMR, 13C-NMR, LC-TOF-MS, and UV-Vis. The antiproliferative effects of isolated compounds were evaluated using a real-time cell analyzer–single plate (RTCA-SP) instrument against HeLa and HT29 cell lines. Results: The isolated PMFs were identified as xanthomicrol (1), 5-hydroxy-6,7,8,4'-tetrametoxy flavanone (2), 5-desmetil sinensetin (3), 5-demetil nobiletin (4), gardenin B (5), 5-hydroxy-6,7,8,3',4'- penta methoxy flavanone (6) and 5-hydroxy-6,7,4'-trimethoxy flavone (7). Compounds 2 and 5 were found to be the most active against both cell lines. Conclusion: The isolated compounds as well as the plant extract of Mentha dumetorum could be promising agents for the drug development process, especially drugs for cancer treatment. Moreover, isolation methods were developed for the corresponding compounds.

Nonribosomal antibacterial peptides isolated from Streptomyces agglomeratus 5-1-3 in the Qinghai-Tibet Plateau

BackgroundNew antibiotics are urgently needed in clinical treatment of superdrug-resistant bacteria. Nonribosomal peptides (NRPs) are a major source of antibiotics because they exhibit structural diversity, and unique antibacterial mechanisms and resistance. Analysis of gene clusters of S. agglomeratus 5-1-3 showed that Clusters 3, 6, 12, 21, and 28 were used to synthesize NRPs. Here, we examined secondary metabolites of S. agglomeratus 5-1-3 isolated from soils in the Qinghai-Tibet Plateau, China, for NRPs with antibacterial activity.ResultsWe isolated a total of 36 Streptomyces strains with distinct colony morphological characteristics from 7 soil samples. We screened 8 Streptomyces strains resistant to methicillin-resistant Staphylococcus aureus (MRSA). We then selected S. agglomeratus 5-1-3 for further study based on results of an antibacterial activity test. Here, we isolated three compounds from S. agglomeratus 5-1-3 and characterized their properties. The crude extract was extracted with ethyl acetate and purified with column chromatography and semipreparative high-performance liquid chromatography (HPLC). We characterized the three compounds using NMR analyses as echinomycin (1), 5,7,4ʹ-trihydroxy-3.3′,5′-trimethoxy flavone (2), and 2,6,2′, 6′-tetramethoxy-4,4-bis(2,3-epoxy-1-hydroxypropyl)-biphenyl (3). We tested the antibacterial activity of pure compounds from strain 5-1-3 with the Oxford cup method. NRP echinomycin (1) showed excellent anti-MRSA activity with a minimum inhibitory concentration (MIC) of 2.0 μg/mL. Meanwhile, MIC of compound 2 and 3 was 128.0 μg/mL for both. In addition, 203 mg of echinomycin was isolated from 10 L of the crude extract broth of strain 5-1-3.ConclusionIn this study, S. agglomeratus 5-1-3 with strong resistance to MRSA was isolated from the soils in the Qinghai-Tibet Plateau. Strain 5-1-3 had a high yield of echinomycin (1) an NRP with a MIC of 2 μg/mL against MRSA. We propose that echinomycin derived from S. agglomeratus 5-1-3 may be a potent antibacterial agent for pharmaceutical use.

Anti-pancreatic lipase and anti-adipogenic effects of 5,7,3′,4′,5′-pentamethoxy and 6,2′,4′-trimethoxy flavone - An in vitro study

In this study, the anti-obesity effects of 5,7,3′,4′,5′-pentamethoxyflavone (PMF) and 6,2′,4′-trimethoxyflavone (TMF) were evaluated through two distinct mechanisms of action: inhibition of crude porcine pancreatic lipase (PL), and inhibition of adipogenesis in 3T3-L1 pre-adipocytes. Both flavones show dose dependent, competitive inhibition of PL activity. Molecular docking studies revealed binding of the flavones to the active site of PL. In 3T3-L1 adipocytes, both flavones reduced the accumulation of lipids and triglycerides. PMF and TMF also lowered the expression of adipogenic and lipogenic genes. They both reduced the expression of peroxisome proliferator-activated receptor-gamma (PPAR-γ), CCAAT/enhancer-binding protein α and β (C/EBP α and β), sterol regulatory element-binding protein 1 (SREBF 1), fatty acid synthase (FASN), adipocyte binding protein 2 (aP2), and leptin gene. In addition, these flavones enhanced adiponectin mRNA expression, increased lipolysis and enhanced the expression of lipolytic genes: adipose triglycerides lipase (ATGL), hormone sensitive lipase (HSL) and monoglycerides lipase (MAGL) in mature 3T3-L1 adipocytes. Overall, PMF was seen to be a more potent inhibitor of both PL activity and adipogenesis versus TMF. These results suggest that PMF and TMF possess anti-obesity activities and can be further evaluated for their anti-obesity effects.

Optimization of Ultrasound-Assisted Extraction of Yields and Total Methoxyflavone Contents from Kaempferia parviflora Rhizomes.

The major bioactive components of Kaempferia parviflora (KP) rhizomes, 3,5,7,3′,4′-pentamethoxyflavone (PMF), 5,7-dimethoxyflavone (DMF), and 5,7,4′-trimethoxyflavone (TMF), were chosen as the quantitative and qualitative markers for this plant material. In order to extract bioactive components (total methoxyflavones) from KP rhizomes, ultrasound-assisted extraction (UAE) was proposed as part of this study. Plackett–Burman design (PBD) and Box–Behnken design (BBD) were utilized to optimize the effects of UAE on extraction yields and total methoxyflavone contents in KP rhizomes. First, PBD was utilized to determine the effect of five independent variables on total yields and total methoxyflavone contents. The results indicated that the concentration of the extracting solvent (ethanol), the extraction time, and the ratio of solvent to solid were significant independent terms. Subsequently, BBD with three-level factorial experiments was used to optimize the crucial variables. It was discovered that the concentration of ethanol was the most influential variable on yields and total methoxyflavone contents. Optimum conditions for extraction yield were ethanol concentration (54.24% v/v), extraction time (25.25 min), and solvent-to-solid ratio (49.63 mL/g), while optimum conditions for total methoxyflavone content were ethanol concentration (95.00% v/v), extraction time (15.99 min), and solvent-to-solid ratio (50.00 mL/g). The relationship between the experimental and theoretical values was perfect, which proved that the regression models used were correct and that PBD and BBD were used to optimize the conditions in the UAE to obtain the highest yield and total methoxyflavone content in the KP rhizomes.

Quantitative analysis of methoxyflavones discriminates between the two types of Kaempferia parviflora.

Kaempferia parviflora or black ginger is abundantly cultivated because its rhizomes contain methoxyflavones that have many pharmacological properties. K. parviflora can be divided into two types, based on morphological characteristics, but differences in their chemical compositions have never been explored. This research aims to find chemical markers that can be used to differentiate between the two types of K. parviflora, the red-leaf and green-leaf types, by quantifying the amounts of methoxyflavones. K. parviflora samples were collected from 39 locations in Thailand. Their genetic diversity was assessed by a genotyping-by-sequencing (GBS) technique to construct the population structure. Their chemical compositions were analyzed by high performance liquid chromatography-photodiode array detection to determine the methoxyflavone contents. The population structure based on >3,000 single nucleotide polymorphism (SNP) markers showed that the samples can be divided into two groups, which were consistent with the classification by leaf margin color (red-leaf and green-leaf types). HPLC analysis revealed 3,5,7,3',4'-pentamethoxyflavone (PMF), 5,7-dimethoxyflavone (DMF), 5,7,4'-trimethoxyflavone (TMF), 3,5,7-trimethoxyflavone and 3,5,7,4'-tetramethoxyflavone as major methoxyflavones that can be used as chemical markers. The red-leaf type showed higher amounts of PMF, TMF and 3,5,7,4'-tetramethoxyflavone than the green-leaf type, while the green-leaf type showed higher amounts of DMF and 3,5,7-trimethoxyflavone than the red-leaf type. These results provide another approach to discriminate the two types of K. parviflora using chemical profiles alongside genetic and morphological analyses. Therefore, a specific type of K. parviflora can be selected over the other based on preferences for a certain methoxyflavone.

Integrating network pharmacology and an experimental validation strategy elucidates the protective effect and mechanism of callicarpa nudiflora against neuroinflammation.

Abnormal activation of microglia promotes neuroinflammation (NI) in Alzheimer's disease (AD). Callicarpa nudiflora Hook et Arn. (CN) is a traditional Chinese herb with a wide range of clinical applications and definite anti-inflammatory effects. However, the anti-inflammatory action and mechanism of NI are not known. The purpose of this research was to survey whether CN could inhibit lipopolysaccharide (LPS)-induced inflammatory activation in BV-2 microglia. This study used a network pharmacology and pharmacophore model-based approach to explore the molecular mechanism of CN anti-NI by combining molecular docking and experimental validation. First, we screened the key active components and targets of CN anti-NI by network pharmacology. Then, the common structural features of these functional molecules in the treatment of neuroinflammation were predicted by 3D-QSAR pharmacodynamic modeling. Finally, the molecular mechanism of the active ingredient 5-hydroxy-3,7,4'-trimethoxyflavone (THF) against neuroinflammation was validated by molecular docking and in vitro experiments. In conclusion, this study established the structure-activity relationships of the active components of CN anti-NI and provided new insights into the pharmacological mechanisms of CN anti-NI at an integrative level.

Protective Effect of Polymethoxyflavones Isolated from Kaempferia parviflora against TNF-α-Induced Human Dermal Fibroblast Damage.

Similar to other organs, the skin undergoes a natural aging process. Moreover, constant direct exposure to environmental stresses, including ultraviolet irradiation, causes the signs of skin aging to appear rather early. Reactive oxygen species (ROS) and inflammatory responses accelerate skin damage in extrinsic aging. In this study, we aimed to investigate the skin protective effects of polymethoxyflavones found in Kaempferia parviflora against oxidative stress and inflammation-induced damage in human dermal fibroblasts (HDFs) stimulated by tumor necrosis factor-α (TNF-α). The experimental data identified 5,7,4′ trimethoxyflavone (TMF) as the most potent constituent in preventing TNF-α-induced HDF damage among the tested compounds and it was not only effective in inhibiting matrix metalloproteinase-1 (MMP-1) production but also in stimulating collagen, type I, and alpha 1 (COLIA1) expression. TMF suppressed TNF-α-stimulated generation of ROS and pro-inflammatory mediators, such as cyclooxygenase-2 (COX-2), interleukin (IL)-1β, and IL-6 in HDFs. TMF also inhibited the pathways regulating fibroblast damage, including mitogen-activated protein kinase (MAPK), activator protein 1 (AP-1), and nuclear factor-kappa B (NF-κB). In conclusion, TMF may be a potential agent for preventing skin aging and other dermatological disorders associated with oxidative stress and inflammation.

Trimethoxy flavone, pachypodol containing pogostemon cablin leaf extract shows broad spectrum antimicrobial activity

Natural products have become a promising therapy for many pathogenic infectious conditions. In the present study, leaves of P. cablin were extracted using Hexane and ethyl acetate. Leaf Ethyl acetate extract showed significantly better antimicrobial activity against both Staphylococcus aureus 6538 (Gram-positive) (SA) and Klebsiella pneumonia ATCC 27,736 (Gram-negative) bacteria compared to the Hexane extract and was subjected to phytochemical analysis and chromatographic seperation. Phytochemical analysis of P. cablin leaf EtOAc extract showed the presence of Tannins, Flavanoids and Terpenoids. Subjecting the EtOAc leaf extract to column chromatographic separation resulted in the isolation of a trimethoxy flavone, pachypodol.

Antiprotozoal Activity of Secondary Metabolites from Salvia circinata

Salvia circinata Cav., Lamiaceae, is commonly used in Mexican traditional medicine to treat gastrointestinal ailments, including diarrhea. An acetone-soluble extract from the aerial parts of S. circinata was suspended in a 9:1 methanol–water mixture and fractionated by partition with hexane and EtOAc. The hexane, EtOAc, and aqueous fractions were evaluated for their antiprotozoal activities, where the EtOAc-soluble fraction displayed the best antiprotozoal activity. Resolution of this fraction by chromatographic methods afforded the known diterpenoids amarissinins A–C (1–3), teotihuacanin (4), and amarisolide F (5), along with two flavones, apigenin (6) and 5,6-dihydroxy-7,3′,4′-trimethoxy flavone (7). Compound 7 was the most active one, with IC50 values of 0.05 μM and 0.13 μM against Entamoeba histolytica and Giardia lamblia, respectively. Interestingly, it was even more active than metronidazole and emetine, used as positive controls. Compounds 1–6 showed moderate antiprotozoal activity with IC50 values ranging from 23.9 to 67.8 μM against Entamoeba histolytica, and 39.4 to 127 μM against Giardia lamblia. These results provide evidence-based support for the traditional use of S. circinata, and suggest that the 5,6-dihydroxy-7,3′,4′-trimethoxy flavone (7) may have an important role in the antidiarrheal activity of the plant.

Two new polyoxygenated flavonoids from Blumea eriantha DC, methanol extract and their anti-proliferative activity

Two new flavonoids, 3, 3', 4' -Trihydroxy- 6, 7, 8 -trimethoxy flavone (1) and 3-Hydroxy-6, 7, 8, 3', 4'-pentamethoxy flavone (2) have been isolated from the methanol extract of Blumea eriantha DC. The structures of these compounds were determined on the basis of spectroscopic techniques such as IR, MS, 1 D, and 2 D NMR spectroscopy. The compounds (1) and (2) were tested for their anti-proliferative activity on NCI-H23 cell line. A standard drug Paclitaxel showed potent anti-proliferative effect (56%) at 100 nM concentration after 24 h treatment whereas compound (2) did not show any anti-proliferative effect. Only compound (1) showed significant reduction in cell viability at concentration 25773 nM (89%) and 257731 nM (68%) after 24 h when compared with 0.1% DMSO. The compound (1) showed significant but much lower reduction in cell viability as compared to the standard drug Paclitaxel.

Modulation of glioma-inflammation crosstalk profiles in human glioblastoma cells by indirubin-3’-(2,3 dihydroxypropyl)-oximether (E804) and 7-bromoindirubin-3′-oxime (7BIO)

Indirubins E804 (indirubin-3’-(2,3 dihydroxypropyl)-oximether) and 7BIO (7-Bromoindirubin-3′-oxime) are synthetic derivatives of natural indirubin, the active compound in Danggui Longhui Wan, a traditional Chinese remedy for cancer and inflammation. Herein, we explore E804 and 7BIO for their potential to modulate key pro-inflammatory genes and cytokines in LN-18 and T98G glioblastoma cells. High grade gliomas typically secrete large amounts of inflammatory cytokines and growth factors that promote tumor growth in an autocrine fashion. Inflammation is emerging as a key concern in the success of new treatment modalities for glioblastomas. Studies indicate that select indirubin derivatives bind and activate signaling of the AHR pathway, as well as inhibit cyclin-dependent kinases and STAT3 signaling. AHR signaling is involved in hematopoiesis, immune function, cell cycling, and inflammation, and thus may be a possible target for glioma treatment. To determine the significance of the AHR pathway in LN-18 and T98G glioma inflammatory profiles, and on the effects of E804 and 7BIO on these profiles, we used 6,2′,4′-trimethoxyflavone (TMF), a putative selective AHR antagonist. It was confirmed that E804 and 7BIO activates the AHR leading to cyp1b1 expression, and that TMF antagonizes expression. We then employed a commercial cancer inflammation and immunity crosstalk qRT-PCR array to screen for anti-inflammatory related properties. TMF alone inhibited expression of ifng, ptsg2, il12b, tnfa, il10, il13, the balance between pd1 and pdl1, and even expression of mhc1a/b. E804 was very potent in suppressing many pro-inflammatory genes, including il1a, il1b, il12a, ptgs2, tlr4, and others. E804 also affected expression of il6, vegfa, and stat3. Conversely, 7BIO induced cox2, but suppressed a different selection of pro-inflammatory genes including nos2, tnfa, and igf1. Secretion of IL-6 protein, an iconic inflammatory cytokine, was decreased by E804. VEGF (vascular endothelial growth factor) protein secretion was upregulated by 7BIO, yet downregulated by E804 and E804 plus TMF. Thus, E804 is both an AHR ligand and regulator of important pro-inflammatory cytokines such as IL-6 and oncogene STAT3, among others. Our results point to the use of E804 and TMF in combination as a promising new treatment for glioblastoma.

Induction of ER Stress-Mediated Apoptosis by the Major Component 5,7,4′-Trimethoxyflavone Isolated from Kaempferia parviflora Tea Infusion

Kaempferia parviflora (KP) is a famous medicinal plant from Thailand, and is a rich source of various kinds of methoxyflavones (MFs). Many kinds of food products such as tea, capsule, and liquor are manufactured from the rhizomes of KP. In this study, KP infusions were prepared with different brewing conditions, and the amounts of three major methoxylflavones, 5,7-dimethoxyflavone (DMF), 5,7,4′-trimethoxyflavone (TMF), and 3,5,7,3′,4′-pentamethoxyflavone (PMF), were analyzed. The antiproliferative activities of DMF, TMF, and PMF isolated from the brewed tea samples were evaluated. TMF was discovered to be significantly effective at inhibiting proliferation of SNU-16 human gastric cancer cells in a concentration dependent manner. TMF induced apoptosis, as evidenced by increments of sub-G1 phase, DNA fragmentation, annexin-V/PI staining, the Bax/Bcl-xL ratio, proteolytic activation of caspase-3,-7,-8, and degradation of poly (ADP-ribose) polymerase (PARP) protein. Furthermore, it was found that TMF induced apoptosis via ER stress, verified by an increase in the level of C/EBP homologous protein (CHOP), glucose regulated protein 78 (GRP78), inositol-requiring enzyme 1 α (IRE1α), activating transcription factor-4 (ATF-4), and the splice isoform of X-box-binding protein-1 (XBP-1) mRNA.

Effect of certain trimethoxy flavones on paclitaxel - induced peripheral neuropathy in mice

BackgroundThe anti - nociceptive effect of 7, 2′, 3′ – trimethoxy flavone, 7, 2′, 4′ – trimethoxy flavone, 7, 3′, 4′ – trimethoxy flavone and 7, 5, 4′ – trimethoxy flavone against inflammatory, neurogenic and thermal pain in mice was reported earlier. The present study was designed to investigate the effect of the above trimethoxy flavones in amelioration of peripheral neuropathy induced by paclitaxel. MethodsPeripheral neuropathy was induced in mice by administration of a single i.p. dose (10mg/kg) of paclitaxel. The manifestations of peripheral neuropathy such as tactile allodynia, cold allodynia and thermal hyperalgesia were assessed 24h later by employing hair aesthesiometer test, acetone bubble test and hot water tail immersion test respectively. Further, the role of inflammatory cytokines like TNF – α, IL - 1β and free radicals in the action of trimethoxy flavones was investigated using in vitro assays. ResultsThe test compounds dose dependently attenuated paclitaxel - induced tactile allodynia, cold allodynia and thermal hyperalgesia in mice. The test compounds inhibited TNF – α, IL - 1β and free radicals in a concentration dependent manner. ConclusionThe investigated trimethoxy flavones attenuated paclitaxel – induced peripheral neuropathy in mice. The inhibition of cytokines and free radicals in addition to many neuronal mechanisms reported earlier may contribute to this beneficial effect.

The wound-healing effect of 7,3',4'-trimethoxyflavone through increased levels of prostaglandin E2 by 15-hydroxyprostaglandin dehydrogenase inhibition.

To find an inhibitor of 15-hydroxyprostaglandin dehydrogenase (15-PGDH) that rapidly metabolises Prostaglandin E2 (PGE2) as a mediator of wound healing, we examined seven flavonoids for this role. 7,3',4'-Trimethoxyflavone (TMF) had the lowest IC50 value of 0.34µM for 15-PGDH inhibition but>400µM for cytotoxicity, indicating a high therapeutic index. TMF elevated PGE2 levels in a concentration-dependent manner in both A549 lung cancer and HaCaT cells. It also significantly increased mRNA expression of multidrug resistance-associated protein 4 (MRP4) and of prostaglandin transporter (PGT) slightly in HaCaT cells. In addition, TMF facilitated in vitro wound healing in a HaCaT scratch model, which was completely inhibited by adding both 15-PGDH and NAD+ as cofactor, confirming the involvement of PGE2 in its wound healing effect. TMF with a high therapeutic index can facilitate wound healing through PGE2 elevation by 15-PGDH inhibition.

Solanum trilobatum beneficially modulates dimethyl benz (a)anthracene induced skin carcinogenesis and erhlich Ascites cell induced solid tumor in mice

The aim of this study was to assess the potential of chloroform extract of S. trilobatum (CST) on 7,12-dimethyl benz (a)anthracene (DMBA) induced skin carcinogenesis and Ehrlich ascites carcinoma cells (EAC) induced solid tumor in mice. CST was obtained by exhaustive extraction with chloroform. Skin carcinogenesis was induced in Swiss albino mice by applying DMBA, while solid tumor was induced by intramuscular injection of EAC cells. For preventing skin carcinogenesis, animals were treated with CST (5 mg/kg body weight/100 μl acetone) before and after DMBA application for 15 days. Solid tumor was treated with CST (400 mg/kg body weight) prophylatically and post inoculation. After the experimental period, several anti tumor parameters and antioxidant status of skin of treated and control animals were determined. Solid tumor progression was determined by measuring the tumor diameter for 36 days. CST was sub-fractionated with different solvents and each fraction was subjected to HPLC-MS. HPLC-MS analysis showed the presence of two components with possible anti-cancer activity viz. 3,5,7 trimethoxy flavone and vitexin per-O-acetyl. The biochemical results showed that CST treatment reduced the number of skin papillomas, tumor incidence as well as modulated the antioxidant status of the skin in a beneficial way. CST reduced the solid tumor volume induced by EAC significantly. In conclusion, CST with its biologically active components may be used as a part of cancer treatment.

Improved dissolution of Kaempferia parviflora extract for oral administration by preparing solid dispersion via solvent evaporation

Kaempferia parviflora, a plant in the family Zingiberaceae, has been used in Thai traditional medicines for treating hypertension and promoting longevity with good health and well-being. However, its limited aqueous solubility and low dissolution restrict its bioavailability. The aim of the study was therefore to improve the dissolution rate of K. parviflora extracted with dichloromethane (KPD) by solid dispersions. Different water-soluble polymers were applied to improve dissolution of KPD. The solid dispersions in different ratios were prepared by solvent evaporation method. Only hydroxypropyl methylcellulose (HPMC) and polyvinyl alcohol-polyethylene glycol grafted copolymer (PVA-co-PEG) could be used to produce homogeneous, powdered solid dispersions. Physical characterization by scanning electron microscopy, hot stage microscopy, differential scanning calorimetry and powder X-ray diffractometry, in comparison with corresponding physical mixtures, showed the changes in solid state during the formation of solid dispersions. Dissolution of a selected marker, 5,7,4′-trimethoxyflavone (TMF), from KPD/HPMC and KPD/PVA-co-PEG solid dispersions was significantly improved, compared with pure KPD. The dissolution enhancement by solid dispersion was influenced by both type and content of polymers. The stability of KPD/HPMC and KPD/PVA-co-PEG solid dispersions was also good after 6-month storage in both long-term and accelerated conditions. These results identified that the KPD/HPMC and KPD/PVA-co-PEG solid dispersions were an effective new approach for pharmaceutical application of K. parviflora.