Chemical structures and induction of cell death via heat shock protein inhibition of the prenylated phloroglucinol derivatives isolated from Hypericum erectum.

Four new prenylated phloroglucinol derivatives (+)-erectumol I (1a), (-)-erectumol I (1b), (-)-erectumol II (2a), and (+)-erectumol II (2b) were isolated from the methanol extracts of the whole plants of Hypericum erectum. These new compounds were isolated as a pair of enantiomers, respectively. The planar chemical structures and relative configurations of the new compounds were suggested by Cu-Kα X-ray diffraction analysis and been confirmed by high-resolution mass and 1D and 2D NMR spectroscopic data. The absolute configuration of the four new compounds were established by comparing the experimental and predicted electronic circular dichroism data. Isolated compounds 1b and 2b induced death of Adriamycin-treated HeLa cells. Their enantiomers 1a and 2a did not. In addition, the apparent mechanism of cell death of 1b was the inhibited expression of heat shock protein 105.

Pueraria montana var. lobata root extract inhibits photoaging on skin through Nrf2 pathway.

Pueraria montana var. lobata is a bioactive substance, in possession of a variety of beneficial health effects, which has long been extensively used as a traditional medication for the treatment of fever, acute dysentery, diabetes, and cardiovascular diseases in North-East Asian countries. The purpose of this study was to evaluate the cytoprotective activity of Pueraria montana var. lobata ethanol extract (PLE) for ultraviolet B (UVB) induced oxidative stress in human dermal fibroblasts (HDF). It was hypothesized that PLE treatment (25-100 µg/mL) would reduce intracellular reactive oxygen species (ROS) levels as well as increase collagen production in UVB-irradiated HDF. The results confirmed this theory, with collagen production increasing in the PLE treatment group in a dose-dependent manner. In addition, regulators of cellular ROS accumulation, including HO-1 and NOQ-1, were activated by Nrf2, which was mediated by PLE. Hence, intracellular levels of ROS were also reduced in the PLE treatment group in a dose-dependent manner. In conclusion, PLE increases collagen production and maintains hyaluronic acid (HA) levels in human dermal fibroblasts exposed to UVB-irradiation, thereby inhibiting photoaging.

Investigation of common chemical components and inhibitory effect on GES-type ß-lactamase (GES22) in methanolic extracts of Algerian seaweeds.

This study aimed to investigate the total phenolic content (TPC), the identification of the common compounds by HPLC-ESI-MS and HPLC-ESI-MS-TOF and the inhibitory effects against class A-type ß-lactamase (GES-22 variant, produced recombinantly) in methanolic extracts (MEs) of four Algerian seaweeds [Ulva intestinalis, Codium tomentosum, Dictyota dichotoma and Halopteris scoparia]. The TPC varied among the four species, ranging between 0.93 ±â€¯0.65 and 2.66 ±â€¯1.33 mg GAEs/g DW. C.tomentosum had higher total phenol content than other seaweeds while, all of them inhibited uncompetitively GES-22 activity in a dose-dependent manner. Nitrocefin was used as chromogenic substrate to evaluate the inhibitory effect on GES-22. The methanolic extract of D.dichotoma exhibited significant inhibitory effect on GES-22 (IC50 = 13.01 ±â€¯0.046 µg/mL) more than clavulanate, sulbactam and tazobactam (classical ß-lactam inhibitors) (IC50 = 68.38 ±â€¯0.17 µg/mL, 52.68 ±â€¯0.64 µg/mL, and 29.94 ±â€¯0.01 µg/mL, respectively). IC50 of the other ME of U.intestinalis, C.tomentosum, and H.scoparia were 16.87 ±â€¯0.10 µg/mL, 16.54 ±â€¯0.048 µg/mL, and 25.72 ±â€¯0.15 µg/mL, respectively. Except H. scoparia, other three seaweed extracts showed almost two times or more inhibition on GES-22. Furthermore, four common compounds in these MEs were identified, α-linolenic acid (C18:3ω3), linoleic acid (C18:2ω6), oleic acid (C18:1ω9), the eicosanoid precursors ''arachidonic acid'' (C20:4ω6). Baicalein (C15H10O5) was identified in U.intestinalis and D.dichotoma seaweeds. The fact that all seaweed extracts inhibited the GES-22 better than commercial samples makes these seaweeds candidate for discovering new inhibitors against ß-lactamases. Besides that, they contain important components with potential health benefits.

Alpha-terpineol affects synthesis and antitumor activity of triterpenoids from Antrodia cinnamomea mycelia in solid-state culture.

To enhance production of Antrodia cinnamomea triterpenoids (ACTs) from mycelia in solid-state culture, α-terpineol was added to the medium as an elicitor at an optimal concentration of 0.05 mL L-1. Multi-stage solvent extraction and HPLC analysis were performed, and the compositions of ACTs-E (from culture with elicitor) and ACTs-NE (from culture without elicitor) were found to be quite different. In assays of in vitro antitumor activity, ACTs-E, in comparison with ACTs-NE, produced stronger viability reduction in several tumor cell lines and stronger apoptosis induction in HeLa in a dose-dependent manner. Several related proteins involved in the mitochondrial pathway of apoptosis (p53, Bax, caspase-3) did not show expression upregulation by ACTs-E, suggesting that apoptosis induction occurred through a p53-independent process. Further analysis revealed that ACTs-E strongly inhibited synthesis of topoisomerase I (TOP1) and tyrosyl-DNA phosphodiesterase I (TDP1), which are involved in DNA repair, at both transcriptional and protein levels. Our findings suggest that ACTs-E have potential for applications in the pharmaceutical, clinical, and functional food industries, as a novel antitumor agent and a dual TOP1/TDP1 inhibitor.

Ginger (Zingiber officinale) phytochemicals-gingerenone-A and shogaol inhibit SaHPPK: molecular docking, molecular dynamics simulations and in vitro approaches.

BACKGROUND: Antibiotic resistance is a defense mechanism, harbored by pathogens to survive under unfavorable conditions. Among several antibiotic resistant microbial consortium, Staphylococcus aureus is one of the most havoc microorganisms. Staphylococcus aureus encodes a unique enzyme 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase (SaHPPK), against which, none of existing antibiotics have been reported. METHODS: Computational approaches have been instrumental in designing and discovering new drugs for several diseases. The present study highlights the impact of ginger phytochemicals on Staphylococcus aureus SaHPPK. Herein, we have retrieved eight ginger phytochemicals from published literature and investigated their inhibitory interactions with SaHPPK. To authenticate our work, the investigation proceeds considering the known antibiotics alongside the phytochemicals. Molecular docking was performed employing GOLD and CDOCKER. The compounds with the highest dock score from both the docking programmes were tested for their inhibitory capability in vitro. The binding conformations that were seated within the binding pocket showing strong interactions with the active sites residues rendered by highest dock score were forwarded towards the molecular dynamic (MD) simulation analysis. RESULTS: Based on molecular dock scores, molecular interaction with catalytic active residues and MD simulations studies, two ginger phytochemicals, gingerenone-A and shogaol have been proposed as candidate inhibitors against Staphylococcus aureus. They have demonstrated higher dock scores than the known antibiotics and have represented interactions with the key residues within the active site. Furthermore, these compounds have rendered considerable inhibitory activity when tested in vitro. Additionally, their superiority was corroborated by stable MD results conducted for 100 ns employing GROMACS package. CONCLUSIONS: Finally, we suggest that gingerenone-A and shogaol may either be potential SaHPPK inhibitors or can be used as fundamental platforms for novel SaHPPK inhibitor development.

Short communication: Cheese supplemented with Thymus algeriensis oil, a potential natural food preservative.

The essential oil of Thymus algeriensis was analyzed as a potential preservative in soft cheese. We developed a novel method to test the preserving properties of essential oil in soft cheese. Contamination incidence of Penicillium aurantiogriseum was absent after 30 d of storage at 4°C with 25 µL of essential oil added. The antimicrobial activity was tested against 8 bacteria and 8 fungi. Thymus algeriensis oil showed inhibitory activity against tested bacteria at 0.03 to 0.09 mg/mL, and bactericidal activity was achieved at 0.05 to 0.15 mg/mL. For antifungal activity, minimum inhibitory concentrations ranged between 0.01 and 0.04 mg/mL and minimum fungicidal concentrations between 0.01 and 0.04 mg/mL. Furthermore, the oil was also screened for antiradical activity using the 1,1-diphenyl-2-picrylhydrazyl assay. The results showed that the oil was active and achieved half-maximal inhibitory activity at 0.132 mg/mL. We used gas chromatography, gas chromatography-mass spectrometry, and nuclear magnetic resonance spectrometry to investigate the volatile compounds from the oil. Carvacrol was identified as the main compound in the oil, represented by 80.9% of the total constituents, followed by p-cymene (7.7%).

Inhibitory Effects of Panduratin A on Periodontitis-Induced Inflammation and Osteoclastogenesis through Inhibition of MAPK Pathways In Vitro.

Periodontitis is an inflammatory disease caused by microbial lipopolysaccharide (LPS), destroying gingival tissues and alveolar bone in the periodontium. In the present study, we evaluated the anti-inflammatory and anti-osteoclastic effects of panduratin A, a chalcone compound isolated from Boesenbergia pandurata, in human gingival fibroblast-1 (HGF-1) and RAW 264.7 cells. Treatment of panduratin A to LPS-stimulated HGF-1 significantly reduced the expression of interleukin-1ß and nuclear factor-kappa B (NF-κB), subsequently leading to the inhibition of matrix metalloproteinase-2 (MMP-2) and MMP-8 compared with that in the LPS control (**p < 0.01). These anti-inflammatory responses were mediated by suppressing the mitogen-activated protein kinase (MAPK) signaling and activator protein-1 complex formation pathways. Moreover, receptor activator of NF-κB ligand (RANKL)-stimulated RAW 264.7 cells treated with panduratin A showed significant inhibition of osteoclastic transcription factors such as nuclear factor of activated T-cells c1 and c-Fos as well as osteoclastic enzymes such as tartrate-resistant acid phosphatase and cathepsin K compared with those in the RANKL control (**p < 0.01). Similar to HGF-1, panduratin A suppressed osteoclastogenesis by controlling MAPK signaling pathways. Taken together, these results suggest that panduratin A could be a potential candidate for development as a natural anti-periodontitis agent.

A hot-water extract of Sanguisorba officinalis ameliorates endotoxin-induced septic shock by inhibiting inflammasome activation.

The inflammasome is a multiprotein signaling complex that mediates inflammatory innate immune responses through caspase 1 activation and subsequent IL-1ß secretion. However, because its aberrant activation often leads to inflammatory diseases, targeting the inflammasome holds promise for the treatment of inflammation-related diseases. In this study, it was found that a hot-water extract of Sanguisorba officinalis (HSO) suppresses inflammasome activation triggered by adenosine 5'-triphosphate, nigericin, microbial pathogens, and double stranded DNA in bone marrow-derived macrophages. HSO was found to significantly suppress IL-1ß production in a dose-dependent manner; this effect correlated well with small amounts of caspase 1 and little ASC pyroptosome formation in HSO-treated cells. The anti-inflammatory activity of HSO was further confirmed in a mouse model of endotoxin-induced septic shock. Oral administration of HSO reduced IL-1ß titers in the serum and peritoneal cavity, increasing the survival rate. Taken together, our results suggest that HSO is an inhibits inflammasome activation through nucleotide-binding domain and leucine-rich repeat pyrin domain 3, nucleotide-binding domain and leucine-rich repeat caspase recruitment domain 4 and absent in melanoma 2 pathways, and may be useful for treatment of inflammasome-mediated diseases.

Anticonvulsant effect of the hydroethanolic leaf extract of Psydrax subcordata (DC.) Bridson in murine models.

ETHNOPHARMACOLOGICAL RELEVANCE: Psydrax subcordata (DC.) Bridson is a tropical medicinal plant used traditionally for the management of epilepsy. However, there is little scientific evidence to support its use. AIM OF STUDY: The current study investigated the anticonvulsant properties of the hydroethanolic leaf extract of Psydrax subcordata (PSE) in animal models. MATERIALS AND METHODS: The anticonvulsant effects were evaluated in mouse models of acute seizures (pentylenetetrazole-, picrotoxin-, 4-aminopyridine-, strychnine- and maximal electroshock-induced seizure tests) and status epilepticus (Lithium/pilocarpine-induced SE). The role of GABAergic mechanisms in the actions of the extract was also examined by pre-treatment of animals with flumazenil in the pentylenetetrazole test. RESULTS: The extract (30, 100 and 300mg/kg, p.o.) significantly delayed the onset and decreased the duration and frequency of pentylenetetrazole- and picrotoxin-convulsions. PSE also reduced the duration of tonic hind limb extensions in the maximal electroshock-induced seizure test. Furthermore, PSE pre-treatment significantly delayed the onset of seizures and improved survival in the 4-aminopyridine-induced seizure test. In the strychnine-induced seizure test, PSE treatment did not significantly affect the latency to convulsions and time until death when compared to controls. PSE exhibited anticonvulsant effects in the lithium/pilocarpine test by delaying the onset of seizures and status epilepticus as well as reducing the severity of seizures and mortality of mice. Again, the anticonvulsant effect of PSE (100mg/kg, p.o.) was blocked by pre-treatment with flumazenil in the PTZ test. CONCLUSION: PSE has anticonvulsant activity in animal models, and this effect may be mediated, at least partly, through GABAergic mechanisms.

Inhibitory Effect of the Ethanol Extract of a Rice Bran Mixture Comprising Angelica gigas, Cnidium officinale, Artemisia princeps, and Camellia sinensis on Brucella abortus Uptake by Professional and Nonprofessional Phagocytes.

In this study, we evaluated the inhibitory effect of a rice bran mixture extract (RBE) on Brucella abortus pathogenesis in professional (RAW 264.7) and nonprofessional (HeLa) phagocytes. We fermented the rice bran mixture and then extracted it with 50% ethanol followed by gas chromatography-mass spectrometry to identify the components in RBE. Our results clearly showed that RBE caused a significant reduction in the adherence of B. abortus in both cell lines. Furthermore, analysis of phagocytic signaling proteins by western blot assay revealed that RBE pretreatment resulted in inhibition of phosphorylation of JNK, ERK, and p38, leading to decline of internalization compared with the controls. Additionally, the intensity of F-actin observed by fluorescence microscopy and FACS was remarkably reduced in RBE-pretreated cells compared with control cells. However, the intracellular replication of B. abortus within phagocytes was not affected by RBE. Taken together, these findings suggest that the phagocytic receptor blocking and suppressive effects of RBE on the MAPK-linked phagocytic signaling pathway could negatively affect the invasion of B. abortus into phagocytes.

Anti-quorum sensing activity of Pistacia atlantica against Pseudomonas aeruginosa PAO1 and identification of its bioactive compounds.

Pseudomonas aeruginosa is a multidrug resistant opportunistic pathogen and an important cause of nosocomial infections. Quorum-sensing (QS) is a process in which bacterial cell-cell communication can regulates production of many virulence factors including pigment formation and the ability to form biofilm which is essential for establishment of chronic infections. We examined the inhibitory effect of Pistacia atlantica (Anacardiaceae) methanolic leaf extract and its bioactive components on biofilm formation and pigment production by P. aeruginosa PAO1. Fractionation of the methanolic leaf extract was carried out using HPLC based activity profiling. Identification of the active compounds was carried out by the integrated approach of HPLC-DAD and LC-MS followed by molecular docking analysis. Pistacia atlantica crude extract at 2 and 1 mg/mL, inhibited 92% and 79% biofilm formation, respectively. Minimum biofilm inhibitory concentration (MBIC) determined by microbroth dilution was 0.25 mg/mL with 39% inhibition. Pyocyanin production measured by spectrophotometry showed 100% and 83% inhibition at 2 and 1 mg/mL and minimum inhibitory concentration (MIC) was 0.5 mg/mL with 40% inhibition. Four active HPLC fractions (11, 15, 16 and 19) showed MBIC values of 0.06, 0.16, 0.10, 0.15 mg/mL, and MICs for pyocyanin production of 0.49, 0.31, 0.76, >0.30 mg/mL, respectively. The active compounds were identified as rutin (1), myricetin, 3-O-rutinoside (2) and kaempferol-3-O-rutinoside (4), all belonging to the flavonoid family. Molecular docking simulation of the active compounds showed that all had high affinity for LasR protein which is an important quorum-sensing signal receptor. The results of this study suggest that the active components of P. atlantica have high anti-QS activities and may have the potential for treatment of chronic infections caused by Pseudomonas aeruginosa.

Investigation of the interaction for three Citrus flavonoids and α-amylase by surface plasmon resonance.

Flavonoids, a class of natural drugs with broad biological activity, exhibit inhibitory effect on α-amylase. Citrus peel is a good source of flavonoids. The real-time interactions between three Citrus flavonoids (naringin, neohesperidin, hesperidin) and α-amylase were investigated by surface plasmon resonance biosensor, and were compared with the α-amylase inhibitors, acarbose. These results showed the binding affinities of naringin, neohesperidin and hesperidin with α-amylase reach the highest at pH6 with KD values of 2.27±0.18mM, 3.09±0.20mM and 3.51±0.09mM, and can be reinforced with 0.2M NaCl and 0.1M CaCl2, respectively. The results of 1, 1-diphenyl-2-picryl hydrazyl radical assay indicate that the antioxidant activities of naringin, neohesperidin and hesperidin are significantly inhibited by interacting with α-amylase, and the inhibition percentage are 47.61±0.034%, 22.81±0.037% and 21.01±0.051%, respectively. Additionally, it is found that both the number and the position of hydroxyl group play an important role in the interaction of three Citrus flavonoids and α-amylase. These results provide useful information for rapid screening inhibitors of α-amylase from plant-based food.

Evidence for the Involvement of Monoaminergic Pathways in the Antidepressant-Like Activity of Cymbopogon citratus in Mice.

Objectives Depression is a complex neuropsychiatric disorder, which affects the quality of life of the sufferers and treatment approach is associated with serious adverse effects and sometimes therapeutic failures. Cymbopogon citratus leaf (CC) has been reported to exert anti-depressant effect but its mechanism of action is yet to be elucidated hence, the need for this study. Methods The anti-depressant-like effect of Cymbopogon citratus aqueous leaf was evaluated using forced swim test (FST), tail suspension test (TST) and yohimbine-induced lethality test (YLT) in aggregated mice. Interaction studies involving p-chlorophenylalanine (pCPA), an inhibitor of serotonin biosynthesis and yohimbine, α2-adrenergic receptor antagonist were carried out to evaluate the role of monoaminergic system in the anti-depressant-like effect of CC. The effect of CC on spontaneous motor activity (SMA) was also assessed using activity cage. ResultsCymbopogon citratus (25 and 50 mg/kg, p.o.) demonstrated antidepressant-like activity devoid of significant stimulation of the SMA in mice. However, the antidepressant-like property of CC was significantly (p<0.05) attenuated by pretreatment with yohimbine suggesting involvement of noradrenergic pathway in the action of the extract. Also, pCPA reversed the anti-immobility effect of CC, indicating the role of serotonergic system in the mediation of its antidepressant activity. Moreover, CC (25 and 50 mg/kg) potentiated the lethal effect of yohimbine in aggregated mice, which further suggest the involvement of monoaminergic systems in its action. Conclusions The results of the study showed that C. citratus might be interacting with serotonergic and noradrenergic pathways to mediate its anti-depressant-like effect in mice.

Mechanisms underlying the diuretic effect of Gomphrena celosioides Mart. (Amaranthaceae).

ETHNOPHARMACOLOGICAL RELEVANCE: Gomphrena celosioides (Amaranthaceae) is a native medicinal plant found in Mato Grosso do Sul State that is used for treating urinary tract and kidney stones. This study aimed to evaluate the diuretic effects of ethanolic extract from G. celosioides (EEGC) on acute and extended diuresis to provide a pharmacological basis for its use in traditional medicine. AIM OF THE STUDY: To evaluate the diuretic and natriuretic activity of EEGC and its mechanism of action in an animal model. MATERIALS AND METHODS: EEGC (30, 100 and 300mg/kg) was orally administered in male Wistar rats, and urinary excretion was measured at intervals of up to 8h after administration. To evaluate participation of the nitric oxide (NO), prostaglandin and bradykinin pathways in its effect, respective inhibitors were also administered together with effectives doses of EEGC and compared with control groups. A 7-day model with daily administration and urine measurement was also carried out. RESULTS: Oral administration of doses of 100 and 300 significantly increased urine output after 8h compared to the control group. It was observed this effect is dependent on the NO, prostaglandin and bradykinin pathways because their inhibitors reduced the diuretic effects of EEGC. Moreover, after 7 days of treatment, the effect was sustained and a decrease in serum aldosterone was observed in the extract group. CONCLUSION: According to the results, G. celosioides extract showed diuretic and natriuretic effects associated with more than one mechanism of action. Considering that all diuretic drugs are currently available for the treatment of volume and electrolyte disturbances, especially hypertensive status, the present results may have clinical relevance and open new possibilities for the development of new natural diuretics from G. celosioides.

Stabilization of natural colors and nutraceuticals: Inhibition of anthocyanin degradation in model beverages using polyphenols.

Anthocyanins are widely used as natural colorants in foods, but they are highly susceptible to chemical degradation during storage leading to color fading. This study examined the potential of natural quillaja saponin and polyphenols (vanillin, epigallocatechin gallate, green tea extract, and protocatechualdehyde) at inhibiting color fading of anthocyanins in model beverages. The purple carrot anthocyanin (0.025%) in model beverages (citric acid, pH 3.0) containing l-ascorbic acid (0.050%) degraded with a first-order reaction rate during storage (40°C/7days in light). The addition of polyphenols (0.2%) delayed color fading, with the most notable improvement observed with green tea extract addition. The half-life for anthocyanin color fading increased from 2.9 to 6.7days with green tea extract. Fluorescence quenching measurements showed that the green tea extract contained components that interacted with anthocyanins probably through hydrophobic interactions. Overall, this study provides valuable information about enhancing the stability of anthocyanins in beverage systems using polyphenols.

Dietary peptides from the non-digestible fraction of Phaseolus vulgaris L. decrease angiotensin II-dependent proliferation in HCT116 human colorectal cancer cells through the blockade of the renin-angiotensin system.

This study aimed to determine the ability of peptides present in the non-digestible fraction (NDF) of common beans to decrease angiotensin II (AngII) through the blockade of RAS and its effect on the proliferation of HCT116 human colorectal cancer cells. Pure synthesized peptides GLTSK and GEGSGA and the peptide fractions (PF) of cultivars Azufrado Higuera and Bayo Madero were used. The cells were pretreated with pure peptides, PF or AGT at their IC50 or IC25 values, in comparison with the simultaneous treatment of peptides and AGT. For western blot and microscopy analysis, 100 µM and 0.5 mg mL(-1) were used for pure peptides and PF treatments, respectively. According to the ELISA tests, GLTSK and GEGSGA decreased (p < 0.05) the conversion rate of AGT to angiotensin I (AngI) by 38 and 28%, respectively. All the peptides tested reduced (p < 0.05) the conversion rate of AngI to AngII from 38 to 50%. When the cells were pretreated with both pure peptides and PF before exposure to AGT, the effectiveness inhibiting cell proliferation was higher than the simultaneous treatment suggesting their preventive effects. GLTSK and GEGSGA interacted with the catalytic site of renin, the angiotensin-I converting enzyme, and the AngII receptor, mainly through hydrogen bonds, polar, hydrophobic and cation-π interactions according to molecular docking. Through confocal microscopy, it was determined that GLTSK and GEGSGA caused the decrease (p < 0.05) of AngII-dependent STAT3 nuclear activation in HCT116 cells by 66 and 23%, respectively. The results suggest that peptides present in the common bean NDF could potentially ameliorate the effects of RAS overexpression in colorectal cancer.

Antagonistic effects of indoloquinazoline alkaloids on antimycobacterial activity of evocarpine.

AIMS: The interaction of quinolone and indoloquinazoline alkaloids concerning their antimycobacterial activity was studied. METHODS AND RESULTS: The antimycobacterial and modulating activity of evodiamine (1), rutaecarpine (2) and evocarpine (3) was tested on mycobacteria including three multidrug-resistant (MDR) clinical isolates of Mycobacterium tuberculosis. Antagonistic effects were concluded from fractional inhibitory concentration (FICI) values. Interaction energies of the compounds were calculated using GLUE docking module implemented in GRID. 1 and 2 exhibited weak inhibition of rapidly growing mycobacteria, however, 1 was active against Myco. tuberculosis H37Rv (MIC = 10 mg l(-1) ) while 2 was inactive. Both 1 and 2 showed a marked antagonistic effect on the susceptibility of different mycobacterial strains to 3 giving FICI values between 5 and 9. The interaction energies between compounds 1 and 2 with compound 3 suggested the possibility of complex formation in solution. CONCLUSIONS: Indoloquinazoline alkaloids markedly reduce the antimycobacterial effect of the quinolone alkaloid evocarpine. Complex formation may play a role in the attenuation of its antimycobacterial activity. SIGNIFICANCE AND IMPACT OF THE STUDY: This study gives a striking example of antagonism between compounds present in the same plant extract which should be considered in natural product based screening projects.

Antidepressant and anxiolytic effects of the methanol root extract of Capparis thonningii: involvement of monoaminergic, cholinergic and GABAergic systems.

BACKGROUND: Capparis thonningii Schum. (Capparaceae) is used in traditional African Medicine for the treatment of mood disorders. OBJECTIVE: The study investigates antidepressant and anxiolytic activities of methanol root extract of C. thonningii (CT). METHODS: CT (25-100 mg/kg, p. o.) was administered 1 h before behavioral studies were carried out in mice. Antidepressant effect was investigated using the forced swimming test (FST) and tail suspension test (TST). The anxiolytic effect was evaluated using the elevated-plus maze test (EPM), hole-board test (HBT), and light-dark test. RESULTS: CT (25 and 50 mg/kg) increased swimming activity (P<0.05) by 92.73% and attenuated immobility time by 35.72%, similar to anti-immobility effect of imipramine (33.87%) in FST. In addition, CT (50 mg/kg) significantly (P<0.01) reduced immobility time by 30.24% in TST. -However, the antidepressant-like effect elicited by CT was reversed by metergoline, cyproheptadine, and sulpiride (40.81, 45.93, and 48.52%, respectively) pretreatment but prazosin, and yohimbine failed to reverse this antidepressant-like effect. Similar to diazepam, CT (25 mg/kg) increased duration of open arms exploration (P<0.05) by 43.73% in EPM, number of head-dips (HBT) (90.32%), and time spent in the light compartment by 45.77% in light/dark test indicating anxiolytic-like effect. The anxiolytic-like effect of CT was reversed by flumazenil pretreatment. CONCLUSION: The findings from this study suggest antidepressant-like effect of C. thonningii involving interaction with serotonergic (5-HT2), dopaminergic (D2), noradrenergic (α1 and α2), and muscarinic cholinergic systems; and anxiolytic effect through an interaction with GABAA benzodiazepine receptor.

Antagonistic interactions of "Ya-Sa-Marn-Phlae" ethanol extract in combination with topical antiseptics against clinical isolates of Staphylococcus aureus.

This investigation was aimed at assessing a possible interaction of a traditional Thai herbal recipe, "Ya-Sa-Marn-Phlae (YSMP)," used for wound treatments with topical antiseptics, povidone-iodine (PI) solution and hydrogen peroxide (H2O2), and effects of THR-SK010 alone and the combinations on Staphylococcus aureus. Antibacterial activities of ethanol extracts from the herbal recipe were determined against both methicillin resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S. aureus (MSSA). YSMP exhibited remarkable antistaphylococcal activity with MIC values of 3.9-7.8 µg/mL. This recipe possessed bacteriostatic activity and did not reduce the tolerance of both MRSA and MSSA isolates to the high ionic strength. Interaction between THR-SK010 and the antiseptics was carried out by checkerboard testing and time-kill assay. Both indifferent and slightly antagonistic effects were observed with THR-SK010/PI and THR-SK010/H2O2 combinations against the tested isolates. In addition to commercially available antiseptics, THR-SK010 offered additional therapeutic options for the decolonization of MRSA and MSSA. Topical application of plant extracts with antioxidant activity, such as THR-SK010, should not be used immediately with PI or H2O2 and further investigation on this interaction is needed.

Rhus verniciflua extract modulates survival of MCF-7 breast cancer cells through the modulation of AMPK-pathway.

Rhus verniciflua STOKES (RVS) is used as an anti-cancer agent in traditional herbal medicine. However, the underlying molecular mechanism of its action is poorly understood. Here, we elucidated the mechanism of the anti-cancer mechanism of RVS in MCF-7 human breast cancer cells. We found that RVS increased the phosphorylation of AMP-activated protein kinase (AMPK) and downstream acetyl-CoA carboxylase (ACC) and suppressed cell viability in an AMPK-dependent fashion. RVS also induced an increase in reactive oxygen species (ROS) levels. RVS-induced AMPK phosphorylation was not observed in the presence of N-acetyl-cysteine (NAC), which indicated that ROS is associated with RVS-induced AMPK phosphorylation. In addition, fluorescent staining (Annexin V/propidium iodide) revealed that RVS increased the expression of Annexin V, which indicates that RVS leads to cancer-induced apoptosis. Moreover, RVS increased the phosphorylation of p53 and the expression of Bax. The inhibition of AMPK blocked RVS-induced p53 phosphorylation and Bax expression, which suggests that AMPK is involved in RVS-induced cancer apoptosis. Taken together, these results demonstrate that RVS has anti-tumor effects on MCF-7 cells through an AMPK-signaling pathway.