Leaf nodule endosymbiotic Burkholderia confer targeted allelopathy to their Psychotria hosts.

After a century of investigations, the function of the obligate betaproteobacterial endosymbionts accommodated in leaf nodules of tropical Rubiaceae remained enigmatic. We report that the α-D-glucose analogue (+)-streptol, systemically supplied by mature Ca. Burkholderia kirkii nodules to their Psychotria hosts, exhibits potent and selective root growth inhibiting activity. We provide compelling evidence that (+)-streptol specifically affects meristematic root cells transitioning to anisotropic elongation by disrupting cell wall organization in a mechanism of action that is distinct from canonical cellulose biosynthesis inhibitors. We observed no inhibitory or cytotoxic effects on organisms other than seed plants, further suggesting (+)-streptol as a bona fide allelochemical. We propose that the suppression of growth of plant competitors is a major driver of the formation and maintenance of the Psychotria-Burkholderia association. In addition to potential agricultural applications as a herbicidal agent, (+)-streptol might also prove useful to dissect plant cell and organ growth processes.

UVA and UVB Photoprotective Capabilities of Topical Formulations Containing Mycosporine-like Amino Acids (MAAs) through Different Biological Effective Protection Factors (BEPFs).

The safety and stability of synthetic UV-filters and the procedures for evaluating the photoprotective capability of commercial sunscreens are under continuous review. The influence of pH and temperature stressors on the stability of certain Mycosporine-like amino acids (MAAs) isolated at high purity levels was examined. MAAs were highly stable at room temperature during 24 h at pH 4.5⁻8.5. At 50 °C, MAAs showed instability at pH 10.5 while at 85 °C, progressive disappearances were observed for MAAs through the studied pH range. In alkaline conditions, their degradation was much faster. Mycosporine-serinol and porphyra-334 (+shinorine) were the most stable MAAs under the conditions tested. They were included in four cosmetically stable topical sunscreens, of which the Sun Protection Factor (SPF) and other Biological Effective Protection Factors (BEPFs) were calculated. The formulation containing these MAAs showed similar SPF and UVB-BEPFs values as those of the reference sunscreen, composed of synthetic UV absorbing filters in similar percentages, while UVA-BEPFs values were slightly lower. Current in vitro data strongly suggest that MAAs, as natural and safe UV-absorbing and antioxidant compounds, have high potential for protection against the diverse harmful effects of solar UV radiation. In addition, novel complementary in vitro tests for evaluation of commercial sunscreens efficacy are proposed.

Bioactive compound 1,8-Cineole selectively induces G2/M arrest in A431 cells through the upregulation of the p53 signaling pathway and molecular docking studies.

BACKGROUND: Callistemon citrinus has been traditionally known for its medicinal property. Recently, our research group identified 1,8-Cineole, as one of the predominant compound present in the hexane extract (HE-C), whose leaves have potent anticancer activity. HYPOTHESIS/PURPOSE: The present study was designed to isolate 1,8-Cineole from Callistemon citrinus plant and to determine their role in anticancer effects in in vitro using skin carcinoma cells. Moreover, the molecular mechanism of apoptosis and molecular docking studies were also investigated. STUDY DESIGN/METHODS: In vitro cytotoxicity test was performed with HE-C fractionates 1F, 2F, and 3F against A431 and HaCaT cell lines. MTT and AB assay demonstrated that 1F was toxic to cancer cells with no adverse effect to non-malignant cells and it was subjected to 1H NMR, 13C NMR spectroscopy and further characterized by FTIR and GC-MS analysis. On the basis of spectroscopic data, the metabolite was confirmed as 1,8-Cineole. RESULTS: Based on the cytotoxicity results, the well-characterized metabolite 1,8-Cineole was investigated upon to understand the mechanism that caused cancer cell death. In this process, the changes in mitochondrial membrane potential (ΔΨm) were confirmed by Rh-123/DAPI staining; the ultra structure was observed by TEM and quantified by flow cytometric analysis. These results proved that the compound effectively induced the apoptosis and G2/M phase arrest in A431 cells by increasing the expression of p53 and that it was monitored by FACS. Further, the expression of apoptotic proteins, such as Bax/Bcl-2, Cyt-c, caspase-9, and caspase-3 was confirmed by western blot. The molecular docking simulations predicted the hydrophobic interaction between 1,8-cineole with Bcl-2 and PARP1 receptor. CONCLUSIONS: 1,8-Cineole is a potential candidate for skin carcinoma, which is possible by regulating the p53 apoptotic signaling pathway.

Effects of Essential Oils from Zingiberaceae Plants on Root-Rot Disease of Panax notoginseng.

Replanting obstacles of Panax notoginseng caused by complex factors, including pathogens, have received great attention. In this study, essential oils (EOs) from either Alpinia officinarum Hance or Amomum tsao-ko (Zingiberaceae) were found to inhibit the growth of P. notoginseng-associated pathogenic fungi in vitro. Subsequent GC-MS analysis revealed the chemical profiles of two plant derived EOs. Linalool and eucalyptol were found to be abundant in the EOs and tested for their antifungal activities. In addition, the synergistic effects of A. tsao-ko EOs and hymexazol were also examined. These findings suggested that Zingiberaceae EOs might be a good source for developing new green natural pesticides fighting against root-rot of P. notoginseng.

Assessment of the antibiofilm and antiquorum sensing activities of Eucalyptus globulus essential oil and its main component 1,8-cineole against methicillin-resistant Staphylococcus aureus strains.

Antibacterial resistance is an increasingly serious threat to global public health. The search for new anti-infection agents from natural resources, with different mode of actions and competitive effects became a necessity. In this study, twenty height methicillin-resistant Staphylococcus aureus (MRSA) strains were investigated for their biofilm formation ability. Subsequently, the antibiofilm effects of Eucalyptus globulus essential oil and its main component 1,8-cineole, against MRSA, as well as their antiquorum sensing potential, were evaluated. Our results displayed the potent efficacy of both E. globulus essential oil and 1,8-cineole against the development of biofilms formed by the methicillin-resistant strains. Additionally, E. globulus essential oil showed more potent of anti-QS activity, even at a low concentration, when compared to 1,8-cineole. All these property of tested agents may pave the way to prevent the development of biofilm formation by MRSA and subsequently the spreading of nosocomial infection.

Phytochemical components, total phenol and mineral contents and antioxidant activity of six major medicinal plants from Rayen, Iran.

The aim of this work was to evaluate the phytochemical components, minerals, the antioxidant activity and total phenol contents of the essential oil from aerial parts of six major medicinal plants in Rayen, Iran. The plants included Ranunculus arvensis, Teucrium polium, Dracocephalum polychaetum, Kelussia odoratissima, Artemisia sieberi and Thymus kotschyanus. Total phenol content ranged from 0.03 to 0.158 mg/mL. A. sieberi showed the highest radical scavenging ability (IC50 = 94 µg/mL). The amount of minerals ranged as follows: P (0.23-29%), K (1.08-4.76%), Ca (0.78-2.35%), Mg (0.24-0.94%), Cu (8.3-15 mg/kg), Cd (0.7-1.1 mg/kg), Pb (2-11.7 mg/kg) and Fe (250-1280 mg/kg). A total of 79 compounds were identified across all plants. The main components studied in the plants were l-perillaldehyde, biosol, carvacrol, 1,8-cineol, terpinyl acetate and 1,2,3,6,7,7 a-hexahydro-5 h-inden 5-one.

Effects of phosphorus sources on volatile organic compound emissions from Microcystis flos-aquae and their toxic effects on Chlamydomonas reinhardtii.

There is diverse phosphorus (P) in eutrophicated waters, but it is considered as a crucial nutrient for cyanobacteria growth due to its easy precipitation as insoluble salts. To uncover the effects of complex P nutrients on the emission of volatile organic compounds (VOCs) from cyanobacteria and their toxic effects on other algae, the VOCs from Microcystis flos-aquae supplied with different types and amount of P nutrients were analyzed, and the effects of VOCs and their two main compounds on Chlamydomonas reinhardtii growth were investigated. When M. flos-aquae cells were supplied with K2HPO4, sodium pyrophosphate and sodium hexametaphosphate as the sole P source, 27, 23 and 29 compounds were found, respectively, including furans, sulfocompounds, terpenoids, benzenes, aldehydes, hydrocarbons and esters. With K2HPO4 as the sole P source, the VOC emission increased with reducing P amount, and the maximum emission was found under Non-P condition. In the treatments of M. flos-aquae VOCs under Non-P condition and two main terpenoids (eucalyptol and limonene) in the VOCs, remarkable decreases were found in C. reinhardtii cell growth, photosynthetic pigment content and photosynthetic abilities. Therefore, we deduce that multiple P nutrients in eutrophicated waters induce different VOC emissions from cyanobacteria, and P amount reduction caused by natural precipitation and algal massive growth results in more VOC emissions. These VOCs play toxic roles in cyanobacteria becoming dominant species, and eucalyptol and limonene are two toxic agents.

Suppression of inflammatory and infection responses in lung macrophages by eucalyptus oil and its constituent 1,8-cineole: Role of pattern recognition receptors TREM-1 and NLRP3, the MAP kinase regulator MKP-1, and NFκB.

Eucalyptus oil (EO) used in traditional medicine continues to prove useful for aroma therapy in respiratory ailments; however, there is a paucity of information on its mechanism of action and active components. In this direction, we investigated EO and its dominant constituent 1,8-cineole (eucalyptol) using the murine lung alveolar macrophage (AM) cell line MH-S. In an LPS-induced AM inflammation model, pre-treatment with EO significantly reduced (P ≤0.01or 0.05) the pro-inflammatory mediators TNF-α, IL-1 (α and ß), and NO, albeit at a variable rate and extent; 1,8-cineole diminished IL-1 and IL-6. In a mycobacterial-infection AM model, EO pre-treatment or post-treatment significantly enhanced (P ≤0.01) the phagocytic activity and pathogen clearance. 1,8-cineole also significantly enhanced the pathogen clearance though the phagocytic activity was not significantly altered. EO or 1,8-cineole pre-treatment attenuated LPS-induced inflammatory signaling pathways at various levels accompanied by diminished inflammatory response. Among the pattern recognition receptors (PRRs) involved in LPS signaling, the TREM pathway surface receptor (TREM-1) was significantly downregulated. Importantly, the pre-treatments significantly downregulated (P ≤0.01) the intracellular PRR receptor NLRP3 of the inflammasome, which is consistent with the decrease in IL-1ß secretion. Of the shared downstream signaling cascade for these PRR pathways, there was significant attenuation of phosphorylation of the transcription factor NF-κB and p38 (but increased phosphorylation of the other two MAP kinases, ERK1/2 and JNK1/2). 1,8-cineole showed a similar general trend except for an opposite effect on NF-κB and JNK1/2. In this context, either pre-treatment caused a significant downregulation of MKP-1 phosphatase, a negative regulator of MAPKs. Collectively, our results demonstrate that the anti-inflammatory activity of EO and 1,8-cineole is modulated via selective downregulation of the PRR pathways, including PRR receptors (TREM-1 and NLRP3) and common downstream signaling cascade partners (NF-κB, MAPKs, MKP-1). To our knowledge, this is the first report on the modulatory role of TREM-1 and NLRP3 inflammasome pathways and the MAPK negative regulator MKP-1 in context of the anti-inflammatory potential of EO and its constituent 1,8-cineole.

Anthelmintic activity of Rosmarinus officinalis against Dactylogyrus minutus (Monogenea) infections in Cyprinus carpio.

Monogenean parasites are important ectoparasites of fish, and are responsible for severe economic impacts in the aquaculture industry. They are usually treated with chemicals, but the chemicals can have harmful side effects in the fish and may pose threats to human health. Rosemary (Rosmarinus officinalis) is a common medicinal herb, with antimicrobial and antitumor properties. Here, we examined the anthelmintic activity of rosemary extract against the monogenean (Dactylogyrus minutus) in vitro and in vivo using bath treatment and oral administration. The in vitro experiments showed that parasite survival was affected by both rosemary extract concentration and the solvent (water and ethanol). Parasites were dead at 61.8±5.6 and 7.8±1.4min when exposed to 100 and 200g aqueous rosemary extract solution/L of water respectively. It took 166.7±48.2 and 5.4±1.01min to kill the parasites when exposed to 1 and 32g ethanol rosemary extract solution/L of water respectively. Moreover, pure component of rosemary extract obtained commercially used in in vitro experiments showed that 1,8-Cineole was the most toxic component of the main components tested. Parasite intensity and prevalence in fish exposed to 50 and 100g aqueous rosemary solution/L water for 30min were significantly lower than they were in controls (p<0.05). In oral treatment experiments, diets of Cyprinus carpio were supplemented with eight different concentrations of aqueous rosemary extract. The intensity of parasites was significantly less in fish fed for 30days with feed containing 60, 80 and 100ml aqueous extract/100g feed than in control (p<0.05). Together these results indicate that rosemary is a promising candidate for prevention and control of monogenean infection.

Antimicrobial efficacy of Cinnamomum javanicum plant extract against Listeria monocytogenes and its application potential with smoked salmon.

Extracts from medicinal plants have been reported to possess good antimicrobial properties, but a majority of them remain unexplored. This study aimed at identifying a novel plant extract with antimicrobial activity, to validate its efficacy in food model, and to elucidate its composition and antimicrobial mechanism. A total of 125 plant extracts were screened, and Cinnamomum javanicum leaf and stem extract showed potential antimicrobial activity against Listeria monocytogenes (MIC=0.13mg/mL). Total phenolic content of the extract was 78.3mg GAE/g extract and its antioxidant activity was 57.2-326.5mg TE/g extract. When applied on cold smoked salmon, strong strain-dependent antimicrobial effectiveness was observed, with L. monocytogenes LM2 (serotype 4b) and LM8 (serotype 3a) being more resistant compared to SSA81 (serotype 1/2a). High extract concentration (16mg/mL) was needed to inhibit or reduce the growth of L. monocytogenes on smoked salmon, which resulted in surface color change. GC-MS revealed that eucalyptol (25.54 area%) was the most abundant compound in the crude extract. Both crude extract and eucalyptol induced significant membrane damages in treated L. monocytogenes. These results suggest anti-L. monocytogenes activity of C. javanicum plant extract, identified its major volatile components, and elucidated its membrane-damaging antimicrobial mechanisms.

Evaluation of in vitro anticancer activity of 1,8-Cineole-containing n-hexane extract of Callistemon citrinus (Curtis) Skeels plant and its apoptotic potential.

Plants are the source of a variety of secondary metabolites, which are often used in the anticancer activity. Discovering new anticancer drug from herbal source is more important in both biological and pharmacological activities. Hence, the objective of this study is to identify the anticancer agent in Callistemon citrinus (Curtis) Skeels (CC) for the treatment of cancer. Very recently we have reported an increased antioxidant activity in the ethanolic and methanolic extracts (EE and ME) of CC but significantly reduced activity (rather increased cytotoxicity), in the n-hexane extract (HE). In this study, the cytotoxicity of all the three solvent extracts was tested against A431, MG-63 and HaCaT cell lines by MTT assay. Interestingly HE has showed increased anti-proliferative effect against the cancer cells but was resisted by non-malignant cells. HPLC and GC-MS analysis revealed the presence of 1,8-Cineole as a predominant compound in HE, the semi-purified bioactive extract. Henceforth, this would be called HE-C and be used for further analyses to understand its mode of action on induced apoptosis/necrosis. Alamar blue assay of HE-C showed cytotoxicity and change in morphological characteristics, which was confirmed by AO/EB staining using fluorescence microscopy, ultra-structural features of apoptosis using SEM and TEM. HE-C induced cell death was also detected by FACS using FITC-labelled Annexin-V and Propidium iodide. ROS generation was monitored using DCF-DA by flow cytometry. The overall results suggested that the selective extract (HE-C) containing 1,8-Cineole has shown potential anti-cancer activity in a dose-dependent manner, and cell death was induced through ROS-mediated apoptosis. Our findings provide an insight into the potential of 1,8-Cineole as a novel drug for killing cancer cells.

Volatile Components of the Essential Oil of Artemisia montana and Their Sedative Effects.

The sedative effects of volatile components in the essential oil of Artemisia montana ("Yomogi") were investigated and measured using gas chromatography-mass spectrometry (GC-MS). Major components identified included 1,8-cineol, camphor, borneol, α-piperitone, and caryophyllene oxide. Among them, 1,8-cineol exhibited the highest flavor dilution (FD) value in an aroma extract dilution analysis (AEDA), followed by borneol, o-cymene, ß-thujone, and bornyl acetate. The sedative effects of yomogi oil aroma were evaluated by sensory testing, analysis of salivary α-amylase activity, and measurement of relative fluctuation of oxygenated hemoglobin concentration in the brain using near-infrared spectroscopy (NIRS). All results indicated the stress-reducing effects of the essential oil following nasal exposure, and according to the NIRS analysis, 1,8-cineol is likely responsible for the sedative effects of yomogi oil.

Targeting Pyrimidine Pathway of Plasmodium knowlesi: New Strategies Towards Identification of Novel Antimalarial Chemotherapeutic Agents.

AIM AND OBJECTIVE: Plasmodium knowlesi has been recently recognized as a human malarial parasite, particularly in the region of south-east Asia. Unlike human host, P. knowlesi cannot salvage pyrimidine bases and relies solely on nucleotides synthesized from de novo pyrimidine pathway. The enzymes involved in this are also unique in terms of their structure and function to its human counterpart. Thus, targeting Dihydroorotase, an enzyme involved in the pyrimidine biosynthesis, provides a promising route for novel drug development. MATERIALS AND METHODS: The 3D structure of P. knowlesi Dihydroorotase was predicted, refined and validated. Multiple docking was performed and the resultant complex was used for 3D structurebased pharmacophore modelling. A combinatorial library of 2,664,779 molecules was generated and used for structure based virtual screening. The stability of resultant compounds was checked using simulation studies. RESULTS: The modelled 3D structure of P. knowlesi Dihydroorotase enzyme is relaxed by running an MD simulation of 20 ns, and structure is validated by using Ramachandran plot and G-factor analysis. A five point based pharmacophore model was created and used as a query for screening in house database. The stability of two negatively charged compounds was studied, and ZINC22066495-DHOase complex was more stable throughout the simulation. CONCLUSION: The present study shows that ZINC22066495 compound has a high potential for disrupting P. knowlesi DHOase enzyme and may be used as a potential lead molecule for effective pyrimidine biosynthesis inhibition in P. knowlesi.

Transient Receptor Potential Cation Channel Subfamily M Member 8 channels mediate the anti-inflammatory effects of eucalyptol.

BACKGROUND AND PURPOSE: Eucalyptol (1,8-cineol), the major ingredient in the essential oil of eucalyptus leaves and other medicinal plants, has long been known for its anti-inflammatory properties. Eucalyptol interacts with the TRP cation channels among other targets, but it is unclear which of these mediates its anti-inflammatory effects. EXPERIMENTAL APPROACH: Effects of eucalyptol were compared in wild-type and TRPM8 channel-deficient mice in two different models: footpad inflammation elicited by complete Freund's adjuvant (CFA) and pulmonary inflammation following administration of LPS. Oedema formation, behavioural inflammatory pain responses, leukocyte infiltration, enzyme activities and cytokine and chemokine levels were measured. KEY RESULTS: In the CFA model, eucalyptol strongly attenuated oedema and mechanical allodynia and reduced levels of inflammatory cytokines (IL-1ß, TNF-α and IL-6), effects comparable with those of ibuprofen. In the LPS model of pulmonary inflammation, eucalyptol treatment diminished leukocyte infiltration, myeloperoxidase activity and production of TNF-α, IL-1ß, IFN-γ and IL-6. Genetic deletion of TRPM8 channels abolished the anti-inflammatory effects of eucalyptol in both models. Eucalyptol was at least sixfold more potent on human, than on mouse TRPM8 channels. A metabolite of eucalyptol, 2-hydroxy-1,8-cineol, also activated human TRPM8 channels. CONCLUSION AND IMPLICATIONS: Among the pharmacological targets of eucalyptol, TRPM8 channels were essential for its anti-inflammatory effects in mice. Human TRPM8 channels are more sensitive to eucalyptol than rodent TRPM8 channels explaining the higher potency of eucalyptol in humans. Metabolites of eucalyptol could contribute to its anti-inflammatory effects. The development of more potent and selective TRPM8 agonists may yield novel anti-inflammatory agents.

Change in Caco-2 cells following treatment with various lavender essential oils.

Lavender is an aromatic evergreen shrub diffused in the Mediterranean basin appreciated since antiquity. The genus Lavandula is part of Lamiaceae family and includes more than 20 species, among which true lavender (L. vera D.C. or L. angustifolia Miller.) and spike lavender (L. latifolia Medikus); there are also numerous hybrids known as lavandins (L. hybrida Rev.). L. vera, spike lavender and several hybrids are the most intensely used breeding species for the production of essential oils. Lavender and lavandin essential oils have been applied in food, pharmaceutical and other agro industries as biological products. In their chemical composition, terpenes linalool and linalyl acetate along with terpenoids such as 1,8-cineole are mostly responsible for biological and therapeutic activities. This study evaluates cytotoxic activity of essential oils derived from four lavender species on human epithelial colorectal adenocarcinoma cells. Analysis of pre- and post-treatment cell morphology has been performed using scanning electron microscope.

Efficacy of α-Copaene, Cubeb, and Eucalyptol Lures for Detection of Redbay Ambrosia Beetle (Coleoptera: Curculionidae: Scolytinae).

Redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is a wood-boring pest that has now invaded nine states in the southeastern United States. The beetle's dominant fungal symbiont (Raffaelea lauricola) is phytopathogenic, inducing laurel wilt in trees within the family Lauraceae. Members of the genus Persea are particularly susceptible to the lethal disease, including native redbay (P. borbonia) and swampbay (P. palustris), as well as commercial avocado (P. americana). Cubeb oil lures are the current standard for detection of X. glabratus, but recently eucalyptol and a 50% α-copaene oil have been identified as additional attractants. This study used a combination of binary-choice bioassays, field cage release-and-recapture assays, and a 12-wk field trial to compare efficacy of eucalyptol and copaene lures relative to commercial cubeb lures. In addition, GC-MS was used to quantify emissions from lures field-aged for 12 wk. In laboratory bioassays, copaene lures were more attractive than eucalyptol lures. In field cage assays, copaene lures recaptured a higher percentage of released beetles than cubeb lures. In the field test, cubeb lures captured fewer beetles than copaene lures, and lowest captures were obtained with eucalyptol lures. Combining eucalyptol with either copaene or cubeb lures did not increase captures over those lures deployed alone. Both copaene and cubeb lures were effective in attracting X. glabratus for 12 wk, but field life of eucalyptol lures was only 4 wk, consistent with the quantification of lure emissions. Results suggest that the 50% α-copaene lure provides the best pest detection currently available for X. glabratus.

In vivo and in vitro inhibitory activity of an ethanolic extract of Sargassum fulvellum and its component grasshopper ketone on atopic dermatitis.

The present study investigated the effect of Sargassum fulvellum ethanol extract (SFEE) on 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD)-like skin lesions in BALB/c mice. The severity of skin dermatitis, production of cytokines, and total IgE content were measured, and the histopathological features were analyzed. SFEE decreased the severity of DNCB-induced dermatitis and suppressed the serum levels of total immunoglobulin E (IgE), tumor necrosis factor (TNF)-α, and interleukin (IL)-4. In addition, SFEE reduced the production of IL-4, IL-5, and IL-13 in mice splenocytes. However, the levels of IL-10 and interferon (IFN)-γ significantly increased in mice sera and splenocytes. Histological examination revealed decreased dermal thickness and infiltration by mast cells after treatment with SFEE. Furthermore, grasshopper ketone, a compound isolated from SFEE, was found to significantly decrease cytokine production in concanavalin A-stimulated splenocytes from BALB/c mice with no cytotoxicity. Taken together, these results indicate that SFEE and the isolated grasshopper ketone have an inhibitory effect on AD by regulating immune mediators and cells and may be a potential effective alternative therapy for AD.

Mentha longifolia protects against acetic-acid induced colitis in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Mentha longifolia L (Wild Mint or Habak) (ML) is used in traditional medicine in treatment of many gastrointestinal disorders. AIM OF THE STUDY: This study aimed to evaluate potential protecting effect of ML and its major constituent, eucalyptol, against acetic acid-induced colitis in rats, a model of human inflammatory bowel disease (IBD). MATERIALS AND METHODS: Rats were divided into ten groups (n=8) given orally for three days (mg/kg/day) the following: normal control, acetic acid-induced colitis (un-treated, positive control), vehicle (DMSO), sulfasalazine (500), ML extract (100, 500, 1000), and eucalyptol (100, 200, 400). After 24h-fasting, two ML of acetic acid (3%) was administered intrarectally. On the fifth day, serum and colonic biochemical markers, and histopathological changes were evaluated. RESULTS: Colitis significantly increased colonic myeloperoxidase activity and malonaldehyde level, and serum tumor necrosis factor-α, interleukin-6, and malonaldehyde levels while significantly decreased colonic and serum glutathione levels. All treatments (except ML 100, ML 1000, and eucalyptol 100) significantly reversed these changes where eucalyptol (400) showed the highest activity in a dose-dependent manner. The colitis-induced histopathological changes were mild in sulfasalazine and eucalyptol 400 groups, moderate in ML 500 and eucalyptol 200 groups, and severe in ML 100, ML 1000, and eucalyptol 100 groups nearly similar to colitis-untreated rats. CONCLUSION: ML (in moderate doses) and eucalyptol (dose-dependently) exerted protective effects against acetic acid-induced colitis in rats possibly through antioxidant and antiinflammatory properties suggesting a potential benefit in treatments of IBD. To our knowledge this is the first report addressing this point.

Choleretic Activity of Turmeric and its Active Ingredients.

Turmeric, a rhizome of Curcumin longa L. is widely used as both a spice and an herbal medicine. The traditional use of turmeric in gastroenterology is mainly based on its choleretic activity. The aim of this study is to determine the effects of turmeric on bile flow (BF) and total bile acids (TBAs) excretion in a bile fistula rat model after acute duodenal administration. A significant dose-dependent enhancement in both BF and TBAs was detected after treatment with the turmeric decoctions which suggested the choleretic activity was bile acid-dependent secretion. In order to direct the active group of compounds, aqueous (AE), ethyl acetate (EtOAc), and petroleum ether (PE) extracts were investigated. The EtOAc and PE extracts showing high effects were purified to locate the active ingredients. Three curcuminoids (curcumin, demethoxycurcumin, and bisdemethoxycurcumin) and 2 sesquiterpenes (bisacurone B and ar-turmerone) were isolated. It was found Bisacurone B was the most potent choleretic ingredient followed by ar-turmerone, bisdemethoxycurcumin demethoxycurcumin, and then curcumin. The amounts of the active ingredients were quantitatively analyzed by high-performance liquid chromatography. The EtOAc and PE extracts had high sesquiterpenes and curcuminoids content, while the AE extract had poor content of sesquiterpenes and curcuminoids which affected neither BF nor TBAs. Based on the results of multiple linear regression analysis, the content of BIS and TUR were dominant factors (P < 0.01) of controlling BL and TBAs in EtOAC and PE extracts.

Effective treatment for sensitive skin: 4-t-butylcyclohexanol and licochalcone A.

BACKGROUND: More than 50% of adults report to suffer from sensitive skin. This common condition is characterized by subjective sensations such as prickling, burning, skin tightness or pruritus, and is often accompanied by objective symptoms like inflammation and erythema. OBJECTIVE: The objective of this study was to develop an active ingredient concept for the treatment of sensitive skin. We tested compounds regarding their potential to (i) decrease the release of proinflammatory mediators, which among others induce erythema and (ii) counteract the hyperresponsiveness of nerve fibres and, thus, exert effects on cutaneous neurosensory dysfunction. METHODS: 4-t-butylcyclohexanol, licochalcone A and acetyl dipeptide-1 cetyl ester were analysed in vitro regarding their potential to (i) decrease the release of PGE2 and activation of NFκB and to (ii) inhibit TRPV1 activation or the release of neuronal CGRP. To assess subjective and objective symptoms of skin sensitivity in vivo, two controlled, single-blind, randomized studies were conducted with 4-t-butylcyclohexanol and the combination with licochalcone A. RESULTS: In vitro, 4-t-butylcyclohexanol significantly reduced TRPV1 activation, while acetyl dipeptide-1 cetyl ester had no effect on receptor activation. Licochalcone A significantly decreased NFκB signalling and PGE2 secretion, at lower concentrations than acetyl dipeptide-1 cetyl ester. A formulation containing 4-t-butylcyclohexanol showed a significant immediate anti-stinging/anti-burning effect in vivo, and a cream base containing a combination of 4-t-butylcyclohexanol and a licochalcone A-rich licorice extract reduced shaving-induced erythema. CONCLUSION: In vitro and in vivo data indicate that the combination of the TRPV1 antagonist 4-t-butylcyclohexanol and the potent anti-inflammatory licochalcone A provide an effective active ingredient concept for the treatment of sensitive skin, as the topical application resulted in an immediate relief from symptoms such as erythema and stinging.