RESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Commelina benghalensis Linn is a perennial plant with upright stems reaching a height of 1 m. Its stem is commonly used to induce abortion in traditional medicine. However, there are insignificant scientific data to evaluate such a claim. AIM OF THE STUDY: The study was conducted to determine the abortifacient and toxicological potential of ethanol extract of Commelina benghalensis Linn stem (EECBS) via selected proinflammatory and oxidative stress biomarkers in pregnant Wistar rats. MATERIALS AND METHODS: To determine the phytochemicals responsible for EECBS's toxicity and abortifacient effects, high-performance liquid chromatography-photodiode array detection (HPLC-PDA) and gas chromatography-mass spectrometry (GC-MS) was used. The abortion rate was determined by monitoring the markers of reproductive system failure in the experimental model. To assess rat hepatotoxicity, biochemical markers and immunohistopathological parameters were used. RESULTS: Results demonstrated the presence of isomeric benzene-mesitylene compounds in EECBS. Also, EECBS significantly altered the markers of liver function and oxidative damage while eliciting a significantly reduced (P < 0.05) number of live fetuses, number of corpora lutea, progesterone, estradiol, and luteinizing hormone, whereas the number of dead fetuses percentage vaginal opening, and post-implantation loss increased significantly (P < 0.05). Estrogenicity studies indicated a significant (P < 0.05) increase in uterine weight, uterine glucose, and ALP dose-dependently. Moreover, EECBS also caused a vaginal hemorrhage preceding the parturition. Also, EECBS treatment significantly increased levels of interleukin-1ß (IL-1ß), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and significantly elevated the expression of COX-2 protein in the liver. CONCLUSION: The current investigation established Commelina benghalensis Linn stem's abortifacient activity. Continuous use, on the other hand, may cause liver damage in pregnant rats by disrupting antioxidant defense mechanisms, promoting the production of pro-inflammatory cytokines, and increasing COX-2 expression. Hence, caution should be excised while consuming this plant's stem for medication purposes, especially during the gestational period.
Assuntos
Abortivos , Doença Hepática Induzida por Substâncias e Drogas , Commelina , Animais , Feminino , Humanos , Gravidez , Ratos , Abortivos/toxicidade , Commelina/química , Ciclo-Oxigenase 2 , Citocinas/farmacologia , Judeus , Estresse Oxidativo , Extratos Vegetais/toxicidade , Ratos WistarRESUMO
Background: Medicinal plants are a source of phytochemicals and they are used for the treatment of several oxidative stress-related or other diseases for their effectiveness, low toxicity and easy availability. Five traditionally used and less characterized herbaceous weeds of West Bengal, India, namely, Heliotropium indicum, Tridax procumbens, Cleome rutidosperma, Commelina benghalensis and Euphorbia hirta, were investigated for the current research study. Methods: Aqueous and 70% ethanolic extracts of the leaves were analyzed for estimation of essential phytochemicals and to evaluate their in vitro antioxidant status, medicinal properties and cytotoxic effects. To the best of our knowledge, several assays and comparative evaluations using these herbs are reported for the first time. For quantitative study, UV-vis spectrophotometry and high-performance liquid chromatography with diode array detector HPLC-DAD techniques were used. Antibacterial properties were investigated using the Kirby-Bauer disc diffusion method. For in vitro anti-lithiatic study, a titration method was used. The cell viability assay was done using peripheral blood mononuclear cells. Results: The aqueous extract exhibits higher content of polyphenols, flavonoids, tannins and inhibition percentage values for free radical scavenging assays, whereas the 70% ethanolic extract exhibits higher content of alkaloids and cardiac glycosides. HPLC-DAD analysis of 70% ethanolic extracts led us to identify 10 predominant phenolic constituents. Euphorbia hirta extracts showed minimum cytotoxicity (cell death ~2.5% and 4% in water and 70% ethanolic extract, respectively ), whereas Cleome rutidosperma and Tridax procumbens' 70% ethanolic extracts showed higher cell death (~13% and 28%, respectively), compared with the control (cell death ~10-12%). Conclusions: The study concluded that of all the medicinal weeds selected for the current study, Euphorbia hirta possesses the highest amount of bioactive compounds and hence exhibits the highest in vitro antioxidant activity and promising in vitro medicinal properties.
Assuntos
Antioxidantes/farmacologia , Extratos Vegetais/farmacologia , Plantas Daninhas/química , Asteraceae/química , Células Cultivadas , Cleome/química , Commelina/química , Euphorbia/química , Heliotropium/química , Humanos , Índia , Leucócitos Mononucleares/efeitos dos fármacos , Compostos Fitoquímicos/farmacologiaRESUMO
The Commelina erecta L. (C. erecta) also known as erva-de-santa-luzia is reported by local population to have medical properties against some pathological conditions. In this study, two extracts of C. erecta leaves (aqueous and ethanolic) were phytochemically analysed and evaluated for their in-vitro antioxidant activities by DPPH, TBARS, NO assays and cell viability assays. The ultra-high performance liquid chromatography followed by tandem mass spectrometry analysis showed the presence of rutin and caffeic acid in aqueous and ethanolic extract. The total polyphenols in aqueous and ethanolic extracts found were 142.7 ± 3.0 and 123.1 ± 5.8 µg/mL of GAE, respectively. The ethanolic extract (5 mg/mL) inhibits TBARS by 33.8%, and the aqueous extract (5 mg/mL) exhibited scavenger property against nitric oxide derivatives to an extent of 77.8%. In cell culture, both extracts improved cell survivability under H2O2 induced oxidative stress. Thus, C. erecta extract is a good candidate to become a phytotherapic medicine.
Assuntos
Antioxidantes/farmacologia , Ácidos Cafeicos/análise , Cromatografia Líquida de Alta Pressão/métodos , Commelina/química , Extratos Vegetais/farmacologia , Rutina/análise , Animais , Técnicas de Cultura de Células , Humanos , Peróxido de Hidrogênio/farmacocinética , Estresse Oxidativo/efeitos dos fármacos , Fenóis/análise , Compostos Fitoquímicos/análise , Folhas de Planta/química , Polifenóis/análise , Espectrometria de Massas em Tandem/métodosRESUMO
Background Commelina benghalensis Linn. (Family: Commelinaceae) is a common weed available in Bangladesh with several uses in traditional medicine. However, the chemical profile of this medicinal plant is scarce in relation to its medicinal uses. The aerial parts of this plant have been investigated for the isolation of secondary metabolites and evaluation of the biological activities. Methods Major phytochemical groups were analyzed using chromogenic reagents, whereas n-hexane soluble fractionates of the methanol extract were subjected to 1H nuclear magnetic resonance (NMR) spectroscopic analysis. The antioxidant property of the obtained compounds was evaluated using 1,1-diphenyl-2-picryl-hydrazyl (DPPH). Results Dammara-12-en-3-one (CB-1), stigmasterol (CB-2) and 3 (2,3,4,5,6-pentahydroxy)-cinnamoyl dammara-12-ene (CB-3) were isolated from the n-hexane fractionate of methanol extract of C. benghalensis. In the study of DPPH radical scavenging activity, IC50 values were predicted to be 790.18, 4186.94 and 2001.16 µg/mL for CB-1, CB-2 and CB-3, respectively, whereas standard ascorbic acid showed IC50 at 1.26 µg/mL. Conclusions Two new dammarane-type triterpene (CB-1 and CB-3) and one phytosterol (CB-2) were identified in C. benghalensis with mild antioxidant property.
Assuntos
Antioxidantes/química , Commelina/química , Fitosteróis/química , Terpenos/química , Ácido Ascórbico/química , Compostos de Bifenilo/química , Hexanos/química , Compostos Fitoquímicos/química , Extratos Vegetais/química , Plantas Medicinais/química , Triterpenos/química , DamaranosRESUMO
BACKGROUND: This study aims to assess the hepatoprotective potential of Commelina nudiflora against CCl4-induced hepatic injury in rats. METHOD: Antioxidant activities were determined. Phytochemical analysis was performed by gas chromatography mass spectrometry (GCMS). In the in vivo study, Sprague Dawley rats were pretreated with C. nudiflora (150, 300, and 450 mg kg body weight (b.wt.)) once daily for 14 days followed by two doses of CCl4 (1 ml/kg b.wt.). After 2 weeks, the rats were sacrificed and hepatoprotective analysis was performed. RESULTS: In vitro studies have shown that the extract possessed strong antioxidant activity and has ability to scavenge 2,2-diphenyl-2-picrylhydrazyl-free radicals effectively. GCMS analysis of the C. nudiflora extract revealed the presence of various bioactive compounds. Administration of C. nudiflora significantly reduced the impact of CCl4 toxicity on serum markers of liver damage, serum aspartate transaminase (AST), and alanine transaminase (ALT). C. nudiflora also increased antioxidant levels of hepatic glutathione (GSH) and antioxidant enzymes and ameliorated the elevated hepatic formation of malondialdehyde (MDA) induced by CCl4 in rats. Histopathological examination indicated that C. nudiflora protect the liver from the toxic effect of CCl4 and healed lesions such as necrosis, fatty degeneration, and hepatocyte injury as irregular lamellar organization and dilations in the endoplasmic reticulum. The immunohistochemical studies revealed that pretreatment of C. nudiflora decreased the formation of 4-hydroxy-2-nonenal (HNE)-modified protein adducts and 8-hydroxy-2'-deoxyguanosine (8-OHdG). Furthermore, overexpression of the proinflammatory cytokines TNF-α, IL-6, and prostaglandin E2 is also reduced. CONCLUSION: These findings exhibited the potential prospect of C. nudiflora as functional ingredients to prevent ROS-related liver damage.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Commelina/química , Fígado/efeitos dos fármacos , Extratos Vegetais/farmacologia , Substâncias Protetoras/farmacologia , Animais , Antioxidantes/metabolismo , Tetracloreto de Carbono/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Relação Dose-Resposta a Droga , Cromatografia Gasosa-Espectrometria de Massas , Masculino , Distribuição Aleatória , Ratos , Ratos Sprague-DawleyRESUMO
Recently, metal nanoparticles have been getting great medical and social interests due to their potential physico-chemical properties such as higher affinity, low molecular weight, and larger surface area. The biosynthesized gold and silver nanoparticles are spherical, triangular in shape with an average size of 24-150 nm as reported in our earlier studies. The biological properties of synthesized gold and silver nanoparticles are demonstrated in this paper. The different in vitro assays such as MTT, flow cytometry, and reverse transcription polymerase chain reaction (RT-qPCR) techniques were used to evaluate the in vitro anticancer properties of synthesized metal nanoparticles. The biosynthesized gold and silver nanoparticles have shown reduced cell viability and increased cytotoxicity in HCT-116 colon cancer cells with IC50 concentration of 200 and 100 µg/ml, respectively. The flow cytometry experiments revealed that the IC50 concentrations of gold and silver nanoparticle-treated cells that have significant changes were observed in the sub-G1 cell cycle phase compared with the positive control. Additionally, the relative messenger RNA (mRNA) gene expressions of HCT-116 cells were studied by RT-qPCR techniques. The pro-apoptotic genes such as PUMA (++), Caspase-3 (+), Caspase-8 (++), and Caspase-9 (++) were upregulated in the treated HCT-116 cells compared with cisplatin. Overall, these findings have proved that the synthesized gold and silver nanoparticles could be potent anti-colon cancer drugs.
Assuntos
Antineoplásicos , Neoplasias do Colo/tratamento farmacológico , Commelina/química , Ouro , Nanopartículas Metálicas/química , Extratos Vegetais/química , Prata , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Ouro/química , Ouro/farmacologia , Humanos , Prata/química , Prata/farmacologiaRESUMO
The effects of homonojirimycin (HNJ), one of alkaloids from Commelina communis L., on protection against influenza virus infection in mice were investigated. HNJ was found to improve the survival rate, prolong the mean survival time and reduce virus yields in lungs on days 4 and 6 post-infection (p.i.), after the agent had been orally administered to the mice from 2 days before infection to 6 days p.i. Administration of HNJ (1 mg/kg) significantly increased interferon (IFN)-γ and interleukin (IL)-10 levels but decreased tumor necrosis factor (TNF)-α and IL-6 levels in serum and lungs of influenza-infected mice on days 2, 4 or 6 p.i. These results showed that HNJ exerted protection against influenza virus infection and produced effective immune responses in vivo.
Assuntos
1-Desoxinojirimicina/análogos & derivados , Commelina/química , Citocinas/metabolismo , Vírus da Influenza A/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Infecções por Orthomyxoviridae/tratamento farmacológico , Fitoterapia , 1-Desoxinojirimicina/farmacologia , 1-Desoxinojirimicina/uso terapêutico , Animais , Citocinas/sangue , Cães , Feminino , Pulmão/metabolismo , Pulmão/virologia , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/metabolismo , Infecções por Orthomyxoviridae/virologia , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêuticoRESUMO
To investigate the chemical constituents from Commelina communis, fifteen compounds were separated and purified by silica gel, Sephadex LH-20, and ODS column chromatography, and semi-preparative HPLC. By analyses of NMR and MS data as well as their physical and chemical properties, the structures of these compounds were identified as chrysoeriol-7-O-beta-D-glucoside( 1), methyl gallate(2), p-coumaric acid(3), protocatechuic acid(4), caffeic acid(5), p-hydroxybenzoic acid(6), 2-phenethyl-beta-D-gly-cosidase(7) , rhaponticin(8) , (7S, 8R) -dihydrodehydrodiconiferyl alcohol-9-O-beta-D-glucoside (9), isovitexin (10) , isofurcatain (11), isorhamnetin-3-O-beta-D-glucoside(12) , quercetin-3-O-alpha-L-rhamnoside (13) , isoquercitrin (14) , and 1, 2-dihydro-6, 8-dime-thoxy-7-1-(3, 5-dimethoxy-4-hydroxyphenyl) -N1, N2-bis-[2-( 4-hydroxyphenyl) ethyl] -2, 3-naphthalene dicarboxamide (15). Compounds 2, 5-9, 11, 13 were obtained from the genus Commelina for the first time.
Assuntos
Commelina/química , Ácidos Cafeicos/análise , Cromatografia Líquida de Alta Pressão , Glucosídeos/análise , Hidroxibenzoatos/análise , Quercetina/análogos & derivados , Quercetina/análiseRESUMO
BACKGROUND: Many plants with antidiabetic properties probably act in part through their content of fibre, vitamins, bioactive or mineral content OBJECTIVES: This study investigated the mineral, proximate, phytochemical compositions and hypoglycaemic effect of Commelina africana and Ageratum conyzoides extracts in diabetic rats, and the likely relationship between this property and the mineral, proximate and phytochemical compositions of the plants. METHODS: The plants were subjected to mineral, proximate composition and phytochemical analysis. Attempt was made to see (if any) the relationship between the hypoglycaemic effect and the mineral, proximate compositions and phytochemistry of the plants. Alloxan-induced diabetic animals were administered 500 mg/kg body weight aqueous extracts of the plants and glibenclamide as the reference hypoglycaemic agent. RESULTS: Aqueous extract of Ageratum conyzoides reduced fasting blood glucose of experimental animals by 39.1% while Commelina africana reduced the same by 78.0%. Alkaloids, cardenolides, saponins, and tannins were detected in both plants. Anthraquinones was absent in C. africana but a trace of it was detected in A. conyzoides. The hypoglycaemic effect of Commelina africana was comparable with the reference hypoglycaemic agent. Ageratum conyzoides showed comparably weaker hypoglycaemic effect than exhibited by reference hypoglycaemic agent. Comparatively, Commelina africana had higher mineral concentrations (except Na) than Ageratum conyzoides. CONCLUSIONS: Plants' extracts minerals (magnesium, potassium and iron) and bioactive components (alkaloids and cardenolides) seemingly enhanced their hypoglycaemic effect. Furthermore, these minerals, alkaloids and cardenolides could be helpful in ameliorating complications of diabetes like hypertension and cardiovascular disease.
Assuntos
Ageratum/química , Commelina/química , Diabetes Mellitus Experimental/tratamento farmacológico , Glibureto/uso terapêutico , Hipoglicemiantes/farmacologia , Fitoterapia , Extratos Vegetais/farmacologia , Animais , Glicemia/efeitos dos fármacos , Masculino , Extratos Vegetais/isolamento & purificação , Folhas de Planta , Ratos , Ratos Wistar , Valores de Referência , ÁguaRESUMO
Whether administration of total alkaloids from Commelina communis L. (TAC) reduces lung damage in influenza virus-infected mice was investigated. Compared with untreated mice, significantly less severe damage was found in the lungs of mice administered TAC at 8 mg/kg per day for 6 days. TAC significantly decreased viral loads in the lungs. The concentrations of IFN-γ in the serum of TAC-treated mice were significantly lower than those of virus control mice at 4 and 6 days post-infection. The results indicate that TAC imparted partial protection to the mice by reducing pulmonary viral loads and limiting lesions in the lungs.
Assuntos
Alcaloides/uso terapêutico , Commelina/química , Pulmão/patologia , Infecções por Orthomyxoviridae/tratamento farmacológico , Animais , Feminino , Interferon gama/biossíntese , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/patologia , Fitoterapia , Fator de Necrose Tumoral alfa/biossínteseRESUMO
The dayflower, Commelina communis L., contains 1-deoxynojirimycin (DNJ) and (2R,3R,4R,5R)2,5-bis(hydroxymethyl)-3,4-dihydroxypyrrolidine (DMDP), potent alpha-glucosidase inhibitors. The extracts and powder of this herb are important food materials for prophylaxis against type 2 diabetes. Eleven flavonoid glycosides as antioxidants, isoquercitrin, isorhamnetin-3-O-rutinoside, isorhamnetin-3-O-beta-D-glucoside, glucoluteolin, chrysoriol-7-O-beta-D-glucoside, orientin, vitexin, isoorientin, isovitexin, swertisin, and flavocommelin, were identified from the aerial parts of C. communis. Their antioxidant activities were measured using in vitro assays employing the 1,1-diphenyl-2-picrylhydrazyl radical- and superoxide radical-scavenging assays. The results showed that glucoluteolin, orientin, isoorientin, and isoquercitrin are the predominant antioxidants in this herb. Moreover, isoquercitrin, isorhamnetine-3-O-rutinoside, vitexin, and swertisin inhibited the activity of alpha-glucosidase from rat intestine.
Assuntos
Commelina/química , Inibidores de Glicosídeo Hidrolases , Extratos Vegetais/farmacologia , Animais , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Diabetes Mellitus Tipo 2/prevenção & controle , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Sequestradores de Radicais Livres/isolamento & purificação , Sequestradores de Radicais Livres/farmacologia , Glicosídeos/isolamento & purificação , Glicosídeos/farmacologia , Mucosa Intestinal/metabolismo , Intestinos/enzimologia , Componentes Aéreos da Planta , Extratos Vegetais/química , Ratos , Superóxidos/metabolismoRESUMO
For detecting polyhydroxyalkaloids-type alpha-glucosidase-inhibiting ingredients of Commelina communis L grown in China, total alkaloids were obtained from the plant by extraction with water, removal of precipitation after the addition of alcohol, enrichment and purification by ion exchange resin and sephadex LH 20 chromatography. Polyhydroxyalkaloids in the total alkaloids were detected by ion trap electron-spray ionization mass spectra (ESIMS). Several reported and unreported polyhydroxyalkaloids in the plant were detected from the material collected from Jixi county, Anhui province. The crude drug growing in China contains alpha-glucosidase-inhibiting polyhydroxyalkaloids and can be used to therapy in diabetes.
Assuntos
Alcaloides/química , Commelina/química , Inibidores de Glicosídeo Hidrolases , Plantas Medicinais/química , alfa-Glucosidases/química , Alcaloides/isolamento & purificação , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Estrutura Molecular , Peso Molecular , Espectrometria de Massas por Ionização por Electrospray/métodos , alfa-Glucosidases/isolamento & purificaçãoRESUMO
Commelina diffusa and Spathodea campanulata are used as wound-healing agents in Ashanti traditional medicine in Ghana. The methanol extracts of Commelina diffusa herb and Spathodea campanulata bark showed some level of antimicrobial activity with C. diffusa exhibiting selective antifungal activity against Trichophyton species. The extracts reduced the peroxidation of bovine brain extract with an IC(50) value of 1.39 mg/mL and 0.24 mg/mL, respectively. In addition the extracts also exhibited significant antioxidant activity by protecting MRC-5 cells from hydrogen peroxide induced oxidant injury at concentrations between 1 microg/mL and 10 microg/mL. The extracts showed no inhibition of NF-kappaB at 100 microg/mL. The antioxidant activities and antimicrobial activities suggest that the use of the plants in wound healing may be based on antioxidant and antiseptic effects of its constituents.
Assuntos
Bignoniaceae/química , Commelina/química , Fitoterapia , Extratos Vegetais/farmacologia , Cicatrização/efeitos dos fármacos , Ferimentos e Lesões/tratamento farmacológico , Animais , Antioxidantes/farmacologia , Bactérias/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Bovinos , Células Cultivadas , Fungos/efeitos dos fármacos , Peróxido de Hidrogênio/administração & dosagem , Concentração Inibidora 50 , Metanol/química , Testes de Sensibilidade Microbiana , Extratos Vegetais/uso terapêuticoRESUMO
A growth-promoting factor (GPF) that promotes the growth of Entamoeba dispar under axenic culture conditions was found in fractions of mitochondria (Mt), hydrogenosomes (Hg) and chloroplasts (Cp) obtained from cells of six different protozoan, mammalian and plant species. We were able to extract the GPF from the Cp-rich leaf cells of a plant (spiderwort: Commelina communis L.) in an acetone-soluble fraction as a complex of chlorophyll with low molecular weight proteins (molecular weight [MW] approximately 4,600). We also found that on treatment with 0.6% complexes of 2-mercapthoethanol (2ME), complexes of chlorophyll-a with iron-sulphur (Fe-S) proteins (e.g., ferredoxins [Fd] from spinach and Clostridium pasteurianum) and noncomplex rubredoxin (Rd) from C. posteurianum have a growth-promoting effect on E. dispar. These findings suggest that E. dispar may lack a sufficient quantity of some essential components of Fe-S proteins, such as Fe-S center.
Assuntos
Commelina/química , Entamoeba/efeitos dos fármacos , Entamoeba/crescimento & desenvolvimento , Ferredoxinas/farmacologia , Proteínas de Plantas/farmacologia , Animais , Cloroplastos/química , Relação Dose-Resposta a Droga , Mitocôndrias/química , Peso Molecular , Extratos Vegetais/farmacologia , Folhas de Planta/química , Rubredoxinas/farmacologiaRESUMO
Guard cell walls combine exceptional strength and flexibility in order to accommodate the turgor pressure-driven changes in size and shape that underlie the opening and closing of stomatal pores. To investigate the molecular basis of these exceptional qualities, we have used a combination of compositional and functional analyses in three different plant species. We show that comparisons of FTIR spectra from stomatal guard cells and those of other epidermal cells indicate a number of clear differences in cell-wall composition. The most obvious characteristics are that stomatal guard cells are enriched in phenolic esters of pectins. This enrichment is apparent in guard cells from Vicia faba (possessing a type I cell wall) and Commelina communis and Zea mays (having a type II wall). We further show that these common defining elements of guard cell walls have conserved functional roles. As previously reported in C. communis, we show that enzymatic modification of the pectin network in guard cell walls in both V. faba and Z. mays has profound effects on stomatal function. In all three species, incubation of epidermal strips with a combination of pectin methyl esterase and endopolygalacturonase (EPG) caused an increase in stomatal aperture on opening. This effect was not seen when strips were incubated with EPG alone indicating that the methyl-esterified fraction of homogalacturonan is key to this effect. In contrast, arabinanase treatment, and incubation with feruloyl esterase both impeded stomatal opening. It therefore appears that pectins and phenolic esters have a conserved functional role in guard cell walls even in grass species with type II walls, which characteristically are composed of low levels of pectins.