Bio-fabrication of silver nanoparticles using Commelina erecta, L.: a mechanistic approach on synthesis, optimization, antibacterial, and antioxidant potential.

The ongoing exploration of economical, sustainable, and environment-friendly methods for synthesizing monodisperse colloidal metal nanoparticles is growing day by day due to their potential application in various fields. The use of plant derivatives in nanoparticle synthesis and their suitability as sustainable catalysts have emerged as significant areas of research. In this study, silver nanoparticles were synthesized using an aqueous extract obtained from the commonly found weed Commelina erecta, L. Extensive study is conducted to optimize various synthesis parameters such as pH, reducing agent concentration, silver nitrate concentration, and temperature. The plant extract utilized in the synthesis process contained variety of antioxidants, including malic acid, phenol, benzoic acid, and catechol, which played a crucial role in both reduction and capping during the synthesis process, thereby making them suitable for biomedical applications. The optimized synthesis process yielded silver nanoparticles with a particle size of 16.2 ± 3.1 nm. These nanoparticles exhibited excellent stability and demonstrated remarkable antibacterial activity compared to the standard antibacterial agent, streptomycin. In addition, the silver nanoparticles displayed promising antioxidant activity attributed to the presence of antioxidant functional groups on their surface. This study reports, for the first time, the synthesis of silver nanoparticles using antioxidant compounds present in C. erecta, L. plant extract. The antioxidant compounds identified through GC-MS belong to phenols, phenolic acids, and carboxylic acid groups. Furthermore, the exceptional antimicrobial and antioxidant properties exhibited by the synthesized silver nanoparticles offer new possibilities for their potential applications.

[Quality evaluation of Commelina communis from different origins based on multicomponent content determination combined with chemometrics].

This research established a high-performance liquid chromatography(HPLC) method for simultaneous determination of isoorientin, orientin, vitexin, and isovitexin in Commelina communis to conduct content difference analysis and quality evaluation of 62 batches of C. communis from different origins. The HPLC content determination was performed on a Dikma Platisil ODS chromatographic column(4.6 mm×250 mm, 5 µm), with acetonitrile-0.1% formic acid(14∶86) as the mobile phase. The detection wavelength was set at 348 nm, the flow rate was 1.0 mL·min~(-1), and the column temperature was 35 ℃. The differences in origins and quality of 62 batches of C. communis were studied by chemometrics. The results showed that the determination of four components mani-fested a good linear relationship in the range of mass concentration(r>0.999 9), and the average recovery rate was 96.17%-103.0%. The relative standard deviations(RSDs) of precision, stability, and repeatability were all less than 2.0%. The content of four components from high to low was isoorientin>isovitexin>orientin>vitexin. Forty-seven batches of C. communis with clear origins were classified into six categories by chemometrics. C. communis from different origins had different qualities. Generally, C. communis from Western China, Central China, and South of China had superior qualities. The HPLC method established in this study is specific, simple, and efficient, which provides references for the comprehensive evaluation of the quality of C. communis. The chemometrics shows that the qualities of C. communis from different origins are largely different. Isoorientin can be used as an index to determine the content of C. communis, and its content limit should be set no less than 0.023%.

Commelina benghalensis (Wandering Jew) Linn exhibits abortifacient potentials and hepatotoxicity in pregnant Wistar rats via elevating indicators of oxidative stress and activating proinflammatory cytokines.

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.

Quality evaluation of Commelina communis from different origins based on multicomponent content determination combined with chemometrics / 中国中药杂志

This research established a high-performance liquid chromatography(HPLC) method for simultaneous determination of isoorientin, orientin, vitexin, and isovitexin in Commelina communis to conduct content difference analysis and quality evaluation of 62 batches of C. communis from different origins. The HPLC content determination was performed on a Dikma Platisil ODS chromatographic column(4.6 mm×250 mm, 5 μm), with acetonitrile-0.1% formic acid(14∶86) as the mobile phase. The detection wavelength was set at 348 nm, the flow rate was 1.0 mL·min~(-1), and the column temperature was 35 ℃. The differences in origins and quality of 62 batches of C. communis were studied by chemometrics. The results showed that the determination of four components mani-fested a good linear relationship in the range of mass concentration(r>0.999 9), and the average recovery rate was 96.17%-103.0%. The relative standard deviations(RSDs) of precision, stability, and repeatability were all less than 2.0%. The content of four components from high to low was isoorientin>isovitexin>orientin>vitexin. Forty-seven batches of C. communis with clear origins were classified into six categories by chemometrics. C. communis from different origins had different qualities. Generally, C. communis from Western China, Central China, and South of China had superior qualities. The HPLC method established in this study is specific, simple, and efficient, which provides references for the comprehensive evaluation of the quality of C. communis. The chemometrics shows that the qualities of C. communis from different origins are largely different. Isoorientin can be used as an index to determine the content of C. communis, and its content limit should be set no less than 0.023%.

Treatment with Commelina communis Extract Exerts Anti-inflammatory Effects in Murine Macrophages via Modulation of the Nuclear Factor-κB Pathway.

The incidence of severe inflammatory diseases caused by chronic inflammation has increased owing to unprecedented changes brought about by industrialization. In this study, we aimed to assess the effect of treatment of lipopolysaccharide- (LPS-) induced murine macrophages with Commelina communis Linne extract (CCE) on synthesis of nitric oxide (NO), hypersecretion of proinflammatory cytokines, intranuclear transition of the p65 subunit of nuclear factor- (NF-) κB, and degradation of the NF-κB inhibitor IκBα. Notably, CCE treatment did not affect cell viability even at a final concentration of 1.5 mg/mL. At a high concentration of CCE, the LPS-induced high levels of NO, tumor necrosis factor-α, interleukin- (IL-) 1ß, and IL-6 were decreased via downregulation of inducible NO synthase and proinflammatory cytokine mRNA expression. Furthermore, phosphorylation of IκBα was significantly decreased upon CCE treatment, and the intranuclear transition of NF-κB p65 triggered by LPS was inhibited at a high concentration of CCE. Polyphenols and flavonoids, secondary metabolites in CCE that regulate the NF-κB pathway, may be responsible for its anti-inflammatory activity. We suggest that CCE has anti-inflammatory effects related to suppression of the NF-κB pathway and can be used to treat chronic inflammation.

Phytochemical composition analysis and evaluation of in vitro medicinal properties and cytotoxicity of five wild weeds: A comparative study.

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.

Identification of caffeic acid and rutin by UHPLC MS/MS and antioxidant activity of Commelina erecta Lineu. in cell culture.

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.

Terpenoids and phytosteroids isolated from Commelina benghalensis Linn. with antioxidant activity.

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.

The potential protective effect of Commelina nudiflora L. against carbon tetrachloride (CCl4)-induced hepatotoxicity in rats, mediated by suppression of oxidative stress and inflammation.

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.

Antidiabetic Medicinal Plants Used by the Basotho Tribe of Eastern Free State: A Review.

Diabetes mellitus (DM) belongs to the group of five leading important diseases causing death globally and remains a major health problem in Africa. A number of factors such as poverty, poor eating habit, and hormonal imbalance are responsible for the occurrence of the disease. It poses a major health challenge in Africa continent today and the prevalence continues to increase at an alarming rate. Various treatment options particularly the usage of herbs have been effective against diabetes because they have no adverse effects. Interestingly, South Africa, especially the Basotho tribe, is blessed with numerous medicinal plants whose usage in the treatment of DM has been effective since the conventional drugs are expensive and often unaffordable. The present study attempted to update the various scientific evidence on the twenty-three (23) plants originating from different parts of the world but widely used by the Sotho people in the management of DM. Asteraceae topped the list of sixteen (16) plant families and remained the most investigated according to this review. Although limited information was obtained on the antidiabetic activities of these plants, it is however anticipated that government parastatals and scientific communities will pay more attention to these plants in future research.

In Vitro Anticancer Activity of Au, Ag Nanoparticles Synthesized Using Commelina nudiflora L. Aqueous Extract Against HCT-116 Colon Cancer Cells.

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.

Antioxidant mediated ameliorative steroidogenesis by Commelina benghalensis L. and Cissus quadrangularis L. against quinalphos induced male reproductive toxicity.

Quinalphos (QP) is speculated to cause endocrine disruption through the generation of reactive oxygen species (ROS) by oxidative stress (OS). Exposure of QP decreased testosterone level considerably which resulted in reduced viable sperms in mice. The QP induced toxicity is initiated by the formation of free radicals as it is evidenced from the increased Lipid peroxidation (LPO) and diminution of antioxidant enzymes in testicular tissue. Increased serum cholesterol and reduced testicular cholesterol indicated the inhibition of cholesterol transport and biosynthesis in testicular tissues. Lack of cholesterol in testicular tissue impaired the steroidogenesis by down-regulating the expression of StAR protein, Cytochrome P450, 3ß-HSD and 17ß-HSD leading to reduced testosterone level. Treatment of Commelina benganlensis (CBE) and Cissus quadrangularis (CQE) significantly recovered the alterations in antioxidant profiles as well as increased LPO, thereby recovering the decreased mRNA expression levels of intermediate enzymes. However, CQE effectively protected the OS and prevented the inhibition of steroidogenesis thereby preventing male infertility.

Semi-purified extracts of Commelina benghalensis (Commelinaceae) induce apoptosis and cell cycle arrest in Jurkat-T cells.

BACKGROUND: Commelina benghalensis (CB) is a small plant whose fleshy stems are used in South Africa to treat skin conditions (e.g., cancerous skin outgrowths). This study was aimed at evaluating the effect of sub-fractions of acetone extracts of CB stems on growth-associated molecular events of apoptosis and cell division cycle of Jurkat-T (JT) cells. METHODS: Acetone extract of CB stems were subfractioned into n-hexane (F1) and dichloromethane (F2) fractions. After treatment of JT cells with these subfractions, cell proliferation, viability and apoptosis were determined using a haemocytometer, the trypan blue dye exclusion assay, and Hoechst 33258 staining, respectively. Cell division cycle distribution profiles were analysed using an Epics Alba Flow Cytometer and the expression of cell division cycle regulatory genes was analysed using RT-PCR, while immunoreactive proteins were detected on western blots. RESULTS: The F1 and F2 fractions inhibited the proliferation and viability of JT cells in a concentration- and time-dependent manner, with IC50 values of 32.5 µg/mℓ and 56 µg/mℓ, respectively. The observed cytotoxicity was established to be a consequence of apoptosis. as verified using Hoechst staining method. Both fractions induced a G1/S interphase arrest of the cell division cycle of JT cells.RT-PCR analyses showed an up-regulatory effect by the F1 fraction in the expression of cyclin B1, cdc2 and bax, with a down-regulatory effect in the expression levels of bcl-2. Fraction F1 also increased the protein expression levels of p53 and its downstream regulators, p21 and Cdc2. However, protein Bax and p21 and p53 transcripts were undetectable under the same experimental conditions. On the other hand, fraction F2 increased the mRNA expression levels of bax, bcl-2, cyclin B1 and cdc2. Concomitantly, fraction F2 showed an up-regulation in the protein expression levels of Cdc2, Bcl-2, Cyclin B1 and p21. Despite the up-regulation in protein expression levels by fraction F2, there was no observable expression levels of the p53 protein and p21 and p53 mRNAs under similar experimental conditions. CONCLUSION: These findings suggest that the F1 and F2 fractions of CB may provide a valuable lead for the development of novel and effective anti-neoplastic drug(s).

Protective effect of homonojirimycin from Commelina communis (dayflower) on influenza virus infection in mice.

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.

[Chemical constituents from Commelina communis].

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.

Differential role of ethylene and hydrogen peroxide in dark-induced stomatal closure.

Regulation of stomatal aperture is crucial in terrestrial plants for controlling water loss and gaseous exchange with environment. While much is known of signaling for stomatal opening induced by blue light and the role of hormones, little is known about the regulation of stomatal closing in darkness. The present study was aimed to verify their role in stomatal regulation in darkness. Epidermal peelings from the leaves of Commelina benghalensis were incubated in a defined medium in darkness for 1 h followed by a 1 h incubation in different test solutions [H2O2, propyl gallate, ethrel (ethylene), AgNO3, sodium orthovanadate, tetraethyl ammonium chloride, CaCl2, LaCl3, separately and in combination] before stomatal apertures were measured under the microscope. In the dark stomata remained closed under treatments with ethylene and propyl gallate but opened widely in the presence of H2O2 and AgNO3. The opening effect was largely unaffected by supplementing the treatment with Na-vanadate (PM H+ ATPase inhibitor) and tetraethyl ammonium chloride (K(+)-channel inhibitor) except that opening was significantly inhibited by the latter in presence of H2O2. On the other hand, H2O2 could not override the closing effect of ethylene at any concentrations while a marginal opening of stomata was found when Ag NO3 treatment was given together with propyl gallate. CaCl2 treatment opened stomata in the darkness while LaCl3 maintained stomata closed. A combination of LaCl3 and propyl gallate strongly promoted stomatal opening. A probable action of ethylene in closing stomata of Commelina benghalensis in dark has been proposed.

Hypoglycaemic activity of Commelina africana and Ageratum conyzoides in relation to their mineral composition.

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.

ABA signaling in stomatal guard cells: lessons from Commelina and Vicia.

Abscisic acid (ABA) signaling mechanisms have been studied in a broad variety of plant species using complementary analyses, taking advantage of different methodologies suitable for each plant species. Early studies on ABA biosynthesis using Solanum lycopersicum mutants suggested an importance of ABA synthesis in stomatal closure. To understand ABA signaling in guard cells, cellular, biochemical and electrophysiological studies in Vicia faba and Commelina communis have been conducted, providing fundamental knowledge that was further reconfirmed by molecular genetic studies of Arabidopsis. In this article, examples of stomatal studies in several plants and prospects in ABA research are discussed.

Effect of total alkaloids from Commelina communis L. on lung damage by influenza virus infection.

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.

Sex expression and breeding strategy in Commelina benghalensis L.

This paper describes the results of a series of experiments conducted to unravel the patterns of sex expression and reproductive output in a fascinating species with high variation in sexuality. Commelina benghalensis L., an andromonoecious rainy season weed, bears male and bisexual flowers in axillary spathes of all the plants investigated. Bisexual flowers are of two types; chasmogamous (CH) and cleistogamous (CL). The former are borne on subaerial and the latter on subterranean shoots, in addition to those on aerial spathes. Three populations of the species, designated JU1, JU2 and JU3, were scanned for three consecutive years from 1996 to 1998, and the number and distribution of male, CH and CL flowers per plant were found to vary. The mere number of CH/CL flowers per plant is by itself not an accurate measure of mixed mating. It is necessary to confirm that CH flowers actually outcross and, if they do so, to what extent. Comparison of the pollen/ovule (P/O) ratio and percentage pollen germination on the stigmas of the CH and CL flowers have been used as indices of the pollination system. Confirmation of this was sought from the fruit and seed sets obtained after manual pollination of emasculated flowers with self- and cross-pollen. Results so obtained were compared with those of natural pollination. In the majority of CH flowers, the male and female reproductive phases (i.e. anther dehiscence and stigma receptivity) overlap, providing for self-pollination. However, two exceptions to this general behaviour were found in some plants of all the three populations. In some CH flowers, the female phase matures prior to anther dehiscence while in others, the anthers are sterile. Such plants, designated as variants 1 and 2, respectively, facilitate cross-pollination. While the CL flowers contribute to the production of selfed progeny, the variants of CH ones permit formation of outcrossed progeny, indicating a mixed mating strategy in C. benghalensis.