Inhibitory Effect Of Aqueous Extract Research Articles

Bacteriostatic or bactericidal action of four aqueous plant extracts on multi-drug resistant bacteremia and their effect on cells morphology recorded using scanning electron microscopy (SEM)

Four aqueous traditional plant extracts from rosemary leaves (Rosmarinus officinalis), clove buds (Syzygium aromaticum [L.] Merr at Perry, Myrtaceae), cinnamon bark (Cinnamomum zeylanicum) and ginger rhizomes (Zingiber officinale) were tested as natural antibiotics against multi-drug resistant bacteremia isolates: Six Gram negative isolates, viz. Acinetobacter baumanni/haemolyticus, Citrobacter freundii, Escherichia coli, E. coli ESβL, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella sp. and four Gram positive isolates viz. methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, Streptococcus pneumoniae and Bacillus sp. were which used to test antibiotic activity. The usage of clove extract (25X) appeared to have maximum antibacterial activity against all tested Gram negative bacteria, when compared with other tested plant extracts at the same concentration. In the case of G+ve bacteria, tested extracts appeared to have almost the same efficiency. Swabs were taken from inhibition zone resulting from the inhibitory effect of aqueous extracts towards the tested isolates and re-inoculated to detect either the bacteriostatic or bactericidal action. Again, clove extract exhibited the highest effect when compared with other tested against the isolates from bloodstream. Scanning electron microscopy was used to record external morphological changes of the bacterial cells such as appendages, shortness and lyses. Key words: Aqueous plants extracts, bacteremia, antibiotics, rosemary, clove, cinnamon, ginger, Escherichia coli, Salmonella, Acinetobacter, Citrobacter, Klebsiella, Pseudomonas, Streptococcus, Bacillus, Staphylococcus.

Ecological and physiological as well as biochemical properties of representatives of the Genus sedum L.

The article deals with the history of the study and the current state of research of physiological and biochemical properties of the plant genus Sedum that are useful for human and has been used in folk medicine for many years. It was noticed that antioxidant properties of extracts from plants S. sarmentosum, S. sempervivoides, S. takesimense were caused by the presence of phenolic compounds. Methanol extract of plants S. takesimense exhibited strong scavenging activities against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals as well as significant inhibitory effects on lipid peroxidation and low density lipoprotein (LDL) oxidation induced by a metal ion Cu2+. Various immunomodulatory activities of various fractions of plants extracts (S. dendroideum, S. kamtschaticum, S. sarmentosum, S. telephium) are observed. It was shown that the ethanol extract of S. sarmentosum and it’s fractions suppressed specific antibody and cellular responses to ovalbumin in mice. The methanol extract of plants S. sarmentosum reduced the levels of anti-inflammatory markers, such as volume of exudates, number of polymorphonuclear leukocytes, suppressed nitric oxide synthesis in activated macrophages via suppressed induction of inducible nitric oxide synthase (iNOS). Polysaccharides fractions from plants S. telephium inducing productions of tumor necrosis factor alpha (TNF-α), increasing the intensity of phagocytosis in vitro and in vivo. Methanol extract from the whole part of S. kamtschaticum strongly inhibit PGE2 production from lipopolysaccharide-induced RAW 264.7 cells, a mouse macrophage cell line via modulating activity in gene expression of the enzyme cyclooxygenase-2 (COX-2). The methanol extract of plants S. sarmentosum and the major kaempferol glycosides from S. dendroideum have antinociceptive activity. It was noticed that anti-adipogenic activity of extracts from plants S. kamtschaticum were caused by inhibition of peroxisome-proliferator-activated receptor γ (PPARγ) expression and it’s dependent target genes, such as genes encoding adipocyte protein 2 (аР2), lipoprotein lipase (LPL), adiponectin and CD36. Polysaccharides fractions from S. telephium cause inhibition of cell adhesion of human fibroblast (MRC5) to laminin and fibronectin via interfere with integrin-mediated cell behaviour and they contributed to the role of polysaccharides in cell-matrix interaction. The methanol extract of plants S. sarmentosum exhibited a significant inhibitory activity in the chick embryo chorioallantoic membrane angiogenesis in a dose-dependent manner. The crude alkaloid fraction of S. sarmentosum caused a dose-dependent inhibition of cell proliferation on murine hepatoma cell line BNL CL.2 and human hepatoma cell line HepG2 without necrosis or apoptosis. Alkaloids from plants S. sarmentosum may improve survival of hepatoma patients via the inhibition of excessive growth of tumor cells. Plant’s juices have antiviral activity (S. sarmentosum, S. spurium, S. stahlii). Crude ethanol extract S. praealtum have spermicidal activity of the in mice and a relevant inhibitory effect of aqueous extract on human spermatozoa motility as well as an anti-fertilizing activity in rats. Hepatoprotective triterpenes, e.g., δ-amyrone, 3-epi-δ-amyrin, δ-amyrin and sarmentolin were isolated from S. sarmentosum. 2- and 2,6-substituted piperidine alkaloids (e.g., norsedamine, allosedridine, sedamine, allosedamine) are observed in plants S. acre, which in the presence of data on the use of pyridine and piperidine derivatives for treating neurodegenerative diseases (e.g., Alzheimer's disease), points on the promising research in this area. Taking into account that biologically active compounds are accumulated in the aboveground vegetative organs of plants of Sedum, the prospects of further study of the use of Sedum for the purposes of biotechnology and in the pharmaceutical industry becomes apparent. This work extends the existing views regarding the use of plants Sedum.

Inhibitory Effects of Aqueous Extracts from Leaves of Common Tropical Green Plants on Nitrification in Soils

An incubation experiment was carried out to investigate the inhibitory effects of aqueous extracts of 32 common tropical green plant species from 24 families on nitrification. The results indicated that the nitrification inhibitory effects of Calliandra haematocephala belonging to Mimosaceae, Dracaena cambodiana belonging to Liliaceae, Duranta repens belonging to Verbenaceae, Alstonia scholaris belonging to Apocynacea, Terminalia mantaly belonging to Combretaceae and Polyalthia longifolia belonging to Annonaceae were better than DCD, which had more obvious potential applications than other plants inhibited nitrification. The inhibitory effects of active substances in plants were affected by extract temperature causing by solubility and thermal stability of active substances. Duranta repens had the most potential for development in this study as a fertilizer additive. The inhibitory effects of aqueous extracts of Duranta repens leaves on nitrification increased with increasing concentration of aqueous extracts, the strongest inhibitory effect on nitrification occurred after 14 d of incubation.

Inhibitory effect of aqueous extracts from Miracle Fruit leaves on mutation and oxidative damage

This study investigated the inhibitory effects of aqueous extracts from Miracle Fruit leaves (AML) on mutation and oxidative damage. The results showed that AML in the range of 1–5mg/plate inhibited the mutagenicity of 2-aminoanthracene (2-AA), an indirect mutagen, and 4-nitroquinoline-N-oxide (4-NQO), a direct mutagen toward Salmonella typhimurium TA 98 and TA 100. On the other hand, AML in the range of 0.05–0.2mg/ml showed radical scavenging, reducing activities, liposome protection as well as decreased tert-butyl hydroperoxide (t-BHP) induced oxidative cytotoxicity in HepG2 cells. High performance liquid chromatography (HPLC) analysis suggested that the active phenolic constituents in AML are p-hydroxybenzoic acid, vanillic acid, syringic acid, trans-p-coumaric acid and veratric acid. These active phenolic components may contribute to the biological protection effects of AML in different models. The data suggest that AML exhibiting biological activities can be applied to antimutation as well as anti-oxidative damage.

Inhibitory Effects of Aqueous Extracts from Leaves of Common Tropical Green Plants on Urea Hydrolysis in Soils

Tropical plants contain a variety of secondary metabolites, and plant aqueous extracts can be used as urease inhibitors to improve nitrogen use efficiency and reduce the negative environmental effects. An incubation experiment was carried out to investigate the effects of aqueous extracts of 32 common tropical green plant species from 24 families on urea hydrolysis. The results indicated that the aqueous extracts from 3 of the common tropical green plants (Pterocarpus indicus, Callistemon rigidus, Terminalia mantaly) belonging to Leguminosae, Myrtaceae and Combretaceae respectively showed better inhibitory effects on urease than hydroquinone as a chemical inhibitor, and had more obvious potential applications. The inhibitory effects of active substances in plants were affected by extract temperature causing by solubility and thermal stability of active substances. T. mantaly had the most potential for development in this study as a fertilizer additive. The inhibitory effects of aqueous extracts of T. mantaly leaves on urea hydrolysis increased with increasing concentration of aqueous extracts, the strongest inhibitory effect on urease occurred after 2-3 d of incubation.

Inhibitory Effects of Aqueous Extracts of Tropical Forest Plants on Urea Hydrolysis and Nitrification in Soil

Tropical forest plants contain a variety of secondary metabolites, and plant aqueous extracts can be used as urease and nitrification inhibitors to improve nitrogen use efficiency and reduce the negative environmental effects. An incubation experiment was carried out to investigate the effects of aqueous extracts of 60 tropical forest plant species from 16 families on urea hydrolysis and nitrification. The results indicated that the aqueous extracts from 3 of the tropical forest plants (Aphanamixis polystachya, Toona sinensis, Vatica mangachapoi) belonging to meliaceae and dipterocarpaceae showed good inhibitory effects on urease, and the aqueous extracts from 5 of the tropical forest plants (Cryptocarya chinensis, Cryptocarya hainanensis, Toona sinensis, Khaya senegalensis, Hopea hainanensis) belonging to lauraceae, meliaceae and ipterocarpaceae showed good inhibitory effects on nitrification. The inhibitory effects of active substances in plants were affected by extract temperature, and the plants can be divided into three types by solubility and thermal stability. Toona sinensis had the most potential for development in this study as urea additive. The inhibitory effects of aqueous extracts of Toona sinensis leaves on urea hydrolysis and nitrification increased with increasing concentration of aqueous extracts, the strongest inhibitory effect on urease occurred after 2-3 d of incubation, and the strongest inhibitory effect on nitrification occurred after 2-3 weeks of incubation.

Fenugreek seed extract inhibit fat accumulation and ameliorates dyslipidemia in high fat diet-induced obese rats.

This study investigated the inhibitory effect of aqueous extract of Trigonella foenum-graecum seeds (AqE-TFG) on fat accumulation and dyslipidemia in high fat diet- (HFD-) induced obese rats. Female Wistar rats were fed with HFD ad libitum, and the rats on HFD were treated orally with AqE-TFG or orlistat ((HFD for 28 days + AqE-TFG (0.5 and 1.0 g/kg) or orlistat (10 mg/kg) from day 8 to 28), respectively. Treatment with AqE-TFG produced significant reduction in body weight gain, body mass index (BMI), white adipose tissue (WAT) weights, blood glucose, serum insulin, lipids, leptin, lipase, and apolipoprotein-B levels and elevation in adiponectin levels. AqE-TFG improved serum aspartate amino transferase (AST), alanine amino transferase (ALT), and lactate dehydrogenase (LDH) levels. AqE-TFG treatment reduced the hepatic and cardiac thiobarbituric acid reactive substances (TBARS) and elevated the antioxidant enzyme (glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT)) levels. In addition, liver and uterine WAT lipogenic enzyme (fatty acid synthetase (FAS) and glucose-6-phosphate dehydrogenase (G6PD)) activities were restored towards normal levels. These findings demonstrated the preventive effect of AqE-TFG on fat accumulation and dyslipidemia, due to inhibition of impaired lipid digestion and absorption, in addition to improvement in glucose and lipid metabolism, enhancement of insulin sensitivity, increased antioxidant defense, and downregulation of lipogenic enzymes.

Study on inhibitory effect of aqueous extract of Taxus chinensis var. mairei on growth of A549 lung cancer xenografts in nude mice and its mechanism

To study the effect of aqueous extract of Taxus chinensis var. mairei (AETC) on the growth of A549 lung cancer xenografts in nude mice and its mechanism. The A549 lung cancer xenograft model was established, and then randomly divided into the control group, and low, middle and high dose AETC experiment groups. After 24 hours, they were orally administered with normal saline and drugs of the same volume for seven weeks. The length and width of the xenografts were measured every three days, and the xenograft growth curve was drawn. The nude mice were sacrificed after the administration for seven weeks, and their xenografts were collected to cultivate the anti-tumor rate. Real-time PCR and Western-blot were adopted to detect mRNA and protein levels. All of AETC experiment groups showed a significant anti-tumor effect (P < 0.05). Compared with the control group, each experimental group showed notable reduction in EGFR and Survivin mRNA in xenograft tissues (P < 0.05), with no significant change in VEGF mRNA level. The analysis on gray value ratio showed that EGFR mRNA were down-regulated (P < 0.05) in xenograft tissues in all experimental groups, but with no statistical significance in difference, and Survivin and p-EGFR were significantly down-regulated. AETC has not significant effect on angiogenesis, but may have the inhibitory effect on xenograft growth by inhibiting Survivin protein and EGFR phosphorylation.

Inhibitory effect of aqueous extract of different parts of unripe pawpaw (Carica papaya) fruit on Fe2+-induced oxidative stress in rat pancreas in vitro

Context: Carica papaya L. (Caricaceae) is widespread throughout tropical Africa; it is cultivated for its fruits and it is eaten in various ways.Objective: This study sought to investigate the inhibitory effect of the aqueous extract of different parts of unripe pawpaw fruit on Fe2+-induced lipid peroxidation in rat’s pancreas in vitro.Materials and methods: The aqueous extract of the unripe pawpaw fruit parts; peel (PG), seed (SG), flesh (FG), flesh with peel (FPG) and a combination of equal amount of all parts (CG) were prepared, the total phenolic content and the antioxidant activities of the extracts were then evaluated using various spectrophotometric methods.Result: PG had the highest total phenol content (1.24 mg GAE/g), flavonoid content (0.63 mg QUE/g), reducing power (7.07 mg AAE/g) and Fe2+ chelating ability while the SG had the highest 1,1-diphenyl-2-picrylhydrazyl radical scavenging ability. Furthermore, all the extracts caused a significant decrease (p < 0.05) in the malondialdehyde contents in the pancreas with SG (IC50 = 4.25 mg/mL) having the highest inhibitory effect on Fe2+-induced lipid peroxidation.Discussion and conclusion: This protective effect of the extracts on Fe2+-induced lipid peroxidation in rat pancreas could be attributed to their phenolic compounds and, the possible mechanism may be through their antioxidant activities. However, the effect of combination of different parts of unripe pawpaw fruit in equal amount (w/w) on the inhibition of Fe2-induced lipid peroxidation in rat pancreas exhibited additive properties.

Aqueous Extracts of Roselle (Hibiscus sabdariffa Linn.) Varieties Inhibit α-Amylase and α-Glucosidase Activities In Vitro

This study sought to investigate the inhibitory effect of aqueous extracts of two varieties (red and white) of Hibiscus sabdariffa (Roselle) calyces on carbohydrate hydrolyzing enzymes (α-amylase and α-glucosidase), with the aim of providing the possible mechanism for their antidiabetes properties. Aqueous extracts were prepared (1:100 w/v) and the supernatant used for the analysis. The extracts caused inhibition of α-amylase and α-glucosidase activities in vitro.The IC(50) revealed that the red variety (25.2 μg/mL) exhibited higher α-glucosidase inhibitory activity than the white variety (47.4 μg/mL), while the white variety (90.5 μg/mL) exhibited higher α-amylase inhibitory activity than the red variety (187.9 μg/mL). However, the α-glucosidase inhibitory activities of both calyces were higher than that of their α-amylase. In addition, the red variety possessed higher antioxidant capacity as exemplified by the (•)OH scavenging abilities, Fe(2+) chelating ability, and inhibition of Fe(2+)-induced pancreatic lipid peroxidation in vitro. The enzyme inhibitory activities and antioxidant properties of the roselle extracts agreed with their phenolic content. Hence, inhibition of α-amylase and α-glucosidase, coupled with strong antioxidant properties could be the possible underlying mechanism for the antidiabetes properties of H. sabdariffa calyces; however, the red variety appeared to be more potent.

The Inhibitory Effects of Aqueous Extract from Guava Twigs, Psidium guajava L., on Mutation and Oxidative Damage

This study examines the inhibitory effects of the aqueous extract from guava twigs (GTE), Psidium guajava L., on mutation and oxidative damage. The results show that GTE inhibits the mutagenicity of 4‐nitroquinoline‐N‐oxide (4‐NQO), a direct mutagen, and 2‐aminoanthracene (2‐AA), an indirect mutagen, toward Salmonella typhimurium TA 98 and TA 100. In addition, GTE shows radical scavenging, reducing activities, tyrosinase inhibition, and liposome protection effects. Meanwhile, GTE in the range of 0.1–0.4 mg/mL protects liver cells from tert‐butyl‐hydroperoxide‐(t‐BHP‐) induced cytotoxicity. Furthermore, the cytotoxicity inhibition of GTE in the t‐BHP‐treated cells was demonstrated in a dose‐dependent manner. High‐performance liquid chromatography analysis suggests that the major phenolic constituents in GTE are gallic acid, ferulic acid, and myricetin. These active phenolic components may contribute to the biological protective effects of GTE in different models. The data suggest that GTE exhibiting biological activities can be applied to antimutation, antityrosinase, and antioxidative damage.

Inhibitory effect of aqueous spinach extract on degranulation of RBL-2H3 cells

The inhibitory effect of an aqueous extract from spinach on degranulation of RBL-2H3 cells is herein reported. The extract significantly suppressed antigen-induced degranulation in a dose-dependent manner without affecting cell viability. Active substances in the extract were heat-stable and trypsin-resistant with molecular weights ranging from 500Da to 14kDa. The extract inhibited elevation of the intracellular Ca2+ concentration caused by stimulation by antigen, while not suppressing degranulation induced by a calcium ionophore A23187. Immunoblot analysis revealed that the inhibitory effect results from downregulation of phosphorylation of both Syk kinase and phosphatidylinositol 3-kinase in the signalling pathways involved in degranulation caused by the antigen–antibody interaction. Taken together, these findings suggest that aqueous spinach extract has an anti-allergic activity that controls degranulation.

In vitro evaluation of calcium oxalate monohydrate crystals influenced by Costus igneus aqueous extract

Calcium oxalate monohydrate (COM) crystals are frequently found in urinary calculi (stones). COM crystals were grown by the single diffusion gel growth technique and the inhibitory effects of aqueous extracts of leaves, stems and rhizome of Costus igneus on the growth of COM crystals were studied. With an increase in the concentration of aqueous extract of C. igneus, the weight of the formed crystals was gradually reduced from 2.15 to 0.07 g(leaves), 0.06 g (rhizome) and 0.03 g (stem). The crystals harvested from the COM were characterized by Fourier transform infrared spectroscopy to confirm the functional groups and powder X-ray diffraction analyses to confirm the crystalline phases of COM crystals. A scanning electron microscopy study confirmed that the morphology of the crystals changed from hexagonal (COM) to bipyramids of calcium oxalate dihydrate (COD). This study confirms that using aqueous extracts of stem and rhizome of C. igneus can promote the formation of COD crystals and reduce the nucleation rate of COM crystals, a major component of calcium urinary stones.

In vitro antioxidant activities and inhibitory effects of aqueous extracts of unripe plantain pulp (Musa paradisiaca) on enzymes linked with type 2 diabetes and hypertension

The dried plantain pulps were crushed and milled into flour (Raw flour), while a portion of its flour was reconstituted in boiling water to form a thick paste known locally in Western Nigeria as ‘amala’. This was dried and milled into ‘Amala’ flour. The aqueous extracts of raw and ‘amala’ flour were prepared (1 g/20 mL). The phenolic contents, vitamin C and antioxidant properties (DPPH and OH radical scavenging ability, reducing power and iron-chelating ability) were analyzed. The α-amylase, α-glucosidase, angiotensin-1-converting enzyme (ACE) inhibitory activities and EC50 values were also determined. The results showed that ‘amala’ flour had higher phenolic contents, reducing properties and DPPH radical scavenging ability while the raw flour had higher iron chelating and hydroxyl radical scavenging ability in a dose dependent manner and vitamin C (3.71mg/g) content. The ‘amala’ flour had higher α-amylase and α-glucosidase inhibitory activities than raw flour. The extracts had stronger inhibitory effects on α-glucosidase than α-amylase activities. The raw flour had higher ACE inhibitory activity (EC50=0.81±1.39 mg/mL). These suggest their potential use in the management of type-2 diabetes and hypertension. This study evaluates the in vitro anti-oxidant activities inhibitory effects of aqueous extracts of unripe plantain on enzymes associated with type 2 diabetes. Key words: Musa paradisiacal, type 2 diabetes, α-amylase, α-glucosidase, angiotensin-1-converting enzyme (ACE), hypertension, anti-oxidant.

Prunella vulgaris Suppresses HG-Induced Vascular Inflammation via Nrf2/HO-1/eNOS Activation

Vascular inflammation is an important factor which can promote diabetic complications. In this study, the inhibitory effects of aqueous extract from Prunella vulgaris (APV) on high glucose (HG)-induced expression of cell adhesion molecules in human umbilical vein endothelial cells (HUVEC) are reported. APV decreased HG-induced expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. APV also dose-dependently inhibited HG-induced adhesion of HL-60 monocytic cells. APV suppressed p65 NF-κB activation in HG-treated cells. APV significantly inhibited the formation of intracellular reactive oxygen species (ROS). HG-stimulated HUVEC secreted gelatinases, however, APV inhibited it. APV induced Akt phosphorylation as well as activation of heme oxygenase-1 (HO-1), eNOS, and nuclear factor E2-related factor 2 (Nrf2), which may protect vascular inflammation caused by HG. In conclusion, APV exerts anti-inflammatory effect via inhibition of ROS/NF-κB pathway by inducing HO-1 and eNOS expression mediated by Nrf2, thereby suggesting that Prunella vulgaris may be a possible therapeutic approach to the inhibition of diabetic vascular diseases.

Inhibitory Effect of Aqueous Extract of Moringa oleifera and Newbuoldia laevis Leaves on Ferrous Sulphate and Sodium Nitroprusside Induced Oxidative Stress in Rat’s Testes in Vitro

Oxidative stress has been identified as one of the factors that affects fertility status. Therefore, this study sought to investigate the inhibitory effect of aqueous extract of Moringa oleifera and Newbuoldia laevis leaves on FeSO4 and Sodium Nitroprusside (SNP) induced lipid peroxidation in rat testes in vitro. Incubation of the testes tissue homogenate in the presence of FeSO4 and SNP caused a significant increase in the malondialdehyde (MDA) contents of the testes. The aqueous extract from both Moringa oleifera and Newbuoldia laevis leaves caused a significant decrease in the MDA contents of the testes in a dose-dependent manner. However, aqueous extract from Moringa oleifera leaf (EC50 = 0.29 mg/ml) had a significant (P2+ induced lipid peroxidation in the rat testes homogenate than that of Newbuoldia laevis leaf extract (EC50 = 0.58 mg/ml); while there was no significant (P2+ chelating and reducing power. Therefore, these plants have potential to prevent oxidative stress in testes and improve fertility outcomes.

Variation in Total Polyphenolics Contents of Aerial Parts of Potentilla Species and Their Anticariogenic Activity

The aerial parts of selected Potentilla species (P. anserina, P. argentea, P. erecta, P. fruticosa, P. grandiflora, P. nepalensis, P. norvegica, P. pensylvanica, P. crantzii and P. thuringiaca) were investigated in order to determine their contents of polyphenolic compounds. The results showed that P. fruticosa has relatively high concentrations of tannins (167.3 ± 2.0 mg/g dw), proanthocyanidins (4.6 ± 0.2 mg/g dw) and phenolic acids (16.4 ± 0.8 mg/g dw), as well as flavonoids (7.0 ± 1.1 mg/g dw), calculated as quercetin. Furthermore, we investigated the in vitro inhibitory effects of aqueous extracts from these species against cariogenic Streptococcus spp. strains. It was found that the tested samples moderately inhibit the growth of oral streptococci. However, all the preparations exhibited inhibitory effects on water-insoluble α-(1→3)-, α-(1→6)-linked glucan (mutan) and artificial dental plaque formation. The extract from P. fruticosa showed the highest anti-biofilm activities, with minimum mutan and biofilm inhibition concentrations of 6.25–25 and 50–100 µg/mL, respectively. The results indicate that the studied Potentilla species could be a potential plant material for extracting biologically active compounds, and could become a useful supplement for pharmaceutical products as a new anticariogenic agent in a wide range of oral care products.

Inhibitory effect of aqueous extract of Leontopodium leontopodioides against D-galactosamineN-induced hepatocyte injury

Inhibitory effect of aqueous extract of <i>Leontopodium leontopodioides</i> against <i>D</i>-galactosamineN-induced hepatocyte injury

Allelopathic effects of Lantana camara on germination and growth behavior of some agricultural crops in Bangladesh

An experiment was conducted to understand the growth inhibitory effects of aqueous extracts derived from Lantana camara L. (a globally recognized invasive alien weed) on six popular agricultural crops of Bangladesh. The test was conducted in sterilized petridishes with a photoperiod of 24 hours and an average temperature of 29°C. The effect of different concentrations of L. camara leaf extracts were recorded and compared with control (i.e., distil water). Result showed different concentrations of aqueous leaf extracts caused significant inhibitory effect on germination, root and shoot elongation and development of lateral roots of receptor crops. Bioassays also indicated that the inhibitory effect was proportional to the concentrations of the extracts and higher concentration had the stronger inhibitory effect whereas the lower concentration showed stimulatory effect in some cases. The inhibitory effect was much pronounced in root and lateral root development rather than shoot and germination.

Inhibitory effects of aqueous extract of Hibiscus sabdariffa on contractility of the rat bladder and uterus

We examined an aqueous extract of Hibiscus sabdariffa calyces extracts (HSE) by close-arterial injection on micturition thresholds (MTs) and on uterine contractions (rate and amplitude). Five doses of HSE were examined (1, 5, 10, 50, and 100 mg/kg) in 3 groups of rats: controls, after bladder inflammation, and after bilateral hypogastric neurectomy. In some rats, uterine contractions were induced by injection of oxytocin (OT) and the effect of HSE was compared with that of nifedipine. HSE increased MTs in a dose-dependent manner in all groups. Neither atropine (0.1 mg/kg) nor propranolol (0.4 mg/kg) had significant effects on cystometric parameters. They also did not affect the responses obtained by HSE on cystometric parameters. As with bladder response, HSE inhibited both the rate and amplitude of uterine contractions in all groups in a dose-dependent manner. The uterine response to HSE was not affected by administration of either atropine or propranolol. A slight, but significant, reduction of contraction amplitude by HSE in the OT precontracted uteri was only noted at a dose of 500 mg/kg. Nifedipine was more potent than HSE in reducing uterine contraction amplitude. The present work documents inhibition by HSE of the rat bladder and uterine contractility in a dose-dependent manner via a mechanism unrelated to local or remote autonomic receptors or calcium channels. However, further investigation is needed to establish the exact mechanism of action.