Sargassum polycystum and Turbinaria conoides Seaweed-based Novel Denture Cleanser: An In Vitro Study.

AIM: The study ventures into evaluating the antifungal and antibacterial efficacy of commercially available denture cleanser with Sargassum polycystum, Turbinaria conoides seaweeds, and the combination of seaweeds. MATERIALS AND METHODS: Poly(methyl methacrylate) disks measuring 10 × 2 mm were fabricated. The samples are divided into four groups of 21 samples each. The denture base was coated with Candida albicans and Streptococcus mutans individually. Group I was treated with Fittydent, group II (S. polycystum and T. conoides seaweeds combination), group III (S. polycystum), and group IV (T. conoides). The colony-formation units present on the surface of the denture were evaluated before and after treatment with different denture cleansers using the serial dilution method. Statistical analysis was done using descriptive statistics, analysis of variance, and post hoc Bonferroni analysis. RESULTS: At 10-5 dilution, T. conoides (group IV) was statistically significant in reducing both C. albicans and S. mutans. At 10-10 dilution, T. conoides (group IV) and S. polycystum and T. conoides combination (group II) had high antibacterial efficacy and were statistically significant. Fittydent (group I) had higher antifungal efficacy and was statistically significant in comparison to S. polycystum (group III) alone. At 10-10 dilution, the T. conoides (group IV), S. polycystum, and T. conoides combination (group II) showed no evidence of a significant difference in comparison to Fittydent (group I). Fittydent had higher antibacterial efficacy and was statistically significant in comparison to S. polycystum (group III) alone. CONCLUSION: Sargassum polycystum and T. conoides combination and T. conoides were found to have higher antibacterial efficacy in comparison to commercially available denture cleanser and also were found to have equal antifungal efficacy in comparison to commercially available denture cleanser.

Comparison of antifungal efficacy of commercially available denture cleanser and the extract of Turbinaria conoides seaweed against Candida albicans adherent to acrylic denture base resin: An in vitro study.

Aim: One of the main factors responsible for the development of Candida albicans on the surface of denture is improper maintenance of dentures. Denture hygiene can be achieved by regular cleansing of dentures using an appropriate denture cleanser. The aim of the study is to evaluate the antifungal efficacy of commercially available denture cleanser and the extract of Turbinaria conoides seaweed against C. albicans adherent to the surface of denture base resin. Settings and Design: This was an in vitro experimental study. Materials and Methods: Twenty-four Acrylic resin samples of dimension 10-mm radius and 2-mm thickness was randomly divided into two groups. The denture base resin was coated with C. albicans. The colonies present on the surface of each denture base resin were evaluated by serial dilution method. Group A was treated with commercially available denture cleanser and Group B was treated with extract of seaweed T. conoides. The colonies were then evaluated using serial dilution. Statistical Analysis Used: The colony count values obtained by serial dilution were tabulated. These values were statistically analysed using t-test. Results: Reduction of colony count is more in T. conoides than commercially available Fittydent; the difference was statistically significant with a mean difference of 65 at dilution 10-2 and 29.25 at dilution 10-3 using t-test with P < 0.001. Conclusion: Within the limitations of this in vitro study, it was proved that the extract of T. conoides seaweed and commercially available denture cleanser Fittydent was effective in reducing the colony count of C. albicans. T. conoides seaweed is statistically significant than commercially available Fittydent.

High-resolution liquid chromatography and mass spectrometry (HR-LCMS) assisted phytochemical profiling and an assessment of anticancer activities of Gracilaria foliifera and Turbinaria conoides using in vitro and molecular docking analysis.

Marine algae's, owing to diverse range of secondary metabolites, opening up the new avenues in new drug development and can be used efficiently in anticancer research. Two seaweeds Gracilaria foliifera and Turbinaria conoides are subjected to phytochemical investigation by HR-LCMS and NMR which confirms presence of different bioactive compounds. The cytotoxicity of the dichloromethane (DCM) fraction of Gracilaria foliifera and Turbinaria conoides was determined using an in vitro methyl thiazolyl tetrazolium (MTT) test and showed considerable dose-dependent cytotoxicity on tumour cell lines. In MCF7, Gracilaria foliifera had an IC50 of 100 µg/ml, while Turbinaria conoides had an IC50 of 200 µg/ml and both the DCM fraction had IC50 values of 100 µg/ml in the A549 cell line. MTT assay for anticancer activity suggest that Gracilaria foliifera has potent anticancer activity in both breast and lung cell lines, while the DCM fraction of Turbinaria conoides has potent activity in lung cell lines and moderate activity in breast cell lines. The anticancer effects of the discovered drugs targeting the most prevalent enzymes VEGFR and AXL tyrosine kinases were confirmed using a computational technique. We believe that residues from VEGFR, like Lys868, Asn923, Asp1046, and Phe1047 and Asp690 from Axl kinase may have contributed to the plausible anti-cancer benefit seen in this study.Communicated by Ramaswamy H. Sarma.

Novel Furanyl-Substituted Isochromanyl Class of Anti-Inflammatory Turbinochromanone from Brown Seaweed Turbinaria conoides.

Organic extract of the brown seaweed Turbinaria conoides (Sargassaceae) was chromatographically fractionated to yield an undescribed furanyl-substituted isochromanyl metabolite, named as turbinochromanone, which was characterized as methyl 4-[(3S)-8-{[(3R)-4-ethyl-2,3-dihydrofuran-3-yl]methyl}-1-oxo-3,4-dihydro-1H-2-benzopyran-3-yl]butanoate. The isochromanyl derivative possessed comparable attenuation potential against 5-lipoxygenase (IC50 3.70 µM) with standard 5-lipoxygenase inhibitor drug zileuton (IC50 2.41 µM). Noticeably, the index of anti-inflammatory selectivity of turbinochromanone (∼1.7) was considerably greater than that exhibited by the standard agent diclofenac (1.06). Antioxidant properties of turbinochromanone against oxidants (IC50 ∼24 µM) further supported its potential anti-inflammatory property. Greater electronic properties (topological polar surface area of 61.8) along with comparatively lesser docking parameters of the studied compound with aminoacyl residues of targeted enzymes (cyclooxygenase-2 and 5-lipoxygenase) (binding energy of -11.05 and -9.40 kcal mol-1 , respectively) recognized its prospective anti-inflammatory potential. In an aim to develop seaweed-based natural anti-inflammatory leads, the present study isolated turbinochromanone as promising 5-lipoxygenase and cyclooxygenase-2 inhibitor, which could be used for pharmaceutical and biotechnological applications.

In vitro cytotoxicity assay of Fucoidan extracted from Turbinaria conoides against cancer cell lines MCF7, A549, and normal cell line L929

Abstract The main aim of the study is to quantify the cytotoxic property of the Fucoidan extracted from the Turbinaria conoides using the MTT assay with the standard fucose. Fucoidan was extracted using the soaked water method and it was determined using the HPLC procedure the obtained Test sample Fucoidan extracted from the Turbinaria conoides and standard fucose was subjected to the cytotoxicity assay against the MCF7 Human breast cancer cell line, A549 lung cancer cell line, and L929 normal mouse fibroblast cell line. From the results it was found that the Test sample showed good IC50 value for MCF7 cell line then A549 with an increasing concentration 24 hours incubation at 37°C The IC50 for MCF7 was 115.21 µg/ml and A549 396.46µg/ml and the Fucoidan extract was checked for its cytotoxicity against the normal mouse fibroblast cell line L929, Fucoidan was found non-lethal to the L929 mouse fibroblast normal cell line. Standard fucose also gave a significant result towards MCF7 and against the L929. This indicates that the Fucoidan extracted from Tubinaria conoides shows better anticancer potential in it. Hence its application can be further extended in the pharmacological fields.

Conoidecyclics A-C from marine macroalga Turbinaria conoides: Newly described natural macrolides with prospective bioactive properties.

Intertidal marine brown alga Turbinaria conoides (J.Agardh) Kützing (family Sargassaceae) is considered as one of the largely abundant species, available in the coastal zones of the Indian subcontinent. Bioactivity-guided chromatographic fractionation of the organic extract of T. conoides resulted in three previously undescribed macrocyclic lactone homologues, named as conoidecyclics A-C. Conoidecyclic A displayed greater attenuation potential against cyclooxygenase-2 (IC50 1.75 mM) and 5-lipoxygenase (IC50 4.24 mM) in comparison with other analogues. Conoidecyclic A exhibited higher attenuation potential against 5-lipoxygenase than that displayed by an anti-inflammatory agent, ibuprofen (IC50 4.51 mM). The higher selectivity index of conoidecyclic A (1.79) recognized its selective attenuation potential against the inducible cyclooxygenase-2 enzyme. Inhibition potential of conoidecyclic A against angiotensin converting enzyme-I (IC50 1.23 mM) and protein tyrosine phosphatase-1B (IC50 1.39 mM) were non-competitive, as deduced by kinetic studies. In-silico molecular modeling study of conoidecyclic A with the allosteric sites of the targeted enzymes exhibited least binding energy of -14.51 to -11.27 kcal mol-1 compared to those exhibited by other studied macrolide homologues. Reaction kinetic studies of conoidecyclic A coupled with lesser apparent Vmax inferred that it could efficiently bind with the allosteric site of targeted enzymes in a non-competitive manner to diminish the reaction velocity resulting in enzyme inhibition. Drug-likeness and predictive pharmacokinetic parameters of conoidecyclic A exhibited an acceptable oral bioavailability. These reports inferred that conoidecyclic A encompassing pentacosa macrocyclic moiety could be a promising therapeutic lead to inhibit the enzymes related to the development and progression of pathological conditions leading to inflammation, hypertension and type-2 diabetes.

Halocarbon emissions by selected tropical seaweeds exposed to different temperatures.

Four tropical seaweeds, Gracilaria manilaensis Yamamoto & Trono, Ulva reticulata Forsskål, Kappaphycus alvarezii (Doty) L.M.Liao and Turbinaria conoides (J.Agardh) Kützing, collected from various habitats throughout Malaysia, were subjected to temperatures of 40, 35, 30, 25 and 20 °C in the laboratory. An exposure range of 21-38 °C is reported for Malaysian waters. The effect of the temperature exposures on the halocarbon emissions of the seaweeds were determined 4 and 28 h after treatment. The emission rates for a suite of six halocarbons commonly emitted by seaweeds, bromoform (CHBr3), dibromomethane (CH2Br2), diiodomethane (CH2I2), iodomethane (CH3I), dibromochloromethane (CHBr2Cl) and dichlorobromomethane (CHBrCl2), were measured using a cryogenic purge-and-trap sample preparation system coupled to a gas chromatography-mass spectrometry. The emission rate of CHBr3 was the highest of the six halocarbons for all the seaweeds under all the temperatures tested, followed by CH2Br2, and CH2I2. The emission rates were affected by temperature change and exposure duration, but overall responses were unique to each seaweed species. Larger decreases in the emissions of CHBr3, CH2Br2, CH2I2 and CHBr2Cl were found for K. alvarezii and T. conoides after 4 h at 40 °C. In both cases there was a >90% (p < 0.05) reduction in the Fv/Fm value suggesting that photosynthetic actitivity was severely compromised. After a 28 h exposure period, strong negative correlations (r = -0.69 to -0.95; p < 0.01) were observed between temperature and the emission of CHBr3, CH2Br2 and CH2I2 for U. reticulata, K. alvarezii and T. conoides. This suggests a potential decrease in the halocarbon emissions from these tropical seaweeds, especially where the temperature increase is a prolonged event. Strong correlations were also seen between seaweed chlorophyll and carotenoid pigment contents and the emission rates for CHBr3, CH2Br2 and CH2I2 (r = 0.48 to 0.96 and -0.49 to -0.96; p < 0.05). These results suggest that the regulation of halocarbon production versus reactive oxygen species production in seaweeds is an area worthy of further exploration.

First report of substituted 2H-pyranoids from brown seaweed Turbinaria conoides with antioxidant and anti-inflammatory activities.

The organic extract of Turbinaria conoides, a brown seaweed harvested from the Gulf of Manner region of Indian peninsular was chromatographically fractionated to yield three substituted 2H-pyranoids, namely methyl-21-yl-[5', 6'- dihydro-5'-yl-{54-(4-hydroxybenzoyl)-oxy-(52-methylbutyl)}-3'-methyl-2H-pyran]-21-methyl butanoate (1), 11-[(3', 6'-dihydro-4'-methyl-2'-oxo-2H-pyran-3'-yl)methyl]-10-methylhexyl benzoate (2), and [6-ethyl-3,4-dimethyl-(tetrahydro-2', 2', 6'-trimethyl-2H-pyran-3'-yl)-2,5-cycloheptadiene]-1-propanoate (3). The compounds 1 and 2 bearing 2H-pyranyl-4-hydroxybenzoyl and 2H-pyranyl-10-methylhexylbenzoate moieties exhibited potential antioxidant activities (IC50 0.54-0.69 mg mL-1) as commercial antioxidant (α-tocopherol IC50 0.63-0.73 mg mL-1). Likewise, potential bioactivity of the 2H-pyran derivative, 1 against 5-lipoxygenase (IC50 ∼ 1 mg mL-1) along with higher index of selectivity (COX-1 inhibitoryIC50/COX-2 inhibitoryIC50 1.88) indicated their selective anti-inflammatory properties against inducible inflammatory mediators than that displayed by commercially available non-steroidal anti-inflammatory drug (ibuprofen, 0.44). Structure activity relationship analysis of the studied compounds showed that the antioxidative and anti-inflammatory properties were directly proportional to their electronic properties. The previously undescribed 2H-pyranoids might constitute as potential antioxidative and anti-inflammatory pharmacophores for medicinal applications. [Formula: see text].

Fucoidan from marine brown algae attenuates pancreatic cancer progression by regulating p53 - NFκB crosstalk.

Poor pancreatic cancer (PC) prognosis has been attributed to its resistance to apoptosis and propensity for early systemic dissemination. Existing therapeutic strategies are often circumvented by the molecular crosstalk between cell-signalling pathways. p53 is mutated in more than 50% of PC and NFκB is constitutively activated in therapy-resistant residual disease; these mutations and activations account for the avoidance of cell death and metastasis. Recently, we demonstrated the anti-PC potential of fucoidan extract from marine brown alga, Turbinaria conoides (J. Agardh) Kützing (Sargassaceae). In this study, we aimed to characterize the active fractions of fucoidan extract to identify their select anti-PC efficacy, and to define the mechanism(s) involved. Five fractions of fucoidan isolated by ion exchange chromatography were tested for their potential in genetically diverse human PC cell lines. All fractions exerted significant dose-dependent and time-dependent regulation of cell survival. Fucoidans induced apoptosis, activated caspase -3, -8 and -9, and cleaved Poly ADP ribose polymerase (PARP). Pathway-specific transcriptional analysis recognized inhibition of 57 and 38 nuclear factor κB (NFκB) pathway molecules with fucoidan-F5 in MiaPaCa-2 and Panc-1 cells, respectively. In addition, fucoidan-F5 inhibited both the constitutive and Tumor necrosis factor-α (TNFα)-mediated NFκB DNA-binding activity in PC cells. Upregulation of cytoplasmic IκB levels and significant reduction of NFκB-dependent luciferase activity further substantiate the inhibitory potential of seaweed fucoidans on NFκB. Moreover, fucoidan(s) treatment increased cellular p53 in PC cells and reverted NFκB forced-expression-related p53 reduction. The results suggest that fucoidan regulates PC progression and that fucoidans may target p53-NFκB crosstalk and dictate apoptosis in PC cells.

In vitro and in silico inhibition properties of fucoidan against α-amylase and α-D-glucosidase with relevance to type 2 diabetes mellitus.

This study investigated the in vitro and in silico inhibitory properties of fucoidan extracted from Turbinaria conoides against α-amylase and α-D-glucosidase. Extracted fucoidan contained 59 and 35% of fucose and sulphate and was characterized using 1H NMR. Dose dependent inhibition assays showed maximum of 85 and 72% of inhibition for α-amylase and α-D-glucosidase at 2.07 and 1.03 µM concentration of fucoidan. The IC50 value of fucoidan was found to be 1.07 and 0.68 µM against α-amylase and α-D-glucosidase. In silico studies (grid based docking) by Schrödinger software revealed that fucoidan as a potent inhibitor for both α-amylase and α-D-glucosidase based on number of interactions, hydrogen bond length and binding energy. Furthermore, fucoidan fulfilled the pharmacokinetic properties thus promising to develop fucoidan as drug for type 2 DM.

Effect of marine protected areas (MPAs) on consumer diet: MPA fish feed higher in the food chain.

Marine Protected Areas (MPAs) are often established to mitigate the effects of overfishing and other human disturbances. In Fiji these are locally managed and, where enforced, have significantly higher coral cover, higher fish biomass, and lower seaweed cover than in the adjacent, unprotected reefs (non-MPAs). We investigated how the isotopic signatures of a common, mid-level consumer, Epinephelus merra, differed among three small (0.5- 0.8km2) MPAs versus adjacent, unprotected reefs. Isotopic ratios suggested that the fish in the MPAs fed higher in the food chain than those in the adjacent non-MPAs, despite being slightly smaller in size. Calculations using a brown alga as representative of the basal level of the food chain estimate this difference to be about half a trophic level. Thus, the isotopic ratio of a mid-level consumer can be noticeably altered over scales of only a few hundred meters. This may result from more complete food webs and hence greater prey choice and availability in the MPAs and implies that MPAs affect not only species' abundance and diversity, but also diet composition and trophic biology of member individuals. Our findings suggest E. merra exhibits considerable site fidelity in its feeding biology and thus provides a localized isotopic signal of its reef of residence. If the isotopic signal of this mid-level carnivore is reflective of the composition of the food web beneath it, the signal might provide an easily obtained indication of reef conditions in that area.

Isolation of turbinaric acid as a chemomarker of Turbinaria conoides (J. Agardh) Kützing from South Pacific Islands.

Several species of the genus Turbinaria coexist along the coasts of islands in the Indian and Pacific Oceans. Among these brown algae, Turbinaria ornata and T. conoides are sister species that are difficult to differentiate using exclusively morphological characters. Based on in vivo nuclear magnetic resonance and chromatographic techniques, i.e., liquid and gas chromatography-mass spectrometry analysis, combined with phylogenetic data, we successfully identified turbinaric acid in T. conoides samples from several Indian and Pacific Ocean islands. This nonvariable discriminant molecule was only identified in T. conoides specimens, but not in the two allied species T. ornata and T. decurrens. Results are discussed with regard to turbinaric acid as an interesting chemomarker isolated from T. conoides and the rapid discrimination of Turbinaria specimens using chemical assays.

Evaluation of phenolic contents and antioxidant activities of brown seaweeds belonging to Turbinaria spp. (Phaeophyta, Sargassaceae) collected from Gulf of Mannar.

OBJECTIVE: To evaluate the antioxidant activities and total phenolic contents of brown seaweeds belonging to Turbinaria spp. [Turbinaria conoides (T. conoides) and Turbinaria ornata (T. ornata) collected from Gulf of Mannar of southeastern coast of India in various in vitro systems. METHODS: The antioxidant activity was evaluated using different in vitro systems, viz., 1, 1-diphenyl-2-picrylhydrazyl (DPPH), 2, 2'-azino-bis-3 ethylbenzothiozoline-6-sulfonic acid diammonium salt (ABTS), H2O2/HO radical scavenging, Fe(2+) ion chelating ability, and reducing potential. Folin-Ciocalteu method was used to determine the total phenolic content of the extracts, and the results were expressed as mg of gallic acid equivalents (GE)/g of the seaweed extracts. Thiobarbituric acid-reactive substances assay was employed to assess the ability of the seaweed extracts to inhibit lipid oxidation. RESULTS: Ethyl acetate (EtOAc) fraction of T. conoides registered significantly higher phenolic content (105.97 mg GE/g) than that of T. ornata (69.63 mg GE/g). Significantly higher antioxidant potential as determined by DPPH (64.14%) radical scavenging activity was registered in EtOAc fraction of T. ornata. A higher ABTS(•+) radical scavenging (IC50 3.16 µg/mL), Fe(2+) chelating (IC50 0.46 mg/mL), H2O2 scavenging (IC50 4.25 mg/mL), lipid peroxidation inhibitory (TBARS, IC50 0.21 mg/mL), and reducing abilities (IC50 52.67 mg/mL) (P<0.05) were realized in EtOAc fraction of T. ornata than other fractions. CONCLUSIONS: This study indicated the potential use of T. conoides and T. ornata as candidate species to be used as food supplements/functional foods to increase shelf-life of food items for human consumption, and nutraceuticals to deter deleterious free radical-induced life-threatening diseases.

Evaluation of phenolic contents and antioxidant activities of brown seaweeds belonging to Turbinaria spp. (Phaeophyta, Sargassaceae) collected from Gulf of Mannar

Objective: To evaluate the antioxidant activities and total phenolic contents of brown seaweeds belonging to Turbinaria spp. [Turbinaria conoides (T. conoides) and Turbinaria ornata (T. ornata) collected from Gulf of Mannar of southeastern coast of India in various in vitro systems. Methods:The antioxidant activity was evaluated using different in vitro systems, viz., 1, 1-diphenyl-2-picrylhydrazyl (DPPH), 2, 2′-azino-bis-3 ethylbenzothiozoline-6-sulfonic acid diammonium salt (ABTS), H2O2/HO radical scavenging, Fe2+ ion chelating ability, and reducing potential. Folin-Ciocalteu method was used to determine the total phenolic content of the extracts, and the results were expressed as mg of gallic acid equivalents (GE)/g of the seaweed extracts. Thiobarbituric acid-reactive substances assay was employed to assess the ability of the seaweed extracts to inhibit lipid oxidation. Results: Ethyl acetate (EtOAc) fraction of T. conoides registered significantly higher phenolic content (105.97 mg GE/g) than that of T. ornata (69.63 mg GE/g). Significantly higher antioxidant potential as determined by DPPH (64.14%) radical scavenging activity was registered in EtOAc fraction of T. ornata. A higher ABTS.+ radical scavenging (IC50 3.16 μg/mL), Fe2+ chelating (IC50 0.46 mg/mL), H2O2 scavenging (IC50 4.25 mg/mL), lipid peroxidation inhibitory (TBARS, IC50 0.21 mg/mL), and reducing abilities (IC50 52.67 mg/mL) (P<0.05) were realized in EtOAc fraction of T. ornata than other fractions. Conclusions: This study indicated the potential use ofT. conoides and T. ornata as candidate species to be used as food supplements/functional foods to increase shelf-life of food items for human consumption, and nutraceuticals to deter deleterious free radical-induced life-threatening diseases.

Evaluation of phenolic contents and antioxidant activities of brown seaweeds belonging to Turbinaria spp. (Phaeophyta, Sargassaceae) collected from Gulf of Mannar

<p><b>OBJECTIVE</b>To evaluate the antioxidant activities and total phenolic contents of brown seaweeds belonging to Turbinaria spp. [Turbinaria conoides (T. conoides) and Turbinaria ornata (T. ornata) collected from Gulf of Mannar of southeastern coast of India in various in vitro systems.</p><p><b>METHODS</b>The antioxidant activity was evaluated using different in vitro systems, viz., 1, 1-diphenyl-2-picrylhydrazyl (DPPH), 2, 2'-azino-bis-3 ethylbenzothiozoline-6-sulfonic acid diammonium salt (ABTS), H2O2/HO radical scavenging, Fe(2+) ion chelating ability, and reducing potential. Folin-Ciocalteu method was used to determine the total phenolic content of the extracts, and the results were expressed as mg of gallic acid equivalents (GE)/g of the seaweed extracts. Thiobarbituric acid-reactive substances assay was employed to assess the ability of the seaweed extracts to inhibit lipid oxidation.</p><p><b>RESULTS</b>Ethyl acetate (EtOAc) fraction of T. conoides registered significantly higher phenolic content (105.97 mg GE/g) than that of T. ornata (69.63 mg GE/g). Significantly higher antioxidant potential as determined by DPPH (64.14%) radical scavenging activity was registered in EtOAc fraction of T. ornata. A higher ABTS(•+) radical scavenging (IC50 3.16 µg/mL), Fe(2+) chelating (IC50 0.46 mg/mL), H2O2 scavenging (IC50 4.25 mg/mL), lipid peroxidation inhibitory (TBARS, IC50 0.21 mg/mL), and reducing abilities (IC50 52.67 mg/mL) (P<0.05) were realized in EtOAc fraction of T. ornata than other fractions.</p><p><b>CONCLUSIONS</b>This study indicated the potential use of T. conoides and T. ornata as candidate species to be used as food supplements/functional foods to increase shelf-life of food items for human consumption, and nutraceuticals to deter deleterious free radical-induced life-threatening diseases.</p>

Antimicrobial potential of selected brown seaweeds from Vedalai coastal waters, Gulf of Mannar.

OBJECTIVE: To evaluate the antimicrobial activity of Turbinaria conoides (T. conoides), Padina gymnospora (P. gymnospora) and Sargassum tenerrimum against human bacterial and fungal pathogens. METHODS: The antimicrobial activities of the extracts against various organisms were tested by using disc diffusion method. RESULTS: The methanol extract showed the better result than the other extracts. Whereas, the strong antibacterial inhibition was noted in methanol extracts of P. gymnospora against Bacillus subtilus (26.33±1.86) and the mild inhibition of ethanol extracts from T. conoides against Klebsiella pneumoniae (2.33±0.51). Acetone extraction of P. gymnospora had strong antifungal inhibition against Cryptococcus neoformans (23.00±1.78), and acetone extract of T. conoides had mild inhibition against Aspergillus niger (3.00±0.89). CONCLUSIONS: The seven different solvent extracts of seaweeds used in the present study have shown significant bacterial action. Further, a detailed study on the principle compound in the seaweeds which is responsible for antimicrobial activity is still needed and it can be achieved by using advanced separation techniques.

Acute toxicity study and antipyretic effect of the brown alga Turbinaria conoides (J. Agardh) Kuetz.

The active principles of brown alga, Turbinaria conoides (J.Agardh) Kuetz. (Sargassaceae) was extracted with n-hexane, cyclohexane, methanol and ethanol-water (1:1) and investigated for acute toxicity and antipyretic activity. Phytochemical analysis of the extracts revealed the presence of steroids, flavonoids and reducing sugars. Acute toxicity study was performed in Wistar rats after administration of extracts orally. No mortality was observed up to the dose of 5 g/kg for methanol and ethanol-water (1:1) extracts whereas n-hexane and cyclohexane extracts were found to be toxic at the dose levels of 1 g/kg and 2 g/kg respectively. In biochemical analysis, n-hexane, cyclohexane and ethanol-water (1:1) extracts caused a significant (P<0.01) increase in serum cholesterol, protein and alkaline phosphatase levels. In haematological studies, a significant difference was observed for cyclohexane and ethanol-water (1:1) extracts in polymorphs, lymphocytes and eosinophils when compared to the control. Antipyretic activity of extracts (100-400 mg/kg doses) was carried out on yeast-induced pyrexia in rats. Cyclohexane extract exhibited more significant antipyretic activity (P<0.01) than the other extracts at a dose of 200 mg/kg (54.43%), which was comparable to that of paracetamol at a dose of 33 mg/kg. The findings validated the use of this brown alga in traditional cure of children's fever.