Assessment of Bioautography and Spot Screening of TLC of Green Tea (Camellia) Plant Extracts as Antibacterial and Antioxidant Agents

This study was carried out as a prerequisite to evaluate the therapeutic potential of Camellia varieties. The crude extracts of six different plants of green tea Camellia assamica and Camellia sinensis were tested against three Gram-positive and four Gram-negative bacteria using agar disk diffusion method at 50 mg/ml concentration. 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and diphenyl-(2,4,6-trinitrophenyl)iminoazanium free radical scavenging methods were performed to evaluate the antioxidant potential. Phytochemical constituents and trace metals were detected through thin layer chromatography and Inductively Coupled Plasma Atomic Emission Spectrophotometer, respectively. The maximum inhibition of Staphylococcus aureus was recorded by dimethyl sulphoxide extracts of green tea varieties. The measured zone of inhibition of dimethyl sulphoxide extracts by Qimen was (10.00±0.0 mm), Japanese (10.00±0.0 mm), Turkish (10.00±0.0 mm), Indonesian (8.33±1.0 mm), P3 clone (10.00±0.0 mm) and Sri Lankan (10.00±0.0 mm). Maximum scavenging potential activity was found with ethanol, methanol and dimethyl sulphoxide extracts. Spot screening of TLC-developed plates indicated that the presence of active biological compounds such as flavonoids, proteins, phenols, alkaloids and glycosides also exhibited strong activity against tested bacterial strains. This study reveals the potential biological activities of Camellia assamica and Camellia sinensis having massive phytochemical constituents and trace elements.     

Antiplasmodial and antimicrobial activities of South African marine algal extracts

Seventy-eight crude organic fractions from nineteen species of marine algae collected from the coast of South Africa were screened for activity against a chloroquine sensitive strain of Plasmodium falciparum (D10), Staphylococcus aureus, Klebsiella pneumoniae, Mycobacterium aurum and Candida albicans. Fifteen crude fractions showed good antiplasmodical activity (IC₅₀?<10 μg/mL). The dichloromethane fraction from Sargassum heterophyllum (Turner) C. Agardh (Sargassaceae) was the most active with an IC₅₀ value of 2.8 μg/mL. Eleven extracts showed MIC values ≤?1?mg/mL against at least one of S. aureus, K. pneumoniae, M. aurum and C. albicans. The broadest spectrum of antimicrobial activity was exhibited by the aqueous-HP20 fraction of Polysiphonia incompta Harvey (Rhodomelaceae). This study shows that marine algae not only produce antimicrobial compounds but also may be a source of antimalarial lead compounds.     

In vitro Antimicrobial Activity and Phytochemical Screening of Clematis Species Indigenous to Ethiopia

The leaves extracts of two indigenous plants of Ethiopia: Clematis longicauda steud ex A. Rich. and Clematis burgensis Engl. are used in Southwestern Ethiopia to treat otorrhoea and eczema. Antimicrobial activity and MIC of crude extracts were determined by disk diffusion and broth dilution. Phytochemical screening was performed on the extracts. The methanol and petroleum ether extracts of both plants showed antibacterial and antifungal activity. Sensitivity of reference strains was concentration dependent. Methanol and petroleum ether extracts of C. burgensis leaves exerted greater inhibitory effects than C. longicauda extracts whereas aqueous extracts of both plants were inactive. The MIC study revealed a concentration of 0.78 mg/ml on bacteria and 3.125 mg/ml on fungi for methanol extract and 1.56 mg/ml on both fungi and bacteria for petroleum ether extract. Phytochemical screening results indicated the presence of proteins, fixed oils, carbohydrates, tannins, saponins, flavonoids, and steroids. Preliminary chromatographic investigation showed fluorescing spots with R_f values that ranged from 0.05 to 0.96 for phenolic compounds and saponins. As the study is one of the first reports on the two indigenous species of Clematis; isolation, purification and characterization of the different primary and secondary metabolites may further yield alternative options to the microbial chemotherapy.     

Phytochemical Screening,Proximate Analysis and Antioxidant Activity of Dracaena reflexa Lam. Leaves

In the present study, the antioxidant activity of successive leaf extracts of Dracaena reflexa was investigated using the scavenging activity on 1,1-diphenyl-2-picrylhydrazyl and reducing power by ferric reducing antioxidant power assay. Methanol extract was found potent in both the assays. IC50 values of 1,1-diphenyl-2-picrylhydrazyl assay for methanol extract was 0.97 mg/ml and ferric reducing antioxidant power value for the same is 1.19. Phytochemical screening, proximate analysis and total phenolic content were also determined. Qualitative screening for phytochemical showed the presence of alkaloids, flavonoids, terpenoids, glycosides and saponins. Highest phenolic content was shown by methanol extract (49.69 mg gallic acid equivalent/g dry weight). Proximate analysis showed moisture content (3.31%), ash content (8.02%), crude fibre (1.31%), crude fat (0.97%), total protein (3.70%), total carbohydrate (86.01) and nutritive value (367.56 kcal/100 g), which would make it a potential nutraceutical. This study suggested that Dracaena reflexa, a potential natural free radical scavenger, which could find use as an antioxidative.     

Evaluation of the in vivo antimalarial activity of ethanolic leaf and stembark extracts of Anthocleista djalonensis

Objective:

To evaluate the in vivo antimalarial activities of ethanolic leaf and stembark extracts of Anthocleista djalonensis used traditionally as malarial remedy in Southern Nigeria in mice infected with Plasmodium berghei berghei.

Methods:

The ethanolic extracts of the A. djalonensis leaf (1000 – 3000 mg/kg/day) and stembark (220 – 660 mg/kg/day) were screened for blood schizonticidal activity against chloroquine-sensitive P. berghei in mice. The schizonticidal effect during early and established infections was investigated.

Results:

The A. djalonensis leaf extract (1000 – 3000 mg/kg/day) exhibited a significant antiplasmodial activity both in the 4-day early infection test and in the established infection with a considerable mean survival time, which was incomparable to that of the standard drug, chloroquine (5 mg/kg/day). The stembark extract (220 – 660 mg/kg/day) also demonstrated a promising blood schizontocidal activity in early and established infections.

Conclusion:

These plant extracts possess considerable antiplasmodial activities, which justify their use in ethnomedicine and can be exploited in malaria therapy.     

A Review on the Taxonomy, Ethnobotany, Chemistry and Pharmacology of Oroxylum indicum Vent

Oroxylum indicum Vent. (O. indicum) is a tree commonly called Indian trumpet tree found in tropical countries, such as India, Japan, China, Sri Lanka, Malaysia. The chemical constituents obtained from different parts of plant include baicalein-7-O-diglucoside (Oroxylin B), baicalein-7-O-glucoside, chrysin, apegenin, prunetin, sitosterol, oroxindin, biochanin-A, ellagic acid, baicalein and its 6- and 7-glucuronides, scutellarein, tetuin, antraquinone and aloe-emodin. Various parts of the plant are used in Ayurveda and folk medicine for the treatment of different ailments such as cancer, diarrhea, fever, ulcer and jaundice. Recent in vivo and in vitro studies have indicated its antiinflammatory, antiulcer, hepatoprotective, anticancer, antioxidant, photocytotoxic, antiproliferative, antiarthritic, antimicrobial, antimutagenic and immunostimulant properties. Exhaustive literature survey reveals that there are some activities which are still not proven scientifically. This article is an attempt to compile an up-to-date and comprehensive review on O. indicum covering its traditional and folk medicinal uses, phytochemistry and pharmacology.     

Safety assessment of methanol extract of red dragon fruit (Hylocereus polyrhizus): Acute and subchronic toxicity studies

Recently, the fruits of Hylocereus polyrhizus, known as red dragon fruit, have received much attention from growers worldwide. However, there is little toxicological information regarding the safety of repeated exposure to these fruits. The present study evaluated the potential toxicity of a methanol extract of H. polyrhizus fruit after acute and subchronic administration in rats. In the acute toxicity study, single doses of fruit extract (1250, 2500 and 5000 mg/kg) were administered to rats by oral gavage, and the rats were then monitored for 14 days. In the subchronic toxicity study, the fruit extract was administered orally to rats at doses of 1250, 2500 and 5000 mg/kg/day for 28 days. There was no mortality or signs of acute or subchronic toxicity. There was no significant difference in body weight, relative organ weight or hematological parameters in the subchronic toxicity study. Biochemical analysis showed some significant changes, including creatinine, globulin, total protein and urea levels. No abnormality of internal organs was observed between treatment and control groups. The lethal oral dose of the fruit extract is more than 5000 mg/kg and the no-observed-adverse-effect level (NOAEL) of the extract for both male and female rats is considered to be 5000 mg/kg per day for 28 days.     

1,4-Naphthoquinone Cations as Antiplasmodial Agents: Hydroxy-, Acyloxy-, and Alkoxy-Substituted Analogues

相似文献   

Design,Synthesis, and Antiplasmodial Activity of Hybrid Compounds Based on (2R,3S)-N-Benzoyl-3-phenylisoserine

相似文献   

Antimicrobial Activity and Phytochemical Constituents of Leaf Extracts of Cassia auriculata

Plants produce a wide variety of phytochemical constituents, which are secondary metabolites and are used either directly or indirectly in the pharmaceutical industry. ‘For centuries, man has effectively used various components of plants or their extracts for the treatment of many diseases, including bacterial infections. In the present study methanol, chloroform and aqueous extracts of Cassia auriculata leaf were subjected for antimicrobial activity by well-diffusion method against six bacterial strains namely Bacillus cereus, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Proteus mirabilis. The results revealed that the methanol and chloroform extracts exhibited strong inhibitory activity against all the tested organisms (zone of inhibition of 12-20 mm), except Pseudomonas aeruginosa (zone of inhibition 10 mm or nil). The aqueous extracts showed moderate activity by ‘Zone of inhibition ≤12 or nil). The extracts were screened for their phytochemical constituents by standard protocols’ and were shown to contain carbohydrates, proteins, alkaloids, flavonoids, steroids, saponins and tannins. The antibacterial activity of these extracts is possibly linked to the presence of flavonoids, steroid, saponins and/or tannins. Further studies are needed to determine the precise active principles from Cassia auriculata.     

In Vitro Antiplasmodial Activity of Phospholipases A2 and a Phospholipase Homologue Isolated from the Venom of the Snake Bothrops asper

The antimicrobial and antiparasite activity of phospholipase A₂ (PLA₂) from snakes and bees has been extensively explored. We studied the antiplasmodial effect of the whole venom of the snake Bothrops asper and of two fractions purified by ion-exchange chromatography: one containing catalytically-active phospholipases A₂ (PLA₂) (fraction V) and another containing a PLA₂ homologue devoid of enzymatic activity (fraction VI). The antiplasmodial effect was assessed on in vitro cultures of Plasmodium falciparum. The whole venom of B. asper, as well as its fractions V and VI, were active against the parasite at 0.13 ± 0.01 µg/mL, 1.42 ± 0.56 µg/mL and 22.89 ± 1.22 µg/mL, respectively. Differences in the cytotoxic activity on peripheral blood mononuclear cells between the whole venom and fractions V and VI were observed, fraction V showing higher toxicity than total venom and fraction VI. Regarding toxicity in mice, the whole venom showed the highest lethal effect in comparison to fractions V and VI. These results suggest that B. asper PLA₂ and its homologue have antiplasmodial potential.     

Phytochemical Screening and Evaluation of Analgesic Activity of Oroxylum indicum

We aimed to study phytochemical screening and analgesic activity of ethanol extract of Oroxylum indicum. The dried powder of the barks of the plant was extracted with 95% ethanol and was subjected to various phytochemical tests to ascertain the principle constituents contained in the extract. The result revealed the presence of alkaloids, flavonoids, tannins, glycosides in the ethanol extract of Oroxylum indicum. The extract was screened for analgesic activity by using hot plate, acetic acid-induced writhing and formalin test. The ethanol extract of the plant at two different doses (250 and 500 mg/kg) showed significant (P<0.05) analgesic effect in all test methods (hot plate, acetic acid-induced writhing and formalin). The analgesic activity was compared with a standard drug (ketorolac at 10 mg/kg). Based on the present findings and previous literature review it can be concluded that flavonoids and tannins might be responsible for the analgesic activity. We suggest that ethanol extract of Oroxylum indicum might have potential chemical constituents that could be used in the future for the development of novel analgesic agent.     

Investigation of Phytochemical and Antioxidant Properties of Methanol Extract and Fractions of Ballota limbata (Lamiaceae)

Ballota limbata (Lamiaceae) has been used for its antispasmodic, antiulcer, diuretic, vermifuge and sedative effects in folk medicine. However, little is known about how does it work to produce these therapeutic actions. Present research investigated phytochemical components and antioxidant properties of methanol extract and different fractions of Ballota limbata. In this study, phytochemical investigation was done by performing different chemical tests. Here, antioxidant property of the extract and fractions was investigated by using 1,1-diphenyl-2-picryl hydrazyl radical scavenging activity, total antioxidant activity by the phosphomolybdenum method, linoleic acid peroxidation, ferric thiocyanate analysis and ferric-reducing antioxidant power. Methanol extract and fractions showed presence of numerous chemical principles including alkaloids, cardiac glycosides, tannins and flavonoids. The ethyl acetate fraction exhibited higher scavenging activity compared to the other fractions under investigation. This fraction displayed 84.16±1.02% 1,1-diphenyl-2-picryl hydrazyl radical inhibition at a dose of 60 μg/ml. IC₅₀ for 1,1-diphenyl-2-picryl hydrazylradical-scavenging activity was 13.53±0.22 μg/ml, relative to the standard, butylatedhydroxytoluene, having IC₅₀ of 12.33±0.88 μg/ml. Thus, Ballota limbata showed significant antioxidant activity, which may contribute in the mechanism of above pharmacological actions.     

Evaluation of the antidiarrheal and antioxidant properties of Justicia hypocrateriformis

Content: Justicia hypocrateriformis Vahl (Acanthaceae) is used as an herbal remedy for diarrhea in Cameroon folk medicine.

Objective: This study evaluates the antidiarrheal and antioxidant properties of the aqueous extract of J. hypocrateriformis (JH).

Materials and methods: Preliminary phytochemical screening and an acute toxicity testing of the extract were carried out. The antidiarrheal activity of JH extract (100, 250, and 500?mg/kg) was assessed at curative and preventive levels in castor oil-induced diarrhea in mice. The antioxidant activity was measured by ferric reducing antioxidant power (FRAP), total phenolic content, and radical scavenging activity.

Results: A high lethal dose (LD₅₀) of 14.35?g/kg obtained in acute toxicity implies the extract is not toxic. Phytochemical screening revealed the presence of phenols, tannins, flavonoids, saponins, anthraquinones, and anthocyanins. JH showed a significant protection against castor oil-induced diarrhea as evidenced by a decrease in the number of defecation and wet stool. JH (100–500?mg/kg, p.o.) produced a non-significant dose-dependent decrease in castor oil-induced intestinal transit in the preventive study. In the curative and in healthy mice study, the decrease was only significant at 500?mg/kg. JH possessed a radical scavenging activity with an IC₅₀ of 9.93?mg/ml compared to 4.90?mg/ml for catechin. JH FRAP of 2703.77?±?0?mg/g (catechin equiv) and phenolic concentration of 14?169.99?±?612.39?mg/g (catechin equiv) were also obtained.

Conclusion: Justicia hypocrateriformis extract possesses antidiarrheal activity supported by its antioxidant potential and phytochemical constituents.     

Formulation and Evaluation of Alstonia boonei Stem Bark Powder Tablets

The aim of this work was to formulate Alstonia boonei dried stem bark powder into tablets by wet granulation method using acacia, gelatine and sodium carboxymethyl cellulose as binders at concentrations of 1, 2, 4 and 8% w/w. The phytochemistry of the stem bark of Alstonia boonei was evaluated. The micromeritic properties of the granules prepared were studied. The tablets were evaluated using the necessary official and unofficial tests. The results of the phytochemical analysis showed that alkaloids, tannins, steroids, saponins, glycosides, flavonoids and terpenoids were present while anthroquinones and acidcompounds were absent. Micromeritic studies showed that Alstonia boonei granules had good flowability. The formulated tablets complied with British Pharmacopoeial specification for weight uniformity, hardness (≥5 kgf) and tablet friability (<1%). For disintegration test, tablets formulated with gelatine and acacia at concentrations of 1, 2 and 4% w/w complied with Pharmacopoeial specification. However, tablets formulated with SCMC (1-8% w/w) and 8% w/w of acacia and gelatine failed the disintegration tests (Disintegration time more than 15 min).     

Wound Healing Potential of Formulated Extract from Hibiscus Sabdariffa Calyx

Wound healing agents support the natural healing process, reduce trauma and likelihood of secondary infections and hasten wound closure. The wound healing activities of water in oil cream of the methanol extract of Hibiscus sabdariffa L. (Malvaceae) was evaluated in rats with superficial skin excision wounds. Antibacterial activities against Pseudomonas aeroginosa, Staphylococcus aureus and Echerichia coli were determined. The total flavonoid content, antioxidant properties and thin layer chromatographic fingerprints of the extract were also evaluated. The extract demonstrated antioxidant properties with a total flavonoid content of 12.30±0.09 mg/g. Six reproducible spots were obtained using methanol:water (95:5) as the mobile phase. The extract showed no antimicrobial activity on the selected microorganisms, which are known to infect and retard wound healing. Creams containing H. sabdariffa extract showed significant (P<0.05) and concentration dependent wound healing activities. There was also evidence of synergism with creams containing a combination of gentamicin and H. sabdariffa extract. This study, thus, provides evidence of the wound healing potentials of the formulated extract of the calyces of H. sabdariffa and synergism when co-formulated with gentamicin.     

Presence of Potential Toxin-Producing Cyanobacteria in an Oligo-Mesotrophic Lake in Baltic Lake District,Germany: An Ecological,Genetic and Toxicological Survey

Massive developments of potentially toxic cyanobacteria in Lake Stechlin, an oligo-mesotrophic lake in the Baltic Lake District of Germany raised concerns about toxic contamination of these important ecosystems. Field samples in the phase of mass developments of cyanobacteria were used for genetic and toxicological analyses. Microcystins and microcystin genes were detected in field samples of the lake for the first time. However, the toxins were not produced by the dominant taxa (Dolichospermum circinale and Aphanizomenon flos-aquae) but by taxa, which were present only in low biomass in the samples (Microcystis cf. aeruginosa and Planktothrix rubescens). The phytoplankton successions during the study period revealed an increase of cyanobacterial populations. The findings contribute to the changes that have been investigated in Lake Stechlin since the mid-1990s. The possible reasons behind these developments may be climate change, special weather conditions and an increased nutrient pool.     

Antibacterial Activity of Rhizome of Curcuma aromatica and Partial Purification of Active Compounds

The hexane extract of Curcuma aromatica, a plant belonging to the family Zingiberaceae was tested on 10 bacterial strains (clinical isolates and standard strains). Agar diffusion method was adopted for determining the antibacterial activity of the extract. The hexane extract was found to be active against all Gram-positive strains tested, but inactive against Gram-negative strains. The minimum inhibitory concentration and minimum bactericidal concentration were determined and found to be 539 μg/ml. The phytochemical analysis of hexane extract by gas chromatography mass spectrometry revealed the presence of 13 compounds. The crude hexane extract was partially purified by thin layer chromatography. The zone showing good antibacterial activity was analysed further by gas chromatography mass spectrometry, UV/Vis spectrophotometry and Fourier transform infrared spectroscopy, which indicated the probable presence of germacrone.     

Evaluation of In Vitro Antioxidant Potential of Cordia retusa

The present study was carried out to investigate the antioxidant potential, total flavonoid and phenolic content in extracts of aerial parts of Cordia retua (Vahl.) Masam. The samples such as ethyl acetate and ethanol extracts were tested using six in vitro models such as 2,2-diphenyl-1-picrylhydrazyl, nitric oxide radical, iron chelating, hydroxyl radical, superoxide radical scavenging activity and total antioxidant activity to evaluate the in vitro antioxidant potential of C. retusa by spectrophotometrically. Total flavonoid and phenolic content in samples were estimated using aluminum chloride colorimetric and Folin-Ciocalteu method. The results were analyzed statistically by the regression method. Half maximal inhibitory concentration (IC₅₀) of the ethanol extract was found to be 596 μg/ml for DPPH, 597 μg/ml for nitric oxide radical, 554 μg/ml for iron chelating, 580 μg/ml for hydroxyl radical, 562 μg/ml for superoxide radical and 566 μg/ml for total antioxidant capacity. Furthermore, the total flavonoid content and total phenolic content of the ethanol extract were found to be 2.71 mg gallic acid equivalent per gram of extract and 1.86 mg quercetin equivalent per gram of extract, respectively. In all the testing, a significant correlation existed between concentrations of the extract and percentage inhibition of free radicals. The results of the present comprehensive analysis demonstrated that C. retusa possess potent antioxidant activity, high flavonoid and phenolic content. The antioxidant property may be related to the polyphenols and flavonoids present in the extract. These results clearly indicated that C. retusa is effective against free radical mediated diseases as a natural antioxidant.