Subcutaneous antifungal screening of Latin American plant extracts against Sporothrix schenckii and Fonsecaea pedrosoi

Context: Subcutaneous mycoses are chronic infections caused by slow growing environmental fungi. Latin American plants are used in folk medicine to treat these afflictions. Moreover, the potential of the rich Latin American biodiversity for this purpose has not been fully explored.

Objectives: The aim of the study was to screen Latin American plant extracts against two species of subcutaneous fungi: Sporothrix schenckii and Fonsecaea pedrosoi.

Materials and methods: One hundred ninety-five organic extracts from 151 Latin American plants were screened against two subcutaneous fungi by the agar dilution method at a concentration of 100 µg/mL, and minimum inhibitory concentrations (MICs) of active extracts were determined. Positive (amphothericin B) and negative (50% ethanol) controls were used.

Results and discussion: Twenty eight extracts showed activity at ≤100 µg/mL. Of these, four extracts from Gnaphalium gaudichaudianum DC (Asteraceae), Plumeria rubra L (Apocynaceae), Tecoma stans (L.) Juss. ex Kunth. (Bignoniaceae), and Trichostigma octandum (L.), H. Walter showed activity against F. pedrosoi at MIC 12.5 µg/mL; and, four extracts from Bourreria huanita (Lex.) Hemsl. (Boraginaceae), Phytolacca bogotensis Kunth (Phytolaccaceae), Monnina xalapensis Kunth (Polygalaceae) and Crataegus pubescens (C. Presl) C. Presl (Rosaceae) against S. schenckii. This is the first report on antifungal activity of the Latin American plants against these two subcutaneous fungi.

Conclusion: S. schenkii and F. pedrosoi were inhibited by B. huanita (MIC: 12.5 and 25 µg/mL), G. gaudichaudianum (MIC: 50 and 12.5 µg/mL) and T. triflora (MIC: 25 µg/mL).     

Anti-Streptococcus mutans efficacy of Thai herbal formula used as a remedy for dental caries

Context: Traditional knowledge of herbal remedies plays an important role in the search for more effective alternative treatment of a variety of disorders. The ethnobotanical surveys in southern Thailand have revealed that 35 Thai herbal formulas have been used by Thai traditional healers against dental caries. However, the scientific evaluation to confirm their rational uses is scarce.

Objective: To test in vitro anti-Streptococcus mutans activity of Thai herbal formulas used against dental caries (THF-DC).

Materials and methods: Ethanol extracts of Thai herbal formulas were evaluated for antibacterial activity against S. mutans. Agar disc diffusion was employed as a preliminary screening assay, followed by broth microdilution assay to assess minimum inhibitory concentration (MIC). Furthermore, medicinal plants contained in the most active THF-DC were investigated for their phytochemicals.

Results: Eleven THF-DC extracts exhibited clear inhibition zones of 7.0–22.5?mm against S. mutans. Subsequent determination of their MIC revealed that the formula containing Albizia myriophylla Benth. (Leguminosae), Alpinia galanga (L.) Willd. (Zingiberaceae), Avicennia marina (Forssk.) Vierh. (Acanthaceae), and Ocimum sanctum L. (Lamiaceae) was the most active, with MIC at 250 µg/mL. Among these medicinal plants, A. myriophylla gave the strongest activity with MIC at 3.9 µg/mL, followed by A. marina with MIC at 62.5 µg/mL. Various classes of bioactive phytochemicals including tannins, flavonoids, alkaloids, and terpenoids were found in these extracts.

Conclusion: Anti-S. mutans activity of THF-DC extracts was established. Further investigations may be required for the isolation and chemical characterization of the active ingredients in A. myriophylla.     

Medicinal plants in the treatment of Helicobacter pylori infections

Abstract

Context: Helicobacter pylori is a small, spiral, Gram-negative bacillus that plays a role in the pathogenesis of a number of diseases ranging from asymptomatic gastritis to gastric cancer. Schedule compliance, antibiotic drug resistance, and side-effects of triple or quadruple therapy have led to research for novel candidates from plants.

Objective: The purpose of this paper is to review the most potent medicinal plants of recently published literature with anti-H. pylori activity. For centuries, herbals have been used by traditional healers around the world to treat various gastrointestinal tract disorders such as dyspepsia, gastritis, and peptic ulcer disease. The mechanism of action by which these botanicals exert their therapeutic properties has not been completely and clearly elucidated. Anti-H. pylori properties may be one of the possible mechanisms by which gastroprotective herbs treat gastrointestinal tract disorders.

Materials and methods: Electronic databases such as PubMed, Google scholar, EBSCO, and local databases were explored for medicinal plants with anti-H. pylori properties between 1984 and 2013 using key words “medicinal plants” and “Helicobacter pylori” or “anti-Helicobacter pylori”.

Results: A total of 43 medicinal plant species belonging to 27 families including Amaryllidaceae, Anacardiaceae, Apiaceae, Apocynaceae, Asclepiadoideae, Asteraceae, Bignoniaceae, Clusiaceae, Chancapiedra, Combretaceae, Cyperaceae, Euphorbiaceae, Fabaceae, Geraniaceae, Lamiaceae, Lauraceae, Lythraceae, Menispermaceae, Myristicaceae, Myrtaceae, Oleaceae, Papaveraceae, Plumbaginaceae, Poaceae, Ranunculaceae, Rosaceae, and Theaceae were studied as herbs with potent anti-H. pylori effects.

Conclusion: Traditional folk medicinal use of some of these plants to treat gastric infections is substantiated by the antibacterial activity of their extracts against H. pylori.     

Antibacterial activity in spices and local medicinal plants against clinical isolates of Karachi,Pakistan

Context: Development of resistance in human pathogens against conventional antibiotic necessitates searching indigenous medicinal plants having antibacterial property. Twenty-seven medicinal plants used actively in folklore, ayurvedic and traditional system of medicine were selected for the evaluation of their antimicrobial activity for this study. Eleven plants chosen from these 27 are used as spices in local cuisine.

Objective: Evaluation of the effectiveness of some medicinal plant extracts against clinical isolates.

Material and methods: Nonedible plant parts were extracted with methanol and evaporated in vacuo to obtain residue. Powdered edible parts were boiled three times and cooled in sterile distilled water for 2?min each and filtrate collected. The minimum inhibitory concentration (MIC) of plant extracts and filtrates/antibiotics was evaluated against clinical isolates by microbroth dilution method.

Results: Water extract of Syzygium aromaticum L. (Myrtaceae) buds, methanol extracts of Ficus carica L. (Moraceae) and Olea europaea L. (Oleaceae) leaves and Peganum harmala L. (Nitrariaceae) seeds had MIC ranges of 31.25–250 µg/ml. S. aromaticum inhibited growth of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, Salmonella enterica serovar Typhi and Pseudomonas aeruginosa. F. carica and O. europaea inhibited growth of S. aureus, S. epidermidis, and S. pyogenes whereas P. harmala was effective against S. aureus, Acinetobacter calcoaceticus and Candida albicans. Ampicillin, velosef, sulfamethoxazole, tetracycline and ceftazidime, cefotaxime, cefepime, which are used as control, had MIC ≥50 and 1.5 µg/ml, respectively, for organisms sensitive to extracts.

Discussion and conclusion: Mono/multiextract from identified plants will provide an array of safe antimicrobial agents to control infections by drug-resistant bacteria.     

Antibacterial effects of 18 medicinal plants used by the Khyang tribe in Bangladesh

Context: The resistance of bacteria to antibiotics is raising serious concern globally. Asian medicinal plants could improve the current treatment strategies for bacterial infections. The antibacterial properties of medicinal plants used by the Khyang tribe in Bangladesh have not been investigated.

Objective: The present study examines the antibacterial properties of 18 medicinal plants used by the Khyang tribe in day-to-day practice against human pathogenic bacteria.

Materials and methods: Leaves, bark, fruits, seeds, roots and rhizomes from collected plants were successively extracted with hexane, ethyl acetate and ethanol. The corresponding 54 extracts were tested against six human pathogenic bacteria by broth microdilution assay. The antibacterial mode of actions of phytoconstituents and their synergistic effect with vancomycin and cefotaxime towards MRSA was determined by time-killing assay and synergistic interaction assay, respectively.

Results and discussion: Hexane extract of bark of Cinnamomum cassia (L.) J. Presl. (Lauraceae) inhibited the growth of MRSA, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii with MIC values below 100 µg/mL. From this plant, cinnamaldehyde evoked at 4?×?MIC in 1?h an irreversible decrease of MRSA count Log10 (CFU/mL) from 6 to 0, and was synergistic with vancomycin for MRSA with fractional inhibitory concentration index of 0.3.

Conclusions: Our study provides evidence that the medicinal plants in Bangladesh have high potential to improve the current treatment strategies for bacterial infection.     

In vitro antioxidant and antitumor activities of six selected plants used in the Traditional Arabic Palestinian herbal medicine

Context: Despite several pharmacological applications of the medicinal plants in the Traditional Arabic Palestinian Herbal Medicine in Palestine (TAPHM), studies on their antioxidant properties are still scarce.

Objective: This work evaluates the antioxidant and antitumor activities of the ethanol extracts from different parts of six plants: [Arum palaestinum Boiss (Araceae), Urtica pilulifera L. (Urticaceae), Coridothymus capitatus (L.) Reichb (Lamiaceae), Majorana syriaca (L.) Rafin. (Lamiaceae), Teucrium creticum L. (Lamiaceae), and Teucrium capitatum L. (Lamiaceae)] used in the TAPHM.

Materials and methods: The antioxidant activity was evaluated for the ethanol extracts by DPPH and β-carotene–linoleic acid assays together with total contents of phenols and flavonoids. For the anti-carcinogenic evaluation, the extracts were tested for the ability to inhibit the proliferation of breast cancer cells (MCF-7) using the MTT reduction assay.

Results: Among the extracts, the U. pilulifera had the highest amount of total phenolics, possessing the second highest total flavonoids. It also showed a maximum cytotoxic activity (IC₅₀?=?63?µg/ml), followed by C. capitatus, and A. palaestinum. Otherwise, the extract of T. creticum was demonstrated to be an efficient scavenger of O₂ (IC₅₀?=?83?µg/ml), followed by M. syriaca, C. capitatus, T. capitatum, A. palaestinum, and U. pilulifera.

Discussion and conclusion: The results suggest that the investigated plants have shown varied antioxidant capacities which were strongly correlated with their contents of phenolics. Accordingly, this study proposes that the therapeutic benefit of these plants can be, at least in part, attributed to its potential inhibition of oxidative processes.     

Screening of in vitro antimicrobial activity of plants used in traditional Indonesian medicine

Context: In many regions of Indonesia, there are numerous traditional herbal preparations for treatment of infectious diseases. However, their antimicrobial potential has been poorly studied by modern laboratory methods.

Objective: This study investigates in vitro antimicrobial activity of 49 ethanol extracts from 37 plant species used in Indonesian traditional medicine for treatment against Candida albicans, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus.

Materials and methods: The plants were collected from the Biopharmaca collection garden, Bogor, Indonesia. The plant material was dried, finely grounded, extracted using ethanol, concentrated, and the dried residue was dissolved in 100% DMSO. Antimicrobial activity was determined in terms of a minimum inhibitory concentration (MIC) using a broth microdilution method in 96-well microplates.

Results: The extract of Orthosiphon aristatus (Blume) Miq. (Lamiaceae) leaf produced the strongest antimicrobial effect, inhibiting the growth of C. albicans (MIC 128?μg/mL), S. aureus (MIC 256?μg/mL), E. faecalis (MIC 256?μg/mL) and P. aeruginosa (MIC 256?μg/mL). The leaf extract of Woodfordia floribunda Salisb. (Lythraceae) also exhibited significant effect against C. albicans (MIC 128?μg/mL), S. aureus (MIC 256?μg/mL) and E. faecalis (MIC 256?μg/mL). Rotheca serrata (L.) Steane &; Mabb. (Lamiaceae) leaf extract inhibited the growth of S. aureus (MIC 256 µg/mL) and C. albicans (MIC 256 µg/mL).

Discussion and conclusions: The leaf extract of O. aristatus and W. floribunda exhibited a significant anti-candidal effect. Therefore, both of these plants can serve as prospective source materials for the development of new anti-candidal agents.     

Antimicrobial activity of traditional medicinal plants from Ankober District,North Shewa Zone,Amhara Region,Ethiopia

Context: Traditional medicinal plants have long been used in Ethiopia to treat human and livestock ailments. Despite a well-documented rich tradition of medicinal plant use in the country, their direct antimicrobial effects are still poorly known.

Objective: To investigate the antimicrobial activity of 19 medicinal plant species that were selected based on the ethnobotanical information on their traditional use to treat infectious diseases in Ankober District.

Methods: About 23 different ethanol extracts of plants obtained by maceration of various parts of 19 medicinal plant species were studied for potential antimicrobial activity using a broth microdilution method against Bacillus cereus, Bacteroides fragilis, Candida albicans, Clostridium perfringens, Enterococcus faecalis, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella enteritidis, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pyogenes.

Results: Plant extracts from Embelia schimperi Vatke (Myrsinaceae) showed the strongest antibacterial activity with a minimum inhibitory concentration (MIC) value of 64 µg/ml against B. cereus, L. monocytogenes, and S. pyogenes. Growth inhibitory activities were also observed for extracts of Ocimum lamiifolium Hochst. (Lamiaceae) against S. pyogenes, and those of Rubus steudneri Schweinf. (Rosaceae) against S. epidermidis at an MIC value of 128 µg/ml. Generally, 74% of ethanol extracts (17 extracts) showed antimicrobial activity against one or more of the microbial strains tested at an MIC value of 512 µg/ml or below.

Discussion and conclusions: Results confirm the antimicrobial role of traditional medicinal plants of Ankober and warrant further investigations on promising medicinal plant species so as to isolate and characterise chemicals responsible for the observed strong antimicrobial activities.     

Antibacterial activity of Thai herbal extracts on acne involved microorganism

Ethyl acetate and methanol extracts of 18 Thai medicinal plants were investigated for their antibacterial activity against Propionibacterium acnes, Stapylococcus aureus, and S. epidermidis. Thirteen plant extracts were capable of inhibiting the growth of P. acnes and S. epidermidis, while 14 plant extracts exhibited an inhibitory effect on S. aureus. Based on the broth dilution method, the ethyl acetate extract of Alpinia galanga (L.) Wild. (Zingiberaceae) rhizome showed the strongest antibacterial effect against P. acnes, with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 156.0 and 312.0 µg/mL, respectively. On the basis of bioassay-guided purification, the ethyl acetate extract was isolated to afford the antibacterial active compound, which was identified as 1′-acetoxychavicol acetate (1′-ACA). 1′-ACA had a strong inhibitory effect on P. acnes with MIC and MBC values of 62.0 and 250.0 µg/mL, respectively. Thus, 1′-ACA was used as an indicative marker for standardization of A. galanga extract using high performance liquid chromatography. These results suggest that A. galanga extract could be an interesting agent for further studies on an alternative treatment of acne.     

Inhibition of urease by extracts derived from 15 Chinese medicinal herbs

Context: Helicobacter pylori is a major causative factor in gastritis-like disorders, and urease plays a key role in Helicobacter pylori colonizing and persisting in the mucous layer of the human stomach. In China, a variety of Chinese medicinal herbs have been prescribed to attenuate or eradicate gastritis-like disorders. However, little is known about the urease inhibition of Chinese medicinal herbs.

Objective: The present study was conducted to investigate the urease inhibition activities of the ethanol and water extracts of 15 Chinese medicinal herbs.

Materials and methods: The ethanol and water extracts derived from 15 medicinal herbs, traditionally used for the treatment of gastritis-like disorders in China, were tested for urease-inhibition activity using the phenol red method.

Results: Screened at 10 µg/mL, 14 ethanol extracts and 10 water extracts showed urease inhibition. The ethanol extracts of Magnolia officinalis Rehd. et Wils. (Magnoliaceae) and Cassia obtusifolia L. (Leguminosae) possessed inhibition rates higher than 50% with IC₅₀ values of 6.5 and 12.3 µg/mL, respectively. After fractionating successively, the petroleum ether fraction of the ethanol extracts of Magnolia officinalis showed the best activity with 90.8% urease inhibition at a concentration of 10 µg/mL. The bioautography of the petroleum ether fraction indicated the existence of the urease inhibitors in the herb.

Discussion and conclusion: The present results indicated that some Chinese medicinal herbs might treat gastritis-like disorders via the inhibition of Helicobacter pylori urease and the further possibility for discovering useful novel urease inhibitors from the Chinese medicinal herbs.     

In Vitro Anthelmintic Effects of Medicinal Plants Used in Czech Republic

The ethanol extracts of 16 Czech medicinal plants, namely, Allium sativum L. (Alliaceae), Artemisia absinthium L. (Asteraceae), Artemisia vulgaris L. (Asteraceae), Carum carvi L. (Apiaceae), Consolida regalis Gray (Ranunculaceae), Cucurbita pepo L. (Cucurbitaceae), Daucus carota L. (Apiaceae), Dryopteris filix-mas (L.) Schott (Dryopteridaceae), Erigeron canadensis L. (Asteraceae), Hedera helix L. (Araliaceae), Inula helenium L. (Asteraceae), Juglans regia L. (Juglandaceae), Satureja hortensis L. (Lamiaceae), Tanacetum vulgare L. (Asteraceae), Thymus vulgaris L. (Lamiaceae), and Valeriana officinalis L. (Valerianaceae), have been tested for their potential in vitro anthelmintic effect against eggs Ascaris suum and infectious larvae Trichostrongylus colubriformis. The extracts of A. sativum, A. absinthium, C. carvi, D. carota, and J. regia possessed the strongest anthelmintic effect on the embryonating eggs at all concentrations tested (62.5, 125, 250, 500, 1000, 2000 μg/mL). The best results, showing a higher effect against the infective third-stage larvae in comparison with synthetic anthelmintic Zentel (albendazole), have been obtained for A. sativum, A. absinthium, C. carvi, C. regalis, I. helenium, J. regia, S. hortensis, and V. officinalis.     

Screening of Spanish Medicinal Plants for Antioxidant and Antifungal Activities

Abstract

Dichloromethane, ethyl acetate, methanol, and aqueous extracts obtained from 16 Spanish medicinal plants were screened for their antioxidant and antifungal activities. The radical scavenging capacity was evaluated by the DPPH method using a rapid screening by TLC and a spectrophotometric assay. Polar extracts obtained from Jasonia glutinosa L. (Lamiaceae), Tanacetum parthenium (L.) Schultz (Lamiaceae), Equisetum telmateia Ehrh. (Equisetaceae), Verbena officinalis L. (Verbenaceae), and Lythrum salicaria L. (Lythraceae) showed high antioxidant properties. Among them, the methanol extract of Lythrum salicaria showed the strongest antiradical capacity with an IC₅₀ value similar to the positive control ascorbic acid. On the contrary, the best antifungal properties against Rhizopus stolonifer were produced by ethyl acetate or dichloromethane extracts from Anthemis arvensis L. subsp. arvensis (Asteraceae), Tanacetum parthenium, Santolina chamaecyparissus L. subsp. squarrosa Nyman (Asteraceae), Anagallis arvensis L. (Primulaceae) and the methanol extract of Anagallis foemina Miller (Primulaceae). The dichloromethane extract of Anthemis arvensis subsp. arvensis was the best inhibitor of fungus growth.     

Medicinal plants of Tamil Nadu (Southern India) are a rich source of antiviral activities

In order to evaluate the potential of medicinal plants of Tamil Nadu as sources of antiviral activities, we used seven different viruses to evaluate the methanol extracts of 30 plants, derived from 22 families and recognized for their local medical applications. Antiviral activity was the minimum concentration of extracts required to completely inhibit viral cytopathic effects (CPE), i.e., MIC₁₀₀ values. Many extracts showed strong activities against Herpes simplex virus (HSV) and mouse corona virus (MCV, the surrogate for human SARS virus). Some extracts were also active against influenza virus and Sindbis virus (SINV, surrogate for hepatitis C virus), but fewer were active against the non-membrane viruses feline calicivirus (FCV, the surrogate for Norovirus), rhinovirus (common cold virus), and poliovirus. The most potent extracts (low MIC₁₀₀ and broad spectrum of activity) were obtained from Gymnema sylvestre R. Br. (Asclepiadaceae), Pergularia daemia (Forsskal) Chiov. (Asclepiadaceae), Sphaeranthus indicus L. (Asteraceae), Cassia alata L. (Caesalpiniaceae), Evolvulus alsinoides L. (Convolvulaceae), Clitoria ternatea L. (Fabaceae), Indigofera tinctoria L. (Euphorbiaceae), Abutilon indicum G. Don. (Malvaceae), Vitex trifolia L. (Verbenaceae), Clerodendrum inerme (L.) Gaertn (Verbenaceae), and Leucas aspera Spr. (Lamiaceae), which showed anti-MCV and anti-HSV activities at a concentration as low as 0.4 μg/mL. In some cases the activities were enhanced by light, suggesting the presence of photosensitizers. Some of these antiviral activities could contribute to the medicinal properties of the plants, and also provide more support for the concept of scientific validation of traditional plant medicines in the fight against infectious diseases.     

Antimycoplasmal activity of some plant species from northern Nigeria compared to the currently used therapeutic agent

Context:?Mycoplasma spp. are obligate parasites of humans and animals. But due to the special requirements needed to culture Mycoplasma in the laboratory, little or no research has been done to evaluate the efficacy of medicinal plants on the organism.

Objective:?To screen medicinal plants traditionally used to treat infections for possible antimycoplasmal and cytotoxic activities.

Materials and methods:?Acetone extracts of 21 Nigerian medicinal plants were analyzed for antimycoplasmal and cytotoxicity activities using the metabolic inhibition and colorimetric methods, respectively. The extract with the best antimycoplasmal activities was also analyzed for its phytochemical constituents using the desktop method.

Results:?Calotropis procera (Aiton) R.Br (Asclepiadaceae) extract had the best antimycoplasmal effect with a minimum inhibitory concentration (MIC) of 80 µg/mL and minimum mycoplasmacidal concentration (MMC) of 160 µg/mL. This extract contained saponins, tannins, cardiac glycosides, alkaloids, and flavonoids. The extract of Vernonia amygdalina Delile (Compositae) was the most cytotoxic with median lethal concentration (LC₅₀) of approximately 17 µg/mL, and that of Anacardium occidentale L. (Anacardiaceae) was the least cytotoxic with an LC₅₀ of approximately 1919 µg/mL.

Discussion:?Calotropis procera is a promising plant for an alternative antimycoplasmal agent because the crude acetone extract had a higher mycoplasmacidal activity than the conventional drug tylosin, which is currently used in treatment of the disease in Nigeria.

Conclusion:?The crude extract of Calotropis procera is worth investigating for the development of a potent agent against cattle Mycoplasma, which has long defied solution by conventional chemotherapy.     

Antibacterial activity of aqueous and methanol extracts of selected species used in livestock health management

Context: Salvadora persica L. (Salvadoraceae), Colophospermum mopane (J.Kirk ex Benth.) J. Léonard (Leguminosae) and Dichrostachys cinerea (L.) Wight &; Arn. (Leguminosae) crude extracts are used by local farmers against many livestock infections with little or no side effects usually associated with synthetic antimicrobials. However, their efficacy has rarely been tested.

Objective: These plants were tested for potential antibacterial activity against clinical isolates of Staphylococcus aureus ATCC33862 and Escherichia coli ATCC25922. Minimal inhibitory concentrations (MIC) of the crude plant extracts were determined.

Materials and methods: Aqueous and methanol extraction of 100?g each of the bark of C. mopane, roots of D. cinerea and leaves of S. persica was done by placing the samples in 250?mL of either water or methanol. Nutrient broth was used as growth medium for the bacteria, and McFarland standard for bacterial standardization. 2,3,5-Triphenyltetrazoliumchloride (TTC) was the indicator salt. Each of the aqueous and methanol extracts (100?μL) was tested. Gentamycin and ampicillin were the controls.

Results: MIC of aqueous extracts ranged from 1.03–14.6?mg/mL against S. aureus, and from 12.1–34.3?mg/mL against E. coli. Methanol extracts ranged between 5.31 and 9.64?mg/mL against S. aureus, and between 7.86 and 13.6?mg/mL against E. coli. Aqueous and methanol extracts of S. persica were significantly higher (p?C. mopane and D. cinerea.

Discussion and conclusion: Colophospermum mopane, S. persica and D. cinerea exhibited antibacterial activity, with methanol extracts performing better than aqueous extracts, justifying use as ethnoveterinary medicine. Further study to isolate the active components should be pursued.     

In vitro antiviral activity of Brazilian plants (Maytenus ilicifolia and Aniba rosaeodora) against bovine herpesvirus type 5 and avian metapneumovirus

Context: Medicinal plants are well known for their use in traditional folk medicine as treatments for many diseases including infectious diseases.

Objective: Six Brazilian medicinal plant species were subjected to an antiviral screening bioassay to investigate and evaluate their biological activities against five viruses: bovine herpesvirus type 5 (BHV-5), avian metapneumovirus (aMPV), murine hepatitis virus type 3, porcine parvovirus and bovine respiratory syncytial virus.

Materials and methods: The antiviral activity was determined by a titration technique that depends on the ability of plant extract dilutions (25 or 2.5 µg/mL) to inhibit the viral induced cytopathic effect and the extracts’ inhibition percentage (IP).

Results: Two medicinal plant species showed potential antiviral activity. The Aniba rosaeodora Ducke (Lauraceae) extract had the best results, with 90% inhibition of viral growth at 2.5 µg/mL when the extract was added during the replication period of the aMPV infection cycle. The Maytenus ilicifolia (Schrad.) Planch. (Celastraceae) extracts at a concentration of 2.5 µg/mL exhibited antiviral activity during the attachment phase of BHV-5 (IP = 100%).

Discussion and conclusion: The biomonitored fractionation of the active extracts from M. ilicifolia and A. rosaeodora could be a potential tool for identifying their active compounds and determining the exact mechanism of action.     

Antibacterial activity of some African medicinal plants used traditionally against infectious diseases

Context: Plants are known to play a crucial role in African traditional medicine for the treatment of infection diseases.

Objectives: To investigate the claimed antimicrobial properties of plants traditionally used in African countries, providing scientific validation for their use.

Materials and methods: Eighty-three polar and non-polar extracts from 22 medicinal plants were screened for their antibacterial activity against Gram-positive (Staphylococcus aureus and Enterococcus faecalis) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae) and Mycobacterium smegmatis using the broth microdilution method.

Results and Discussion: In vitro antibacterial activity against one or more tested bacteria was shown by 83% of the extracts. The highest activity was obtained with the methanol extracts of the aerial parts of Acacia karroo Hayne (Fabaceae) and Anacardium occidentale L. (Anacardiaceae) and the roots of Bridelia cathartica G. Bertol (Euphorbiaceae), against S. aureus (minimum inhibitory concentration (MIC)?=?7.5 µg/mL). The same MIC values were exhibited against E. faecalis by the methanol extract of A. occidentale, the dichloromethane and methanol extracts of B. cathartica and the ethyl acetate extract of Momordica balsamina l. (Curcubitaceae) leaves. Gram-negative bacteria were less sensitive; the growth of P. aeruginosa was significantly inhibited (MIC?=?31 µg/mL) by the n-hexane and methanol extracts of Gomphocarpus fruticosus (l.) Ait. (Asclepiadaceae) fruits and by the dichloromethane extract of Trichilia emetica Vahl (Meliaceae) seeds. Most of the active extracts were rich in fenols/flavonoids.

Conclusion: This study supports the use of most of the studied plants in traditional medicine, for the treatment of infectious diseases. Some of them are worthy of further investigation.     

Antimicrobial activity of pomegranate fruit constituents against drug-resistant Mycobacterium tuberculosis and β-lactamase producing Klebsiella pneumoniae

Abstract

Context: The global surge in multi-drug resistant bacteria and the imminence of tuberculosis pandemic necessitate alternative therapeutic approaches to augment the existing medications. Pomegranate, the fruit of Punica granatum Linn. (Punicaceae), widely recognized for potency against a broad spectrum of bacterial pathogens, deserves further investigation in this respect.

Objective: This study determines the therapeutic potential of pomegranate juice, extracts of non-edible peel prepared with methanol/water, and its four polyphenolic constituents, namely caffeic acid, ellagic acid, epigallocatechin-3-gallate (EGCG) and quercetin, against drug-resistant clinical isolates.

Materials and methods: Phenotypic characterisation of Mycobacterium tuberculosis, extended-spectrum β-lactamase (ESBL) and KPC-type carbapenemase producing Klebsiella pneumoniae was performed by biochemical and molecular methods. Resistance profiles of M. tuberculosis and K. pneumoniae were determined using LJ proportion and Kirby–Bauer methods, respectively. Pomegranate fruit extracts, and the compounds, were evaluated at a dose range of 1024–0.5?µg/mL, and 512–0.25?µg/mL, respectively, to determine minimum inhibitory (MIC) and bactericidal concentrations (MBC) against the drug-resistant isolates by the broth micro-dilution method.

Results: The peel extracts exhibited greater antimycobacterial activity (MIC 64–1024?μg/mL) than the potable juice (MIC 256?-?>?1024?μg/mL). EGCG and quercetin exhibited higher antitubercular (MIC 32–256?μg/mL) and antibacterial (MIC 64–56?μg/mL) potencies than caffeic acid and ellagic acid (MIC 64–512?μg/mL).

Discussion and conclusion: The pomegranate fruit peel and pure constituents were active against a broad panel of M. tuberculosis and β-lactamase producing K. pneumoniae isolates. EGCG and quercetin need further investigation for prospective application against respiratory infections.     

Assessment of in vitro antipsoriatic activity of selected Indian medicinal plants

Abstract

Context: Phyllanthus simplex Retz. (Phyllanthaceae), Crotolaria juncea Linn. (Leguminosae), Leucas aspera Linn. (Lamiaceae), and Vitex glabrata R.Br. (Verbenaceae) are well-known Indian medicinal plants. Different parts of these plants are used for healing purposes traditionally in the treatment of psoriasis and various other disorders. This prompted us to assess the antipsoriatic activities of these plants.

Objectives: Petroleum ether and ethanol extracts of the selected plants, i.e., P. simplex (whole plant), C. juncea (seeds), L. aspera (aerial parts), and V. glabrata (leaves) were investigated for their in vitro antipsoriatic activity.

Materials and methods: Antipsoriatic activity of the extracts was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, using HaCaT cells. About 200?µl of different concentrations (25, 50, 100, 200, and 400?µg/ml) of test samples were prepared in the cell culture medium and incubated for 24?h before MTT assay to determine the viable cells. The effect of these extracts on nitric oxide (NO) production and lipid peroxidation was also evaluated.

Results: Our findings revealed that these plants showed promising skin keratinocyte antiproliferative activity. However, the petroleum ether extract of C. juncea (CJPE) and ethanol extract of L. aspera (LAEE) were found to exhibit significant activity (IC₅₀ value?=?45.45 and 55.36?µg/ml, respectively).

Discussion and conclusions: The inhibitory action against NO production and lipid peroxidation in HaCaT cells suggested that the antipsoriatic activity of the extracts was mediated by an antioxidant mechanism. These findings validate the claims of the use of these plants in the treatment of psoriasis.     

The antibacterial and antifungal activity of essential oils extracted from Guatemalan medicinal plants

Abstract

Context: Essential oils are prevalent in many medicinal plants used for oral hygiene and treatment of diseases.

Objective: Medicinal plant species were extracted to determine the essential oil content. Those producing sufficient oil were screened for activity against Staphylococcus aureus, Escherichia coli, Streptococcus mutans, Lactobacillus acidophilus, and Candida albicans.

Materials and methods: Plant samples were collected, frozen, and essential oils were extracted by steam distillation. Minimum inhibitory concentrations (MIC) were determined using a tube dilution assay for those species yielding sufficient oil.

Results: Fifty-nine of the 141 plant species produced sufficient oil for collection and 12 species not previously reported to produce essential oils were identified. Essential oil extracts from 32 species exhibited activity against one or more microbes. Oils from eight species were highly inhibitory to S. mutans, four species were highly inhibitory to C. albicans, and 19 species yielded MIC values less than the reference drugs.

Discussion: Results suggest that 11 species were highly inhibitory to the microbes tested and merit further investigation. Oils from Cinnamomum zeylanicum Blume (Lauraceae), Citrus aurantiifolia (Christm.) Swingle (Rutaceae), Lippia graveolens Kunth (Verbenaceae), and Origanum vulgare L. (Lamiaceae) yielded highly significant or moderate activity against all microbes and have potential as antimicrobial agents.

Conclusion: Teas prepared by decoction or infusion are known methods for extracting essential oils. Oils from 11 species were highly active against the microbes tested and merit investigation as to their potential for addressing health-related issues and in oral hygiene.