In vitro antimicrobial activity of extracts and compounds of some selected medicinal plants from Cameroon

Evaluation of Total Phenolic Content, HPLC Analysis, and Antioxidant Potential of Three Local Varieties of Mushroom: A Comparative Study

Functional foods such as mushrooms are rich in polyphenolic compounds and secondary metabolites with health-promoting properties such as antioxidant, antimicrobial, antidiabetic and immunostimulatory effects. The present study is aimed to investigate the ethanolic extracts of three varieties of mushrooms, namely, G. lucidum, G. tropicum, and C. indica grown in Bangladesh for phenolic and flavonoid content and their antioxidant properties. Moreover, the phenolic composition of the extracts was analyzed by using the HPLC-DAD system. G. lucidum extract exhibited the highest antioxidant potential as evidenced by its lowest IC₅₀ value in all the tested assay models (40.44 ± 2.09 μg/mL, 151.32 ± 0.35 μg/mL, 137.89 ± 1.85 μg/mL in DPPH, H₂O_2, and NO scavenging assay, respectively) along with the highest phenolic content (81.34 ± 0.68 GAE g⁻¹ extract). G. tropicum and C. indica extracts also showed significant antioxidant properties and a good amount of phenolic content, 52.16 ± 0.25 GAE g⁻¹ extract, and 47.1 ± 0.26 GAE g⁻¹ extract, respectively. The scavenging activity increased with the increasing concentration of extracts in all cases. The total phenolic content of the ethanolic extracts of mushroom species was highly correlated with antioxidant effects with Pearson's correlation coefficient (r) values ranging from 0.8883–0.9851. The α-amylase inhibitory and antibacterial activity of G. lucidum was evaluated by using 3,5-dinitrosalicylic acid and disc diffusion method, respectively. The maximum inhibitory activity recorded against α-amylase was 70.98 ± 0.042% at a concentration of 500 μg/mL. G. lucidum extract exhibited the highest antibacterial activity against Pseudomonas aeruginosa with 23.00 ± 1.00 mm clear zone of inhibition and an MIC value of 3.5 mg/mL. The results indicate that the mushroom species tested in this study could serve as a potential source of natural antioxidants in the development of nutraceuticals and herbal drugs for the management of oxidative stress-associated diseases as well as infectious diseases.

An Annotated Inventory of Tanzanian Medicinal Plants Traditionally Used for the Treatment of Respiratory Bacterial Infections

This review comprehensively covers and analyzes scientific information on plants used in Tanzanian traditional medicine against respiratory diseases. It covers ethnobotanical and ethnopharmacological information extracted from SciFinder, Google Scholar, and Reaxys as well as the literature collected at the Institute of Traditional Medicine in Dar-es-Salaam. Crude extracts and fractions of 133 plant species have literature reports on antimicrobial bioassays. Of these, 16 plant species had a minimum inhibitory activity of MIC ≤ 50 µg/mL. Structurally diverse compounds were reported for 49 plant species, of which 7 had constituents with MIC ≤ 5 µg/mL against various bacteria: Bryophyllum pinnatum (Lam.) Oken, Warburgia ugandensis Sprague, Diospyros mespiliformis Hochst. ex DC., Cassia abbreviata Oliv., Entada abyssinica A. Rich., Strychnos spinosa Lam., and Milicia excelsa (Welw.) C.C. Berg. The low number of antimicrobial active extracts and compounds suggests that antibacterial and antimycobacterial drug discovery needs to have a fresh look at ethnobotanical information, diverting from too reductionist an approach and better taking into account that the descriptions of symptoms and concepts of underlying diseases are different in traditional African and modern Western medicine. Nevertheless, some structurally diverse compounds found in anti-infective plants are highlighted in this review as worthy of detailed study and chemical modification.

The Metabolic Response of Brachypodium Roots to the Interaction with Beneficial Bacteria Is Affected by the Plant Nutritional Status

The potential of plant growth promoting (PGP) bacteria in improving the performance of plants in suboptimal environments is increasingly acknowledged, but little information is available on the mechanisms underlying this interaction, particularly when plants are subjected to a combination of stresses. In this study, we investigated the effects of the inoculation with the PGP bacteria Azospirillum brasilense (Azospirillum) on the metabolism of the model cereal Brachypodium distachyon (Brachypodium) grown at low temperatures and supplied with insufficient phosphorus. Investigating polar metabolite and lipid fluctuations during early plant development, we found that the bacteria initially elicited a defense response in Brachypodium roots, while at later stages Azospirillum reduced the stress caused by phosphorus deficiency and improved root development of inoculated plants, particularly by stimulating the growth of branch roots. We propose that the interaction of the plant with Azospirillum was influenced by its nutritional status: bacteria were sensed as pathogens while plants were still phosphorus sufficient, but the interaction became increasingly beneficial for the plants as their phosphorus levels decreased. Our results provide new insights on the dynamics of the cereal-PGP bacteria interaction, and contribute to our understanding of the role of beneficial microorganisms in the growth of cereal crops in suboptimal environments.

Julbernardia paniculata and Pterocarpus angolensis: From Ethnobotanical Surveys to Phytochemical Characterization and Bioactivities Evaluation

Julbernardia paniculata and Pterocarpus angolensis are two plant species with important application in African traditional medicine, particularly in Angola, in the treatment of several diseases. However, scientific studies concerning these species are scarce. The goal of this work was to know better which medicinal approaches are used by the Huíla population in Angola by means of ethnobotanical surveys. Furthermore, extracts of both plants were phytochemically characterized. Antioxidant, anti-inflammatory, wound-healing activities, and potential cytotoxicity were also studied. With this study it was possible to verify that 67% of the individuals that use medicinal plants are women, and their main therapeutic uses are the treatment of problems of the digestive system and skin disorders. Barks of J. paniculata and leaves of P. angolensis are the most often used plant parts. Through high-performance liquid chromatography coupled to diode-array detector (HPLC-DAD) and GC-MS it was possible to characterize the chemical composition of the two species, which are rich in phenolic compounds, terpenes, terpenoids, sesquiterpenoids and fatty acids. Both plants showed to possess antioxidant, anti-inflammatory proprieties, and wound-healing activity. To the best of our knowledge, this is the most comprehensive study of these two species and the first ethnobotanical and ethnopharmacological study of medicinal plants from this region of Angola.

The comparative study of medicinal plants utilization as herbal antibiotics by college students

The medicinal plant utilization has become more and more popular and increasing number of consumers prefer alternative medicine to synthetic antibiotic. Research dealing with evaluation of medicinal plant usage as herbal antibiotics including the sample of 584 quizzed college students aged 19 – 25 years (337 women, 217 men) originated from Slovak Republic (n = 338), Czech Republic (n = 112) and Hungary (n = 134). According to university and the study programme the following groups were evaluated: Constantine the Philosopher University CPU (PEES – Pre-school and elementary education in Slovak language, PEEH – Pre-school and elementary education in Hungarian language, BI – Biology, RT – Regional Tourism), Mendel University in Brno MU (H – Horticulture), Slovak University of Agriculture SUA (H – Horticulture), University of Pécs UP (PE – Physical education), Comenius University CU (PE – Physical education). The study was aimed at the evaluation of the significance of the country and the study programme for the use of the most commonly used herbs: plantain, elderberry, stinging nettle, ginger and coneflower (Echinacea). Our results showed that the choice of preferred medicinal plants as herbal antibiotics during illness had not been clearly influenced by country or field of study programme. Plantain was the most frequently used herb by students of UP/PE (51.5%), CPU/PEES and CPU/PEEH (47.9%; 41.1%). Elderberry was the most popular herb among the students CPU/BI (52.9%), CPU/RT and SUA/H (37.8%). Stinging nettle was preferred as the most popular herb in groups of CPU/RT (46%). The significantly lower consumption of Echinacea was noticed in MU/H 4.5% in comparison with groups, CU/PE 26.4% (p <0.05), CPU/PEEH 27.4% (p <0.01), UP/PE 17.2% (p <0.05) and CPU/RT 28% (p <0.05). Regularly, all the year round the highest utilization of Echinacea was evident in CPU/BI 30.0%. The highest percentage formed respondent’s utilized Echinacea only during illness. Otherwise, the differences between the frequencies of Echinacea usage cannot be considered as statistically significant. Generally, a significantly higher level of ginger usage was assayed within groups SUA/H 80.0% (p <0.001), CPU/PEEH 66.3% (p <0.001), UP/PE 36.6% (p <0.001), CPU/BI 58.8% (p <0.001), CPU/RT 56.0% (p <0.001), MU/H 78.6% (p <0.001) and CPU/PEES 77.1% (p <0.001) in comparison with the rest of the groups. Daily the respondents from CU/PE 20.8% consumed ginger significantly more often than students belonging to CPU/BI 0.0% (p <0.05) and MU/H 0.0% (p <0.05). Respondents from CPU/PEEH consumed statistically significantly more ginger once a week in comparison with students belonged to MU/H 0.9% (p <0.05). To sum up the research results, we can claim that state or study programme had no clear statistically significant evidence on the regular consumption of medicinal plants as herbal antibiotics.

Alleviation of carbon tetrachloride-induced hepatocellular damage and oxidative stress with a leaf extract of Glyphae brevis (Tiliaceae)

Background Glyphae brevis leaf is reported in ethnomedicine as a treatment for hepatitis and jaundice; however, no studies have hitherto investigated the mechanistic basis of these claims. Methods A hepato-protective role of G. brevis hydromethanolic (GBH) leaf extract was established against carbon tetrachloride (CCl4)-induced hepatotoxicity. Twenty-four hours after a CCl4 challenge, rats were sacrificed and serum hematological indices, lipid profile, and biochemical parameters were determined. The antioxidant enzymes parameters (glutathione, catalase, and superoxide dismutase) and lipid peroxidation product (thiobarbituric reactive substances) levels in liver homogenates were evaluated. Changes in the liver cyto-architecture of different treatment groups were also investigated. Results The GBH extract produced no significant impact on weight and hematological indices. Intoxication with CCl4 significantly (p<0.001-0.05) increased total cholesterol (TC) and low-density lipoproteins (LDL) compared with control rats. Pretreatment with GBH leaf extract significantly reduced triglycerides, TC, and LDL to approaching control levels (p<0.001-0.05). The GBH leaf extract significantly alleviated CCl4-induced elevation of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and the CCl4-induced depression of total protein, and albumin. Liver antioxidant parameters were significantly increased in plant extract-treated rats, and this antagonized the pro-oxidant effect of CCl4. Histopathological studies also supported a hepato-protective effect of GBH. Collectively, the GBH leaf extract alleviated the CCl4-induced hepatotoxicity through improvement of innate antioxidant enzyme levels and lipid metabolism and stabilized the hepatocyte cyto-architecture of intoxicated rats. Conclusions This study establishes the ethnomedicinal role of G. brevis leaf in hepatitis and the mechanistic basis of hepato-protection against CCl4-induced hepatotoxicity.

Secondary metabolites from Tetracera potatoria stem bark with anti-mycobacterial activity

ETHNOPHARMACOLOGICAL RELEVANCE

Tetracera potatoria Afzel. Exg. Don (Dilleniaceae) is a medicinal plant used traditionally in Africa for the treatment of tuberculosis related ailments and respiratory infections. The antibacterial activity of the medium polar extracts of T. potatoria leaves and stem bark was recently reported against Mycobacterium smegmatis (MIC 25µg/mL) and M. aurum (65µg/mL), two fast-growing Mycobacterium strains used as model micro-organisms for the more pathogenic strain Mycobacterium tuberculosis (Fomogne-Fodjo et al., 2014). The aim of this study was consequently to isolate the compounds possibly contributing to this activity, and which may therefore be promising precursors to be used for the development of novel anti-TB drugs.

MATERIALS AND METHODS

T. potatoria medium polar extract [MeOH/DCM (1:1, v/v)] was fractionated sequentially with petroleum ether to which EtOAC and MeOH were gradually added to increase the polarity. The examination of T. potatoria extract and its fractions was guided by bioassays for anti-mycobacterial activity against M. smegmatis (ATCC 23246) and M. aurum (NCTC 10437) using the minimum inhibitory concentration (MIC) method. All the isolated compounds were structurally elucidated using spectroscopic techniques and evaluated for their anti-mycobacterial activity.

RESULTS

Two novel secondary metabolites (1, 2) named tetraceranoate and N-hydroxy imidate-tetracerane, together with five known compounds [β-stigmasterol (3), stigmast-5-en-3β-yl acetate (4), betulinic acid (5), betulin (6) and lupeol (7)] were isolated and identified. Tetraceranoate exhibited the best activity against M. smegmatis with a minimum inhibitory concentration (MIC) of 7.8µg/mL, while β-stigmasterol, betulinic acid and betulin showed appreciable anti-mycobacterial activity against both strains (MIC 15µg/mL).

CONCLUSION

Seven compounds were isolated from the medium polar extract [MeOH/DCM (1:1, v/v)] of T. potatoria stem bark. Only tetraceranoate one of the isolated compounds showed antibacterial activity against M. smegmatis having efficacy as high as rifampicin (one of a three drug regimen recommended in the initial phase short-course anti-tuberculosis therapy). Thus, tetraceranoate might be an interesting target for systematic testing of anti-TB treatment and management. This research supports the use of T. potatoria in African traditional medicine for the treatment of tuberculosis related symptoms.

Cytotoxicity of 91 Kenyan indigenous medicinal plants towards human CCRF-CEM leukemia cells

ETHNOPHARMACOLOGICAL RELEVANCE

Plants from Kenyan flora are traditionally used against many ailments, including cancer and related diseases. Cancer is characterized as a condition with complex signs and symptoms. Recently there are recommendations that ethnopharmacological usages such as immune and skin disorders, inflammatory, infectious, parasitic and viral diseases should be taken into account when selecting plants that treat cancer.

AIM

The present study was aimed at investigating the cytotoxicity of a plethora of 145 plant parts from 91 medicinal plants, most of which are used in the management of cancer and related diseases by different communities in Kenya, against CCRF-CEM leukemia cell line.

MATERIALS AND METHODS

Extracts from different plant parts (leaves, stems, stem bark, roots, root barks, aerial parts and whole herb) were obtained by cold percolation using different solvent systems, such as (1:1v/v) dichloromethane (CH2Cl2) and n-hexane (1), methanol (MeOH) and CH2Cl2 (2); neat MeOH (3), 5% H2O in MeOH (4) and with ethanol (EtOH, 5); their cytotoxicities were determined using the resazurin reduction assay against CCRF-CEM cells.

RESULTS

At a single concentration of 10μg/mL, 12 out of 145 extracts exhibited more than 50% cell inhibition. These include samples from the root bark of Erythrina sacleuxii (extracted with 50% n-hexane-CH2Cl2), the leaves of Albizia gummifera, and Strychnos usambarensis, the stem bark of Zanthoxylum gilletii, Bridelia micrantha, Croton sylvaticus, and Albizia schimperiana; the root bark of Erythrina burttii and E. sacleuxii (extracted with 50% CH2Cl2-MeOH), the stem bark of B. micrantha and Z. gilletii (extracted using 5% MeOH-H2O) and from the berries of Solanum aculeastrum (extracted with neat EtOH). The EtOH extract of the berries of S. aculeastrum and A. schimperiana stem bark extract displayed the highest cytotoxicity towards leukemia CCRF-CEM cells, with IC50 values of 1.36 and 2.97µg/mL, respectively. Other extracts having good activities included the extracts of the stem barks of Z. gilletii and B. micrantha and leaves of S. usambarensis with IC50 values of 9.04, 9.43 and 11.09µg/mL, respectively.

CONCLUSIONS

The results of this study provided information related to the possible use of some Kenyam medicinal plants, and mostly S. aculeastrum, A. schimperiana, C. sylvaticus, Z. gilletii, B. micrantha and S. usambarensis in the treatment of leukemia. The reported data helped to authenticate the claimed traditional use of these plants. However, most plants are used in combination as traditional herbal concoctions. Hence, the cytotoxicity of corresponding plant combinations should be tested in vitro to authenticate the traditional medical practitioners actual practices.

Medicinal plants used as excipients in the history in Ghanaian herbal medicine

ETHNOPHARMACOLOGICAL RELEVANCE

The present study was carried out to investigate the traditional use, pharmacology and active compounds of four plants commonly used as excipients in herbal medicine in Ghana.

MATERIALS AND METHODS

A comprehensive literature search was conducted to gain knowledge about the traditional use, pharmacology and active compounds of the four plant excipients. The broth dilution antibacterial assay and the DPPH radical scavenging antioxidant assay were used to evaluate the antibacterial and antioxidant activity of the plants, respectively. Ethanol, warm water and cold water extracts were prepared from the dried seeds/fruits of Aframomum melegueta, Piper guineense, Xylopia aethiopica and Monodora myristica, and tested in the assays.

RESULTS

A. melegueta and P. guineense seemed to act as pharmacoenhancers, since they have been shown to inhibit specific CYP-enzymes. A. melegueta could act as an antioxidant to preserve herbal preparations. None of the plant excipients had antibacterial activity against the bacteria tested in this study. Compounds with an aromatic or pungent smell had been identified in all the plant excipients. An explanation for the use of the plants as excipients could rely on their taste properties.

CONCLUSION

The present study suggests that there may be more than one simple explanation for the use of these four plants as excipients. Plausible explanations have been proven to be: (1) a way to increase the effect of the medicine, (2) a way to make the medicine more palatable or (3) a way to preserve the activity of the medicinal preparation over time.

Quantification of polyphenols and evaluation of antimicrobial, analgesic and anti-inflammatory activities of aqueous and acetone-water extracts of Libidibia ferrea, Parapiptadenia rigida and Psidium guajava

ETHNOPHARMACOLOGICAL RELEVANCE

Vast numbers of plant species from northeastern Brazil have not yet been phytochemically or biologically evaluated.

AIM OF THE STUDY

The goal of this work was to obtain, characterize and show the antimicrobial, analgesic and anti-inflammatory activities of aqueous and acetone-water extracts of Libidibia ferrea, Parapiptadenia rigida and Psidium guajava.

MATERIALS AND METHODS

The plant material (100g) was dried, and the crude extracts were obtained by using turbo-extraction (10%; w/v) with water or acetone:water (7:3, v/v) as the extraction solvent. High-performance liquid chromatography (HPLC) methods were used to screen the crude extracts for hydrolysable tannins (gallic acid) and condensed tannins (catechins). The antibacterial activity was evaluated by agar-diffusion and microdilution methods against Gram-positive strains (Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis INCQS 00016, Enterococcus faecalis ATCC 29212 and a clinical isolate of methicillin-resistant Staphylococcus aureus) as well as Gram-negative strains (Escherichia coli ATCC 25922, Salmonella enteritidis INCQS 00258, Shigella flexneri and Klebsiella pneumoniae). To evaluate the anti-inflammatory activity, a leukocyte migration model was used. Analgesic activity was determined by the hot plate test and the acetic acid-induced abdominal writhing test. Data were analyzed by analysis of variance (ANOVA) at a significance level of 5%.

RESULTS

Parapiptadenia rigida presented the highest amount of total polyphenols (35.82 ± 0.20%), while the greatest catechin content was found in the acetone-water extract of Psidium guajava (EAWPg; 1.04 μg/g). The largest amounts of catechins were found in the aqueous extract of Libidibia ferrea (EALf; 1.07 μg/g) and the acetone-water extract of Parapiptadenia rigida (EAWPr; 1.0 μg/g). All extracts showed activity against Gram-positive bacteria. The aqueous and acetone-water extracts of Psidium guajava showed the greatest inhibition zones in the agar diffusion tests. In the evaluation of the minimum inhibitory concentration (MIC), the most susceptible Gram-positive bacterium was Staphylococcus epidermidis and the most susceptible Gram-negative bacterium was Shigella flexneri. EAPg and EAWPg showed the greatest MIC values. All extracts were significant inhibitors of leukocyte migration (p<0.05). Using the writhing test, significant analgesic activity was found for EAPr (50 mg/kg), EAWPr (100 mg/kg and 200 mg/kg) and EAWPg (50 mg/kg) (p<0.05).

CONCLUSIONS

Thus, the appropriate extraction procedure preserves the chemical components such as gallic acid and catechin, and showed antimicrobial, anti-inflammatory and analgesic properties.

Antimicrobial, antibiofilm and cytotoxic activities of Hakea sericea Schrader extracts

Background:

Hakea sericea Schrader is an invasive shrub in Portuguese forests.

Objective:

The goal of this work was to evaluate the antimicrobial activity of H. sericea extracts against several strains of microorganisms, including the ability to inhibit the formation of biofilms. Additionally the cytotoxic properties of these extracts, against human cells, were assessed.

Materials and Methods:

The antimicrobial activity of the methanolic extracts of H. sericea was assessed by disk diffusion assay and Minimum Inhibitory Concentration (MIC) value determination. The antibiofilm activity was determined by quantification of total biofilm biomass with crystal violet. Cytotoxicity was evaluated by hemolysis assay and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test.

Results:

For Gram-positive bacteria, MIC values of H. sericea methanolic extracts ranged between 0.040 and 0.625 mg/mL, whereas the fruits extract yielded the lowest MIC for several strains of microorganisms, namely, S. aureus, B. cereus, L. monocytogenes and clinical methicillin-resistant S. aureus (MRSA). Stems and fruits extract at 2.5 mg/mL effectively eradicated the biofilm of S. aureus ATCC 25923, SA 01/10 and MRSA 12/10. Regarding leaves extract, hemolysis was not observed, and in the case of stems and fruits, hemolysis was verified only for higher concentrations, suggesting its low toxicity. Fruits extract presented no toxic effect to normal human dermal fibroblasts (NHDF) cells however for concentrations of 0.017 and 0.008 mg/mL this extract was able to decrease human breast adenocarcinoma cells (MCF-7) viability in about 60%, as MTT test results had confirmed. This is a clearly demonstrator of the cytotoxicity of this extract against MCF-7 cells.

The therapeutic potential of medicinal foods

Pharmaceutical and nutritional sciences have recently witnessed a bloom in the scientific literature geared towards the use of food plants for their diversified health benefits and potential clinical applications. Health professionals now recognize that a synergism of drug therapy and nutrition might confer optimum outcomes in the fight against diseases. The prophylactic benefits of food plants are being investigated for potential use as novel medicinal remedies due to the presence of pharmacologically active compounds. Although the availability of scientific data is rapidly growing, there is still a paucity of updated compilation of data and concerns about the rationale of these health-foods still persist in the literature. This paper attempts to congregate the nutritional value, phytochemical composition, traditional uses, in vitro and in vivo studies of 10 common medicinal food plants used against chronic noncommunicable and infectious diseases. Food plants included were based on the criteria that they are consumed as a common food in a typical diet as either fruit or vegetable for their nutritive value but have also other parts which are in common use in folk medicine. The potential challenges of incorporating these medicinal foods in the diet which offers prospective opportunities for future drug development are also discussed.

Antiallergic and Antiarthritic Effects of Stem Bark Extract of Glyphaea brevis (Spreng) Monachino (Tiliaceae) in Murine Models

Background. Various parts of Glyphaea brevis (Spreng) Monachino (Tiliaceae) find a use in traditional medicine in the treatment of pain and oedema among others. This study evaluates the anti-inflammatory, antiallergic, and antiarthritic effects of a 70% (v/v) aqueous ethanol extract of the stem bark of Glyphaea brevis in murine models. Materials and Methods. The effect of the aqueous ethanol extract of Glyphaea brevis extract (GBE) was assessed on the maximal and total oedema responses in the carrageenan-induced paw oedema in mice to evaluate the acute anti-inflammatory actions of the extract. Systemic anaphylaxis was induced with compound 48/80 and survival rates monitored for 1 h in mice with prior treatment with GBE to assess the anti-allergic action of the extract. The indirect antihistamine effect of GBE was evaluated on clonidine-induced catalepsy. Rat adjuvant-induced arthritis model was used to study GBE's antiarthritic action. Results. GBE significantly suppressed the mean maximal swelling and the total paw swellings over 6 h in the carrageenan-induced paw oedema when administered either prophylactically or therapeutically. GBE dose dependently increased the time for compound 48/80-induced mortality. Administered either prophylactically or therapeutically, GBE inhibited clonidine-induced catalepsy while it had no effect on haloperidol-induced catalepsy. GBE caused a significant dose-dependent suppression of Freund's adjuvant-induced arthritis. Conclusion. Glyphaea brevis inhibits the in vivo degranulation of mast cells and thereby suppress allergy. In addition it exhibits anti-inflammatory action and attenuates Freund's adjuvant-induced arthritis. The results of this work contribute to validate the traditional use of Glyphaea brevis in the management of inflammatory disorders.

Chemical constituents from Glyphaea brevis and Monodora myristica: chemotaxonomic significance

A chemical investigation of the Glyphaea brevis leaves and of the Monodora myristica fruits led to the identification of thirteen compounds, seven linear long-chain aliphatic compounds, 1, 2, 4, 6, and 9-11, three steroids, 3a, 3b, and 7, two triterpenes, 5a and 5b, and one polyol, 8. The compounds 2 and 8, previously mentioned in the literature, are here characterized by their complete (1)H- and (13)C-NMR assignments. This is the first report of a full NMR assignment for linear fatty acid esters of aliphatic primary alcohols and for meso-erythritol. Compound 5b and 8 were isolated for the first time from plant extracts of the Tiliaceae family, and compounds 9-11 from the Annonaceae plant family. Our results constitute the basis for further chemotaxonomic studies on the two species.

Ceramide, cerebroside and triterpenoid saponin from the bark of aerial roots of Ficus elastica (Moraceae)

Three compounds, ficusamide (1), ficusoside (2) and elasticoside (3), were isolated from the bark of aerial roots of Ficus elastica (Moraceae), together with nine known compounds, including four triterpenes, three steroids and two aliphatic linear alcohols. The chemical structures of the three compounds were established by extensive 1D and 2D NMR spectroscopy, mass spectrometry and by comparison with published data. The growth inhibitory effect of the crude extract and isolated compounds was evaluated against several microorganisms and fungi. The cytotoxicity against human cancer cell lines was also assessed. Ficusamide (1) displayed a moderate in vitro growth inhibitory activity against the human A549 lung cancer cell line and a strong activity against Staphylococcus saprophyticus, while elasticoside (3) showed a potent activity on Enterococcus faecalis.

Evaluation of antimicrobial activity of ethanol extract and compounds isolated from Trichodesma indicum (Linn.) R. Br. root

ETHNOPHARMACOLOGICAL RELEVANCE

The roots are reportedly used to treat diarrhoea, dysentery, leprosy, skin diseases and fever.

AIM OF STUDY

The aim of present study was to investigate the in vitro antimicrobial potential of ethanol extract of Trichdesma indicum root, and its purified compounds and to validate scientifically its use in traditional medicine.

MATERIAL AND METHODS

The root of Trichdesma indicum was extracted with ethanol and subjected to chromatographic separation for isolation of phytochemical compounds. Structures of isolated compounds were elucidated by spectroscopic methods. The antimicrobial activities of the ethanol extract of T. indicum and isolated compounds were primarily evaluated by a disc diffusion test. The anti-microbial efficacy of the ethanol extract or isolated compounds was then assessed in vitro by determining minimal inhibition concentration (MIC) and minimal bactericidal or fungicidal concentration (MBC/MFC).

RESULTS

n-Decanyl laurate (1), n-tetradecanyl laurate (2), n-nonacosanyl palmitate (3), stigmast-5-en-3β-ol-21(24)-olide (4), n-pentacos-9-one (5), n-dotriacont-9-one-13-ene (6), stigmast-5-en-3β-ol-23-one (7) and lanast-5-en-3β-D-glucopyranosyl-21 (24)-olide (8) were isolated from ethanol extract of T.indicum. The ethanol extract and isolated compounds (1-8) showed varying degrees of antimicrobial activities. The ethanol extract exhibited potent growth inhibitory activity against S. aureus, B. subtilis and C. albicans with an MIC value of 19.2 μg/ml. Among all the isolated compounds, lanast-5-en-3β-D-glucopyranosyl-21 (24)-olide (8) displayed strongest antibacterial activity against S. aureus with MIC value of 2.4 μg/ml.

CONCLUSIONS

The results of present study provide ground basis for the potential use of the ethanol extract Trichodesma indicum root as well as the some of the isolated compounds in the treatment of infections associated with the studied microorganisms.

Emergence of Candida spp. and exploration of natural bioactive molecules for anticandidal therapy--status quo

The opportunistic yeast pathogen Candida albicans and the emerging non-albicans Candida spp. cause life-threatening infections in immuno-compromised patients, leading to an increase in mortality rate. At present, the emergence of non-albicans Candida spp. causes serious infections that are difficult to treat the human populations worldwide. The available, synthetic antifungal drugs show high toxicity to host tissues causing adverse effects. Many metabolites of terrestrial and marine plants, microbes, algae, etc., contain a rich source of unexplored novel leads of different types, which are under use to treat various diseases. Such natural drugs are less expensive and have lower toxicity to host tissues. The patent search on identified and potential anticandidal-lead molecules, from various patent databases, has been described in this review. Furthermore, this article consolidates the trends in the development of anticandidal drug discovery worldwide. Most of the investigations on natural, bioactive molecules against candidiasis are in various phases of clinical trials, of which, two drugs Caspofungin acetate and Micafungin sodium were approved by the U.S. FDA. In conclusion, the exploration of drugs from natural resources serves as a better alternative source in anticandidal therapeutics, having great scope for drug discovery in the future.

Antibacterial, anti-inflammatory, and antioxidant effects of the leaves and stem bark of Glyphaea brevis (Spreng) Monachino (Tiliaceae): A comparative study

Background:

Glyphaea brevis (Spreng) Monachino (Tiliaceae) have traditional uses in the management of conditions characterized by infections, inflammatory disorders and oxidative stress. The paper aims to report the comparative data on the leaves and stem bark of Glyphaea brevis with respect to their antibacterial, anti-inflammatory and antioxidant effects.

Materials and Methods:

The antibacterial effects of the 70% ethanol extracts of the leaves and stem bark were determined using the agar well diffusion and micro dilution assays. The anti-inflammatory activity was assessed using the carrageenan-induced oedema model in 7-day old cockerels. Using the DPPH free radical scavenging, total antioxidant and total phenol content assays, the antioxidant potential of the extract was assessed.

Results:

The bark extract had the higher antibacterial effect against 6 of the 8 microorganisms used. Noteworthy are its activity against Bacillus subtilis and Enterococcus faecalis with lowest MIC value of 500 μg/mL respectively. In doses of 30, 100 and 300 mg/kg, both extracts reduced the carrageenan-induced oedema in 7-day old cockerels. Based on the ED₅₀ values, both extracts demonstrated similar potencies (ED₅₀ =21.00 mg/kg). The stem bark extract exhibited higher free radical scavenging activity (IC₅₀ = 1.392 mg/mL) compared to the leaf extract (IC₅₀ = 9.509 mg/mL). In the total phenol content, the bark extract showed higher content (15.91 mg/g of dry mass) compared to the leaf extract (2.68 mg/g dry mass). Both extracts demonstrated equal potencies in the total antioxidant capacity determinations (0.60 mg/g dry weight of extract).

Conclusions:

The results of this work provide scientific evidence for the traditional uses of Glyphaea brevis.

Plants used to treat malaria in Nyakayojo sub-county, western Uganda

AIM OF STUDY

We performed an ethnobotanical study of plants used to treat malaria in Nyakayojo sub-county in south western Uganda because malaria in this region, and in Uganda at large, is still the single most important reason for ill health and mortality. Two of the most vulnerable groups affected by malaria are young children and pregnant women and plants are commonly used in their treatment.

MATERIALS AND METHODS

Twenty-eight traditional birth attendants were interviewed about how they used plants to treat malaria. Review of the literature available on all species identified was undertaken.

RESULTS

Altogether 56 plant species were used by the informants, 48 of which have been identified to species level. Thirty-two (67%) of the species used by the respondents are documented for antimalarial use in other studies, and nearly half (44%) have documented anti-plasmodial activity. Fifty-five percent of the species were used by 2 or more of the respondents. The most commonly used species were Vernonia amygdalina, the indigenous Aloe species, Justicia betonica, Vernonia adoensis and Tithonia diversifolia. It was common to use more than one plant in a recipe (43%). The respondents had good knowledge of the symptom of malaria, and fairly good understanding of the causes.

CONCLUSION

The interviews show that the group of traditional birth attendants has an extensive and diverse knowledge on plants used in the treatment of malaria. The literature survey may indicate a possible explanation for the use of several plants.

Assessment of the antibacterial activity and the antidiarrheal function of flavonoids from bayberry fruit

Chinese bayberry fruits are used as a folk medicine to cure diarrhea. However, the active compounds have not yet been reported. We found that bayberry fruit extract showed significant antibacterial activity against Salmonella, Listeria, and Shigella, and the minimal inhibitory concentration (MIC) ranged from 2.07 to 8.28 mg/mL. Positive relationships were found between the antibacterial activity and the total polyphenol (r = 0.88) and flavonoid contents (r = 0.92) of samples using different extraction times. The active compounds showed green or blue fluorescence under UV light using the bioautography method and were purified using a polyamide column. The fraction F1 with the most activity was comprised of flavonoids, which included cyanidin-3-O-glucoside, myricetin deoxyhexoside, quercetin-3-O-glucoside, and quercetin deoxyhexoside, and it also possessed an antidiarrheal activity (p < 0.10) at 80 mg/kg in mice. These findings provide scientific evidence for the antidiarrheal function of bayberry.

In vitro antibacterial effect of aqueous and ethanolic Moringa leaf extracts

OBJECTIVE

To evaluate the antibacterial effect of aqueous and ethanolic moringa leaf extracts (Moringa oleifera) on the growth of gram-positive and negative bacteria.

METHODS

Paper disks were soaked with 100, 200, 300 and 400 μL of extract at 20 g/180 mL and 10 g/190 mL. All extracts were tested against Escherichia coli (ATCC25922), Staphylococcus aureus (ATCC25923), Vibrio parahaemolyticus, Enterococcus faecalis (ATCC29212), Pseudomonas aeruginosa (ATCC27853), Salmonella enteritidis (IH) and Aeromonas caviae. The susceptibility tests were performed using the modified disk diffusion method.

RESULTS

The strains E. coli, P. aeruginosa and S. enteritidis (IH) were resistant to all treatments. In general, disks with 400 μL extract were the most efficient against S. aureus, V. parahaemolyticus, E. faecalis and A. caviae.

CONCLUSIONS

The study indicates a promising potential for aqueous and ethanolic Moringa leaf extracts as alternative treatment of infections caused by the tested strains.