Methanol Extracts Of Medicinal Plants Research Articles

Structural characterization of chlorogenic acid-metal complexes derived from the aqueous extracts of medicinal plants and their DNA cleavage and antibacterial activities

The discovery of organic components with pharmacological activities in medicinal plants is crucial for new drug development. We examined chlorogenic acid (CGA) using high-performance liquid chromatography to analyze the aqueous and methanolic extracts of medicinal plants dissolved in methanol or methanol containing 15% formic acid. We found that for the aqueous extract, the peak areas of various components dissolved in 15% formic acid methanol were significantly larger than those dissolved in methanol. For the differences in the methanolic extract, the peak areas of all chromatographic peaks were relatively small between the samples dissolved in the two solvents. Electrospray ionization time-of-flight mass spectrometry showed that CGA could react in hot water with the eight most common plant metal ions (Ca2+, Cu2+, Fe3+, Mg2+, Mn2+, Ni2+, Sr2+, and Zn2+) to form complexes with different coordination forms. The bioactivity experiments showed that CGA-Cu complexes could cause DNA cleavage through oxidative damage. CGA-Ni, CGA-Mn, and CGA-Zn showed significantly stronger inhibition against Staphylococcus aureus than CGA and the corresponding metal ions. These results suggest that, during the decoction process of medicinal plants, CGA forms complexes with metal ions, which are likely to be one of the active ingredients in medicinal plants. Subsequently, further research is needed on the antibacterial mechanism of chlorogenic acid-metal complexes not mentioned in this article.

In vitro antimycobacterial activity of medicinal plants Lantana camara, Cryptolepis sanguinolenta, and Zanthoxylum leprieurii

BackgroundImperative need exists to search for new anti-TB drugs that are safer, and more effective against drug-resistant strains. Medicinal plants have been the source of active ingredients for drug development. However, the slow growth and biosafety level requirements of M. tuberculosis culture are considerable challenges. M. smegmatis can be used as a surrogate for M. tuberculosis. In the current study, preliminary phytochemical screening and antimycobacterial activity evaluation of crude methanolic extracts of medicinal plants against M. smegmatis, and two M. tuberculosis strains, were conducted. Materials and MethodsCrude methanolic extracts, obtained from the leaves of L. camara, roots of C. sanguinolenta, and stem barks of Z. leprieurii, were tested for antimycobacterial activity against M. smegmatis (mc2155), pan-sensitive (H37Rv), and rifampicin-resistant (TMC-331) M. tuberculosis, using visual Resazurin Microtiter Assay (REMA) on 96 well plates. Preliminary qualitative phytochemical screening tests were performed using standard chemical methods. ResultsThe three methanolic extracts inhibited mycobacterial growth in vitro. They were more active against rifampicin-resistant strain with MICs of 176, 97, and 45 µg/mL for L. camara, C. sanguinolenta, and Z. leprieurii extracts, respectively. The lowest activity was observed against M. smegmatis with MICs of 574, 325, and 520 µg/mL, respectively. Against H37Rv, activity was intermediate to those of TMC-331 and mc2155. However, L. camara extract showed the same activity against H37Rv and M. smegmatis. Preliminary phytochemical analysis revealed alkaloids, flavonoids, phenolic compounds, saponins, tannins, and terpenoids. ConclusionsLeaves of L. camara, roots of C. sanguinolenta, and stem barks of Z. leprieurii exhibit antimycobacterial activity against M. smegmatis, pan-sensitive, and rifampicin-resistant M. tuberculosis. This offers the possibilities for novel therapeutic opportunities against TB including multidrug-resistant TB. Further investigations on safety and mechanisms of action are required. These studies could be done using M. smegmatis as a surrogate for the highly pathogenic M. tuberculosis.

Determination of α-Amylase Inhibitory potential of leaf extracts of Rhododendron arboreum Sm. and Rhododendron campanulatum D. Don

The biological activity of plant-derived substances/metabolites may be considered as a source of new anti-enzyme drugs. Therefore, traditional Indian plants i.e. Rhododendron arboreum and R. campanulatum which are commonly used as remedies to control different diseases were screened to discover possible plant-derived α-amylase inhibitors. In the present investigation, inhibitory effects of leaf extracts of Rhododendron arboreum and R. campanulatum were determined against porcine α-amylase at a concentration range of 0.2-1.0 mg/mL. R. arboreum displayed 51.10, 44.00 and 35.40% inhibition at a concentration of 1 mg/mL for methanol, acetone and aqueous leaf extracts respectively. On the other hand, R. campanulatum showed 21.15, 18.25 and 15.85% α-amylase inhibition for methanol, acetone and aqueous extracts respectively at 1 mg/mL. The inhibitory activity increased altogether with increasing concentration of each plant extract. The results further indicated that methanol extracts of medicinal plants exhibited maximum inhibitory effects than other solvent (acetone, methanol) extracts.
 Keywords: Rhododendron arboreum, Rhododendron campanulatum, porcine α-Amylase, Leaf extracts, Inhibition

Antihyaluronidase and Alkaline Phosphatase (ALP) Activities of Medicinal Plants to Combat Echis carinatus Venom-Induced Toxicities.

Snakebite is one of the most neglected diseases of developing countries. Deaths due to snakebite envenoming are quite high in Pakistan, and many deaths are caused by Echis carinatus envenomation. Traditional use of medicinal plants against snakebites is a common practice in Pakistan due to countless benefits. The current study was performed with the objective to evaluate eighteen Pakistani medicinal plants inhibitory potential against hyaluronidase and alkaline phosphatase enzymes of Pakistani Echis carinatus venom. Hyaluronidase activity (0.2-1.6 mg/0.1 mL) and alkaline phosphatase activity (0.1-0.8 mg/0.1 mL) were measured in dose-dependent manner. Crude methanolic extracts of medicinal plants were used for in vitro investigation of their inhibitory activity against toxic enzymes. All active plants were fractioned using different solvents and were again analyzed for inhibitory activity of same enzymes. Results indicated all plants were able to neutralize hyaluronidase that Swertia chirayita (Roxb. ex Flem.) Karst., Terminalia arjuna Wight and Arn, Rubia cordifolia Thumb., and Matthiola incana (L.) R.Br. inhibited maximum hyaluronidase activity equivalent to standard reference (p > 0.5). Pakistani medicinal plants are dense with natural neutralizing metabolites and other active phytochemicals which could inhibit hyaluronidase activity of Pakistani Echis carinatus venom. Further advanced studies at molecular level could lead us to an alternative for envenoming of Pakistani Echis carinatus venom.

Antibacterial efficacy of different combinations of clove, eucalyptus, ginger, and selected antibiotics against clinical isolates of Pseudomonas aeruginosa.

Background:Nosocomial infections caused by multidrug-resistant Pseudomonas aeruginosa are commonly treated with conventional antibiotic which may lead to some serious side effects in the patients. Conventionally, medicinal plants, including clove, eucalyptus, and ginger, are used for the safe and effective treatment of several diseases.Aims and objectives:The aim and objective of this study is to evaluate the combined antibacterial efficacy of medicinal plants (clove, eucalyptus, and ginger) and selected antibiotic and also combined efficacy of different plants extracts against clinical isolates of P. aeruginosa.Materials and methods:A total of seven clinical isolates and one reference strain (PA01) of P. aeruginosa were included in this study. The antibacterial activity of crude methanol extracts of medicinal plants and selected antibiotics was screened using well-diffusion assay and their minimum inhibitory concentration (MIC) was determined by the microdilution method. Combined efficacy of ceftazidime and plant extracts was tested using standard checkerboard method and different plant extracts were evaluated using broth macrodilution method.Results:All of the seven clinical isolates of P. aeruginosa showed multidrug resistance pattern and were found highly sensitive to ciprofloxacin followed by ceftazidime and gentamicin. Clove exhibited better antibacterial activity as compared to eucalyptus and ginger. Synergistic interaction was found between ceftazidime and plants extracts against reference PA01 and clinical isolate 2. Highest two-fold reduction in MIC was found in the combination of clove-ginger against reference PA01 and clinical isolate 3.Conclusion:The selected medicinal plants are highly efficient for enhancing the antibacterial activity of antibiotic.

Screening of antioxidant property of Eclipta alba

The aim of the study was to examine the possible antioxidant activities of the methanolic extracts of medicinal plants, Eclipta alba. We examined for such properties such as nitric oxide radical scavenging assay, DPPH radical scavenging activity. Free radicals are atoms or molecules that have one or more unpaired electrons on its outer orbital, highly reactive, and could damage cell inside human body. Human body produce antioxidant to neutralize free radicals, but human ageing and stress oxidative conditions would increase the formation of free radicals, therefore an exogenous antioxidant are needed. Asteraceae is the largest family among the plant kingdom, therefore it has a great potential as source of exogenous antioxidant. The flavonoid content of the plant extract was estimated by the method of (Lamaison and Carnat, 1990). Briefly 1.0 ml of plant extract was mixed with 1.0 ml of aluminium chloride reagent and resultant colour was read at 430 nm. The flavonoid content of the extract was expressed as mg quercetin equivalent/gm dry wt. of extract. The coarsely powdered plant materials of Eclipta alba (2000 g) were extracted separately to exhaustion in Soxhlet apparatus for 72 hours by using methanol solvent The crude extract was filtered using 125 mm Whatman® qualitative filter paper under sterile condition. A methanol solution of the sample at various concentrations was added to 0.5 ml of 0.1 mM methanolic solution of DPPH and allowed to stand for 30 min at 25°C in darkness. The absorbance of the sample was measured at 517 nm. A 0.1 mM solution of DPPH in methanol was used as control, whereas ascorbic acid was used as reference standard. The absorbance of the pink chromophore formed during the diazotization of the nitrite with sulphanilamide and the subsequent coupling with naphthyl ethylenediamine dihydrochloride was measured at 546 nm. The percentage of inhibition of the extract shown 39% in 25µg and in 100µg it was 73 percent.

EVALUATION OF BIOACTIVE COMPOUNDS, ANTIOXIDANT, AND ANTIBACTERIAL PROPERTIES OF MEDICINAL PLANTS SAUROPUS ANDROGYNUS L. AND ERYTHRINA VARIEGATA L.

Objectives: The aim of the present study was to evaluate the bioactive, antioxidant, and antibacterial activity of methanolic extracts of medicinal plants Erythrina variegata L., and Sauropus androgynus L.Methods: Total phenolic, flavonoid, tannin content, total antioxidant capacity, 1, 1diphenyl-2-picryl hydrazyl radical scavenging activity, and reducing power assay of the extracts were determined by spectrophotometric methods.Results: Total phenolic, flavonoid, and tannin content was more in E. variegata compared to S. androgynus, and the alkaloid, saponin, and carotenoid content was high in S. androgynus. The overall antioxidant activity of S. androgynus was found to be higher than E. variegata. Antibacterial activities of the selected plants were studied against human pathogenic organisms, namely Escherichia coli and Staphylococcus aureus. Conclusions: The present study reveals that the selected plants would exert several beneficial effects by virtue of their natural antioxidant activity; further characterization of the phenolic composition is needed and could be harnessed as drug formulation.

The cosmetic potential of plants from the Eastern Cape Province traditionally used for skincare and beauty

Cosmetic products are directly and indirectly applied to the skin in order to enhance its beauty. Cosmetic products that are directly applied to the skin include creams, lotions and soaps while tablets and supplements are indirectly administered to achieve similar benefits. The aim of the current study was to investigate the cosmetic potential of plants from the Eastern Cape Province used traditionally for skincare and beauty by evaluating their antimicrobial activity, antioxidant potential, photo-protective effect and anti-tyrosinase activity. The antimicrobial activity of petroleum ether (PE), dichloromethane (DCM), 70% aqueous ethanol (v/v) and water extracts was tested against infectious skin microorganisms and skin dermatophytes. Methanolic extracts of medicinal plants were tested for their DPPH (2, 2-diphenyl-1-picryhydrazyl) radical scavenging activity, Ferric reducing antioxidant power (FRAP) and their ability to delay the oxidation of β-carotene in the β-carotene linoleic acid model. Ethanol extracts of medicinal plants were tested for their photo-protective effects and anti-tyrosinase activity. Ethanol extracts of Arctotis arctotoides (L.f.) O.Hoffm and Cassipourea flanaganii (Schinz) Alston were very potent against all infectious skin microorganisms and skin dermatophytes included in the study with minimum inhibitory concentration (MIC) values less than 1 mg/mL. Methanol extracts of C. flanaganii, Symphytum officinale L and Urtica urens L showed high antioxidant potential. Ethanol extracts from Plantago lanceolata L., C. flanaganii, Acokanthera oblongifolia (Hochst.) Codd, Ilex mitis (L.) Radlk., A. arctotoides and Aloe ferox Mill expressed moderate protection against ultraviolet (UV) radiation with sun protection factor (SPF) values between 12 and 30. Furthermore, extracts from Rorippa nasturtium-aquaticum (L.) Hayek, Clausena anisata (Willd.) Hook.f. ex Benth., S. officinale and C. flanaganii showed good anti-tyrosinase activity similar to the positive control with IC50 values between 19.64 and 22.24 μg/mL. The results from the study have shown that extracts from A. arctotoides and C. flanaganii have potential for incorporation into hygiene products such as soaps, creams and sanitizers due to their potential to combat a range of microorganisms. Furthermore, extracts from C. flanaganii, S. officinale and P. lanceolata have potential for incorporation into beauty creams and sunscreen products.

Antimicrobial and Anti-Biofilm Activities of the Methanol Extracts of Medicinal Plants against Dental Pathogens Streptococcus mutans and Candida albicans.

Several medicinal plants are ethnomedically used in Korea as agents for treating infection, anti-inflammation, and pain relief. However, beyond typical inhibitory effects on cell growth, little is known about the potential anti-biofilm activity of these herbs, which may help to prevent cavities and maintain good oral health. This study aimed to investigate the antimicrobial and anti-biofilm activities of the methanol extracts of 37 Korean medicinal plants against dental pathogens Streptococcus mutans and Candida albicans, which synergize their virulence so as to induce the formation of plaque biofilms in the oral cavity. The antimicrobial activities were investigated by broth dilution and disk diffusion assay. The anti-biofilm and antioxidant activities were evaluated based on the inhibitory effect against glucosyltransferase (GTase) and the DPPH assay, respectively. Among 37 herbs, eight plant extracts presented growth and biofilm inhibitory activities against both etiologic bacteria. Among them, the methanol extracts (1.0 mg/ml) from Camellia japonica and Thuja orientalis significantly inhibited the growth of both bacteria by over 76% and over 83% in liquid media, respectively. Minimum inhibitory concentration (MIC) values of these methanol extracts were determined to be 0.5 mg/ml using a disk diffusion assay on solid agar media. Biofilm formation was inhibited by more than 92.4% and 98.0%, respectively, using the same concentration of each extract. The present results demonstrate that the medicinal plants C. japonica and T. orientalis are potentially useful as antimicrobial and anti-biofilm agents in preventing dental diseases.

Comparative evaluation of antimicrobial activity of herbal extracts with 5.25% sodium hypochlorite against multispecies dentinal biofilm

Aims: To check the antimicrobial activity of Tinospora cordifolia (TC) (Giloy), Ocimum sanctum (Tulsi), and 5.25% sodium hypochlorite (NaOCl) against 21-day-old multispecies biofilm formed on tooth substrate of extracted human teeth. Settings and Design: In vitro dentin disinfection model used to check the antimicrobial efficacy of herbal extracts. Materials and Methods: The in vitro dentin disinfection model was used to check the antimicrobial activity of the methanolic extracts of medicinal plants along with NaOCl. The polymicrobial biofilm was allowed to grow on extracted teeth sections for a period of 21 days. Remaining microbial load in the form of CFU/ml after the antimicrobial treatment was tabulated and data were statistically analyzed using ANOVA and Bonferroni post-hoc tests. Statistical Analysis Used: SPSS version 17 one-way ANOVA, Bonferroni post-hoc test. Results: Both the plant extracts showed considerable antimicrobial efficacy as compared to negative control. About 5.25% NaOCl was the most effective antimicrobial agent having statistically significant difference against plant extracts and negative control (saline). Conclusions: The methanolic extract of TC (Giloy), O. sanctum (Tulsi), and 5.25% NaOCl has considerable antimicrobial activity against polymicrobial dentinal biofilm of Streptococcus mutans, Enterococcus faecalis, Staphylococcus aureus, and Candida albicans.

Traditional Preparations and Methanol Extracts of Medicinal Plants from Papua New Guinea Exhibit Similar Cytochrome P450 Inhibition.

The hypothesis underlying this current work is that fresh juice expressed from Papua New Guinea (PNG) medicinal plants (succus) will inhibit human Cytochrome P450s (CYPs). The CYP inhibitory activity identified in fresh material was compared with inhibition in methanol extracts of dried material. Succus is the most common method of traditional medicine (TM) preparation for consumption in PNG. There is increasing concern that TMs might antagonize or complicate drug therapy. We have previously shown that methanol extracts of commonly consumed PNG medicinal plants are able to induce and/or inhibit human CYPs in vitro. In this current work plant succus was prepared from fresh plant leaves. Inhibition of three major CYPs was determined using human liver microsomes and enzyme-selective model substrates. Of 15 species tested, succus from 6/15 was found to inhibit CYP1A2, 7/15 inhibited CYP3A4, and 4/15 inhibited CYP2D6. Chi-squared tests determined differences in inhibitory activity between succus and methanol preparations. Over 80% agreement was found. Thus, fresh juice from PNG medicinal plants does exhibit the potential to complicate drug therapy in at risk populations. Further, the general reproducibility of these findings suggests that methanol extraction of dried material is a reasonable surrogate preparation method for fresh plant samples.

Methanol Extracts of Medicinal Plants Used for Oral Healthcare in Cameroon

Background: Traditional healers in Cameroon are actively involved in oral healthcare and traditional herbs are used for management of oral diseases. However the analysis of phytoconstituents of medicinal plants used for oral healthcare in Cameroon has not been done. The objective of the study was to determine the phytoconstituents of medicinal plants used for oral healthcare in Cameroon. Methods: Samples of fresh plants used for dental treatment collected from South west and litorral regions of Cameroon that were free from diseases were obtained from the traditional healers.The plants were dried and the dried powder was macerated with intermediate stirring for 48 hours in methanol before filtering with Whattman filter paper. The filtrate was evaporated to dryness of solvent using the rotative evaporator in order to obtain the concentrated extracts of each plant sample. The plant extracts were then qualitatively tested for the presence of phytochemicals such as alkaloids, flavonoids, saponins, terpenoids, steroids and tannins using the standard procedures. Results: All the six (6) plants were found to be rich in at least one of the secondary metabolites. Steroids, terpenoids and flavonoids were found in all the plants samples. Alkaloids were present in Ageratum conyzoides and Carica papaya. Tannins were present in Ageratum conyzoides, Emilia coccinea, Gossypium sp and Carica papaya. Saponins were present in Ageratum conyzoides, Carica papaya and Momordica charantia. Phlobatannins was present in Emilia coccinea, Gossypium sp, Carica papaya and Spilanthes africana. Cardiac glycosides were present in Emilia coccinea, Carica papaya, and Momordica charantia. Carica papaya contained all these phytochemicals. Conclusion: This study revealed the presence of active secondary metabolites in herbs used for different dental treatment. The clinical trial of phytochemicals on the oral conditions is necessary to determine their pharmacological activity.

Ethnomedicinal and phytochemical review of Pakistani medicinal plants used as antibacterial agents against Escherichia coli.

Medicinal plants have always been part of human culture and have the potential to cure different diseases caused by microorganisms. In Pakistan, biologists are mainly focusing on plants’ antimicrobial activities against Escherichia coli due to its increasing resistance to antibiotics. In total, extracts from 34 ethnomedicinally valuable Pakistani plants were reported for in-vitro anti-E. coli activities. Mostly methanolic extracts of medicinal plants were used in different studies, which have shown comparatively higher inhibitory activities against E. coli than n-hexane and aqueous extracts. It has been found that increasing concentration (mg/ml) of methanolic extract can significantly increase (p < 0.01) anti-E. coli activities. Not all medicinal plants are extracted in solvents others than above, which should also be tested against E. coli. Moreover, medicinal plant species must be fully explored phytochemically, which may lead to the development of new drugs.

Optimisation of the microplate resazurin assay for screening and bioassay-guided fractionation of phytochemical extracts against Mycobacterium tuberculosis.

Because of increased resistance to current drugs, there is an urgent need to discover new anti-mycobacterial compounds for the development of novel anti-tuberculosis drugs. The microplate resazurin assay (MRA) is commonly used to evaluate natural products and synthetic compounds for anti-mycobacterial activity. However, the assay can be problematic and unreliable when screening methanolic phytochemical extracts. To optimise the MRA for the screening and bioassay-guided fractionation of phytochemical extracts using Mycobacterium tuberculosis H37Ra. The effects of varying assay duration, resazurin solution composition, solvent (dimethyl sulphoxide - DMSO) concentration and type of microtitre plate used on the results and reliability of the MRA were investigated. The optimal bioassay protocol was applied to methanolic extracts of medicinal plants that have been reported to possess anti-mycobacterial activity. The variables investigated were found to have significant effects on the results obtained with the MRA. A standardised procedure that can reliably quantify anti-mycobacterial activity of phytochemical extracts in as little as 48 h was identified. The optimised MRA uses 2% aqueous DMSO, with an indicator solution of 62.5 µg/mL resazurin in 5% aqueous Tween 80 over 96 h incubation. The study has identified an optimal procedure for the MRA when used with M. tuberculosis H37Ra that gives rapid, reliable and consistent results. The assay procedure has been used successfully for the screening and bioassay-guided fractionation of anti-mycobacterial compounds from methanol extracts of Canadian medicinal plants.

Anti-oxidant and Anti-hyperglycemic Properties of Methanolic Extracts of Medicinal Plants

Total phenolic content, DPPH free radical scavenging activity and alpha amylae inhibitory potential was determined for three selected medicinal plants - Gymnema sylvestre, Terminalia arjuna and Tinospora cordifolia. The plant extracts were prepared with methanol. The total phenolic content of methonolic extracts of Gymnema sylvestre, Terminalia arjuna and Tinospora cordifolia. were 6.862, 20.862 and 7.987 mg GAE/g plant material respectively . All the three plants showed anti oxidant activities with their IC50 values were 6.862, 20.862 and 7.987 I¼g/ml compared to IC50 value of the standard L-Ascorbic acid, which was 11.59I¼g/ml. The extracts of Gymnema sylvestre showed ±- amylase inhibition. Thus the results provided evidence that among the studied plants, Gymnema s ylvestre potential sources of natural antioxidant and antidiabetic activity.

Screening of anti-dengue activity in methanolic extracts of medicinal plants

BackgroundDengue fever regardless of its serotypes has been the most prevalent arthropod-borne viral diseases among the world population. The development of a dengue vaccine is complicated by the antibody-dependent enhancement effect. Thus, the development of a plant-based antiviral preparation promises a more potential alternative in combating dengue disease.MethodsPresent studies investigated the antiviral effects of standardised methanolic extracts of Andrographis paniculata, Citrus limon, Cymbopogon citratus, Momordica charantia, Ocimum sanctum and Pelargonium citrosum on dengue virus serotype 1 (DENV-1).ResultsO. sanctum contained 88.6% of total flavonoids content, an amount that was the highest among all the six plants tested while the least was detected in M. charantia. In this study, the maximum non-toxic dose (MNTD) of the six medicinal plants was determined by testing the methanolic extracts against Vero E6 cells in vitro. Studies also determined that the MNTD of methanolic extract was in the decreasing order of M. charantia >C. limon >P. citrosum, O. sanctum >A. paniculata >C. citratus. Antiviral assay based on cytopathic effects (CPE) denoted by degree of inhibition upon treating DENV1-infected Vero E6 cells with MNTD of six medicinal plants showed that A. paniculata has the most antiviral inhibitory effects followed by M. charantia. These results were further verified with an in vitro inhibition assay using MTT, in which 113.0% and 98.0% of cell viability were recorded as opposed to 44.6% in DENV-1 infected cells. Although methanolic extracts of O. sanctum and C. citratus showed slight inhibition effect based on CPE, a significant inhibition was not reflected in MTT assay. Methanolic extracts of C. limon and P. citrosum did not prevent cytopathic effects or cell death from DENV-1.ConclusionsThe methanol extracts of A. paniculata and M. charantia possess the ability of inhibiting the activity of DENV-1 in in vitro assays. Both of these plants are worth to be further investigated and might be advantageous as an alternative for dengue treatment.

Antibacterial Activities of Selected Cameroonian Plants and Their Synergistic Effects with Antibiotics against Bacteria Expressing MDR Phenotypes.

The present work was designed to assess the antibacterial properties of the methanol extracts of some Cameroonian medicinal plants and the effect of their associations with currently used antibiotics on multidrug resistant (MDR) Gram-negative bacteria overexpressing active efflux pumps. The antibacterial activities of twelve methanol extracts of medicinal plants were evaluated using broth microdilution. The results of this test showed that three extracts Garcinia lucida with the minimal inhibitory concentrations (MIC) varying from 128 to 512 μg/mL, Garcinia kola (MIC of 256 to 1024 μg/mL), and Picralima nitida (MIC of 128 to 1024 μg/mL) were active on all the twenty-nine studied bacteria including MDR phenotypes. The association of phenylalanine arginine β-naphthylamide (PAβN or efflux pumps inhibitor) to different extracts did not modify their activities. At the concentration of MIC/2 and MIC/5, the extracts of P. nitida and G. kola improved the antibacterial activities of some commonly used antibiotics suggesting their synergistic effects with the tested antibiotics. The results of this study suggest that the tested plant extracts and mostly those from P. nitida, G. lucida and G. kola could be used alone or in association with common antibiotics in the fight of bacterial infections involving MDR strains.

Antitubercular and Phytochemical Investigation of Methanol Extracts of Medicinal Plants Used by the Samburu Community in Kenya

Purpose: To determine the potential benefits of nine medicinal plants used by the Samburu community for the treatment of tuberculosis.Methods: The extract was tested against four strains of Mycobacteria namely; Mycobacterium tuberculosis (Mtb), M. Kansasii (Mk), M. fortuitum (Mf), and M. smegmatis (Ms) using BACTEC MGIT960 system. The crude extracts were also analyzed for the presence of phytochemical constituents. Results: Both the extracts of Scadoxus multiflorus and Acacia nilotica showed strong antimycobacterialactivity against the four tuberculosis-causing strains. Eurphobia scarlatina was the most active against both the slow (Mtb and Mk) and the fast (Mf and Ms) growers with Zero GUs at 0.5mg/ml. Phytochemical screening indicated presence or absence of tannins, saponins and flavonoids, terpenoids, cardiac glycosides and alkaloids in the extracts. Conclusion: The data suggest that some of the methanol extracts could be a rich source of antituberculosis agents. The results further show that there is some merit in the use of some of the plants studied in alternative medical practice. Pharmacological and toxicological studies of the active plants are still under investigation.Keywords: Medicinal plants, Methanol extract, Antituberculosis, Samburu.

NF-κB Inhibitory Activities of the Methanol Extracts and Some Constituents therein of Some Vietnamese Medicinal Plants

Eighty-seven methanol extracts of medicinal plants, most of them are currently used in Vietnamese oriental medicine, were screened for NF-κB inhibitory activity. Seven methanol extracts showed strong to moderate inhibitory activity. These include the extracts of Crinum latifolium (leaves), Evodia rutaecarpa (fruits), Polygonum cuspidatum (rhizoma), Perilla ocymoides (leaves), Rubia cordifolia (leaves), Scutellaria barbata (leaves) and Sparganium stenophyllum (leaves). The NF-κB inhibitory activities of several metabolites isolated from some of these plants were also reported.

Further screening of Venda medicinal plants for activity against HIV type 1 reverse transcriptase and integrase

The use of medicinal plants for AIDS-related conditions is common in South Africa. In order to establish an antiviral rationale for the use of these plants we screened fractions of the methanol extracts of medicinal plants for activity against HIV-1 reverse transcriptase (RT) and integrase (IN). The n-butanol fraction obtained from the crude methanol extracts of the roots of Bridelia micrantha (Hochst) Baill. (Euphorbiaceae) was observed to be as the most active inhibiting the RNA-dependent-DNA polymerization (RDDP) activity of HIV-1 RT with an IC50 of 7.3 �g/ml. However, it had no activity on the 3’-end processing activity of HIV integrase. Bioassay-guided fractionation of the n-butanol fraction yielded friedelin and �-sistosterol, which did not inhibit the RDDP of RT or 3’-end processing functions of IN even at a concentration of 500 �M. An uncharacterized fraction obtained in the bioassay-guided fractionating process inhibited the RDDP with an IC50 of 9.6 �g/ml, but had no inhibition on IN. Phytochemical screening indicated the presence of flavonoids and tannins in the uncharacterized fraction.