Screening the antimicrobial potential of twelve medicinal plants against venereal diseases causing pathogens

The antimicrobial potential of selected ethnomedicinal plants in traditional healers of Silent valley, Palakkad district of Kerala, India against venereal diseases causing pathogens. Twelve medicinal plants and their parts were collected from the various places of Silent Valley, Kerala, India. These plant parts were dried and mixed with different kinds of solvents respectively hexane, chloroform, methanol and water. In this study, six microbial strains were selected, in which five bacterial and a fungal strain. Among the bacterial strains, two strains were gram positive and three strains for gram negative bacteria. Totally, twelve medicinal plant parts mixed with various solvents were treated against the selected pathogenic organisms. Among them, methanolic extract of A. occidentate, C. indica, H. rosa-sinensis and M. oleifera exhibited excellent antibacterial activity than other parts of plants and standard drugs. As well as, methanolic extract of H. rosa-sinensis showed good antifungal activity against C. albicans. While,the least inhibition was noted with aqueous extract of C. indica against S. aureus. The MIC ranges from 0.78μg/ml to 50μg/ml and MBC/MFC 1.52μg/ml to 50μg/ml. The methanolic flower extract of H. rosa-sinensis has showed effective zone of inhibition against all the pathogens, particularly N. gonorrhoeae (30 mm) and C. albicans (26mm), than other extracts and standard drugs. Therefore, we concluded that, flower extract had potential therapeutic activity against venereal diseases. This research will be helpful to discover the new therapeutic drug molecule in Pharmaceutical sectors.     

Screening of some Australian Flacourtiaceae species for in vitro antioxidant,cytotoxic and antimicrobial activity

A total of 27 methanol extracts obtained from different plant parts of 10 species of rain forest trees belonging to four genera of the Flacourtiaceae and originating from Australia were investigated. In vitro cytotoxicity was measured by an ATP Lite-M assay method against the mouse P388 lymphocytic leukemia cell line. The total antioxidant activity has been assessed based on scavenging activity of stable ABTS free radicals. The minimum inhibition concentration (MIC) was determined by the dilution method performed in 96 well plates against four different microbes. The leaf extract of Casearia sp. (RB 3051), mature stem extract of Casearia grayi and stem extract of Scolopia braunii were found to have most antioxidant activity (IC₅₀=2.9 μg/ml), cytotoxic activity (LC₅₀=0.89 μg/ml) and antimicrobial activity against all four different microbes, respectively. The results obtained suggested that among the four genera studied Casearia is the most promising in respect of finding significant antioxidant, cytotoxic and also antimicrobial activity.     

New antimicrobial anthraquinone 6,61-bis (1,5,7-trihydroxy-3-hydroxymethylanthraquinone) isolated from Streptomyces sp. isolate ERI-26

The present report is about Streptomyces sp. isolate ERI-26 isolated from the soil sample of Nilgiri forest, Western Ghats. The methanol extract of ERI-26 showed good antimicrobial activity against tested microbes. The antimicrobial novel anthraquinones were purified by bioactivity-guided fractionation using a silica gel column and preparative HPLC. The compound was characterized and identified by UV, IR, NMR and MASS spectral data. The compound named as 6,6¹-bis (1,5,7-trihydroxy-3-hydroxymethylanthraquinone), showed significant antimicrobial activities against tested microbes. The isolated compound inhibited the tested bacterial growth, Staphylococcus aureus at 62.5 μg/ml, Staphylococcus epidermidis at 15.62 μg/m, Bacillus subtilis at 62.5 μg/ml, fungi; Trichophyton mentagrophytes at 15.62 μg/m Trichophyton simii at 15.62 μg/ml, Aspergillus niger at. 7.81 μg/ml, Aspergiller flavus at 3.90 μg/ml, Trichophyton rubrum 296 at 62.5 μg/ml, T. rubrum 57/01 at 7.81 μg/ml, Magnaporthe grisea at 15.62 μg/ml. and Botrytis cinerea at 3.90 μg/ml. Isolated anthraquinone compound and its antimicrobial activity were newly reported.     

A comparison of the pharmacological properties of garden cultivated and muthi market-sold Bowiea volubilis

Biological activities of petroleum ether (PE), dichloromethane (DCM), 70% ethanol (EtOH) and water extracts of Botanical Garden-grown (BG) and muthi market-sourced (MM) Bowiea volubilis bulbs were compared. Bulb extracts were subjected to the microdilution technique using five test organisms for antimicrobial activity and cyclooxygenase (COX-1 and -2) inhibition as well as the Ames test for potential mutagenicity. Overall, both the MM and BG bulb extracts demonstrated a comparatively weak antimicrobial potency. The best minimum inhibitory concentration (MIC: 1.56 mg/ml) was detected in the MM bulb water extract against Candida albicans. In both MM and BG bulbs, 63% of the extracts, particularly the non-polar solvent extracts, exhibited a high (> 70% inhibition) COX-1 and -2 inhibitory activity. Both MM and BG bulb extracts were not mutagenic against the Salmonella typhimurium TA98 tester strain. Current findings indicate the potential substitution of cultivated B. volubilis bulbs (BG) for the wild population (MM) which is often utilized and preferred in traditional medicine. Inevitably, this will contribute to the conservation of the species as the strain on the wild population due to overharvesting will be alleviated.     

Antimicrobial activity of highly stable silver nanoparticles embedded in agar-agar matrix as a thin film

Highly stable silver nanoparticles (Ag NPs) in agar-agar (Ag/agar) as inorganic-organic hybrid were obtained as free-standing film by in situ reduction of silver nitrate by ethanol. The antimicrobial activity of Ag/agar film on Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Candida albicans (C. albicans) was evaluated in a nutrient broth and also in saline solution. In particular, films were repeatedly tested for antimicrobial activity after recycling. UV-vis absorption and TEM studies were carried out on films at different stages and morphological studies on microbes were carried out by SEM. Results showed spherical Ag NPs of size 15-25 nm, having sharp surface plasmon resonance (SPR) band. The antimicrobial activity of Ag/agar film was found to be in the order, C. albicans > E. coli > S. aureus, and antimicrobial activity against C. albicans was almost maintained even after the third cycle. Whereas, in case of E. coli and S. aureus there was a sharp decline in antimicrobial activity after the second cycle. Agglomeration of Ag NPs in Ag/agar film on exposure to microbes was observed by TEM studies. Cytotoxic experiments carried out on HeLa cells showed a threshold Ag NPs concentration of 60 μg/mL, much higher than the minimum inhibition concentration of Ag NPs (25.8 μg/mL) for E. coli. The mechanical strength of the film determined by nanoindentation technique showed almost retention of the strength even after repeated cycle.     

Preventive effect of Ligularia fischeri on inhibition of nitric oxide in lipopolysaccharide-stimulated RAW 264.7 macrophages depending on cooking method

Background

Ligularia fischeri (common name Gomchwi) is known for its pharmaceutical properties and used in the treatment of jaundice, scarlet-fever, rheumatoidal arthritis, and hepatic diseases; however, little is known about its anti-inflammatory effect. In this study the influence of blanching and pan-frying on the anti-inflammatory activity of Ligularia fischeri (LF) was evaluated.

Results

Fresh LF and cooked LF showed no significant effect on the viability of macrophages after 24 h incubation. Fresh LF was found to be the most potent inhibitor of nitric oxide (NO) production at 100 μg/ml, while pan-fried LF showed little inhibitory effect on lipoloysaccharide (LPS) stimulated murine machrophage RAW264.7 cells. In contrast with its effect on NO production, pan-fried LF showed significant attenuation of the expression of inducible nitiric oxide synthase (iNOS) compared with fresh LF. In the cooking method of LF, PGE₂ production was not affected in the LPS-induced RAW 264.7 cells. In LPS-induced RAW 264.7 cells, pretreatment by fresh and cooked LF increased COX2 mRNA expression. The 3-O-caffeoylquinic acid content of blanching and pan-frying LF increased by 4.92 and 9.7 fold with blanching and pan-frying respectively in comparison with uncooked LF.

Conclusions

Regardless of the cooking method, Ligularia fischeri exhibited potent inhibition of NO production through expression of iNOS in LPS-induced RAW264.7 cells.     

Antimicrobial activity and phytochemical screening of Ocimum americanum L extracts against pathogenic microorganisms

The aim of the present study is to assess the antimicrobial activities of various leaf extracts of Ocimum americanum were tested against pathogenic microorganisms. Preparation of different extracts viz., aqueous, acetone, ethyl acetate and methanol through soxhlet extraction method. Various extracts were investigated against MTCC strains of Bacillus cereus, Clostridium penfrigens, Klebsilla pnemoniae, Salmonella paratyphi, Candida albicans and Aspergillus niger by agar well diffusion and disc diffusion methods. Minimum inhibitory concentration (MIC), Minimum Bactericidal/Fungicindal Concentration (MBC/MFC) were determined through micro dilution method. Elucidation of phytochemicals and functional groups were observed by HPLC and FT-IR respectively. Ethyl acetate leaf extract of O.americanum showed significant antimicrobial activity against the all tested pathogens in agar well diffusion method in which B.cereus (17 mm) was observed high zone of inhibition. Whereas lowest inhibition was observed in aqueous extract against C.pentrigens (7 mm). The ranges of MIC values from 0.78 μg/ml to 50 μg/ml and MBC/MFC 1.56 μg/ml to 50 μg/ml were observed. Phytochemicals such as alkaloids, steroids, saponins, flavonoids, tannins, terepenes, phenolic compounds cardiac glycosides were detected. Saponinns, flavonoids, tannins, phenolic compounds were observed in only ethyl acetate leaf extracts. Functional group of the leaf extracts was exhibited by FTIR and HPLC analysis of the ethyl acetate leaf extract was elutated at six peaks. Based on the results we concluded that ethyl acetate leaf extract of O.americanum has proved to be potentially effective than the other extracts. Therefore, ethyl acetate leaf extract of O.americanum could act as antimicrobial agent and further studies are recommended for isolation of compounds and toxicological studies.     

Nanoparticles combined with cefixime as an effective synergistic strategy against Salmonella enterica typhi

Enteric fever caused by Salmonella typhi has been the most crucial health issue in rural people, especially in Southeast Asia and Africa. Another disease, Salmonellosis, caused by a large group of bacteria of the genus Salmonella, cause substantial economic loss resulting from mortality and morbidity. Higher concentration and repeated use of antibiotics to treat these diseases will likely develop antibiotic resistance among the microbes. The nanoparticle has good penetration power and can kill microbes. Combining two strategies by using nanoparticles with antibiotics kills microbes and reduces the chances of the development of antibiotics resistance. Silver, Nickel, Copper, and Zinc oxide Nanoparticles were chemically synthesized and characterized in this study. Silver nanoparticles at a concentration of 10 µg/ml inhibit all the strains under study.In comparison, silver nanoparticles (16.90 µg/ml), Nickel nanoparticles (83 µg ml^?1), Copper nanoparticles (249 µg ml^?1), and Zinc oxide (1614 µg ml^?1) along with 50 µg/ml cefixime gave maximum zone of inhibition of 35 mm, 19 mm, 31 mm and 23 mm respectively. The antimicrobial assay showed that silver nanoparticles presented good antibacterial performance against all multi-drug-resistant pathogenic Salmonella sp alone as well as in combinations. The present study proved that silver nanoparticles at the lowest concentration along with cefixime could be a possible alternative to control the multi-drug-resistant pathogens.     

The antimicrobial effects of propolis collected in different regions in the Basque Country (Northern Spain)

The antimicrobial activity of 19 propolis extracts prepared in different solvents (ethanol and propylene glycol) (EEP/PEP), was evaluated against some bacterial and fungal isolates using the agar-well diffusion method. It was verified that all the samples tested showed antimicrobial activity, although results varied considerably between samples. Results revealed that both types of propolis extracts showed highly sensitive antimicrobial action against Gram-positive bacteria and fungi at a concentration of 20% (Staphylococcus aureus, Streptococcus mutans, Candida albicans and Saccharomyces cerevisae) with a minimal inhibitory concentration (MIC) ranging from 0.5 to 1.5 mg/ml, with a moderate effect against Streptococcus pyogenes (MIC from 17 to 26 mg/ml). To our knowledge, this is the first study showing elevated antimicrobial activity against Gram-negative bacteria [Salmonella enterica (MIC from 0.6 to 1.4 mg/ml)] and lesser activity against Helicobacter pylori (MIC from 6 to 14 mg/ml), while Escherichia coli was resistant. This concluded that the Basque propolis had a strong and dose-dependent activity against most of the microbial strains tested, while database comparison revealed that phenolic substances were responsible for this inhibition, regardless of their geographical origin and the solvent employed for extraction. Statistical analysis showed no significant differences (P ≤ 0.05) between EEP and PEP extracts.     

What makes Allium species effective against pathogenic microbes?

The antimicrobial activity of garlic (Allium sativum L.) has been known since ancient times. The first citation dates back to the Egyptian period of fifteenth century BC when garlic was reported to be used in folk medicine as a remedy for microbial infections. Scientific investigations on garlic started in 1858 with the work of Pasteur who first noted antibacterial properties of garlic extracts. From that date to the discovery of antibiotics, garlic has been used against amoebic dysentery and epidemic diseases such as typhus, cholera, diphtheria, and tuberculosis. But what makes garlic and Allium species effective against pathogenic microbes? The volatile allicin and other thiosulfinates, giving pungency to Allium plants, are well-studied antimicrobial agents. The thiosulfinates can decompose to form additional sulfur constituents, including diallyl, methyl allyl, and dipropyl mono-, di-, tri- e tetra-sulfides, and (E)- and (Z)-ajoene without losing antimicrobial activity. Besides these compounds, onion and garlic are characterized by polar compounds of steroidal and phenolic origin, often glycosilated, not pungent and more stable during cooking, showing also antimicrobial activity. Recently, there has been increasing scientific attention given to such compounds. Nitrogen organic compounds, like alkaloids and polypeptides, have also been isolated from these plants and have shown antimicrobial activity. In this paper, the literature about the major volatile and non-volatile organic compounds of garlic and other Allium plants has been reviewed. Particular attention is given to the compounds possessing antimicrobial activity and to the correlation between the observed activity and the chemical structure of the tested compounds.     

Comparative assessment of biological activities of different parts of halophytic plant Tamarix articulata (T. articulata) growing in Saudi Arabia

Owing to extremely high salinity and harsh environmental conditions, T. articulata is one of the most abundant wild plants growing in the deserts of Saudi Arabia. Such plants may contain novel compounds to display promising biological activities. Here, in this study, we evaluate the biological activities of methanolic extracts of fresh leaves, dry leaves, stem, and roots of T. articulata. The antioxidant activity was determined by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and total phenolic and flavonoid content were determined using standard colorimetric methods. Whereas antimicrobial and ant-proliferative activities were determined by standard well-diffusion and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) methods, respectively. Our results demonstrate that all methanolic extracts of T. articulata showed antioxidant activity, however, the methanolic extract of dry leaves exhibits promising antioxidant effect with IC₅₀ value 49.08 ± 1.98, which was strongly supported by total phenolic (409.92 ± 6.03 mg GAE/g DW) and flavonoid (177.71 mg QE/g DW) content. Although, antimicrobial activity was also exhibited by all the methanolic extracts, however, methanolic extract of dry leaves exhibits promising antimicrobial activity in Gram-positive bacteria Staphylococcus epidemidis. Furthermore, MTT assay revealed that all methanolic extracts exhibit antiproliferative activity in MCF-7 (breast cancer) and RKO (colorectal cancer) cells with IC₅₀ values ranges from 219 ± 5.112 µg/ml to 253 ± 5.231 µg/ml and 220 ± 4.330 µg/ml to 325 ± 6.213 µg/ml, respectively. However, the most promising antiproliferative effect was displayed by methanolic extract of dry leaves with IC₅₀ values 219 ± 5.112 µg/ml and 220 ± 4.330 µg/ml, respectively. In summary, these findings provide evidence that T. articulata has promising biological activities and can be used for many pharmaceutical activities in the future.     

In vitro assessment of Thimerosal cytotoxicity and antimicrobial activity

BackgroundThimerosal (Merthiolate) is a well-known preservative used in pharmaceutical products, the safety of which was a matter of controversy for decades. Thimerosal is a mercury compound, and there is a debate as to whether Thimerosal exposure from vaccination can contribute to the incidence of mercury-driven disorders. To date, there is no consensus on Thimerosal safety in Vaccines. In 1977, a maximum safe dose of 200 μg/ml (0.5 mM) was recommended for Thimerosal by the WHO experts committee on biological standardization. Up-to-date guidelines, however, urge national control authorities to establish their own standards for the concentration of vaccine preservatives. We believe such safety limits must be studied at the cellular level first. The present study seeks a safe yet efficient dose of Thimerosal exposure for human and animal cells and control microorganism strains.MethodsThe safety of Thimerosal exposure on cells was analyzed through an MTT cell toxicity assay. The viability of four cell types, including HepG2, C2C12, Vero Cells, and Peripheral blood mononuclear cells (PBMCs), was examined in the presence of different Thimerosal concentrations and the maximum tolerable dose (MTD) and the half maximal inhibitory concentration (IC50) values for each cell line were determined. The antimicrobial effectiveness of Thimerosal was evaluated on four control strains, including Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, and Aspergillus brasiliensis, to obtain the minimum inhibitory concentration (MIC) of Thimerosal. The MIC test was performed in culture media and under optimal growth conditions of microorganisms in the presence of different Thimerosal concentrations.ResultsThe viability of all examined cell lines was suppressed entirely in the presence of 4.6 μg/ml (12.5 μM) of Thimerosal. The MTD for HepG2, C2C12, PBMC, and Vero cells was 2, 1.6, 1, and 0.29 μg/ml (5.5, 4.3, 2.7 and 0.8 μM), respectively. The IC50 of Thimerosal exposure for HepG2, C2C12, PBMC, and Vero cells was 2.62, 3.17, 1.27, and 0.86 μg/ml (7.1, 8.5, 3.5 and 2.4 μM), respectively. As for antimicrobial effectiveness, the growth capability of Candida albicans and Staphylococcus aureus was suppressed entirely in the presence of 6.25 µg/ml (17 μM) Thimerosal. The complete growth inhibition of Pseudomonas aeruginosa in culture media was achieved in 100 µg/ml (250 µM) Thimerosal concentration. This value was 12.5 µg/ml (30 μM) for Aspergillus brasiliensis.ConclusionAccording to our results Thimerosal should be present in culture media at 100 μg/ml (250 µM) concentration to achieve an effective antimicrobial activity. We showed that this amount of Thimerosal is toxic for human and animal cells in vitro since the viability of all examined cell lines was suppressed in the presence of less than 5 μg/ml (12.5 μM) of Thimerosal. Overall, our study revealed Thimerosal was 333-fold more cytotoxic to human and animal cells as compared to bacterial and fungal cells. Our results promote more study on Thimerosal toxicity and its antimicrobial effectiveness to obtain more safe concentrations in biopharmaceuticals.     

Development of alternative medicinal sources from golden berry,bananas and carrot wastes as antioxidant,cytotoxic and antimicrobial agents

Discovering new medicinal sources from food wastes is a beneficial and valuable way instead of their disposal. Fruits and vegetables waste can be an inexpensive and readily available source of bioactive compounds to be used in pharmaceutical industries. The aim of this study is to highlight the in vitro antioxidant, cytotoxic, and antimicrobial activities of the total extracts of banana peels (Musa acuminate), carrot peels (Daucus carota) and golden berry husk (Physalis peruviana) besides evaluating their in vivo acute and chronic toxicity profiles as well as their antimutagenic activity. Also, we investigated their phenolic and flavonoid contents spectrophotometrically and by HPLC. Results showed that D. carota peels revealed the highest antioxidant activity (29.903 mg TE/g) using DPPH free radical scavenging assay. Cytotoxic outcomes (SulphoRhodamine-B method) showed that the highest cytotoxic activity of M. acuminate peels (IC₅₀: 20.7 μg/mL) was exerted on HEPG2 cell line, where D. carota peels (IC₅₀: 18.8 μg/mL) showed the highest cytotoxic activity on PC-3 cell line. In addition, pH. peruviana husk (IC₅₀: 10.5 ± 1.0 μg/mL) showed a potent cytotoxic activity on HCT-116 that is non-significant from the standard Doxorubicin (IC₅₀: 11.5 ± 0.8 μg/mL). For the antimicrobial activity (agar diffusion assay), most of the total extracts revealed notable activities against all tested pathogens relative to the standards; ciprofloxacin and ketoconazole, specially Ph. peruviana husk that showed a potent inhibitory activity (inhibition zone diameter of 29 mm.) against C. albicans even more than the standard ketoconazole (inhibition zone diameter of 28 mm.). These promising biological activities are mainly related to the high content of flavonoids and phenolic compounds identified and quantified in their total extracts. Moreover, the three extracts proved their in vivo safety on the short and long terms as well as their possible antimutagenic effect on the genotoxicity of the drug cyclophosphamide (CP) in both bone marrow cells and spermatocyte cells.     

Cytotoxic,antimicrobial activities,AChE and BChE inhibitory effects of compounds from Tanacetum chiliophyllum (Fisch. & Mey.) Schultz Bip. var. oligocephalum (D.C.) Sosn. and T. chiliophyllum (Fisch. & Mey.) Schultz Bip. var. monocephalum Grierson

Tanacetum L. species traditionally used for insecticidal purposes as well as in folk medicine for their antitumor, antimicrobial, antifungal activities. In our previous study a novel sesquiterpene lactone and triterpene lactone together with 12 known flavonoids, coumarin and a triterpene were isolated from T. chiliophyllum var. oligocephalum and T. chiliophyllum var. monocephalum extracts which have insecticidal and antimicrobial activity. In this study, cytotoxic, antimicrobial activities and acetylcholinesterase (AChE), butyrylcholinesterase (BChE) inhibitory effects of pure compounds isolated from these plants were investigated. The tested compounds showed AChE and BChE inhibition which ranged between 7.20–80.37% and 9.19%–76.99% respectively. The highest AChE and BChE inhibition was observed for ulubelenolide which afforded 80.37% and 76.99% inhibition respectively. The cytotoxic effect of the compounds ranged between 22.34–49.77 μg/mL IC₅₀ values. Highest cytotoxic activity was observed against MCF-7 and HEK 293 cell line by 5–hydroxy-3′,4′,7-trimethoxy flavone and 5-hydroxy-3′,4′,6,7-tetramethoxyflavone that produced 25.80 ± 0.17 and 22.34 ± 0.70 IC₅₀ values respectively. Compounds eupatilin, cirsilineol, 5–hydroxy-3′,4′,7-trimethoxy flavone and ulubelenolide showed significant antimicrobial effect on C. albicans with 7.8 μg/mL MIC. The new compound ulubelenolide afforded high AChE and BChE inhibition as well as high antifungal activity. In our opinion activity of this substance should be evaluated further against other fungal species.     

In-vitro antioxidant,antimutagenic and cancer cell growth inhibition activities of Rhododendron arboreum leaves and flowers

In the current investigation, the active principles of the methanol extracts of Rhododendron arboreum leaves (MEL) and flowers (MEF) were investigated with the help of ultra-high performance liquid chromatography (UHPLC), amino acid analyzer and gas chromatography mass spectrometry (GC-MS). UHPLC revealed different polyphenols present in the extracts. GC-MS identified 20 phytochemicals in leaves and 17 in the flowers, whereas, amino acid analyzer confirmed 11 amino acids in leaves and 10 in the flowers. The extracts were subjected to the investigation of biological activity through analysis of antioxidant activity in different in vitro assays, antimutagenic activity in Ames assay and cancer cell growth inhibition activity by MTT (3-4,5 dimethylthiazol-2,5 diphenyltetrazolium bromide) assay. MEL showed higher antioxidant activity in lipid peroxidation inhibition assay (95.32 ± 0.37%) than MEF (77.09 ± 4.17%) with IC₅₀103.6 µg/ml for MEL and 271.17 µg/ml for MEF. In nitric oxide scavenging assay, an activity of 94.46 ± 0.32% (IC₅₀ 150.13) was observed in MEF followed by 83.71 ± 0.74% (IC₅₀ 179.52) in MEL. The antimutagenic activity of both the extracts was evaluated against sodium azide, 4-nitro-O-phenylenediamine and 2-aminofluorene mutagens in TA-98 and TA-100 strains of Salmonella typhimurium. The analysis was carried out using pre- and co-incubation modes. However, both extracts were observed to possess considerable antimutagenic activity against different known mutagens, flowers came out to be more effective than the leaves in terms of % inhibition. The extracts also exhibited significant cancer cell growth inhibition activity, when tested against 3 cancer cell lines namely, Human cervical cancer cell line (HeLa), Breast cancer cell line (MCF7) and Lung cancer cell line (A549). In case of HeLa and A549, MEL showed higher activity of 64.62 ± 2.65 and 75.08 ± 1.68% as compared to 53.11 ± 2.84 and 45.92 ± 2.43% in MEL, respectively. The EC₅₀ values for MEL in HeLa and A549 were noted to be 232.76 and 155.38 µg/ml, respectively, whereas, MEF had EC₅₀ of 395.50 µg/ml in HeLa and 660.26 µg/ml in A549. Further, MEF showed higher cytotoxicity in MCF7 cell line (84.93 ± 1.17%) followed by the MEL (73.57 ± 1.27%) with EC₅₀ value of 95.16 µg/ml for MEF followed by 172.19 µg/ml for MEL. The biological activities of the extracts can be attributed to the phyto-constituents identified by sophisticated instruments.The biological activities of the extracts can be attributed to the active principles identified by sophisticated instruments.     

2,2′-Dithienyl diselenide pro-oxidant activity accounts for antibacterial and antifungal activities

The aim of this study was to explore if 2,2′-dithienyl diselenide (DTDS) pro-oxidant activity is related to its antibacterial and antifungal actions. The antimicrobial activity of DTDS against bacterial and fungal was investigated in the broth microdilution assay (3.02–387 μg/ml). Additionally, the survival curve of microorganisms in the presence of DTDS (12.09–193.5 μg/ml) was performed. The involvement of pro-oxidant activity in the DTDS antimicrobial action was investigated by supplementing the growth medium with 10 mM glutathione or ascorbic acid in the disk diffusion technique (0.64–640 μg DTDS/discs). The levels of reactive species (RS) induced by 25 mM DTDS were also determined. The results demonstrated that DTDS was effective in preventing the Gram-positive bacteria and Candida albicans growth. The minimum inhibitory concentration, twice and half concentrations of DTDS confirmed that the activity of compound was bactericidal for some microorganisms (Enterococcus faecalis, and Staphylococcus saprophyticus), bacteriostatic for Bacillus cereus and fungistatic for C. albicans. Antibacterial and antifungal actions of DTDS are related to the increase of reactive species levels. The presence of antioxidants in the growth medium avoided the DTDS antimicrobial action. In conclusion, DTDS showed promising antibacterial and antifungal actions, possibly related to its pro-oxidant activity.     

Antimicrobial and cytotoxic activities of the crude extracts of Dietes bicolor leaves,flowers and rhizomes

The crude extracts of Dietes bicolor leaves, flowers and rhizomes were subjected to comparative antimicrobial screening against two Gram-positive, two Gram-negative bacteria and four fungal strains using the agar well diffusion method. The minimum inhibitory concentrations (MIC) of the tested extracts were also determined. Furthermore, the cytotoxic activity was evaluated. D. bicolor extracts generally demonstrated notable broad spectrum antimicrobial activities (MIC values ≤ 500 μg/mL) against all tested pathogens. D. bicolor leaf extract showed potent broad spectrum antimicrobial activity with MIC values ranging between 0.24 and 31.25 μg/mL against all tested pathogens. Moreover, the flowers extract exhibited promising antimicrobial activities, displaying MIC values ranging between 1.95 and 125 μg/mL against the tested bacteria and fungi. However, the rhizomes extract showed moderate antimicrobial activity with MIC values ranging between 31.25 and 500 μg/mL. Despite the potent antimicrobial activity of D. bicolor extracts, they were ineffective as cytotoxic agents against nine tested cancer cell lines, displaying 50% inhibitory concentration (IC₅₀) values above 100 μg/mL. The reported potent antimicrobial activity along with the lack of measurable cytotoxic activity indicated that the antimicrobial activity of D. bicolor crude extracts is mediated through a mechanism other than cytotoxicity. These results suggest that D. bicolor can act as a potential source for natural antibacterial and antifungal agents with a good safety profile at a preliminary level.     

A new fused tetracyclic heterocyclic antioxidant from Serratia sp. PAMC 25557

A new fused tetracyclic heterocyclic compound, (4bR,10bR)-4b-hydroxy-10b,12-dihydrodibenzo[c,h][2,6]naphthyridine-5,11(4bH,6H)-dione (1), and a known compound, butyl 2-[(benzoyloxy)methyl]benzoate, spatozoate 2, were isolated from the broth culture of Serratia sp. PAMC 25557. The structure of 1 was determined by analyzing spectroscopic data. Compound 1 did not exhibit antimicrobial activity against Escherichia coli, Staphylococcus aureus, or Candida albicans. In addition, up to 100 μg/ml compound 1 did not show any toxicity against Artemia salina larvae. However, compound 1 showed DPPH free radical scavenging activity (IC₅₀ = 16.7 ± 0.34 μg/ml). This was the first report of spatozoate isolation from bacterial sources.     

Onion and garlic extracts lessen cadmium-induced nephrotoxicity in rats

Cadmium (Cd) is a well-known nephrotoxicant inducing kidney damage via oxidative stress. Since kidney is the critical target organ of Cd toxicity, this study was designed to evaluate the protective effects of onion (Allium cepa L.) and garlic (Allium sativum L.) aqueous extracts on Cd-induced renal oxidative stress in male Wistar rats. The control group received double distilled water alone and Cd group was challenged with 3CdSO₄ · 8H₂O (as Cd) (1.5 mg/100 g bw/day per oral) alone. Extract-treated groups were pre-treated with varied doses (0.5 ml and 1.0 ml/100 g bw/day per oral) of onion and/or garlic extract for 1 week after which they were co-treated with Cd (1.5 mg/100 g bw/day per oral) for 3 weeks. The results showed that the levels of renal lipid peroxidation (LPO) and glutathione-S transferase (GST) were significantly (P < 0.001) increased in rats that received Cd alone relative to the control group. More so, the levels of renal glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and Na⁺/K⁺-ATPase were significantly (P < 0.001) decreased in rats that received Cd alone. Treatment of Cd-intoxicated rats with varied doses of onion and/or garlic extract significantly (P < 0.05) restored the alterations in these parameters relative to the group that received Cd alone. While treatment with high dose of onion extract exerted a significant dose-dependent restoration of these parameters, treatment with high dose of garlic elicited a pro-oxidant effect, relative to their respective low dose. Our study suggests that onion and garlic extracts may exert their protective effects via reduction in LPO and enhanced antioxidant defense. These extracts may, therefore, be useful nutritional option in alleviating Cd-induced renal damage.     

In vitro inhibitory potential of Cynara scolymus,Silybum marianum,Taraxacum officinale,and Peumus boldus on key enzymes relevant to metabolic syndrome

Boldocynara®, a proprietary dietary supplement product consisting of the plants Cynara scolymus, Silybum marianum, Taraxacum officinale, and Peumus boldus, used to promote functions of the liver and the gallbladder. It was the aim of the present study to look from a different perspective at the product by investigating the in vitro potential of Boldocynara® as a combination product and its individual extracts on key enzymes relevant to metabolic syndrome. Peumus boldus extract exhibited pronounced inhibitory activities on α-glucosidase (80% inhibition at 100 µg/ml, IC₅₀: 17.56 µg/ml). Silybum marianum had moderate pancreatic lipase (PL) inhibitory activities (30% at 100 µg/ml) whereas Cynara scolymus showed moderate ACE inhibitory activity (31% at 100 µg/ml). The combination had moderate to weak effects on the tested enzymes. In conclusion, our results indicate some moderate potential of the dietary supplement Boldocynara® and its single ingredients for the prevention of metabolic disorders.