Source Of Novel Agents Research Articles

The petroleum ether extracts of Chloranthus fortunei(A. Gray) Solms-Laub.with bioactivities: A rising source in HCC drug treatment

Ethnopharmacological relevanceHepatocellular Carcinoma (HCC) is an aggressive killer worldwide with high incidence and mortality. The herb Chloranthus fortunei (A. Gray) Solms-Laub is known as “Si Ji Feng” and is classified as a Feng-type medicine in classic Yao medicines. According to Yao's medical beliefs, Chloranthus fortunei has the functions of dispelling Feng, regulating qi, detoxifying, promoting blood circulation, etc. Folk uses its decoctions to treat stagnant liver conditions, such as liver abscesses, cirrhosis, hepatitis, and liver cancer. However, the bioactivity and mechanisms of Chloranthus fortunei extract against HCC have not been reported. Aim of the studyTo investigate the anti-HCC bioactivity and potential mechanism of the extract of Chloranthus fortunei (CFS). Materials and methodsUsing 70% ethanol for reflux extraction of CFS resulted in the CFS ethanol extract, followed by sequential extractions with petroleum ether, chloroform, ethyl acetate, and n-butanol, yielding four fractions. The CCK-8 assay was utilized to examine the cytotoxic effects of 4 fractions on MHCC97-H and HepG2 cells, exploring the most effective component, namely petroleum ether extracts of CFS (PECFS). The major active ingredients of PECFS were identified using LC/MS technology, and the impact on cell proliferation and apoptosis in HCC cells was studied. The key genes and proteins in the pathway were validated using RT-PCR and Western blotting. BALB/c nude mice were chosen for tumor xenotransplantation and PECFS therapy. hinders the proliferation of HCC cells and promotes apoptosis. ResultsAmong the four fractions, it was found that PECFS have the highest antiproliferative activity against MHCC97-H and HepG2 cells (IC50 = 13.86, 10.55 μg/mL), with sesquiterpene compounds being the primary active constituents. The antiproliferative activity of PECFS on HCC cells was linked to the inhibition of cell cloning, invasion, and metastasis abilities, as well as the arrest of the cell cycle at the G2/M phase. Additionally, exerts pro-apoptotic effects on HCC cells by upregulating the pro-apoptotic protein Bax, downregulating the anti-apoptotic protein Bcl-2, and activating the expression of the Caspase family. Moreover, protein and m-RNA expression data showed that PECFS inhibits HCC cell proliferation and promotes apoptosis by regulating the PI3K/AKT/mTOR pathway. Besides, after PECFS treatment, tumor growth in nude mice was suppressed. ConclusionPECFS can inhibit the viability of HCC cells by acting on the PI3K/AKT/mTOR pathway, demonstrating anti-tumor potential. This study's findings suggest that PECFS may represent a promising source of novel agents for liver cancer treatment, providing scientific evidence for the traditional application of CFS in treating HCC.

In-vitro Antimicrobial Effects and Phytochemical Contents of Stingless Bee Meliponula beccarii Honey and Pollen from Baringo County, Kenya

Background: Afro-tropical stingless bees produce several products including honey, propolis, cerumen and pollen, which are widely used as traditional medicine and food. In Baringo County, Kenya stingless bee honey in particular is widely used as a traditional remedy for respiratory disorders, stomach disorders and oral thrush, commonly associated with bacterial and fungal infections. However, scientific data on the antimicrobial activities and phytochemical content of stingless bee products from Baringo is scarce. Objectives: The objective of this study was to investigate the in vitro antimicrobial activities and phytochemical content of Meliponula beccarii stingless bee honey and pollen from Baringo County. Materials and methods: Eleven honey and pollen samples were conveniently sampled from eleven wild occurring stingless bee nests in three ecologically distinct areas. Increasing concentrations of honey and pollen samples were then prepared and tested against H. influenzae, E. coli, MRSA and C. albicans using agar well diffusion assay. The broth microdilution test was further performed to determine the Minimum Inhibitory Concentrations (MICs) and Minimum Bactericidal Concentrations (MBCs). Standard qualitative methods were used to analyse the phytochemical contents of the honey and pollen samples. Data was analysed by two-way ANOVA and Tukey’s post-hoc tests. Results: in comparison to distilled water (negative control), the honey samples had a significantly higher mean zones of inhibition at concentration of 100% v/v against E. coli (9.0±4.7 mm vs 0 mm, p<0.0001, N=11), H. influenzae (11.1±5.0 mm vs 0 mm, p<0.0001, N=11), and MRSA (10.8±5.9 mm vs 0 mm, p>0.0001, N=11). However, compared to ciprofloxacin standard (30ug/ml), all the concentrations of honey samples had significantly lower mean zones of inhibition against H. influenzae (8.8±2.4 mm vs 25±0.58 mm, p<0.0001, N=11), E. coli (5.7±3.4 mm vs 31.7±1.5 mm, p<0.0001, N=11) and MRSA (8.1±2.8 mm vs 27±0 mm). All the honey samples did not exhibit activity against C. albicans even at 100% (v/v). The mean MICs against E. coli, H. influenzae and MRSA were 9.38% (v/v), 18.75% (v/v) and 18.75% (v/v), respectively. Notably, the honey samples exhibited bactericidal activity, only against MRSA with a mean MBC of 60.94% (v/v). All the pollen samples showed no antibacterial and antifungal activities against the tested micro-organisms. Qualitative analyses revealed that the honey and pollen samples of Meliponula beccarii contain alkaloids, phenolics, triterpenoids, flavonoids, saponins, tannins, glycosides and steroids, but not terpenoids. Conclusion: Some but not all Meliponula beccarii honey samples from Baringo County has antibacterial activities. The honey and pollen are rich in various phytochemical compounds. Our findings validate the use of Meliponula beccarii honey in traditional treatment of bacterial infections and its further investigation as a potential source of novel agents against drug resistant pathogenic bacteria.

Pharmacological Potentials and Nutritional Values of Tropical and Subtropical Fruits of India: Emphasis on their Anticancer Bioactive Components.

Fruits are an important dietary component, which supply vitamins, minerals, as well as dietary fiber. In addition, they are rich sources of various biological and pharmacologically active compounds. Among these, temperate fruits are well studied for their pharmacological potentials, whereas tropical/subtropical fruits are less explored for their health impacts. In India, most of the consumed fruits are either tropical or subtropical. This mini review aims to provide a health impact of major tropical and sub-tropical fruits of India, emphasizing their anticancer efficacy. In addition, the identified bioactive components from these fruits exhibiting anticancer efficacy are also discussed along with the patent literature published. The literature was collected from various repositories, including NCBI, ScienceDirect, Eurekaselect, and Web of Science; literature from predatory journals was omitted during the process. Patent literature was collected from google patents and similar patent databases. Tropical fruits are rich sources of various nutrients and bioactive components including polyphenols, flavonoids, anthocyanin, etc. By virtue of these biomolecules, tropical fruits have been shown to interfere with various steps in carcinogenesis, metastasis, and drug resistance. Their mode of action is either by activation of apoptosis, regulation of cell cycle, inhibition of cell survival and proliferation pathways, increased lipid trafficking or inhibiting inflammatory pathways. Several molecules and combinations have been patented for their anticancer and chemoprotective properties. Overall, the present concludes that Indian tropical/ subtropical fruits are nutritionally and pharmacologically active and may serve as a source of novel anticancer agents in the future.

Flavonoids from Marine-Derived Actinobacteria as Anticancer Drugs.

Flavonoids represent a large diverse group of natural products that are used as a traditional medicine against various infectious diseases. They possess many biological activities including antimicrobial, antioxidant, anti-inflammatory, anti-cancer and anti-diabetic activities. Commercially, flavonoids are mainly obtained from plants, however, several challenges are faced during their extraction. Microorganisms have been known as natural sources of a wide range of bioactive compounds including flavonoids. Actinobacteria are the most prolific group of microorganisms for the production of bioactive secondary metabolites, thus facilitating the production of flavonoids. The screening programs for bioactive compounds revealed the potential application of actinobacteria to produce flavonoids with interesting biological activities, especially anticancer activities. Since marine actinobacteria are recognized as a potential source of novel anticancer agents, they are highly expected to be potential producers of anticancer flavonoids with unusual structures and properties. In this review, we highlight the production of flavonoids by actinobacteria through classical fermentation, engineering of plant biosynthetic genes in a recombinant actinobacterium and the de novo biosynthesis approach. Through these approaches, we can control and improve the production of interesting flavonoids or their derivatives for the treatment of cancer.

Secondary metabolites (essential oils) from sand-dune plants induce cytotoxic effects in cancer cells

Ethnopharmacological relevanceDespite advances in modern therapeutic strategies, cancer remains the second leading cause of death worldwide. Therefore, there is a constant need to develop more efficient anticancer targeting strategies. The anticancer therapeutic proprieties of medicinal plants and their bioactive compounds have been reported for several years, making natural extracts and/or compounds derived from these a promising source of novel anticancer agents. Sand dune plants are subjected to severe environmental stresses, leading to the development of adaptations, including the production of secondary metabolites with a wide range of bioactivities, such as: anti-inflammatory, analgesic, antiseptic, hypoglycaemic, hypotensive, antinociceptive, antioxidant and anticancer.Aim of the study: The anticancer potential of sand dune plants remains under-investigated, so this research describes the characterisation of the composition of bioactive EOs from sand-dune plants of Peniche (Portugal), and assessment of their activity in vitro and potential mechanism of action. Materials and methodsEOs were extracted from six sand-dune species of plants from Peniche sand dunes: Crithmum maritimum L., Seseli tortuosum L., Artemisia campestris subsp. maritima (DC.) Arcang., Juniperus phoenicea var. turbinata (Guss.) Parl., Otanthus maritimus (L.) Hoffmanns. & Link, and Eryngium maritimum L.. EOs composition was fully characterised chemically using Gas Chromatography-Mass Spectrometry (GC-MS). The assessment of anticancer activity and mechanism of action was performed in vitro using breast and colorectal cancer 2D and 3D spheroid cell line models, through cell proliferation assay, western blotting analysis, and cell cycle analysis. ResultsEOs from the majority of the species tested (S. tortuosum, A. campestris subsp. maritima, O. maritimus, and E. maritimum) were mainly composed by hydrocarbon compounds (sequisterpenes and monoterpenes), showing antiproliferative activity in both 2D and 3D models. EO extracted from S. tortuosum and O. maritimus were identified as having the lowest IC50 values for both cell lines when compared with the other species tested. Furthermore, this antiproliferative activity was associated with increased p21 expression and induction of apoptosis. ConclusionsThe present study suggests that EOs extracted from S. tortuosum and O. maritimus present promising cytotoxic properties. Further evaluation of the extracts and their key components as potential anticancer agents should therefore be explored.

Invertebrates living in polluted environments are potential source of novel anticancer agents

Invertebrates living in polluted environments are potential source of novel anticancer agents

Codonopsis lanceolata attenuates allergic lung inflammation by inhibiting Th2 cell activation and augmenting mitochondrial ROS dismutase (SOD2) expression

Allergic asthma is a chronic inflammatory disease induced by the inhalation of allergens, which trigger the activation of T helper type 2 (Th2) cells that release Th2 cytokines. Recently, herbal medicines are being considered a major source of novel agents to treat various diseases. In the present study, we evaluated the anti-asthmatic effects of a Codonopsis lanceolata extract (CLE) and the mechanisms involved in its anti-inflammatory effects. Treatment with CLE reduced infiltration of inflammatory cells, especially eosinophils, and the production of mucus in lung tissues. Levels of Th2 cytokines, such as IL-4, IL-5, and IL-13, and chemokines were also decreased following treatment with CLE. Moreover, Th2 cell proportion in vivo and differentiation in vitro were reduced as evidenced by the decreased expression of GATA3+. Furthermore, the expression of superoxide dismutase (SOD)2, a mitochondrial ROS (mROS) scavenger, was increased, which was related to Th2 cell regulation. Interestingly, treatment with CLE increased the number of macrophages in the lungs and enhanced the immune-suppressive property of macrophages. Our findings indicate that CLE has potential as a novel therapeutic agent to inhibit Th2 cell differentiation by regulating mROS scavenging.

Anticancer activity of Adiantum capillus veneris and Pteris quadriureta L. in human breast cancer cell lines.

Breast cancer is the most common cancer worldwide that costs lives of millions of people every year. Plant products with potential anticancer activities have become a vital source of novel agents in treating cancer. Adiantum capillus veneris (ACV) and Pteris Quadriureta (PQ) are such traditional herbs with potential pharmacological properties. In this study, both crude methanol extract and gold nanoparticles of ACV and PQ were tested for their anticancer activities in MCF7 and BT47 cell lines. By using GC-MS, we have identified 23 and 28 bioactive compounds in ACV and PQ respectively. We analysed the effects of ACV and PQ nanoparticles on various proteins involved in cell cycle and apoptosis using western blotting and PCR. With the help of flow cytometry, we measured number of cells undergoing apoptosis. We found that both the crude extract and nanoparticles have anti-proliferative and apoptosis inducing properties against MCF7 and BT47 cell lines. We also performed molecular docking to check whether there were any interactions between proteins involved in apoptosis and cell cycle and bioactive compounds present in the plant extracts. By using docking analysis, we also showed that phytol and eicosapentaenoic acid present in ACV and PQ interact with Bcl2 and cyclin D1. These findings demonstrate that ACV and PQ possess anticancer activities by modulating proteins involved in cell cycle and apoptosis. ACV and PQ that effectively modulate various oncogenic molecules can be used as promising agent for cancer therapy.

Ciprofloxacin triggers the apoptosis of human triple-negative breast cancer MDA-MB-231 cells via the p53/Bax/Bcl-2 signaling pathway.

Fluoroquinolone antibiotics induce cytotoxicity in various cancer cell lines and may therefore represent a potentially important source of novel anticancer agents. The aim of the present study was to examine the effect of ciprofloxacin on the viability, redox balance, apoptosis, expression of p53, Bax and Bcl-2, cell cycle distribution and DNA fragmentation of triple-negative MDA-MB-231 breast cancer cells. The results of the present study demonstrated that ciprofloxacin decreases cell viability in a dose- and time-dependent manner. The half maximal inhibitory concentration values of ciprofloxacin in MDA-MB-231 cells following treatment for 24, 48 and 72h were 0.83, 0.14 and 0.03µmol/ml, respectively. Furthermore, it was demonstrated that ciprofloxacin altered the redox signaling pathway, as determined by intracellular glutathione depletion. The results of AnnexinV/propidium iodide staining revealed that ciprofloxacin triggered the apoptosis of MDA-MB-231 cells. Furthermore, cipfloxacin treatment stimulated the loss of the mitochondrial transmembrane potential via the Bax/Bcl-2-dependent pathway, thus inducing apoptosis. Ciprofloxacin induced cell cycle arrest at the S-phase; therefore it was hypothesized that ciprofloxacin inhibits topoisomeraseII. Oligonucleosomal DNA fragmentation and the elevation of p53 expression were observed in the present study, indicating that this late-apoptotic event may be mediated by the p53-dependent pathway. Therefore, the results of the current study provide important molecular data concerning the cellular cascade, which may explain the cytotoxicity induced by ciprofloxacin in human triple-negative breast cancer cells, thus providing a novel insight into the therapeutic properties of this drug.

P31 Role of sesquiterpene lactones against human ovarian cancer

Ovarian cancer is the most severe of the gynaecological malignancy associated with poor patient survival. This is in part due to the lack of symptoms preventing early diagnosis. In addition, ovarian cancer cells may become resistant to first line chemotherapy, paclitaxel and carboplatin. Natural compounds from plants offer a great source of novel anti-cancer agents. In particular, sesquiterpene lactones showed potent anticancer activities in various types of cancer through a range of different mechanisms (e.g. modulation of DNA methylation). Hence, this study evaluated the anticancer activities and mechanism of action of four selected sesquiterpene lactones from medicinal plants as potential alternative treatment for ovarian cancer. The cytotoxicity of these compounds was initially evaluated in human ovarian cancer cell (Ovcar-4 and Ovarc-8) lines using the Sulforhodamine B assay. Dehydroleucodine, parthenolide, costunolide and alantolactone inhibited the growth of cultures of Ovcar-4 ovarian cancer cells with IC 50 values of 7.4 ± 3.4 μM, 10.7 ± 3.5 μM, 12.2 ± 1.2 μM and 7.4 ± 1.3 μM, respectively. They also inhibited the growth of Ovcar-8 cells with IC 50 values of 4.1 ± 1.5 μM, 7.2 ± 2.4 μ M, 7.8 ± 1.9 μM and 4.6 ± 0.5 μ M, respectively. Further studies on their effects on the change of DNA methylation as inhibitors of DNA methyltransferase and re-expression of suppressed genes are in progress.

Synthesis and SAR Study of Anticancer Protoflavone Derivatives: Investigation of Cytotoxicity and Interaction with ABCB1 and ABCG2 Multidrug Efflux Transporters.

There is a constant need for new therapies against multidrug-resistant (MDR) cancer. Natural compounds are a promising source of novel anticancer agents. We recently showed that protoflavones display activity in MDR cancer cell lines that overexpress the P-glycoprotein (P-gp) drug efflux pump. In this study, 52 protoflavones, including 22 new derivatives, were synthesized and tested against a panel of drug-sensitive parental cells and their MDR derivatives obtained by transfection with the human ABCB1 or ABCG2 genes, or by adaptation to chemotherapeutics. With the exception of protoapigenone, identified as a weak ABCG2 substrate, all protoflavones bypass resistance conferred by these two transporters. The majority of the compounds were found to exhibit mild to strong (up to 13-fold) selectivity against the MCF-7Dox and KB-V1 cell lines, but not to transfected MDR cells engineered to overexpress the MDR transporters. Our results suggest that protoflavones can overcome MDR cancer by evading P-gp-mediated efflux.

Growth inhibitory and chemo-sensitization effects of naringenin, a natural flavanone purified from Thymus vulgaris, on human breast and colorectal cancer.

BackgroundNatural products with diverse bioactivities are becoming an important source of novel agents with medicinal potential. Cancer is a devastating disease that causes the death of millions of people each year. Thus, intense research has been conducted on several natural products to develop novel anticancer drugs.MethodsChromatographic and spectral techniques were used for the isolation and identification of naringenin (Nar). MTT, flow cytometry, western blotting, Real Time PCR were used to test anticancer and chemosensitizing effects of Nar, cell cycle, apoptosis, and expression of cell cycle, apoptosis, pro-survival and anti-survival-related genes.ResultsIn the present study, Thymus vulgaris ethanol extract was purified repeatedly to produce several compounds including the known flavanone, Nar which was identified using different spectral techniques. Nar was shown to inhibit both human colorectal and breast cancer cell growth in a dose- and time-dependent manner through cell cycle arrest at S- and G2/M-phases accompanied by an increase in apoptotic cell death. Additionally, Nar altered the expression of apoptosis and cell-cycle regulatory genes by down-regulating Cdk4, Cdk6, Cdk7, Bcl2, x-IAP and c-IAP-2 and up-regulating p18, p19, p21, caspases 3, 7, 8 and 9, Bak, AIF and Bax in both colorectal and breast cancer cells. Conversely, it diminished the expression levels of the cell survival factors PI3K, pAkt, pIκBα and NFκBp65. Moreover, Nar enhanced the sensitivity of colorectal and breast cancer cells to DNA-acting drugs.DiscussionThese findings provide evidence that Nar’s pro-apoptotic and chemo-sensitizing effects are mediated by perturbation of cell cycle, upregulation of pro-apoptotic genes and down-regulation of anti-apoptotic genes and inhibition of pro-survival signaling pathways.ConclusionIn conclusion, Nar might be a promising candidate for chemoprevention and/or chemotherapy of human cancers. However, further studies exploring this therapeutic strategy are necessary.

Antiproliferative efficacy of Tabernaemontana divaricata against HEP2 cell line and Vero cell line.

Background:Laryngeal cancer may also be called cancer of the larynx or laryngeal carcinoma. Conventional plants are a precious source of novel anticancer agents and are still in performance better role in health concern. The study was intended to estimation of the anticancer activity of the chloroformic extract of Tabernaemontana divaricata on the human epidermoid larynx carcinoma cell line (Hep 2).Materials and Method:The aerial parts (leaves, stem, and flowers) of T. divaricata were tested for its inhibitory effect in 96 microplate formats against Hep 2 cell line. The anticancer activity of samples on Hep 2 and Vero was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and various enzymatic parameters like catalase, reduced glutathione (GSH), GSH peroxidase, and superoxide anion scavenging activity. Viable cells were determined by the absorbance at 540 nm. Measurements were performed, and the concentration required for a 50% inhibition of viability (IC50) was determined graphically. The effect of the samples on the proliferation of Hep 2 and Vero cells was expressed as the % cell viability.Results:The extract on Hep 2 cell line up to 7.8 μg/ml and that IC50 value on Hep 2 cell line was 112 μg whereas 94 μg for Vero cell line. Hence, T. divaricata has lesser significant action on Vero cell line.Conclusion:Medicinal plant drug discovery continues to provide new and important leads against various pharmacological targets including cancer. Our results clearly indicate the anticancer property of the medicinal plant T. divaricata against the human laryngeal carcinoma cell lines (Hep 2 cell line).

Potentially bioactive organotin(IV) compounds: Synthesis, characterization, in vitro bioactivities and interaction with SS-DNA

Fourteen new organotin(IV) complexes with general formula R2SnL2 or R3SnL where R = CH3, C2H5, C4H9, C6H5, C6H11, CH2–C6H5, C(CH3)3, C8H17 and L = N-[(2-methoxyphenyl)]-4-oxo-4-[oxy]butanamide were synthesized and characterized by elemental analyses, FT-IR, NMR (1H, 13C and 119Sn), mass spectrometry and single crystal X-ray structural analysis. Crystallographic data for four triorganotin(IV) complexes (R3SnL, R = CH3, C2H5, C4H9, CH2–C6H5) showed the tin has approximate trigonal bipyramidal geometry with the R groups in the trigonal plane. The carboxylate groups of ligands L bridge adjacent tin atoms, resulting in polymeric chains. In case of the diorganotin(IV) derivatives a six-coordinate geometry at the tin atom is proposed from spectroscopic evidence. The Me–Sn–Me bond angle in complex 7 was determined from the 2J[119Sn–1H] value as 166.3° that falls in the range of six-coordinate geometry. The ligand and its complexes (1–14) were screened for their antimicrobial, antitumor, cytotoxic and antileishmanial activities and found to be biologically active. The ligand and its complexes bind to DNA via intercalative interactions resulting in hypochromism and minor bathochromic shifts as confirmed by UV–visible spectroscopy. Based on in vitro studies such as the potato disc method, the synthesized compounds were found to possess significant antitumor activity. Also, from cytotoxicity and DNA interaction studies, these compounds can also be used for the prevention and treatment of cancer. Gel electrophoresis assay was used to investigate the damage to double stranded super coiled plasmid pBR322 DNA by the synthesized compounds and compounds 1 and 7 were found to cause the maximum damage. All the synthesized compounds exhibit strong antileishmanial activity that was even higher than that of Amphotericin B, with significant cytotoxicity. This study, therefore, demonstrated the potential use of these compounds as source of novel agents for the treatment of leishmaniasis.

The potential of seaweed as a source of drugs for use in cancer chemotherapy

This review discusses studies on marine macroalgae that have been investigated for their potential as sources of novel anti-cancer drugs. The review highlights the very large number of studies of crude, partially purified and purified seaweed extracts, collected from many locations, which have shown potential as sources of potent anti-cancer drugs when tested in vitro and/or in vivo. The activity of polysaccharides, polyphenols, proteinaceous molecules, carotenoids, alkaloids, terpenes and others is described here. In some reports, mechanistic studies have identified specific inhibitory activity on a number of key cellular processes including apoptosis pathways, telomerase and tumour angiogenesis. However, despite the potential shown by these studies, translation to clinically useful preparations is almost non-existent. It is hoped this review will serve as a source document and guide for those carrying out research into the potential use of macroalgae as a source of novel anti-cancer agents.

Prospecting for Bioactive Constituents from Traditional Medicinal Plants through Ethnobotanical Approaches

Pharmacologically active constituents from traditional medicinal plants have received great attention as sources of novel agents, pharmaceutical intermediates, and chemical entities for synthetic or semisynthetic drugs due to their potent pharmacological activities, low toxicity, and economic viability. Numerous components have been isolated from traditional medicinal plants, including alkaloids, flavonoids, and terpenoids, and clinical and experimental studies suggested that these components have useful pharmacological properties such as antiinfectious, antioxidative, and antiinflammatory effects. In this review, modern ethnobotanical approaches to explore folk medicinal plants as candidates for drug discovery with the greatest possibility of success are discussed. Determining the bioactive mechanisms and tracing structure-activity relationships will promote the discovery of new drugs and pharmacological agents.

Glabridin induces oxidative stress mediated apoptosis like cell death of malaria parasite Plasmodium falciparum

Plants are known as the source of novel agents for developing new antimalarial drugs. Glabridin is a polyphenolic flavonoid, a main constituent in the roots of Glycyrrhiza glabra possesses various biological activities. However, its anti-plasmodial activity is unexplored. In the present work, it is for the first time demonstrated that glabridin inhibits Plasmodium falciparum growth in vitro with an IC50 23.9±0.43μM. Glabridin showed poor cytotoxicity in vitro with an IC50 246.6±0.88μM against Vero cell line and good selectivity index (9.6). In erythrocytic cycle, trophozoite stage was found to be most sensitive to glabridin. In silico study showed that glabridin inhibits Pf LDH enzyme activity by acting on NADH binding site. Glabridin induced oxidative stress by the generation of reactive oxygen and nitrogen species. Glabridin could induce apoptosis in parasite as evidenced by the depolarization of mitochondrial membrane potential (Δψm), activation of caspase like proteases and DNA fragmentation. These results indicate that glabridin exhibits antiplasmodial activity and is suitable for developing antimalarial agent from a cheap and sustainable source.

Wild-growing lignicolous mushroom species as sources of novel agents with antioxidative and antibacterial potentials

Crude extracts of two edible and two medicinal lignicolous mushroom species: Meripilus giganteus, Agrocybe aegerita, Fomes fomentarius and Xylaria polymorpha, growing wild in Serbia, were analyzed for their antioxidative and antibacterial potentials. Free radical scavenging capacity (RSC) on DPPH• and •OH was evaluated both by spectrophotometer and by Electron Spin Resonance (ESR) spectroscopy against DPPH•. The highest antioxidant and antibacterial bioactivity was obtained with F. fomentarius extracts (IC50 ≈ 10.7 µg/ml in DPPH• assay; 136.6 mg ascorbic acid equivalents (AAE)/g dry weight (d.w.) for ferric reducing antioxidant power FRAP). It also showed the highest total phenol (TP) (82.54 mg gallic acid equivalents (GAE)/g dry weight (d.w.)) and total flavonoid (TF) content (76.8 µg rutin equivalents (RE)/g dry weight (d.w.)). A. aegerita showed the best antioxidant activity (IC50 = 0.87 mg/ml) against DPPH• in ESR analysis. Total redox potential of extracts was in direct positive correlation with TP content (r2 = 0.98) and TF content (r2 = 0.58). GC/MS analysis detected major constituents of extracts, confirming the presence of the following organic and phenolic acids: fumaric, succinic, mallic, 4-hydroxy benzoic, gentisic, protocatechuic, vanillic, gallic and p-coumaric acid.

Apoptosis-like death in Leishmania donovani promastigotes induced by eugenol-rich oil of Syzygium aromaticum

Leishmaniasis consists of a complex spectrum of infectious diseases with worldwide distribution of which visceral leishmaniasis or kala-azar caused by Leishmania donovani is the most devastating. In the absence of vaccines, chemotherapy remains the mainstay for the control of leishmaniasis. The drugs of choice are expensive and associated with multiple adverse side effects. Because of these limitations, the development of new antileishmanial compounds is imperative and plants offer prospects in this regard. The present work was conducted to study the antileishmanial potential of oil from Syzygium aromaticum flower buds (clove). The S. aromaticum oil was characterized by gas chromatography and GC-MS and eugenol as well as eugenyl acetate were found to be the most abundant compounds, composing 59.75 % and 29.24 %, respectively of the oil. Our findings have shown that eugenol-rich essential oil from S. aromaticum (EROSA) possesses significant activity against L. donovani, with 50 % inhibitory concentration of 21 ± 0.16 µg ml(-1) and 15.24 ± 0.14 µg ml(-1), respectively, against promastigotes and intracellular amastigotes. Alterations in cellular morphology and growth reversibility assay substantiated the leishmanicidal activity of EROSA. The leishmanicidal effect was mediated via apoptosis as confirmed by externalization of phosphatidylserine, DNA nicking by TdT-mediated dUTP nick-end labelling (TUNEL) assay, dyskinetoplastidy, cell cycle arrest at sub-G0-G1 phase, loss of mitochondrial membrane potential and reactive oxygen species generation. EROSA presented no adverse cytotoxic effects against murine macrophages even at 200 µg ml(-1). Our studies authenticate the promising antileishmanial activity of EROSA, which is mediated by programmed cell death, and, accordingly, EROSA may be a source of novel agents for the treatment of leishmaniasis.

In vitro Evaluation of Antileishmanial Activity and Toxicity of Essential Oils of Artemisia absinthium and Echinops kebericho

Potential toxicity, costs, and drug-resistant pathogens necessitate the development of new antileishmanial agents. Medicinal and aromatic plants constitute a major source of natural organic compounds. In this study, essential oils of Artemisia absinthium L. and Echinops kebericho Mesfin were investigated by GC and GC/MS analyses. Isolated oils were screened for antileishmanial activity against two Leishmania strains (L. aethiopica and L. donovani), and toxicity on the human monocytic leukemia (THP-1) cell line and red blood cells in vitro. GC/MS Analysis revealed 65 compounds (93.74%) for Artemisia absinthium and 43 compounds (92.85%) for Echinops kebericho oil. The oils contained the oxygenated monoterpene camphor (27.40%) and the sesquiterpene lactone dehydrocostus lactone (41.83%) as major constituents, respectively. Both oils showed activity against promastigote (MIC 0.0097-0.1565 μl/ml) and axenic amastigote forms (EC(50) 0.24-42.00 nl/ml) of both leishmania species. Weak hemolytic effect was observed for both oils, showing a slightly decreased selectivity index (SI 0.8-19.2) against the THP-1 cell line. Among the two oils tested, E. kebericho exerted strong antileishmanial activity that was even higher than that of amphotericin B with significant cytotoxicity. This study, therefore, demonstrated the potential use of both oils as source of novel agents for the treatment of leishmaniasis.