Natural compounds and extracts from Mexican medicinal plants with anti-leishmaniasis activity: An update

Leishmaniasis is considered as an emerging, uncontrolled disease and is endemic in 98 countries. Annually, about 2 million cases of cutaneous and 500000 cases of visceraltype leishmaniasis are recorded and 60000 persons died from the disease. In Mexico,cutaneous leishmaniasis is known as chiclero's ulcer and is reported in 22 states, it is considered as a health problem. For its treatment, pentavalent antimonial drugs are administered. These drugs cause severe side effects, are costly. Drug-resistant cases have been reported and have been developing for over 70 years. One alternative to the drugs that are currently available is to find active molecules in medicinal plants. Dihydrocorynantheine, corynantheine and corynantheidine are active against Leishmania major,while harmane, pleiocarpin, buchtienin, luteolin and quercetin are active against Leishmania donovani. In Mexico, about 20 medicinal plants have been evaluated against Leishmania mexicana, among which the most active are Tridax procumbens, Lonchocarpus xuul and Pentalinon andrieuxii. From these plants, active compounds with IC_(50)≤30 mg/mL or m M have been isolated, such as 3(S)-16,17-didehydrofalcarinol or Oxylipin, cholestra-4,20,24-trien-3-one or pentalinosterol, 24-methylcholest-4-24(28)-dien-3-one, cholest-4-en-3-one, 6,7-dihydroneridie-none, neridienone, cholest-5,20,24-trien-3β-ol, and isocordoin. Today, only pentalinonsterol has been synthesized and assayed in the visceral leishmaniasis experimental model using BALB/c mice infected with Leishmania donovani. Liposome formulation of this compound administered by intravenous route at 2.5 mg/kg showed a significant reduction of parasite load in mouse liver and spleen.

Sonme Factors that Affect the Free Radical-scavenging Activity of Tea Extracts

Some factors that affect the free radical-scavenging activety of two tea extracts were studied in vitro. It was found that concentration of tea extract or heating tea extract or treating with activated carbon and diatomite all had obvious effect on the scavenging activety of green tea extract ,but heating or treating with diaomite had less effect on the scavenging activity of black tea extract. Ascorbic acid, for having synergic effect with tea extracts, could enhance the scavenging activity of tea extracts markedly, and the contrary was cupric ion. Reducing sugars such as fructose and glucose also had some syncrgic effect to tea extracts.

Identification and Evaluation of Antioxidant Activities of Bamboo Extracts

The antioxidant activity of solvent extracts from two main bamboo species, moso bamboo (Phyllostachys pubescens) and madake bamboo (P. bambusoides) in Japan, was first evaluated by scavenging free radical of 1,1-diphenyl-2-picrylhydrazyl (DPPH), the inhibition activity for peroxidation of linoleic acid, and the reduction power. The methanol-extracts of moso bamboo culms and madake bamboo leaves presented stronger antioxidant activity compared with DPPH scavenging activity. Methanol-extract of moso bamboo culms was further fractionated by different solvents and n-butanol soluble fraction exhibited the most significant activity in the DPPH scavenging assay. The fractionation of n-butanol soluble extract was isolated by silica gel column with gradient mixture solvent of chloroform and methanol. The isolated fractions were directed by the antioxidant activity measured by scavenging the stable DPPH free radical. It was observed that most of the eluted fractions showed the antioxidative activity. Fractions acquired from elution with the mixture solvent of chloroform and methanol (10:1–5:1) showed stronger antioxidant activity than the other fractions.

THE MECHANISM OF ANTITUMOR ACTIVITY OF TOTAL GLUCOSIDES EXTRACTED FROM CYNANCHUM AURICULA-TUM ROYLE (CA)

Since the chemical structure of total glucosides from Cynanchum Auriculatum Royle (CA) is similar to that of the steroline of Marsdenia Condurago Reich, a compound which exhibits antitumor activity, research into the antitumor activity of CA was carried out. Its mechanism of action was studied in vivo with C 57BL/6 mice bearing Lewis lung carcinoma and in vitro, with two mouse tumor cell lines: S180 and EAC. CA inhibited to a certain extent the growth of subcutaneously inoculated Lewis lung carcinoma and its pulmonary metastasis, and augmented the antitumor effect of cyclophosphamide. It showed a killing effect on the EAC and S180 tumor cells of mice in vitro as well. It blocked the tumor cells of solid Lewis lung carcinoma from entering into the S stage from G1 and inhibited DNA synthesis of S180 and EAC tumor cells of mice in vitro. It also markedly increased the number of mononuclear Mφ of tumor bearing mice, stimulated the macrophagic activity of their intraperitoneal Mφ, raised the percentage of ANAE(+) lymphocytes in peripheral blood and enhanced the ABC reaction and antibody formation in tumor bearing mice.

Optimization of Ultrasonic-Assisted Extraction Process of Polysaccharides from American Ginseng and Evaluation of Its Immunostimulating Activity

Ultrasonic-assisted extraction （UAE） of American ginseng polysaccharides （AGP） was investigated using response surface methodology. Three-factor-three-level Box-Behnken design was employed to optimize the ultrasonic power, extraction time and ratio of water to raw material to obtain a high AGP yield. The analysis of variance and response surface plots indicated that ultrasonic power was the most important factor affecting the extraction yield. The optimal conditions were ultrasonic power 400 W, extraction time 71 min, and ratio of water to raw material 33 mL g-1. Under these conditions, the yield of AGP was 8.09%, which was agreed closely to the predicted value. Gas chromatography （GC） analysis showed that AGP was composed of arabinose, rhamnose, galactose, glucose, and galacturonic acid. Fourier transform infrared spectra revealed the general characteristic absorption peaks of AGP. In addition, AGP exhibited good immunostimulating activities by up-regulating the production of nitric oxide and cytokines. Compared with hot water extraction, UAE required shorter extraction time and gave a higher extraction yield, without changing the structure and immunostimulating activity of AGP. The results indicated that UAE could be an effective and advisable technique for the large scale production of plant polysaccharides.

Essential Oil from Inula britannica Extraction with SF-CO_2 and Its Antifungal Activity

The aim of this study was to determine the extraction technique of supercritical fluid carbon dioxide（SF-CO 2） for the essential oil from Inula britannica flowers and its antifungal activities against plant pathogenic fungi for its potential application as botanical fungicide.The effects of factors,including extraction temperature,extraction pressure,SF-CO 2 flow rate,flower powder size,and time on the essential oil yield were studied using the single factor experiment.An orthogonal experiment was conducted to determine the best operating conditions for the maximum extraction oil yield.Adopting the optimum conditions,the maximum yield reached 10.01% at 40°C temperature,30 MPa pressure,60 mesh flower powder size,20 L h-1SF-CO 2 flow rate,and 90 min extraction time.The antifungal activities of I.britannica essential oil using the SF-CO 2 against the most important plant pathogenic fungi were also examined through in vitro and in vivo tests.Sixteen plant pathogenic fungi were inhibited to varying degrees at 1 mg mL-1concentration of the essential oil.The mycelial growth of Gaeumannomyces graminis var.tritici was completely inhibited.The radial growths of Phytophthora capsici and Fusarium monilifome were also inhibited by 83.76 and 64.69%,respectively.In addition,the essential oil can inhibit the spore germination of Fusarium oxysporum f.sp.vasinfectum,Phytophthora capsici,Colletotrichum orbiculare,and Pyricularia grisea,and the corresponding inhibition rates were 98.26,96.54,87.89,and 87.35% respectively.The present study has demonstrated that the essential oil of I.britannica flowers extracted through the SF-CO 2 technique is one potential and promising antifungal agent that can be used as botanical fungicide to protect crops.

Antibacterial and Antioxidant Activities of ZnO Nanoparticles Synthesized Using Extracts of Allium sativum,Rosmarinus officinalis and Ocimum basilicum

ZnO nanoparticles（ZnO NPs） were synthesized by chemical method（coprecipitation） and biological method using aqueous extracts of garlic（Allium sativum）,rosemary（Rosmarinus officinalis） and basil（Ocimum basilicum）.The influence of plant extract on the antibacterial and antioxidant activities of green synthesized nanoparticles was investigated.The X-ray diffraction studies reveal that all ZnO samples have hexagonal wurtzite structure.The particle size of ZnO NPs estimated by transmission electron microscopy analysis（between 14 and 27 nm） varies depending on the synthesis method of nanoparticles and the type of extracts from the plants used.The functional groups involved in the biosynthetic procedure were evidenced by Fourier transform infrared spectroscopy.The presence of Mn^（2＋）ions,Zn vacancy complexes and oxygen vacancies in ZnO samples was highlighted by electron paramagnetic resonance spectroscopy.The green synthesized ZnO NPs have shown a good bactericidal activity against Staphylococcus aureus,Bacillus subtilis,Listeria monocytogenes,Escherichia coli,Salmonella typhimurium and Pseudomonas aeruginosa bacterial strains.ZnO NPs synthesized using extracts of the selected plant species have been found to exhibit more enhanced antibacterial and antioxidant activities as compared to chemical ZnO NPs.

Sesquiterpenes and prenylated C_6–C_3 compounds from the stems of Illicium henryi

One new sesquiterpene compound, namely, illihenlactone A（1）, and one new prenylated C6–C3 compound, illihenryione H（2）, along with three known sesquiterpenes（3–5） were isolated from the stems of Illicium henryi. The structures of 1 and 2 were elucidated by spectroscopic evidence including NMR, HRESIMS and circular dichroism（CD）. Compound 2 exhibited a weak inhibitory ratio for bglucuronidase release induced by platelet-activating factor（PAF） in rat polymorphonuclear leukocytes（PMNs） in vitro.