The effect of Kappaphycus alvarezii active fraction on oxidative stress and inflammation in streptozotocin and nicotinamide-induced diabetic rats

Background High glucose concentration increases the glycation process which leads to oxidative stress and inflammation, that can cause complications in diabetes. Several medicinal plants have been used in the treatment of diabetes and its complications. One of them is Kappaphycus alvarezii, an algae that has known antidiabetic abilities. This study aimed to examine the effect of K. alvarezii active fraction on plasma hydrogen peroxide (H2O2) and Tumor Necrosis Factor α (TNFα) levels, renal NADPH oxidase 4 (NOX4) and Nuclear Factor κ B (NFκB) gene expressions. Methods Active fraction was obtained from bioassay-guided fractionation with antiglycation ability. In vivo study was performed on twenty Wistar male rats. The level of H2O2 was measured using H2O2 Assay Kit, the Optical Density value measured using spectrophotometer at a wavelength of 405 nm. Plasma TNFα level was measured using ELISA. Renal NOX4 and NFκB gene expression was analyzed using qPCR. Results Active fraction significantly reduced plasma H2O2 but not TNFα levels. Furthermore, renal NOX4 gene expression was lower in the diabetic rat group treated with active fraction compared to the untreated group but not NFκB gene expression. Conclusions K. alvarezii active fraction has an activity to reduce plasma H2O2 as well as renal NOX4 gene expression. Therefore, this fraction could be developed as a potential candidate for diabetes treatment through oxidative stress mechanisms.

Cytotoxic and Antimigration Activity of Etlingera alba (A.D.) Poulsen Rhizome

Etlingera alba is one of the Etlingera plants that might have anticancer activity. This study aims to investigate the cytotoxic and antimetastatic activity of E. alba rhizome fractions and migration cell assay against MDA-MB-231 cell lines, which are used for triple-negative breast cancer (TNBC) treatment assay. The cytotoxic activity was assayed using CCK-8 assay, while the antimetastatic was assayed using migration cell assay for the fractions A–F. They were followed by LCMS/MS profiling to determine the chemical contents in the most active fraction. According to results obtained, fraction B was the most active fraction for cytotoxic activity with an IC50 value of 65.43 μg/mL, while fraction E was the most active fraction for antimetastasis activity against migration rate doses of 50, 100, and 200 ppm which were 6.80, 3.66, and 3.00%, respectively. Several compounds in fraction B, such as rengyolone, licochalcone A, sugiol, and spinasterol, might have been known to have activity against cancer cells, as well as aschantin and lirioresinol B dimethyl ether from fraction E. In conclusion, the chemical components from E. alba rhizome fractions provided potency for discovering new agents for cancer treatment, specifically for TNBC.

Immunity acquired by a minority active fraction of the population could explain COVID-19 spread in Greater Buenos Aires (June-November 2020)

The COVID-19 pandemic had an uneven development in different countries. In Argentina, the pandemic began in march 2020 and, during the first 3 months, the vast majority of cases were concentrated in a densely populated region that includes the city of Buenos Aires (country capital) and the Greater Buenos Aires area that surrounds it. This work focuses on the spread of COVID-19 between June and November 2020 in Greater Buenos Aires. Within this period of time there was no vaccine, basically only the early wild strain of SARS-CoV-2 was present, and the official restriction and distancing measures in this region remained more or less constant. Under these particular conditions, the incidences show a sharp rise from June 2020 and begin to decrease towards the end of August until the end of November 2020. In this work we study, through mathematical modelling and available epidemiological information, the spread of COVID-19 in this region and period of time. We show that a coherent explanation of the evolution of incidences can be obtained assuming that only a minority fraction of the population got involved in the spread process, so that the incidences decreased as this group of people was becoming immune. The observed evolution of the incidences could then be a consequence at the population level of lasting immunity conferred by SARS-CoV-2.

Biological activities and chemical composition of Mentha piperita and Syzygium aromaticum essential oil fractions against cowpea weevil, Callosobruchus maculatus (Fabricius) (Coleoptera: Bruchidae)

Callosobruchus maculatus (Fabricius) is one of the major, common, pests of stored grains as it causes quantitative and qualitative losses in legume crops. This research sought to find the most active fraction in Mentha piperita and Syzygium aromaticum essential oils, to evaluate bioactivity of those crude essential oils and active fractions against C. maculatus, and to identify the compounds contained in the active fraction. The essential oils were fractionated using three solvents, namely n-hexane, ethyl acetate, and methanol. The n-hexane fraction was identified as the active fraction, causing mortality, oviposition deterrence, and ovicidal effects. In fumigation chambers, LD95 values of M. piperita (Mnf) and S. aromaticum n-hexane fractions (Snf) were 0.045 ml/l and 0.057 ml/l respectively. ED50 values for oviposition deterrence were 0.016 ml/l for Mnf and 0.022 ml/l for Snf. ED50 value of ovicidal effects for Mnf- and Snf-treated eggs were 0.014 ml/l for both fractions. GC-MS analysis showed 8 dominant compounds in Mnf and 5 dominant compounds in Snf. Overall it is concluded that Mnf and Snf oils have effective biological activities against stored pest C. maculatus and have potential to be considered as alternatives to synthetic insecticides.

Pesticidal Activity of Sundarban Mangrove Plant Extracts against Sitophilus Pests and Identification of Active Constituents Using LC-MS

Plants act as a rich source of novel natural pesticides. In the backdrop of the recent revival of interest in developing plant-based insecticides, this study was carried out to investigate the pesticidal activity of Sundarban mangrove plants. A total of nine different plant parts from five plants, namely, Aegiceras corniculatum, Excoecaria agallocha, Heritiera fomes, Xylocarpus moluccensis, and Xylocarpus granatum, were extracted with methanol and tested for insecticidal activity against two common stored product pests Sitophilus oryzae and Sitophilus zeamais using direct contact feeding deterrent wafer disc method. Three bark extracts from A. corniculatum, E. agallocha, and H. fomes showed potent and statistically significant insecticidal activity against both S. oryzae and S. zeamais pests (80–100% mortality). All the active bark extracts were further fractionated using C-18 solid-phase extraction (SPE) columns and tested for their insecticidal activity against S. oryzae pest to identify the active fraction. Only the SPE4 fraction (100% MeOH) from all the three active plants showed the activity against S. oryzae pest with a lethal concentration 50% (LC50) value of 0.5, 1.0, and 1.5 mg/disc for A. corniculatum, E. agallocha, and H. fomes, respectively. The active fraction of A. corniculatum was further profiled for identification of active compounds using LC-ESI-MS and identified (along with some unknown peaks) two previously reported compounds at m/z 625.17630 (isorhamnetin 3-O-rutinoside) and 422.25346 (paspaline) as major constituents. Insecticidal activities of these plants are reported in this study for the first time and would be useful in promoting research aiming for the development of new biopesticides from mangrove plants.

Central nervous system depressant activity of fractions of Globimetula braunii Engl. (Loranthaceae) growing on Terminalia catappa L. (Combretaceae) and isolation of lupeol

Globimetula braunii is a parasitic plant belonging to the family Loranthaceae. Traditionally, the plant has been reported to be used in the treatment of insomnia. The study was carried out to investigate the central nervous system (CNS) depressant activity of the fractions of Globimetula braunii growing on Terminalia catappa and to isolate the phytochemical compound(s) present in the most active fraction. The CNS depressant activity of all the fractions was investigated using diazepam induced sleep. The most active fraction was further subjected to the hole board test and beam walk assay. The chromatographic technique was used for the isolation of phytochemical compound. Hexane fraction significantly (p<0.05) reduced latency to sleep and prolonged the sleeping time. Both chloroform and ethylacetate fractions at highest and median doses showed significant increase in the duration of sleep compared to normal saline. The n-butanol fraction at all doses tested do not have any effect on time of onset and duration of sleep when compared with normal saline treated group. Hexane fraction significantly (p<0.05) decreased the number of head dip in a dose dependent manner and delayed the time to reach the goal box compared to normal saline treated group. Lupeol was isolated from n-hexane fraction.

Anti-Cancer Assessment of a Ramie (Boehmeria nivea L. Gaud.) Leaf Extract Using Mcf-7 Cell Line and a Yeast-Based Bioassay

Introduction: One strategy for molecular cancer therapy is to know the key mechanism of cytotoxic compounds that can kill cancer cells. Ramie (Boehmeria nivea L. Gaud.) leaves contain active compounds that have important effects on cancer chemoprevention. Objective: To obtain the active fraction of a Ramie leaf extract in inhibiting the proliferation of MCF-7 breast cancer cell lines and to determine the mechanism of apoptosis induction using MCF-7 and Saccharomyces cerevisiae strains 1140, 1353, and 1138. Method: Fractions were prepared using n-hexane, dichloromethane (CH2Cl2), ethyl acetate, and n-butanol as solvents. All fractions were tested qualitatively through phytochemical. The MTT-based cytotoxicity assay used MCF-7 (in vitro) to obtain the IC50 value, whereas the model system that targets the enzymatic (topoisomerase) used a yeast-based bioassay to obtain the IC12 value. Apoptotic induction of the active fraction in MCF-7 was performed using flow cytometry and qPCR (2-ΔΔCt method). Results: The phytochemical analysis indicated that the extract fraction consisted of alkaloids and steroids. The smallest IC50 value was obtained from the CH2Cl2 fraction as 3.79 g/mL, potentially act as an anticancer. A higher percentage of apoptosis than that of necrotizing cells and live cells was observed through flow cytometry. The CH2Cl2 fraction with an IC12 value < 8000 in strains 1140, 1353, and 1138 consistently showed the mechanism of apoptosis induction as topoisomerase I and II inhibitors. Also, another mechanism could be through the intrinsic pathway, indicated by the highest expression level in p53. Conclusions: The CH2Cl2 fraction of Ramie leaves can inhibits the proliferation of MCF-7 cells in the active and strong categories. The CH2Cl2 fraction induces apoptosis by increasing p53 gene expression and inhibiting topoisomerase I and II. Thus, it showed potential as an anticancer drug candidate.

Three New Phthalide Glycosides from the Rhizomes of Cnidium officinale and Their Recovery Effect on Damaged Otic Hair Cells in Zebrafish

The extract from Cnidium officinale rhizomes was shown in a prior experiment to markedly recover otic hair cells in zebrafish damaged by neomycin. The current study was brought about to identify the principal metabolite. Column chromatography using octadecyl SiO2 and SiO2 was performed to isolate the major metabolites from the active fraction. The chemical structures were resolved on the basis of spectroscopic data, including NMR, IR, MS, and circular dichroism (CD) data. The isolated phthalide glycosides were assessed for their recovery effect on damaged otic hair cells in neomycin-treated zebrafish. Three new phthalide glycosides were isolated, and their chemical structures, including stereochemical characteristics, were determined. Two glycosides (0.1 μM) showed a recovery effect (p < 0.01) on otic hair cells in zebrafish affected by neomycin ototoxicity. Repeated column chromatography led to the isolation of three new phthalide glycosides, named ligusticosides C (1), D (2), and E (3). Ligusticoside C and ligusticoside E recovered damaged otic hair cells in zebrafish.