Chemical Composition and Bioactive Potential of Extracts from Diospyros capricornuta F. White against Aspergillus flavus and Aspergillus parasiticus

Diospyros capricornuta is an endemic species widely distributed along the coast of Tanzania that is used as food condiments and traditional medicine. The chemical compositions of Diospyros capricornuta leaves, stem-bark, and root-bark extracts; and their bioactive potentials against Aspergillus flavus and Aspergillus parasiticus were investigated. The leaves, stem-bark, and root-bark samples of D. capricornuta were extracted using Soxhlet apparatus and the resultant extracts were analyzed using Gas Chromatography-Mass Spectrometry (GC-MS). A total of 14 compounds were identified from the extracts, whereby 2,4-di-tert-butylphenol was the most abundant compound in all extracts. The growth and aflatoxin production inhibitions against A. flavus and A. parasiticus were determined via antifungal and antiaflatoxigenic bioassays of the extracts at the concentrations of 0.0, 62.5, 125.0, and 250.0 µg/mL using a poisoned-food method. The High-Performance Liquid Chromatography (HPLC) technique was used to quantify the aflatoxins after bioassays to evaluate aflatoxin inhibitions. The stem-bark extracts at the highest dose of 250.0 µg/mL inhibited aflatoxin production by A. flavus for over 99% and A. parasiticus for over 94%. Overall, the results show that the leaves, stem-bark, and root-bark extracts of D. capricornuta are potential inhibitors against A. flavus and A. parasiticus-the producers of aflatoxins. Keywords: Diospyros capricornuta; Growth inhibitions; Aflatoxin inhibitions; Aspergillus flavus; and Aspergillus parasiticus

Antimicrobial activities of against selected pathogenic fungi and bacteria strains.

This research article published by Taylor & Francis Online, 2019and are dangerous pathogens causing fungal diseases. and developed resistance to fungicides such as fluconazole. Similarly, pathogenic bacteria have become resistant to antibiotcs such as methicillin. Thus, searching for alternative antimicrobial agents is inevitable. used traditionally for management of fungal and bacterial diseases is potential source of antimicrobial agents. It is in this vein that, antimicrobial activities of leaf and root extracts of were evaluated against (ATCC 90028), (clinical isolate), (ATCC25923), (ATCC29953), (ATCC 700603) and (NCTC 8385). A two-fold serial dilution method using the sterilised 96 wells of polystyrene microlitre plates used to determine the minimum inhibitory concentration (MIC) of extracts. Hexane and dichloromethane extracts exhibited the lowest activity against fungi strains with MICs >10 mg/mL. Root and leaf methanolic extracts exhibited activity at MICs of 5 and 1.25 mg/mL, respectively, against both tested fungi. Dichloromethane and methanolic extracts exhibited antibacterial activity with MICs ranging from 2.5 - 10 mg/mL and 0.625 - 5 mg/mL, respectively. Antimicrobial activities of the extracts of revealed potentiality of bioactives against fungal and bacterial diseases

The in vivo toxicity evaluation of leaf and root methanolic extracts of Tephrosia vogelii Hook.f using animal model

This research article published by Springer Nature, 2020Background: Traditionally, herbal medicines are commonly used to cure several diseases since immemorial of human life. Nevertheless, the safety of some traditionally used medicinal plants is uncertain. Since Tephrosia vogelii Hook.f is a traditionally used medicinal plant, the effects of its extracts were evaluated on lethality (LD50) and subacute toxicity in this study. Methods: Phytochemistry screening and an in vivo toxicity evaluation of leaf and root methanolic extracts of T. vogelii using laboratory albino rats were conducted. Methanolic extracts of doses 600, 1200, 2000 and 5000 mg/kg body weights were administered single dose in rats to observe deaths within 72 h in order to determine the LD50. Methanolic extracts doses of 600, 1200 and 2000 mg/kg body weights were consecutively administered for 14 days in order to evaluate sub-acute toxicity. Results: Tannins, steroids, terpenoids, flavonoids and saponins were identified in the phytochemical screening. The LD50 experiments revealed zero deaths of rats for the administered doses, 600 to 5000 mg/kg body weight. Histopathological examination of liver and kidney for sub-acute toxicity test showed safety at all doses except root methanolic extracts dose of 2000 mg/kg which exhibited necrosis and vacuolation of liver cells on the 14th day. Nonetheless, hepatic necrosis and hepatic vacuolation disappeared upon time elongation without dose administration to 28th day. Conclusion: The conducted toxicity evaluation of methanolic leaf and root extracts in albino rats revealed no deleterious effects, henceforth, suggesting that T. vogelii could be safe to users using it as a medicinal plant

Synthesis of a kairomone and other chemicals from cardanol, a renewable resource

Synthesis of a tsetse fly kairomone component (3-propylphenol), a detergent [sodium 2-(dec-8-enyl)-6-hydroxybenzenesulfonate], a polymer additive (1-octene), and a detergent precursor [3-(non-8-enyl)phenol] using cardanol [3-(pentadec-8-enyl)phenol], has been accomplished. Both carboncarbon double bond isomerization and metathesis methodologies were employed in the syntheses of these target molecules. The kairomone component was obtained, albeit in low yield, in three steps starting with cardanol. Synthesis of a new detergent, sodium 2-(dec-8-enyl)-6-hydroxybenzenesulfonate, was achieved by direct metathesis of cardanol with cis-2-butene followed by sulfonation and basification. Finally, synthesis of 1-octene and 3-(non-8-enyl)phenol was accomplished in one pot by direct metathesis of cardanol with ethylene. These products have been characterized spectroscopically, especially using 1H and 13C NMR.</p

Aflatoxin levels in sunflower seeds and cakes collected from micro- and small-scale sunflower oil processors in Tanzania

<div><p>Aflatoxin, a mycotoxin found commonly in maize and peanuts worldwide, is associated with liver cancer, acute toxicosis, and growth impairment in humans and animals. In Tanzania, sunflower seeds are a source of snacks, cooking oil, and animal feed. These seeds are a potential source of aflatoxin contamination. However, reports on aflatoxin contamination in sunflower seeds and cakes are scarce. The objective of the current study was to determine total aflatoxin concentrations in sunflower seeds and cakes from small-scale oil processors across Tanzania. Samples of sunflower seeds (n = 90) and cakes (n = 92) were collected across two years, and analyzed for total aflatoxin concentrations using a direct competitive enzyme-linked immunosorbent assay (ELISA). For seed samples collected June-August 2014, the highest aflatoxin concentrations were from Dodoma (1.7–280.6 ng/g), Singida (1.4–261.8 ng/g), and Babati-Manyara (1.8–162.0 ng/g). The highest concentrations for cakes were from Mbeya (2.8–97.7 ng/g), Dodoma (1.9–88.2 ng/g), and Singida (2.0–34.3 ng/g). For seed samples collected August-October 2015, the highest concentrations were from Morogoro (2.8–662.7 ng/g), Singida (1.6–217.6 ng/g) and Mbeya (1.4–174.2 ng/g). The highest concentrations for cakes were from Morogoro (2.7–536.0 ng/g), Dodoma (1.4–598.4 ng/g) and Singida (3.2–52.8 ng/g). In summary, humans and animals are potentially at high risk of exposure to aflatoxins through sunflower seeds and cakes from micro-scale millers in Tanzania; and location influences risk.</p></div

Incidence rates of aflatoxin contamination for each location across and within the two years of 2014 and 2015.

<p>Incidence rates of aflatoxin contamination for each location across and within the two years of 2014 and 2015.</p

Recovery of AFB₁ spiked in aflatoxin-free sunflower seed and cakes^a.

<p>Recovery of AFB₁ spiked in aflatoxin-free sunflower seed and cakes<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0175801#t001fn001" target="_blank">^a</a>.</p

Aflatoxin concentrations in sunflower seeds collected from micro- and small-scale sunflower oil processors in Tanzania in the sunflower-harvesting season of 2015.

<p>Aflatoxin concentrations in sunflower seeds collected from micro- and small-scale sunflower oil processors in Tanzania in the sunflower-harvesting season of 2015.</p