Bioassay Guided Fractionation of Senna singueana and Its Potential for Development of Poultry Phytogenic Feed Additives

There has been burgeoning interest in plant-based feed additives following restrictions placed on the use of antibiotic feed additives in many countries. Phytogenic feed additives are recommended to have a range of useful properties to support the growth and development of poultry to a similar level as that obtained by supplementing feed with antibiotics. The aim of this study was to evaluate the antibacterial, anti-lipoxygenase and antioxidant activity, and in vitro safety of fractions and isolated compounds from leaves of Senna singueana. Antibacterial activities of the fractions and isolated compounds were determined against a panel of bacteria using a two-fold serial microdilution assay and qualitative bioautography assays. Anti-lipoxygenase activity was evaluated using the ferrous oxidation-xylenol orange (FOX) method. Antioxidant activity was assessed qualitatively and quantitatively using radical scavenging assays. Dichloromethane and ethyl acetate fractions from solvent-solvent partitioning had the best antibacterial activity with MIC values ranging from 156 to 313 μg/ml. Fractions obtained from column chromatography had significant to weak antibacterial activity with MIC values ranging from 50 to 1,250 μg/ml. Bioautography showed clear bands of bacterial inhibition, indicating the presence of a number of active compounds in several fractions. The ethyl acetate fraction and all the tested column fractions had potent anti-lipoxygenase activity with IC50 values of ≤2.5 μg/ml which were lower than that of quercetin (positive control), indicating anti-inflammatory potential. The ethyl acetate fraction and several column fractions had powerful antioxidant activity with IC50 values of ≤5 μg/ml in the ABTS assay. Cytotoxicity values against Vero kidney cells ranged from LC50 = 40.0–989.3 μg/ml. Bioassay-guided fractionation led to the isolation and identification of a known bioactive compound, luteolin. S. singueana is a promising candidate for the development of poultry phytogenic feed additives.

Lipoxygenase in Wheat: Genetic Control and Impact on Stability of Lutein and Lutein Esters

Preservation of lutein concentrations in wheat-based end-products during processing is important both for product quality and nutritional value. A key constituent involved in lutein degradation is endogenous lipoxygenase. Lutein and lutein ester concentrations were compared at intervals during storage of noodle sheets prepared from flour of wheat varieties representing a range in lipoxygenase activity, as well as in different mill streams and in different grain tissues. Higher lipoxygenase concentration was associated with an increased loss of free lutein and lutein mono-esters whereas lutein diesters appeared to be more resistant to degradation. Lutein degradation was reduced in the presence of a lipoxygenase inhibitor, when noodle sheets were heated to destroy enzyme activity or when pH was increased. In addition, three populations were used to investigate the genetic control of lipoxygenase. A previously reported mutation of Lpx-B1.1 was associated with a reduction in activity from high to intermediate whilst a new locus on chromosome 4D was associated with variation between intermediate and near-zero. The gene underlying the 4D locus is a putative lipoxygenase. Stability of lutein could be improved by deployment of the mutations at the 4B and 4D loci and/or by post-harvest storage of grain under conditions that promote esterification.

In vitro and in vivo biological approach to validate folkloric claims of Trianthema triquetra Rottler & Willd

Trianthema triquetra Rottler & Willd (Tt.Cr) is used in traditional practices as a remedy for various ailments. Hence current research was commenced to authenticate the folkloric uses. To discover spasmolytic potential, Tt.Cr was applied to isolate jejunum, while isolated tracheal and aorta tissues were used to determine the tissue relaxing properties of the extract. Anti-lipoxygenase activity was determined in vitro using Baicalein as standard. In vivo testing was carried to examine the potentiality of the herb to treat pyrexia and pain. Tt.Cr showed dose-dependent (0.01 - 3.0 mg/ml) spasmolytic effects in jejunum tissues and relaxed K+ (80 mM)-induced spasm and triggered rightwards shift of Ca+2 concentration-response curves. Carbachol (1μM)- together with K+ (80 mM) - induced tracheal spasm was also relaxed by Tt.Cr (0.01 to 1.0 mg/ml). Additionally, Tt.Cr (0.01 - 1.0 mg/ml) relaxed phenylephrine (1 μM) and K+ (80 mM) - treated constricted rabbit aorta. Tt.Cr (0.5 mM) inhibited lipoxygenase enzyme. Tt.Cr (80 mg/kg) settled pyrexia in rabbits comparable to aspirin and prolonged tail deflection time in mice (100 mg/kg) hence proving analgesic activity. The Tt.Cr demonstrated antispasmodic, bronchodilation and vasodilation properties probably by blocking calcium channels. These outcomes generate logic behind ancient application of herb for numerous ailments such as asthma, cough, heart problems and spasm.