The accuracy of several in vitro methods in estimating in vivo digestibility of the tropical dairy ration

In vitro digestibility methods have been developed to overcome problems in the in vivo digestibility measurement, but its accuracy should be tested in a local setting. In vitro methods developed by Tilley and Terry (T2), Theodorou (T3) and Sutardi (T4) have been compared to in vivo method (T1) in a block randomized design study. Four heifers FH (337.50 ± 45.87 kg BW) were used in T1, and two fistulated FH bulls (510 ± 20 kg BW) were used as inoculant sources in the in vitro methods. Dairy cattle ration consisted of 54.0% Napier grass and 46.0% concentrate with 58.8% DM, 12.1% ash, 10.0% CP, 3.3% EE, 26.5% CF, and 61.1% TDN. The observed parameters were ration fermentability (pH, NH3, and VFA concentration) and digestibility (DMD and OMD). The data were analyzed using analysis of variance (ANOVA) followed by the Tukey test. The correlation was made before regression analysis to estimate the in vivo parameters from the in vitro. The results showed that pH values are in the normal range (6.7 – 6.8), and insignificantly different between treatments (P>0.05). The concentration of NH3 and VFA were significantly different between the treatments (P<0.05), but T2 produced similar NH3 and VFA concentrations to T1. Similar results were also found in the DMD and OMD. Correlation analysis showed that pH value of T3 correlated significantly with T1, while DMD value of T4 correlated to T1. The T1 DMD (Y) could be estimated from T4 DMD (X) using formula Y (%) = y = -0.091x2 + 9.1632x - 168.4. It is concluded that tropical dairy feedstuffs in vitro digestibility using Tilley and Terry’s method produced similar result to in vivo digestibility method, but in vivo dry matter digestibility can be estimated accurately by in vitro dry matter digestibility using Sutardi method.

Assessment of bioscompatibility of isocyanurate-containing polyurethanes with ifosphamide by in vivo and in vitro methods.

Background. The creation of polymeric composite materials with pronounced biological activity, which are able to act as implants with local prolonged action of the immobilized substance can be widely used in medical practice. Objective. Study of cellular reactions of surrounding tissues of experimental animals to implantation of polymeric composite materials based on isocyanurate-containing polyurethanes with ifosfamide, study of histotoxicity of the obtained materials by tissue culture method. Methods. Polymeric composite materials based on isocyanate-containing polyurethanes without and with ifosfamide were implanted into the body of white laboratory Wistar rats. Cellular responses of the organism and possible changes in the structure of test specimens after implantation were studied by light microscopy by analysis of histological micropreparations. In order to study the peculiarities of the dynamics of growth and development of fibroblastic elements, the method of tissue culture was used. Results. Conducted biological studies by in vivo and in vitro methods allowed to evaluate the effect of immobilized ifosfamide in the structure of isocyanurate-containing polyurethanes on cellular reactions of surrounding tissues during implantation in experimental animals, as well as the effect of extracts from developed polymer samples on cultured cell growth. Conclusion. It was found that the implantation of isocyanurate-containing polyurethanes with ifosfamide led to the development of intense cellular reactions in the area of implant placement, primarily the reaction of round cell elements. The presence of ifosfamide in the structure of the polymeric implantation material probably affected the proliferation of cellular elements, inhibited regenerative processes in the early stages of the study and delayed the formation of a mature connective tissue capsule around the implanted samples. The tissue culture method showed that when making an extract of isocyanurate-containing polyurethanes with ifosfamide in the culture medium, there was a large variability of cell forms, which led to the appearance of macrophage-like elements.

Phytochemical composition and biological screening of two Lophophytum species

Lophophytum species are holoparasites that grow on tree roots. The objectives of the work were to explore the chemical composition of the tubers of two Lophophytum species and to analyze the antioxidant, anti-inflammatory and antilithiatic activity of their extracts using in vitro methods. The chemical composition was determined by histochemical, phytochemical and TLC tests. In addition, the profile of phenolic compounds was determined by HPLC-MS. The presence of secondary metabolites of recognized activity was demonstrated. The results of the HPLC-MS/MS allowed the tentative identification of catechin, luteolin and glycosides of eriodictyol, naringenin and luteolin in the extract of Lophophytum leandri and eriodictyol, naringenin, luteolin and their glycosylated derivatives in Lophophytum mirabile. The extracts showed promising antioxidant (DPPH, ABTS and β-carotene-linoleic acid), anti-inflammatory (inhibition of 5-LOX) and anti-urolytic (by bioautographic TLC) activity. It is noteworthy that these are the first results of the phytochemical composition and biological activity of L. mirabile. However, in vivo studies are required to corroborate these activities.

Designing an ideal alcohol-based hand sanitizer: in vitro antibacterial responses of ethanol and isopropyl alcohol solutions to changing composition

This study aimed to achieve an in vitro quantification of the effects of composition and formulation factors on the killing rates of alcohol-based hand sanitizers. The killing rates of 85% ethyl alcohol (ET) and isopropyl alcohol (IPA) were studied under different conditions such as pH, electrolyte concentration, or inclusion of herbal extracts (cucumber, carrot, and aloe vera), a quaternary ammonium compound, or thickener over different time intervals. Changes in the activities were retested after 3 months as an indication of stability. From two-way ANOVA, both the time of exposure and the sanitizer type affected the activity against Staphylococcus aureus (P = 0.001 for both alcohols), whereas for Escherichia coli, time of exposure was significant (P = 0.027), while sanitizer type was less significant (P = 0.063). Extreme pHs, the presence of ions, and the inclusion of additives such as benzalkonium chloride (BAC), plant extracts, or carbomer impacted the 3-month activity of the samples differently. Important differences existing in the activities of ET and IPA, as a function of formulation factors or use conditions have been quantified using in vitro methods. Formulations should best be tailored for particular purposes and the all-purpose hand sanitizer may not exist. Graphic Abstract