An improved MTT colorimetric method for rapid viable bacteria counting

The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay has been employed in the analysis of bacterial growth. In comparison to experiments conducted on mammalian cells, the MTT bacterial assay encounters a greater number of interfering factors and obstacles that impact the accuracy of results. In this study, we have elucidated an improved MTT assay protocol and put forth an equation that establishes a correlation between colony-forming units (CFU) and the amount of formazan converted by the bacteria, drawing upon the fundamental principle of the MTT assay. This equation is represented as CFU=kF. Furthermore, we have explicated a methodology to determine the scale factor "k" by employing S. aureus and E. coli as illustrative examples. The findings indicate that S. aureus and E. coli reduce MTT by a cyclic process, from which the optimal reduction time at room temperature was determined to be approximately 30 mins. Furthermore, individual E. coli exhibits an MTT reduction capacity approximately four times greater than that of S. aureus. HPLC analysis proves to be the most accurate method for mitigating interferences during the dissolution and quantification of formazan. Additionally, this study has identified a new constraint related to the narrow linear range (0-125 μg/mL) of formazan concentration-absorbance and has presented strategies to circumvent this limitation.fals

Recent advances in encapsulation techniques for cinnamon bioactive compounds: A review on stability, effectiveness, and potential applications

Cinnamon is renowned worldwide for its beneficial health-promoting properties. However, its application in the food industry faces significant challenges due to chemical instability, leading to the degradation of its bioactive compounds, as well as the development of undesirable sensory characteristics caused by the precipitation of salivary proteins by the bioactives. To address these issues, encapsulation methods (both micro and nano) have been developed and studied extensively. This review focuses on recent advances in such encapsulation techniques used to safeguard and deliver cinnamon bioactives, with special emphasis on the spray drying method. The methods employed to evaluate the physicochemical, rheological, and sensorial properties of nano and microparticles are also comprehensively reviewed. The review addresses the challenges associated with encapsulation, including encapsulation efficiency, long-term stability, and release kinetics, and proposes potential strategies to overcome these challenges. Furthermore, the paper presents future perspectives and research directions in cinnamon encapsulation, shedding light on novel materials, advanced characterization techniques, and hybrid encapsulation systems. Overall, encapsulation demonstrates the potential to preserve and harness the therapeutic benefits of cinnamon's bioactive compounds for a wide array of food, pharmaceutical, and nutraceutical applications. With ongoing research and advancements in encapsulation techniques, cinnamon bioactives can be effectively utilized to develop functional and health-enhancing products, catering to the diverse needs of consumers worldwide.fals

Phenolic compounds from macadamia husk: An updated focused review of extraction methodologies and antioxidant activities

This review explores the potential of agri-food waste materials, with a particular focus on macadamia nut by-products. Industrial processing of macadamia nuts yields a significant volume of by-products, including green husk and woody shell. Recent research has highlighted these by-products as readily available, cost-effective rich sources of phenolic compounds, renowned for their potent antioxidant and antibacterial properties. This paper emphasizes the importance of selecting an optimal extraction method to fully harness the bioactive potential of these phenolic compounds. In this work, we provide a comprehensive overview of conventional and advanced extraction techniques that are used to extract phenolic compounds from macadamia by-products, with a particular focus on the methods applied to macadamia green husk. Among the various techniques, it appears that ultrasound-assisted extraction, especially when combined with aqueous organic solvents, is more efficient than other methods for this purpose. This review also addresses the challenges in phenolic compound recovery, primarily due to the lack of a standardized extraction process. This often results in the extensive use of extraction solvents to achieve an extract that is rich in phenolic compounds. Overall, this research offers a valuable understanding of the most effective methods for the extraction and recovery of phenolic compounds from macadamia by-products and discusses the potential for scaling up these extraction processes. Hence, it can serve as a useful resource for researchers and industry professionals interested in sustainable and efficient utilization of by-products of the nut industry.fals

Rapid identification of main antibacterial components from New Zealand ‘Hass’ avocado peel hexane extract

‘Hass’ avocado (Persea americana Mill) is a very popular tropical fruit that contains several nutrients, including vitamins, proteins, minerals, and unsaturated fatty acids. ‘Hass’ avocado peel is one of the by-products obtained from the New Zealand (NZ) avocado processing industry. The current study focused on the antibacterial components from hexane ‘Hass’ avocado peel extract. The aim was to perform microbiological screening of NZ hexane ‘Hass’ avocado peel extract using Staphylococcus aureus. We used thin- layer chromatography (TLC) with direct microbiological detection to isolate the individual components that showed antibacterial activity. Mass spectrometry (MS) analysis characterized the isolated components from hexane peel extract. (15Z)-9,12,13-Trihydroxy-15-octadecenoic acid, (±)9-HpODE, and NP-011548 are the three fatty acids that have been tentatively identified. Present findings provide new bioactive components from avocado peel and suggest potential applications for this extract as a natural antibacterial additive in soaps, and detergents.fals

Reduction of the attachment, survival and growth of L. monocytogenes on lettuce leaves by UV-C stress

Mild stress of leafy greens by UV-C radiation has been reported to stimulate plant defences capable of reducing pathogens on produce surfaces. In this study, the attachment, survival and growth of Listeria monocytogenes was investigated on lettuces stressed with mild UV-C radiation (1.3 and 2.6 kJm−2). Attachment of L. monocytogenes to UV-C stressed (1.3 kJm−2) lettuce leaves after 1 h was significantly (p < 0.05) reduced by 1.4–1.5 log cfu/cm2. UV-C stress also reduced the survival of L. monocytogenes on lettuce by 1.8–1.9 log cfu/g 96 h after inoculation, however a higher dosage of UV-C stress (2.6 kJm−2) did not inhibit the survival of L. monocytogenes. The total phenolic compounds in lettuce significantly increased following UV-C stress (1.3 kJm−2) indicating the accumulation of polyphenols might have contributed to the inhibition of L. monocytogenes attachment and growth. Appropriate dosage of mild UV-C stress of lettuce can reduce the attachment, survival and growth of L. monocytogenes in lettuce and can therefore be explored further for application in fresh produce safety.fals

20(S)-25-methoxyl-dammarane-3β, 12β, 20-triol, a novel natural product for prostate cancer therapy: activity in vitro and in vivo and mechanisms of action

We recently isolated 20(S)-25-methoxyl-dammarane-3β, 12β, 20-triol (25-OCH3-PPD), a natural product from Panax notoginseng, and demonstrated its cytotoxicity against a variety of cancer cells. Here we report the effects of this compound in vitro and in vivo on human prostate cancer cells, LNCaP (androgen-dependent) and PC3 (androgen-independent), in comparison with three structurally related ginsenosides, ginsenoside Rh2, ginsenoside Rg3, and 20(S)-protopanaxadiol. Of the four test compounds, 25-OCH3-PPD was most potent. It decreased survival, inhibited proliferation, induced apoptosis, and led to G1 cell cycle arrest in both cell lines. It also decreased the levels of proteins associated with cell proliferation (MDM2, E2F1, cyclin D1, and cdks 2 and 4) and increased or activated pro-apoptotic proteins (cleaved PARP, cleaved caspase-3, -8, and -9). In LNCaP cells, 25-OCH3-PPD inhibited the expression of the androgen receptor and prostate-specific antigen. Moreover, 25-OCH3-PPD inhibited the growth of prostate cancer xenograft tumours. Combining 25-OCH3-PPD with conventional chemotherapeutic agents or with radiation led to potent antitumour effects; tumour regression was almost complete following administration of 25-OCH3-PPD and either taxotere or gemcitabine. 25-OCH3-PPD also demonstrated low toxicity to noncancer cells and no observable toxicity in animals. In conclusion, our preclinical data indicate that 25-OCH3-PPD is a potential therapeutic agent against both androgen-dependent and androgen-independent prostate cancer

Strategies for the Use of Fallback Foods in Apes

Researchers have suggested that fallback foods (FBFs) shape primate food processing adaptations, whereas preferred foods drive harvesting adaptations, and that the dietary importance of FBFs is central in determining the expression of a variety of traits. We examine these hypotheses in extant apes. First, we compare the nature and dietary importance of FBFs used by each taxon. FBF importance appears greatest in gorillas, followed by chimpanzees and siamangs, and least in orangutans and gibbons (bonobos are difficult to place). Next, we compare 20 traits among taxa to assess whether the relative expression of traits expected for consumption of FBFs matches their observed dietary importance. Trait manifestation generally conforms to predictions based on dietary importance of FBFs. However, some departures from predictions exist, particularly for orang-utans, which express relatively more food harvesting and processing traits predicted for consuming large amounts of FBFs than expected based on observed dietary importance. This is probably due to the chemical, mechanical, and phenological properties of the apes’ main FBFs, in particular high importance of figs for chimpanzees and hylobatids, compared to use of bark and leaves—plus figs in at least some Sumatran populations—by orang-utans. This may have permitted more specialized harvesting adaptations in chimpanzees and hylobatids, and required enhanced processing adaptations in orang-utans. Possible intercontinental differences in the availability and quality of preferred and FBFs may also be important. Our analysis supports previous hypotheses suggesting a critical influence of the dietary importance and quality of FBFs on ape ecology and, consequently, evolution

Screening for paclitaxel and other taxanes in kernel and shell of Corylus avellana (Hazelnut)

Interestingly, paclitaxel was found in shells and leaves of hazelnut plant Corylus avellana. The aim of this present work was to verify whether hazelnut kernel contained paclitaxel. Hazelnut kernels were obtained from two places (local market and Oregon, USA) were analyzed by HPLC-MS. Paclitaxel and other taxanes 10-deacetylbaccatin III, Baccatin III, 10-deacetyl-7-xylosylcephalomannine, 10-deacetyl-7- xylosylpaclitaxel, 10-deacetylpaclitaxel, 7-xylosylpaclitaxel, Cephalomanine, 10-deacetyl-7- epipaclitaxel, 7-epi-paclitaxel were analyzed based on m/z value of molecular ion but none was found except for molecular ion of m/z=854 in the crude extract of kernel from a local market and shell from Oregon, US. The molecular ion was suspected belonging to 7-epi-paclitaxel, an isomer of paclitaxel. 7- epi-paclitaxel could be present in the extract of kernel and shell of tested varieties in this study. Paclitaxel was not detected it could have degraded during sampling process or the tested varieties did not produce paclitaxel or was too low to be detected.fals