Total phenolic content, antioxidant and cytotoxic activity of cocoa (Theobroma cacao L.) polyphenols extracts on cancer cell lines

Introduction: Cancer chemopreventive agents from natural sources have been actively investigated over the years to seek prevention against cancer. In this study, cocoa polyphenols extract (CPE) was examined to explore its antioxidant and cytotoxicity activities. Methods: CPE was analysed for total phenolic content (TPC) and antioxidant activity (DPPH radical scavenging activity and FRAP ferric-reducing antioxidant power assays). In vitro cytotoxicity effect of CPE against HepG2, HT-29, HeLa, MCF-7, MDA-MB-231 and WRL-68 cell lines after 48 h exposure was measured by MTT assay. Results: The study showed that CPE had higher total phenolic content (13560.0±420.1 mg GAE/100g dry weight of sample) than vitamin E (p<0.05). CPE exhibited strong antioxidant activity comparable with ascorbic acid in both DPPH (IC50 = 14.73±1.47 μg/ml) and FRAP (2130.33±2.33 μM of FE/1 mg of dry weight of sample). The cytotoxicity study showed that CPE exhibited the highest cytotoxicity effect against MCF-7 with lowest IC50 value (3.00±0.29 mg/ml) compared to other cancer cell lines after 48 h treatment (p<0.05). Conclusion: Our results indicate that CPE demonstrated high total phenolic content, free radical scavenging activity, ferric reducing ability and cytotoxicity activity towards HepG2, HT-29, HeLa, A549, MDA-MB- 231 and MCF-7 cancer cell lines. Further isolation of bioactive constituents from CPE should be done to characterise its potential chemopreventive activity as well as to elucidate the mechanism of cancer cell death induced by CPE

Total phenolic content and antioxidant activities of corchorus capsularis and stevia rebaudiana extracts

The purposes of this study were to determine total phenolic content (TPC) and antioxidant activities of C.capsularis and S.rebaudiana. Methodology: C.capsularis was extracted successively with methanol and chloroform methanol separately while S.rebaudiana was extracted using methanol and chloroform solvent. The plant extracts were used to conduct various antioxidant assays. TPC assay using Folin-Ciocalteu method was used to assess the presence of phenolic compounds in each sample. The extracts samples were also subjected to assess their potential antioxidant activities through DPPH, ABTS and FRAP assay. The present study showed that both methanol extract of C.capsularis and S.rebaudiana had highest TPC, followed by chloroform extract of S.rebaudiana and chloroform methanol extract of C.capsularis. Next, the DPPH radical scavenging assay was found to be higher in the methanol extract of S.rebaudiana at the concentration of 154.67μg/ml. The cation radical scavenging activity, measured by ABTS assay was shown that methanol extract of S.rebaudiana (278μg/ml) had the lowest EC50 as compared to the other samples. Interestingly, among the various samples, the methanol extract of S.rebaudiana demonstrated a very significant antioxidant activity in FRAP assay (p<0.05). The results of the present study showed that all the extract samples contain significantly high phenolic compounds with superior antioxidant activity as evidence by scavenging of free radical including DPPH and ABTS. In conclusion, it is conceivable that the C.capsularis and S.rebaudiana have shown potential as sources of natural antioxidants

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Physicochemical properties of palm oil and palm kernel oil blend fractions after interesterification

Abstract The objective of this study was to determine the physicochemical properties of olein and stearin fractions obtained from non-interesterified (NIE), chemically interesterified (CIE) and enzymatically interesterified (EIE) 50:50 palm oil and palm kernel oil blend. The potential applications of both olein and stearin fractions were also identified. Stearin and olein fractions were obtained through a single stage dry fractionation at 25°C. The physicochemical properties analysed include percent yield, fatty acid composition (FAC), iodine value (IV), smoke point, cloud point, slip meting point (SMP) and solid fat content. Results indicated that the percent olein yield was higher from the EIE (85%) and NIE blends (82.2%) than in CIE blend (41.8%). The EIE blend produce liquid fraction with the highest amount of unsaturated fatty acid (~50%). Hence, the olein fraction of EIE blend best met the requirement to be used as frying oil based on the highest smoke point (265.1°C) and lowest cloud point (6.2°C). On the other hand, the stearin fraction of CIE blend might be suitable to be used in margarine formulation as it has SMP close to body temperature

First report on a diverse Neogene cartilaginous fish fauna from Borneo (Ambug Hill, Brunei Darussalam)

The highest biodiversity of marine fishes occurs in South-east Asia in the Indo-Australian Archipelago (IAA). However, the fossil record of fishes is very sparse and extremely incomplete in the IAA. Here we present a diverse fossil cartilaginous fish fauna from Borneo, found in late Miocene sediments in Brunei Darussalam. This fauna provides the first insight into the types of fishes that existed in the IAA region about 6.5\u20138 million years ago. The chondrichthyan remains belong to 24 selachian and batoid taxa. The shark fauna is dominated by Carcharhiniformes, comprising three families with at least 12 taxa, most related to modern species: Hemigaleidae (one species), Carcharhinidae (nine) and Sphyrnidae (two). In addition, the teeth of one Lamniformes shark, the extinct giant macro-predator Otodus (Megaselachus) megalodon, are present in the fauna. The batoids are dominated by Myliobatiformes from the following families: Dasyatidae (three species), Aetobatidae (one), Myliobatidae (three), Rhinopteridae (one), while three taxa of the order Rhinopristiformes were also recovered: Pristidae (one species), and Rhinidae (two). Such diversity of fossil cartilaginous fish has never before been reported from the tropical region of South-east Asia. The dominance of the carcharhinid sharks and small rays suggests a shallow marine, coastal palaeoenvironment. The presence of the freshwater shark genus Glyphis indicates a nearby fluvial influence. Some species of the ray genera, such as Himantura or Pastinachus, have also been reported from estuaries and fresh water. The lack of some generally common Neogene taxa, such as Odontaspididae, Lamnidae and Alopidae, may be linked to such local factors and the coastal shallow-water environment