A Review: Aspects of the African Oil Palm (Elaeis guineesis jacq.) and the Implications of its Bioactives in Human Health

Repeatedly heated palm olein disrupts male reproductive system of rat: A histological and biochemical study

The aim of this study was to investigate the effect of heated and unheated palm olein in different doses on the male reproductive system of rats. Forty male rats were randomly classified into five groups (n = 8) including Control, Low palm, High palm, Heated low palm and Heated high palm. The palm olein was administrated orally for 6 months. Histological and biochemical parameters of the male reproductive system were measured. There was a significant reduction in sexual hormones, serum levels of superoxide dismutase, high-density lipoprotein, testis weight and sperm parameters in the high dose and heated palm olein groups compared to the other group (p < 0.05). The levels of malondialdehyde, apoptosis rate, proteins levels (TNF-α, IL-1β, IL-6), low-density lipoprotein, cholesterol, triglyceride and the weight of the rats were significantly higher in the high dose and heated palm olein groups than the others (p < 0.05). High dose and heated palm olein treatment could damage the male rat's reproductive indices that were related to increased inflammatory markers, decreased sex hormone levels, and negative effects on testicular tissue and sperm parameters.

Tropical Oil Consumption and Cardiovascular Disease: An Umbrella Review of Systematic Reviews and Meta Analyses

The health effects of saturated fat, particularly tropical oil, on cardiovascular disease are unclear. We investigated the effect of tropical oil (palm and coconut oils), lard, and other common vegetable oils (soybean and rice bran oils) that are widely used in tropical and Asian countries on lipid profiles. We performed an umbrella review of meta-analyses and systematic reviews. Electronic databases (Medline, Scopus, Embase, and Cochrane) were searched up to December 2018 without language restriction. We identified nine meta-analyses that investigated the effect of dietary oils on lipid levels. Replacement of polyunsaturated fatty-acid-rich oils (PUFAs) and monounsaturated FA-rich oils (MUFAs) with palm oil significantly increased low-density lipoprotein cholesterol (LDL-c), by 3.43 (0.44-6.41) mg/dL and 9.18 (6.90-11.45) mg/dL, respectively, and high-density lipoprotein cholesterol (HDL-c), by 1.89 (1.23-2.55) mg/dL and 0.94 (-0.07-1.97) mg/dL, respectively. Replacement of PUFAs with coconut oil significantly increased HDL-c and total cholesterol -by 2.27 (0.93-3.6) mg/dL and 5.88 (0.21-11.55) mg/dL, respectively-but not LDL-c. Substituting lard for MUFAs and PUFAs increased LDL-c-by 8.39 (2.83-13.95) mg/dL and 9.85 (6.06-13.65) mg/dL, respectively-but not HDL-c. Soybean oil substituted for other PUFAs had no effect on lipid levels, while rice bran oil substitution decreased LDL-c. Our findings show the deleterious effect of saturated fats from animal sources on lipid profiles. Replacement of unsaturated plant-derived fats with plant-derived saturated fats slightly increases LDL-c but also increases HDL-c, which in turn may exert a neutral effect on cardiovascular health.

The estimated intake of palm oil in Spain and Germany

Palm oil is one of the most widely used vegetable oils by the food industry but there is limited information on actual intake. A detailed intake assessment of palm oil for Spain and Germany was conducted. For Spain, mean palm oil intakes ranged from 2.06 g/day in the elderly to 4.54 g/day in children and adolescents, while high-level intakes ranged from 10.34 g/day in the elderly to 20.88 g/day in toddlers. For Germany, mean palm oil intakes ranged from 3.06 g/day in toddlers to 6.22 g/day in the very elderly, while high-level intakes ranged from 13.61 g/day in toddlers to 30.10 g/day in the elderly. For both countries, the main contributing food categories to mean palm oil intake were biscuits, cakes, bread, breakfast cereal and margarine. In summary, the present paper provides a realistic assessment of the intake of palm oil in two EU countries for different population groups.

Safety and Neuroprotective Efficacy of Palm Oil and Tocotrienol-Rich Fraction from Palm Oil: A Systematic Review

Background: Several natural products have been reported to elicit beneficial effects against neurodegenerative disorders due to their vitamin E contents. However, the neuroprotective efficacy of palm oil or its tocotrienol-rich fraction (TRF) from the pre-clinical cell and animal studies have not been systematically reviewed. Methods: The protocol for this systematic review was registered in “PROSPERO” (CRD42019150408). This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The Medical Subject Heading (MeSH) descriptors of PubMed with Boolean operators were used to construct keywords, including (“Palm Oil”[Mesh]) AND “Nervous System”[Mesh], (“Palm Oil”[Mesh]) AND “Neurodegenerative Diseases”[Mesh], (“Palm Oil”[Mesh]) AND “Brain”[Mesh], and (“Palm Oil”[Mesh]) AND “Cognition”[Mesh], to retrieve the pertinent records from PubMed, Scopus, Web of Science and ScienceDirect from 1990 to 2019, while bibliographies, ProQuest and Google Scholar were searched to ensure a comprehensive identification of relevant articles. Two independent investigators were involved at every stage of the systematic review, while discrepancies were resolved through discussion with a third investigator. Results: All of the 18 included studies in this review (10 animal and eight cell studies) showed that palm oil and TRF enhanced the cognitive performance of healthy animals. In diabetes-induced rats, TRF and α-tocotrienol enhanced cognitive function and exerted antioxidant, anti-apoptotic and anti-inflammatory activities, while in a transgenic Alzheimer’s disease (AD) animal model, TRF enhanced the cognitive function and reduced the deposition of β-amyloid by altering the expression of several genes related to AD and neuroprotection. In cell studies, simultaneous treatment with α-tocotrienols and neurotoxins improved the redox status in neuronal cells better than γ- and δ-tocotrienols. Both pre-treatment and post-treatment with α-tocotrienol relative to oxidative insults were able to enhance the survival of neuronal cells via increased antioxidant responses. Conclusions: Palm oil and its TRF enhanced the cognitive functions of healthy animals, while TRF and α-tocotrienol enhanced the cognitive performance with attenuation of oxidative stress, neuroinflammation and apoptosis in diabetes-induced or transgenic AD animal models. In cell studies, TRF and α-tocotrienol exerted prophylactic neuroprotective effects, while α-tocotrienol exerted therapeutic neuroprotective effects that were superior to those of γ- and δ-tocotrienol isomers.

Development of High-Density SNP Markers and Their Application in Evaluating Genetic Diversity and Population Structure in Elaeis guineensis

High-density single nucleotide polymorphisms (SNPs) are used as highly favored makers to analyze genetic diversity and population structure, to construct high-density genetic maps and provide genotypes for genome-wide association analysis. In order to develop genome-wide SNP markers in oil palm (Elaeis guineensis), single locus amplified fragment sequencing (SLAF-seq) technology was performed in a diversity panel of 200 oil palm individuals and 1,261,501 SNPs were identified with minor allele frequency > 0.05 and integrity > 1. Among them, only 17.81% can be mapped within the genic region and the remaining was located into the intergenic region. A positive correlation was detected between the distribution of SNP markers and retrotransposons [transposable elements (TEs)]. Population structure analysis showed that the 200 individuals of oil palm can be divided into five subgroups based on cross-validation errors. However, the subpopulations divided for the 200 oil palm individuals based on the SNP markers were not accurately related to their geographical origins and 80 oil palm individuals from Malaysia showed highest genetic diversity. In addition, the physical distance of linkage disequilibrium (LD) decay in the analyzed oil palm population was 14.516 kb when r² = 0.1. The LD decay distances for different chromosomes varied from 3.324 (chromosome 15) to 19.983 kb (chromosome 7). Our research provides genome-wide SNPs for future targeted breeding in palm oil.

Changes in oxidation indices and minor components of low free fatty acid and freshly extracted crude palm oils under two different storage conditions

This article reports on the changes of oxidation indices and minor components of low free fatty acid (FFA) and freshly extracted crude palm oils after storage at ambient (28 ± 1 C) and 60 C for 77 days. The changes in peroxide value (PV), FFA, extinction coefficient at 233 and 269 nm (K₂₃₃ and K₂₆₉), bleachability index (DOBI), carotene and vitamin E contents were monitored. PV, FFA, K₂₃₃ and K₂₆₉ of both oil samples increased as storage progressed while the values of carotene and vitamin E contents decreased. At the end of storage period at 60 °C, the carotene content of low FFA crude palm oil was 4.24 ppm. The storage conditions used led to the loss of entire vitamin E fractions of both oil samples as well as a reduction in DOBI values except for freshly extracted crude palm oil stored at ambient temperature.

Method developments to extract proteins from oil palm chromoplast for proteomic analysis

Proteins from the plant chromoplast are essential for many physiological processes such as fatty acid biosynthesis. Different protein extraction methods were tested to find the most robust method to obtain oil palm chromoplast proteins for mass spectrometry analysis. Initially, two different solvents were employed to reduce the fruit lipids. Then, two plant cell wall digestive enzymes were used to acquire the protoplasts to increase the protein extraction effectiveness. A two-stage centrifugation-based fractionation approach enhanced the number of identified proteins, particularly the fatty acid biosynthetic enzymes. The effectiveness of each extraction method was assessed using protein yields and 2DE gel profiles. The ideal method was successfully used to establish the 2DE chromoplast proteome maps of low and high oleic acid mesocarps of oil palm. Further nanoLC–MS/MS analysis of the extracted chromoplast proteins led to the identification of 162 proteins, including some of the main enzymes involved in the fatty acid biosynthesis. The established procedures would provide a solid foundation for further functional studies, including fatty acid biosynthetic expression profiling and evaluation of regulatory function.

Independent origins and incipient speciation among host-associated populations of Thielaviopsis ethacetica in Cameroon

Thielaviopsis ethacetica was recently reinstated as a distinct taxon using DNA phylogenies. It is widespread affecting several crop plants of global economic importance. In this study, microsatellite markers were developed and used in conjunction with sequence data to investigate the genetic diversity and structure of Th. ethacetica in Cameroon. A collection of 71 isolates from cacao, oil palm, and pineapple, supplemented with nine isolates from other countries were analysed. Four genetic groups were identified. Two of these were associated with oil palm in Cameroon and showed high genetic diversity, suggesting that they might represent an indigenous population of the pathogen. In contrast, the remaining two groups, associated with cacao and pineapple, had low genetic diversity and, most likely, represent introduced populations. There was no evidence of gene flow between these groups. Phylogenetic analyses based on sequences of the tef1-α as well as the combined flanking regions of six microsatellite loci were consistent with population genetic analyses and suggested that Th. ethacetica is comprised of two divergent genetic lineages.