Bioactive Compounds in Red Palm Oil Can Modulate Mechanisms of Actions in In Vitro Anoxic Perfused Rat Hearts
van Rooyen
Red palm oil is refined red-orange commercial oil obtained from the mesocarp of the oil palm (Elaeis guineensis). It consists mainly of glycerides and nonglycerides, such as free fatty acids, carotenoids, tocotrienols, tocopherols, sterols, phospholipids, squalene, coenzyme Q10, and hydrocarbons. The anoxic perfused rat heart model has been used to perform drug testing and examine methods of treatment, both before and after episodes of anoxia/ischemia, to elucidate mechanisms of action in the area of cardiovascular disease. Several studies have shown that animals fed with RPO, added to both a normal and a cholesterol-high diet, exhibit significantly improved postischemic function and reduced infarct size. These findings suggest that RPO can protect the heart in the ischemic and reperfusion period through various mechanisms including NO-cGMP, MMP-2, LDH, prosurvival kinases, and apoptosis. The optimal dose used was 200 μl per day per diet with a 5-week supplementation period.

Tumor suppressive effects of tocotrienol in vivo and in vitro
Sayori Wadaa, Yoshiko Satomia, Michiaki Murakoshib, Noriko Noguchic, Toshikazu Yoshikawae, Hoyoku Nishino

18 November 2005
Tocotrienols have been reported to have higher biological activities than tocopherols. We investigated the antitumor effect of tocotrienols both in vivo and in vitro. Oral administration of tocotrienols resulted in significant suppression of liver and lung carcinogenesis in mice. In human hepatocellular carcinoma HepG2 cells, δ-tocotrienol exerted more significant antiproliferative effect than α-, β-, and γ-tocotrienols. δ-Tocotrienol induced apoptosis, and also tended to induce S phase arrest. On the other hand, gene expression analysis showed that δ-tocotrienol increased CYP1A1 gene, a phase I enzyme. Although further study will be necessary to investigate possible adverse effect, the data obtained in present study suggest that tocotrienols could be promising agents for cancer prevention.

Carotenoid stability during storage of yellow gari made from biofortified cassava or with palm oil
Aurelie Bechoffa, Ugo Chijiokeb, Keith I. Tomlinsa, Pesila Govindena, Paul Ilonac, Andrew Westbya, Erick Boy
June 2015
The carotenoid composition of gari made from biofortified cassava (BG) was compared to that of existing gari of similar appearance but made from white cassava with added red palm oil (RPG). Storage of both yellow gari products was modelled at ambient temperatures typical of tropical areas (19–40 °C) over a 3-month-period at constant relative humidity. Carotenoid content and hence vitamin A activity of the gari products decreased markedly with time and temperature. Trans-β-carotene degradation fitted well the kinetics predicted by the Arrhenius model, in particular for BG. Activation energies for trans-β-carotene were 60.4 and 81.0 kJ mol−1 for BG and RPG respectively (R2 = 0.998 and 0.997, respectively); hence the minimum energy to cause degradation of trans-β-carotene in gari was lower with BG. Rates of degradation of 9-cis-β-carotene in gari were of the same order as with trans-β-carotene. Although the initial content of trans-β-carotene was twice as high in the BG compared to RPG, trans-β-carotene in BG degraded much faster. Results showed that the average shelf life at ambient temperature for BG was significantly shorter than for RPG and therefore carotenoids in BG were less stable than in RPG.

Red Palm Oil Carotenoids: Potential Role in Disease Prevention
A.J.S. Benadé
Refined red palm oil (RPO) contains a spectrum of natural carotenoids which exhibit diverse biological activity. Based on available scientific evidence the inclusion of moderate amounts of RPO or RPO-based products into the daily diet is a healthful and sustainable dietary approach to the prevention of sub-clinical vitamin A deficiency. Carotenoids have the potential to influence molecular and cellular processes which could be instrumental in reducing the risk for chronic diseases such as cardiovascular disease and cancer.

Cholesterol vehicle in experimental atherosclerosis. 22. Refined, bleached, deodorized (RBD) palm oil, randomized palm oil and red palm oil
David Kritchevsky, PhD, Shirley A. Tepper, Arnis Kuksis, PhD, Scott Wright, Susanne K. Czarnecki, PhD
The atherogenic effects of refined, bleached and deodorized (RBD) palm oil were compared with those of randomized RBD palm oil and red palm oil. RBD palm oil contains 41.2% palmitic acid, 2.6% at the SN2 position. In randomized palm oil, 13.6% of the palmitic acid is in the SN2 position. Randomized palm oil is significantly more atherogenic for rabbits than is RBD palm oil, supporting our earlier findings that the increasing amounts of palmitic acid in the SN2 position of a fat lead to an increased atherogenic effect. Red palm oil is the oil initially obtained from the palm fruit which contains carotenes and Vitamin E that are removed during refining. Red palm oil was significantly less atherogenic than RBD palm oil supporting the hypothesis that carotenoids and Vitamin E may protect against atherosclerosis. The oils tested had similar effects on serum and liver lipids.

Effect of red palm oil on some hepatic drug-metabolizing enzymes in rats
Manorama, N. Chinnasamy, C. Rukmini
August 1993
Red palm oil (RPO) from Elaeis guineensis is being considered for use as an edible oil in India as it is one of the richest natural sources of carotenoids. The effect of RPO on the host detoxification system, which is a vital mechanism in cancer prevention, was studied in three separate batches of Wistar/NIN inbred albino rats, and compared with controls, groundnut oil (GNO) and refined bleached deodorized palmolein oil (RBDPO).

Significantly higher levels of GSH-T were observed in F2b and F3b rats given RPO than in those given GNO or RBDPO. In the second experiment. GSH-T induction was also noted, together with increased levels of reduced GSH. Phase I enzymes and total cytochrome P − 450 levels were comparable between groups, indicating that no induction attributable to RPO had occurred. Thus, enhancement of one of the detoxifying phase II enzymes, in conjunction with the lack of induction of those activating phase I enzymes that are known to metabolize phenobarbitone and polycyclic aromatic hydrocarbons, suggests that RPO affords protection against chemical carcinogens, probably because of its carotenoid content.

Red palm oil suppresses the formation of azoxymethane (AOM) induced aberrant crypt foci (ACF) in Fisher 344 male rats
Boatenga, M. Verghesea, C.B. Chawana, L. Shackelforda, L.T. Walkerb, J. Khatiwadaa, D.S. Williams
October 2006
Red palm oil (RPO) contains significant levels of carotenoids and Vitamin E. In this experiment we compared the inhibitory effects of RPO (7% and 14% levels) and soybean oil (7% and 14%) on azoxymethane (AOM) induced aberrant crypt foci (ACF).
The results of this study showed that RPO reduced the incidence of AOM induced ACF and may therefore have a beneficial effect in reducing the incidence of colon cancer.

Effect of palm oil on oxidative stress-induced hypertension in sprague-dawley rats
Agaba A Ganafaa, Robin R Soccia, Danita Eatmana, Natalia Silvestrovc, Imad K Abukhalafa, Mohamed A Bayorh
August 2002
Palm oil reduces BSO-induced oxidative stress and attenuates hypertension by mechanisms involving changes in endothelium-derived factors

Proposed mechanisms for red palm oil induced cardioprotection in a model of hyperlipidaemia in the rat
Johan S. Esterhuysea, Jacques van Rooyenb, Hans Strijdomc, Dirk Bestera, Eugene F. du Toit
High-cholesterol diets alter myocardial and vascular NO-cGMP signaling and have been implicated in ischaemic/reperfusion injury. We investigated the effects of dietary red palm oil (RPO) containing fatty acids, carotonoids, tocopherols and tocotrienols on myocardial ischaemic tolerance and NO-cGMP pathway function in the rat. Wistar rats were fed a standard rat chow±RPO, or a standard rat chow+cholesterol±RPO diet. Myocardial mechanical function and NO-cGMP signaling pathway intermediates were determined before, during and after 25 min ischaemia. RPO-supplementation improved aortic output recovery and increased myocardial ischaemic cGMP concentrations. Simulated ischaemia (hypoxia) increased cardiomyocyte nitric oxide levels in the two RPO supplemented groups, but not in control non-supplemented groups. RPO supplementation also increased hypoxic nitric oxide levels in the control diet fed, but not the cholesterol fed rats. These data suggest that dietary RPO may improve myocardial ischaemic tolerance by increasing bioavailability of NO and improving NO-cGMP signaling in the heart.

p38-MAPK and PKB/Akt, possible role players in red palm oil-induced protection of the isolated perfused rat heart?
Anna-Mart Engelbrechta, Johan Esterhuysea, Eugene F. du Toitc, Amanda Lochnerc, Jacques van Rooyen
April 2006
It has been shown that dietary red palm oil (RPO) supplementation improves reperfusion function. However, no exact protective cellular mechanisms have been established. To determine a potential mechanism for functional improvement, we examined the regulation of both mitogen-activated protein kinases (MAPKs) and PKB/Akt in the presence and absence of dietary RPO supplementation in ischemia/reperfusion-induced injury. Wistar rats were fed a control diet or control diet plus 7 g RPO/kg diet for 6 weeks. Hearts were excised and mounted on an isolated working heart perfusion apparatus. Cardiac function was measured before and after hearts were subjected to 25 min of total global ischemia. Hearts subjected to the same conditions were freeze clamped and used to characterize the degree of phosphorylation of extracellular signal-regulated kinase, p38, c-Jun NH2-terminal protein kinase (JNK) and PKB/Akt. Dietary RPO supplementation significantly improved aortic output recovery (72.1±3.2% vs. 54.0±3.2%, P<.05). This improved aortic output recovery was associated with significant increases in p38 and PKB/Akt phosphorylation during reperfusion when compared with control hearts. Furthermore, a significant decrease in JNK phosphorylation and attenuation of poly(ADP-ribose) polymerase cleavage occurred in the RPO-supplemented group during reperfusion. Our results suggest that dietary RPO supplementation caused differential phosphorylation of the MAPKs and PKB/Akt during ischemia/reperfusion-induced injury. These changes in phosphorylation were associated with improved functional recovery and reduced cleavage of an apoptotic marker, arguing that dietary RPO supplementation may confer protection via the MAPK and PKB/Akt signaling pathways during ischemia/reperfusion-induced injury.

Inclusion of crude palm oil in the broodstock diets of female Nile tilapia, Oreochromis niloticus, resulted in enhanced reproductive performance compared to broodfish fed diets with added fish oil or linseed oil
Wing-Keong Ng, Yan Wang
April 2011
The intensive farming of tilapia is rapidly expanding and the need to produce sufficient quantities of quality fry is becoming crucial to meet increasing global demands for stocking tilapia farms. The present study was conducted to evaluate the effects of dietary lipid source on the reproductive performance of tilapia broodfish. Four isonitrogenous (35% protein) and isolipidic (10%) casein-based diets were formulated with added fish oil (FO), FO and crude palm oil (FO + CPO; 1:1), CPO or linseed oil (LSO) as the lipid source, respectively. Pre-spawning female Nile tilapia (Oreochromis niloticus, GIFT strain) was individually color-tagged, and six females and two males were stocked into a one-tonne breeding tank. Each diet was fed to two tanks of broodfish and the reproductive performance of 12 individual female fish was monitored over 25 weeks. Female broodfish fed the two CPO-based diets showed significantly (P < 0.05) larger gonad sizes and lower intraperitoneal fat compared to fish fed the FO or LSO diets. First spawning occurred earliest in broodfish fed the CPO diet at 30.8 ± 9.9 days compared to 44.1, 45.5 or 76.3 days for fish fed the FO + CPO, FO or LSO diet, respectively. The highest number of actively spawning tilapia was observed in fish fed the FO + CPO diet, followed by fish fed the CPO, FO or LSO diet, respectively. At the end of 25 weeks, tilapia fed the two CPO-based diets produced the highest total number of eggs per fish due to the shorter inter spawning interval and higher spawning frequency. Mean diameter, volume and weight of eggs did not vary among dietary treatments. Egg hatchability was significantly higher in broodfish fed the CPO-based diets. The fatty acid composition of the muscle, gonad, egg and newly hatched larvae was influenced by dietary lipid source. However, evidence of preferential fatty acid conservation, conversion and utilization was also observed in these tissues. The fatty acid composition of tilapia eggs did not vary over four consecutive spawns. The gonads, eggs and larvae of tilapia fed the CPO diet contained the highest relative concentration of saturates, monoenes, arachidonic acid and n-6/n-3 ratio. The high total n-3 PUFA concentration observed in the gonads of fish fed the LSO diet, and to a lesser degree the FO diet, seemed to be detrimental to the reproductive performance of tilapia. In conclusion, the inclusion of CPO in tilapia broodstock diets can be a cost-effective method to increase tilapia fry production.

Tocopherols and tocotrienols plasma levels are associated with cognitive impairment
Francesca Mangialasche, Weili Xu, Miia Kivipelto, Emanuela Costanzi, Sara Ercolani, Martina Pigliautile, Roberta Cecchetti, Mauro Baglioni, Andrew Simmons, Hilkka Soininen, Magda Tsolaki, Iwona Kloszewska, Bruno Vellas, Simon Lovestone, Patrizia Mecocci, AddNeuroMed Consortium
Vitamin E includes 8 natural compounds (4 tocopherols, 4 tocotrienols) with potential neuroprotective activity. α-Tocopherol has mainly been investigated in relation to cognitive impairment. We examined the relation of all plasma vitamin E forms and markers of vitamin E damage (α-tocopherylquinone, 5-nitro-γ-tocopherol) to mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Within the AddNeuroMed-Project, plasma tocopherols, tocotrienols, α-tocopherylquinone, and 5-nitro-γ-tocopherol were assessed in 168 AD cases, 166 MCI, and 187 cognitively normal (CN) people. Compared with cognitively normal subjects, AD and MCI had lower levels of total tocopherols, total tocotrienols, and total vitamin E. In multivariable-polytomous-logistic regression analysis, both MCI and AD cases had 85% lower odds to be in the highest tertile of total tocopherols and total vitamin E, and they were, respectively, 92% and 94% less likely to be in the highest tertile of total tocotrienols than the lowest tertile. Further, both disorders were associated with increased vitamin E damage. Low plasma tocopherols and tocotrienols levels are associated with increased odds of MCI and AD.

Tocotrienol-rich fraction of palm oil induces cell cycle arrest and apoptosis selectively in human prostate cancer cells
Janmejai K. Srivastavaa, Sanjay Gupta
July 2006
These results suggest that the palm oil derivative TRF is capable of selectively inhibiting cellular proliferation and accelerating apoptotic events in prostate cancer cells. TRF offers significant promise as a chemopreventive and/or therapeutic agent against prostate cancer.

Modulation of antioxidant status in streptozotocin-induced diabetic male wistar rats following intake of red palm oil and/or rooibos
Ademola Ayelesoa, Nicole Brooksb, Oluwafemi Oguntibejua
July 2014
The results revealed the anti-oxidative potentials of red palm oil, rooibos and their combination in diabetic conditions and hence, they could be useful in the management of diabetes and its complications.

Effect of adding palm oil to the diet of dairy sheep on milk production and composition, function of liver and kidney, and the concentration of cholesterol, triglycerides and progesterone in blood serum
Anderson E. Bianchia, Vicente P. Macedoa, Raqueli T. Françab, Sonia T.A. Lopesb, Leandro S. Lopesc, Lenita M. Stefanic, d, Andréia Volpatoc, Horácio L. Limac, Diovani Paianoc, Gustavo Machadoe, Aleksandro S. Da Silva
March 2014
The aim of this study was to evaluate the effect of adding palm oil to the diet of dairy sheep on milk production and composition, function of liver and kidney, and the concentration of cholesterol, triglycerides and progesterone in blood serum. Thirty ewes in early lactation were divided into three groups (n = 10) receiving an isoproteic and isoenergetic diet. Palm oil (PALM) was added to the diet at different concentrations: 0% (PALM0), 4.0% (PALM4) and 6.0% (PALM6). Milk production was evaluated on days 0, 60, 120, and blood samples were collected in the same periods. Sera samples were analyzed for aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), urea, creatinine, cholesterol, triglycerides, and progesterone. Changes in the volume of milk produced and milk composition (fat, protein, and lactose) in sheep fed with palm oil were not observed between groups. No significant difference was observed between groups for AST, GGT, and creatinine at day 60. However, an increase was observed in AST and GGT activities in the sera of animals from the group PALM4 compared to the control group (PALM0) at day 120. Urea, cholesterol, triglycerides, and progesterone levels had a significant increase in animals from groups PALM4 and PALM6 when compared to the group PALM0 at days 60 and 120. In summary, the addition of palm oil in the diet of dairy sheep influences the metabolism of lipid and protein and caused an increase on liver enzyme activity in proportion to palm oil concentration. The protected fat increased the levels of progesterone, which may improve reproductive performance.

Dietary red palm oil improves reperfusion cardiac function in the isolated perfused rat heart of animals fed a high cholesterol diet
A.J. Esterhuysea, E.F. du Toitb, A.J.S. Benadèc, J. van Rooyen
March 2005
It has been shown that dietary red palm oil (RPO) supplementation improved reperfusion function. However, no exact protective cellular mechanisms have been established. Our aim was to search for a possible cellular mechanism and a role for fatty acids. Rats were fed a standard rat chow, plus cholesterol and/or RPO-supplementation for 6 weeks. Functional recovery, myocardial phospholipid and cAMP/cGMP levels were determined in isolated rat hearts subjected to 25 min of normothermic total global ischaemia. Dietary RPO in the presence of cholesterol improved aortic output (AO) recovery (63.2±3.06%, P<0.05) vs. cholesterol only (36.5±6.2%). The improved functional recovery in hearts supplemented with RPO vs. control was preceded by an elevation in the cGMP levels early in ischaemia (RPO 132.9±36.3% vs. control 42.7±24.4%, P<0.05). Concurrently, cAMP levels decreased (RPO −8.3±6.9% vs. control 19.9±7.7%, P<0.05). Our data suggest that dietary RPO-supplementation improved reperfusion AO through mechanisms that may include activation of the NO-cGMP and inhibition of the cAMP pathway.