Juliana Md. Jaffri

Antihypertensive and cardiovascular effects of catechin-rich oil palm (Elaeis guineensis) leaf extract in nitric oxide-deficient rats.

Oil palm (Elaeis guineensis) leaf extract (OPLE) possesses good ex vivo vasodilation and antioxidant properties. This study evaluated the catechin-rich OPLE antioxidant, antihypertensive, and cardiovascular effects in normal and nitric oxide (NO)-deficient hypertensive rats. OPLE was administered orally (500 mg/kg of body weight/day) to normotensive Wistar rats and N(ω)-nitro-L-arginine methyl ester (L-NAME)-induced NO-deficient hypertensive rats. OPLE significantly (P<.05) attenuated blood pressure increases, increased serum NO, reduced lipid peroxidation, and showed antioxidant effects in NO-deficient hypertensive rats. OPLE decreased the coronary arteriole wall-to-lumen ratio to near normal values under NO deficiency. Although OPLE showed good antihypertensive and antioxidant effects under NO deficiency, it was not hypotensive to normal rats and produced no chronic cardiovascular toxicity in any of the rats throughout the 12-week study. This is the first report on the in vivo antihypertensive properties of green tea catechins extracted from an alternative source, namely, oil palm leaf, for use as a medicinal food for hypertension and cardiovascular ailments.

Effects of catechin-rich oil palm leaf extract on normal and hypertensive rats' kidney and liver

Catechin-rich oil palm (Elaeis guineensis) leaf extract (OPLE) possesses good ex vivo vasodilation, antioxidant and cardiovascular properties. This study evaluated the beneficial or toxic effects of OPLE on the liver and kidneys of normal and hypertensive rats. The OPLE (500mg/kg body weight) were administered orally to normal Wistar Kyoto rats, spontaneously hypertensive rats (SHR) and N-ω-nitro-l-arginine methyl ester (l-NAME)-induced NO-deficient hypertensive rats. The OPLE reduced hypertension in NO-deficient rats, but not in SHR. Hepatocytes or glomeruli injury and oxidative markers were high in hypertensive rats compared to normal rats, and they were reduced (p<0.05) by OPLE supplementation, even when there was no blood pressure reduction. Unlike the hypertensive drug captopril, the OPLE showed no toxicity to normal rats. The dose reported is equivalent 0.5g of catechins/day for humans or 2.5cups of tea. The catechins are from an abundant alternative source for potential use as functional food.

PVA-PEG physically cross-linked hydrogel film as a wound dressing: Experimental design and optimization

Abstract The development of hydrogel films as wound healing dressings is of a great interest owing to their biological tissue-like nature. Polyvinyl alcohol/polyethylene glycol (PVA/PEG) hydrogels loaded with asiaticoside, a standardized rich fraction of Centella asiatica, were successfully developed using the freeze–thaw method. Response surface methodology with Box–Behnken experimental design was employed to optimize the hydrogels. The hydrogels were characterized and optimized by gel fraction, swelling behavior, water vapor transmission rate and mechanical strength. The formulation with 8% PVA, 5% PEG 400 and five consecutive freeze–thaw cycles was selected as the optimized formulation and was further characterized by its drug release, rheological study, morphology, cytotoxicity and microbial studies. The optimized formulation showed more than 90% drug release at 12 hours. The rheological properties exhibited that the formulation has viscoelastic behavior and remains stable upon storage. Cell culture studies confirmed the biocompatible nature of the optimized hydrogel formulation. In the microbial limit tests, the optimized hydrogel showed no microbial growth. The developed optimized PVA/PEG hydrogel using freeze–thaw method was swellable, elastic, safe, and it can be considered as a promising new wound dressing formulation.

Cognitive enhancement and neuroprotection by catechin-rich oil palm leaf extract supplement

BACKGROUND Catechin-rich oil palm (Elaeis guineensis) leaf extract (OPLE) has good cardiovascular and phytoestrogenic properties. The OPLE (0.5 g day(-1) ) was supplemented to young, healthy, adult human volunteers, and their cognitive learning abilities were compared to placebo-controlled groups (N = 15). Their short-term memories, spatial visualisations, processing speeds, and language skills, were assessed over 2 months by cognitive tests computer programs. RESULTS Relative to the controls, volunteers taking OPLE had improved (P < 0.05) short-term memory, after 1 month of intervention which became highly significant (P < 0.005) after 2 months. The spatial visualisation ability and processing speed improved (P < 0.05) after 2 months consumption. The dietary OPLE showed neuroprotection in nitric oxide-deficient rats. The mechanisms involved systemic and cellular modulations that eventually enhance neuron survival. The longer the duration of OPLE consumption, the more significant was the enhancement, as shown for short-term memory. CONCLUSION This is the first report on the cognitive-enhancing effects of dietary OPLE in humans. The computer-assisted cognitive tests were simple, low in cost, errors and man hours, and hence are better than conventional cognitive test methods. In rats, the equivalent OPLE dose showed brain antioxidant enzymes modulating properties and neuroprotection under nitric oxide deficiency, with possibly neurogenesis in normal rats. This supported the effects in humans.

Selected natural agents used for cholesterol controls

Purpose Various studies suggest that some of natural agents create a specific action of hypocholesterolemic effect. Considering this fact, the aim of this paper is to work on describing selected natural agents that may reduce cholesterol concentrations by different mechanism of actions. Design/methodology/approach The advantages, phytochemical components and the mechanisms of the agents were reviewed and supported from the findings of the in vitro, double-blind and clinical studies from published journals, books and articles. The journals used in this review were published between 1987 and 2016, and are available from PubMed, ScienceDirect and Google Scholar. Findings Plant stanols and sterols, turmeric, fenugreek, avocado, tomato, artichoke, red yeast rice and garlic showed a positive effect in maintaining cholesterol levels by specific mechanisms or actions. These agents each had a specific action in creating a hypocholesterolemic effect either by inhibition of the enzyme significant to the synthesis process, disturbing the absorption of cholesterol, conversion of cholesterol to other related forms and through the reduction of the oxidative stress. Research limitations/implications However, this field still needs more studies as, currently, there is not any detailed information regarding the main active ingredients responsible for the mechanism to reduce cholesterol levels in humans. Originality/value This paper enlightens the authors’ understanding of some natural agents that have the potential to be used in controlling cholesterol.

α-glucosidase inhibitors isolated from Mimosa pudica L.

Abstract The aim of the study was to isolate digestive enzymes inhibitors from Mimosa pudica through a bioassay-guided fractionation approach. Repeated silica gel and sephadex LH 20 column chromatographies of bioactive fractions afforded stigmasterol, quercetin and avicularin as digestive enzymes inhibitors whose IC50 values as compared to acarbose (351.02 ± 1.46 μg mL−1) were found to be as 91.08 ± 1.54, 75.16 ± 0.92 and 481.7 ± 0.703 μg mL−1, respectively. In conclusion, M. pudica could be a good and safe source of digestive enzymes inhibitors for the management of diabetes in future. Antidiabetic active principles (stigmasterol, quercetin, avicularin) isolated from neglected weed Mimosa pudica