Inhibitory effect of Morinda citrifolia L. on lipoprotein lipase activity.

Efficacy of Morinda citrifolia L. leaf (MLE) and fruit extracts (MFE) in inhibiting lipoprotein lipase (LPL) was determined in vitro. The result of the study showed that the highest inhibition on the LPL activity was exhibited by MLE (66%± 2.1%), which is significantly higher than that demonstrated by MFE (54.5%± 2.5%), green tea extract (GTE) (54.5%± 2.6%), and catechin (43.6%± 6.1%). Percent of LPL inhibition increase with concentration of the extracts. Quantitative analysis of the extracts revealed the presence of high levels of (+)−catechin at 63.5 ± 17 and 53.7 ± 5.7 mg/g in MLE and MFE, respectively, although not as high as that found in GTE (530.6 ± 42 mg/g). Appreciable amount of epicatechin was found in all extracts tested, while rutin was only found in MLE and MFE. The study suggested that both leaf and fruit of M. citrifolia may be used as antiobesity agents in body weight management

Effect of different drying methods on the degradation of selected flavonoids in Centella asiatica

The effect of different drying methods on the degradation of flavonoids in Centella asiatica was evaluated. C. asiatica leaf, root and petiole were dried using air-oven, vacuum oven and freeze drier. Flavonoid was determined utilizing reverse-phase high performance liquid chromatography (RP-HPLC). Results of the study revealed the presence of high concentration of flavonoids in C. asiatica leaf, root and petiole, which include, naringin (4688.8 ± 69 μg/100 g, 3561.3 ± 205 μg/ 100 g, and 978.3 ± 96 μg/ 100 g), rutin (905.6 ± 123 μg/ 100 g, 756.07 ± 95 μg/ 100 g, and 557.25 ± 58 μg/ 100 g), quercetin (3501.1 ± 107 μg/ 100 g, 1086.31 ± 90 μg/ 100 g, and 947.63 ± 83 μg/ 100 g) and catechin (915.87 ± 6.01 μg/ 100 g, 400.6 ± 67 μg/ 100 g, and 250.56 ± 18 μg/ 100g). Luteolin, kaempferol and apigenin on the other hand, were inconsistently present in some parts of C. asiatica. Air-oven treatment resulted in the highest total flavonoids degradation followed by vacuum oven and freeze dried with percent degradation of 97%, 87.6% and 73%, respectively. Catechin and rutin were found to be the most stable flavonoids with percent degradation up to 35%, 66% and 76% for freeze dried, vacuum oven and air oven, respectively

Antibacterial property of Hylocereus polyrhizus and Hylocereus undatus peel extracts

Food-borne diseases have always been a major concern to the consumers, food safety authorities and food industries. Hylocereus spp or Pitaya peels are normally treated as wastes and will be discarded during processing. In this study, the antibacterial activity of ethanol, chloroform and hexane extracts from Hylocereus polyrhizus (red flesh pitaya) and Hylocereus undatus (white flesh pitaya) peels against nine pathogens was evaluated using disc diffusion method and broth micro-dilution method. Result from disc diffusion method showed that chloroform extracts from H. polyrhizus and H. undatus peel were found to exhibit good antibacterial activity where almost all the pathogens studied were successfully inhibited. Result of the minimum inhibitory concentration (MIC) showed that all extracts inhibit the growth of bacteria in the range of 1.25-10.00 mg/mL for all bacteria while their minimum bacteriacidal concentrations (MBC) indicated double of the MICs concentration except for B. cereus, L. monocytogenes and C. jejuni. Even though there is no clear trend indicating which bacteria were sensitive most to the extract, it can be concluded that chloroform extract of both H. polyrhizus and H. undatus peel showed the most potent antibacterial activity. Thus, these findings could be used further to understand the antibacterial property of the peel of pitaya fruits

Identification and characterization of genes involved in the fruit color development of european plum

European plum fruit (Prunus domestica) are normally blue-black to dark purple. However, some genotypes remain green/yellow after ripening. We hypothesized that in such genotypes anthocyanin biosynthesis is genetically disturbed. To examine this hypothesis, six european plum genotypes with diverse fruit colors were investigated for the expression pattern of several anthocyanin biosynthetic genes (ABGs)—e.g., phenylalanine ammonia-lyase, chalcone synthase (CHS), dihydroflavonol 4-reductase (DFR), anthocyanin synthase (ANS), and UDP-glucose:flavonoid 3-O-glucosyltransferase 1 and 2 (UFGT 1 and 2). Expression profiles indicated that ABGs, especially Pd-CHS and UFGT 2, were significantly downregulated in the green/yellow fruit compared with the dark-purple fruit. Furthermore, the quantification of total polyphenols and individual flavonoid compounds showed substantial differences between the off-colored and the purple genotype. To further examine the contribution of each of the ABGs in color development, the open reading frame (ORP) of Pd-CHS, Pd-DFR, Pd-ANS, and Pd-UFGT 2 was ectopically expressed in tobacco (Nicotiana tabacum). The characterization of transgenic plants showed that the petals of plants expressing Pd-CHS were darker in color and had higher anthocyanin content than control or even other transgenic types, suggesting the significant contribution of CHS in determining anthocyanin production levels and hence fruit coloration. The results of this study provides better understanding of color development in european plum, which can be rewarding in developing european plum cultivars with desired colors through classical or modern breeding tools

Modulation of lipid metabolism by Centella asiatica in oxidative stress rats.

A study was carried out to investigate the effects of Centella asiatica leaf on lipid metabolism of oxidative stress rats. The rats were fed 0.1% hydrogen peroxide (H2O2) with either 0.3% (w/w) C. asiatica extract, 5%C. asiatica powder (w/w), or 0.3% (w/w) α-tocopherol for 25 wk. Results of the study showed that C. asiatica powder significantly (P < 0.05) lowered serum low-density lipoprotein compared to that of control rats (rats fed H2O2 only). At the end of the study C. asiatica-fed rats were also found to have significantly (P < 0.05) higher high-density lipoprotein and lower triglyceride level compared to rats fed only normal diet. However, cholesterol level of rats fed both C. asiatica extract and powder was found to be significantly (P < 0.05) higher compared to that of control rats. It was interesting to note that consumption of C. asiatica significantly decreased body and liver weights of the rats. Histological examinations revealed no obvious changes in all rats studied. Quantitative analysis of C. asiatica leaf revealed high concentration of total phenolic compounds, in particular, catechin, quercetin, and rutin

Optimized aqueous extraction conditions for maximal phenolics, flavonoids and antioxidant capacity from Artocarpus heterophyllus (jackfruit) leaves by response surface methodology (RSM)

Introduction: There are numerous studies on the therapeutic properties of Artocarpus heterophyllus. However, studies on the aqueous extraction of A. heterophyllus leaves are limited. This present study was conducted to optimize the extraction conditions of A. heterophyllus leaves to yield the highest phenolic, flavonoids and antioxidant contents. Methods: Response surface methodology (RSM) was employed to obtain a higher phenolic extraction parameter(s) of A. heterophyllus leaves using Central Composite Design (CCD). The antioxidant activity was then determined via ABTS (2,29-azinobis (3 ethylbenzothiazoline-6-sulfonic acid)) and DPPH (2,2-Diphenyl-1-picrylhydrazyl) assay and analysis of the individual phenolics was performed by high performance liquid chromatography (HPLC). Results: The optimum extraction conditions with higher phenolics content and antioxidant activity was achieved at 81°C, 100 min and 40 mL/g sample with a good desirability value of 0.87. Under these optimized parameters, total phenolics and flavonoids were 174.48 ± 4.05 mg GAE/g sample and 21.44 ± 0.05 mg RE/g sample, respectively. Meanwhile, antioxidant activity via ABTS and DPPH assays were 90.88% ± 0.09 and 87.22% ± 0.62, respectively. Finally, under optimal extraction conditions revealed 4 compounds identified as chlorogenic acid, quercetin, rutin and kaempferol. Conclusion: The optimisation are promising to improve phenolic yield and antioxidant activity in A. heterophyllusleaves. It also proved that A. heterophyllus leaves can be used as an alternative natural antioxidant especially in medicinal applications since all identified compound possess significant biological activities for human health

Fatigue onset through oxidative stress, dehydration and lactic acid accumulation and its in vivo study using experimental animals

Among athletes, endurance is one of the key elements to victory. In addition to training, athletes normally used supplement to prevent fatigue during the event. With prolonged and intense activity, our body started to experience decrease in muscle performance due to several factors such as oxidative stress, dehydration and accumulation of lactic acid in the body fluids. The free radicals generated during intense exercise will expose the cells to oxidative damages. In the event of dehydration, there will be significant losses of water and functional electrolytes during intense exercise which affected the body fluid balance. Fatigue will also occur during reduced oxygen in aerobic metabolism which later caused accumulation of lactic acid in the muscle. This will change the pH balance toward more acidic and caused the muscles to lose contractile efficiency. In addition, fatigue can also be studied using rats as model organism. Results from this activity can be useful to analyse cellular metabolism and physiology effects of the tested rats toward physical exercise. Therefore, this review aims to discuss the causes of fatigue through oxidative stress, dehydration and lactic acid accumulation. In addition, the effectiveness of using rats as a model system in measuring fatigue is also included in illustrating examples on fatigue assessment in vivo

Effects of extraction techniques on phenolic components and antioxidant activity of Mengkudu (Morinda citrifolia L.) leaf extracts.

The effect of four extraction techniques namely; solvent extraction (SE), microwave-assisted extraction (MAE), ultrasonic-assisted extraction (UAE) and supercritical fluid extraction (SFE) on the phenolic components and antioxidant activity of Morinda citrifolia leaf extracts was investigated. Total phenolics compounds (TPC) were quantified spectrophotometrically using Follin-Ciocalteu regent method, while the catechins were analyzed by reverse-phase high performance liquid chromatography (RP-HPLC). Antioxidant activity of the extracts was evaluated by determining 2,2-diphenyl-1-picrylhydrazyl (DPPH) capacity and ferric ion reducing antioxidant potential (FRAP). Overall, MAE produced extract exhibited the maximum amount of TPC and catechin while UAE-extract had the highest antioxidant activity. It could be concluded that, even though MAE extract contained high TPC and catechin, the accelerated temperature used during this extraction technique might have attributed to reduce the antioxidant activity of this extract. Therefore, UAE can be recommended for recovery of potent natural antioxidant components from M. citrifolia leaf offering better antioxidant activity

Production of high tannin content and antioxidant activity extract from an unripe peel of Musa acuminata (Cavendish) using ultrasound-assisted extraction (UAE)

Musa acuminata (Cavendish) unripe peel is a waste product of limited value that is generated in large quantities. Therefore, the conversion of this by-product into a more useful product is necessary. This study aimed to optimize the ultrasound-assisted extraction (UAE) parameters, including extraction temperature, extraction time, preincubation time, and solid to solvent concentration from an unripe banana peel using response surface methodology (RSM). The UAE parameters affected the recovery of yield, total tannin content, and flavonoid content with antioxidant activities. The optimum extraction temperature was 60 °C with an optimum extraction time of 30.0 min. Additional optimum conditions included 25.0 min for the preincubation time and 5.03% solid to solvent concentration. The optimum yield processing parameter of crude extract of unripe peel was 14.9% and the total tannin content was 119.2 mg TAE per g of the sample. Furthermore, the content of flavonoid was 29.0 mg RE per g of the sample and the DPPH and ABTS scavenging activity was 80.8% and 84.7%, respectively. The results from this study can be used for further isolation and purification of tannin from unripe banana peel. Further explorations could lead to the possible application of bio-based polymer in packaging materials

Anti-pancreatic lipase and antioxidant activity of selected tropical herbs.

The anti-pancreatic lipase and antioxidant activity of Momordica charantia, Morinda citrifolia fruit, and Centella asiatica extract were evaluated for potential use as an anti-obesity agent. Antioxidant activity of the extracts was determined using 2,2-diphenyl-1-picrylhdrazyl and ferric-reducing antioxidant power assays. Inhibition of pancreatic lipase was measured in vitro. Results from this study showed that Momordica charantia, Morinda citrifolia fruit, and Centella asiatica extract exhibited different levels of antioxidant activity, with IC50 ranging from 0.90 ± 0.1 to 3.7 ± 0.8 mg/mL of extracts. All extracts were found to inhibit pancreatic lipase activity, with Momordica charantia, Morinda citrifolia fruit, and Centella asiatica extract demonstrating 21.0 ± 1.3, 25.8 ± 0.1, and 25.3 ± 0.4% inhibition, respectively