Xinbo Guo

Effect of Germination on Phytochemical Profiles and Antioxidant Activity of Mung Bean Sprouts (Vigna radiata)

Epidemiological studies have shown that regular consumption of fruits and vegetables is associated with reduced risk of chronic diseases. It is recommended to increase consumption of fruits and vegetables to prevent chronic diseases related to free radical-induced oxidative stress. Different varieties of fruits and vegetables provide different vitamins, phenolics, flavonoids, minerals, and dietary fibers for optimal health benefits. Mung bean sprouts are one of the major vegetables in human diet. However, the profiles of phytochemicals and effect of germination on phytochemical content and antioxidant activity of mung bean sprouts have not been studied. The objective of this study was to determine the effect of germination on phytochemical profiles and antioxidant activity of mung bean sprouts. Germination of mung beans dramatically increased vitamin C content in mung bean sprouts in a time-dependent manner and reached the peak on day 8 of germination up to 285 mg/100 g DW, almost 24 times higher than the initial concentration in mung bean seeds (p < 0.05). On fresh weight basis, one serving of mung bean sprouts (about 104 g) provides 21.6 mg of vitamin C, which could meet 36% of Daily Value (DV). In addition, the germination dramatically increased total phenolic compounds and total flavonoids in mung bean sprouts in a time-dependent manner, up to 4.5 and 6.8 times higher than the original concentration of mung bean seeds, respectively. Quercetin-3-O-glucoside content was significantly increased in mung bean sprouts after germination. The total antioxidant activity of mung bean sprouts was increased by 6 times higher than that of mung bean seeds. Therefore, the germination of mung bean sprouts significantly increased phytochemical content, vitamin C content, and antioxidant activity.

Comparison of phytochemical profiles, antioxidant and cellular antioxidant activities of different varieties of blueberry (Vaccinium spp.)

Numerous reports have demonstrated that the consumption of fruits and vegetables is beneficial for the human health. Blueberries, in particular, are rich in phytochemicals including free and bound forming. Phytochemical profiles of 14 varieties of blueberry were compared in this study. 12 compounds were analyzed and had significant changes in blueberry fruits. Total antioxidant activities in different blueberry varieties varied about 2.6times by oxygen radical absorbance capacity (ORAC) assay, and 2times by peroxyl radical scavenging capacity (PSC) assay. The cellular antioxidant activities (CAA) in different varieties varied about 3.9times without phosphate buffer saline (PBS) wash, and 4.7times with PBS wash by CAA assay. Blueberry extracts had potent antiproliferative activities against HepG2 human liver cancer cells, indicating the potential protective benefits associated with their use as functional foods. The anti-proliferative activity was observed to be dose-dependent in blueberry extracts.

Ethnomedicinal values, phenolic contents and antioxidant properties of wild culinary vegetables.

ETHNOPHARMACOLOGICAL RELEVANCE Traditional medicines comprise a variety of health practices, approaches, knowledge, and beliefs. Documentation of traditional knowledge, estimation of total phenolics and antioxidant properties of plant species used as wild vegetables and in traditional medicines by the local communities of Lesser Himalayas-Pakistan are targeted. MATERIALS AND METHODS Interviews, questionnaires, and focus group conversation with local informants were carried out to record ethno-medicinal values. Used value, percentage of people who have traditional knowledge, preference ranking and informant consensus factors were also measured. Standard analytical methods were applied to estimate phenolic contents and antioxidant properties in water and acetone extracts. RESULTS A total of 39 plant species used as culinary vegetables and to treat 44 different health disorders are investigated. Significant levels of use value (0.571) and preference ranking (58% PPK, PR-5) are calculated for Ficus palmata, Ficus carica and Solanum nigrum. Elevated levels of total phenolics (144.5 mg GAE/100 g, FW), and flavonoid contents (142.5 mgRtE/100 g, FW) were measured in the water extracts of Origanum vulgare, while Ficus palmata exhibits the highest flavonol contents (142.7 mg RtE/100 g, FW). Maximum DPPH activity is noted in the flowering buds of Bauhinia variegata (85.34%). However, highest values for OH(-) radical scavenging activity (75.12%), Fe(3+) reducing antioxidant power (54.50 µM GAE/100 g, FW), and total antioxidant capacity (180.8 µM AAE/100 g, FW) were measured in the water extracts of Origanum vulgare. CONCLUSION Lesser Himalayas is a rich source of traditional cultural heritage, and plant biodiversity, which are under threat and necessitate urgent documentation. Present study is focused on the plant species used in traditional medicines and culinary vegetables as well. Preliminary determinations of phenoloic contents and antioxidant properties of various plant species were carried out. Present work will introduce new resource of medicinal and food plants, which could be used as functional food. Furthermore, phytochemical profiles, cellular based antioxidant properties, and isolation of active ingredients will be useful for consumers, and in the pharmaceutical and nutraceutical industries of the country.

Phytochemical Profiles and Antioxidant Activities in Six Species of Ramie Leaves

Increased consumption of vegetables or plant food has been associated with decreased risk of developing major chronic diseases, such as cancers, diabetes, cardiovascular diseases, and age-related functional decline. Ramie leaves are rich in phenolics and flavonoids, which have been suggested for human health benefits. Phenolic contents, flavonoid contents, phenolic compounds, and anti-cancer properties in six species of ramie leaves were analyzed by Folin-reagent method, sodium borohydride/chloranil-based assay (SBC), HPLC method and antiproliferation, cytoxicity, respectively. Antioxidant activities were measured through peroxyl radical scavenging capacity (PSC) method, oxygen radical absorbance capacity (ORAC) method, and cellular antioxidant activity (CAA). Research indicated that Boehmeria penduliflora contained the highest total phenolic content (2313.7±27.28 mg GAE/100 g FW), and flavonoid content (1682.4±27.70 mg CAE/100 g FW). Boehmeria tricuspis showed the highest PSC value (9574.8±117.63 µM vit. C equiv./100 g FW), while Boehmeria penduliflora indicated the highest ORAC value (330.44±16.88 µmol Trolox equiv./g FW). The antioxidant activities were correlated with phenolic contents and flavonoid contents. Boehmeria tricuspis had the highest antiproliferative capacity with the lowest EC50 (4.11±0.19 mg/mL). The results for the analyzed ramie for CAA were significantly different from each other (p<0.05), Boehmeria tricuspis had the highest CAA value (133.63±7.10 µmol QE/100 g). Benzoic acid, 4-coumaric acid, caffeic acid, and ferulic acid were the dominant phenolic ingredients in the ramie leaves according to HPLC analysis. Our research is the first report to study the phytochemical profiles and antioxidant activities in different species of ramie leaves for their health benefit.

Comparative assessment of phytochemical profiles, antioxidant and antiproliferative activities of Sea buckthorn (Hippophaë rhamnoides L.) berries

Phytochemical profiles, antioxidant and antiproliferative activities of berry extracts were evaluated and compared in four subspecies of Sea buckthorn (Hippophaë rhamnoides L.). Among the subspecies, Hippophaë rhamnoides L. subsp. sinensis exhibited highest total phenolics content (38.7±1.3mgGA equiv./g DW) and corresponding total antioxidant activity. Whereas maximum cellular antioxidant and antiproliferative activities were determined in Hippophaë rhamnoides L. subsp. yunnanensis. Total antioxidant activity was significantly associated to total phenolics, isorhamnetin-3-rutinoside and isorhamnetin-3-glucoside. The cellular antioxidant activity and antiproliferative activity of phytochemicals were fairly correlated to phenolic acids and flavonoid aglycones. Lower median effective dose (EC50) of individual compounds against human liver cancer HepG2 cells proliferation studies confirmed the better correlation between antiproliferative activity of Sea buckthorn extracts and flavonoid aglycones, including isorhamnetin, quercetin and kaempferol.

Effect of germination on lignan biosynthesis, and antioxidant and antiproliferative activities in flaxseed (Linum usitatissimum L.).

Flaxseed is one of the richest seed sources of lignan and other bioactive compounds. The present study characterized lignan biosynthesis and potential health benefits in flaxseeds during 10-day germination. The transcription levels of lignan biosynthesis, along with variation of bioactivities, including cellular antioxidant activity and antiproliferative activity of flaxseed sprouts during germination, were studied. The results showed that 8-day germination brought about a 6.3-fold increase in secoisolariciresinol diglucoside and 4.5-fold increase in secoisolariciresinol compared to ungerminated flaxseeds. The highest amount of total phenolics and total flavonoids were found in 10-day geminated flaxseed, namely a 5.6-fold and 55-fold increase compared to ungerminated flaxseed. Transcription analysis revealed that five key-encoding genes in the lignan biosynthetic pathway were up-regulated during germination. Furthermore, the highest antioxidant and antiproliferative activities were found on day 10. These findings suggest that germination for 8-10 days leads to optimal lignan production and potential health benefits if incorporated into the human diet.

Traditional uses of medicinal plants against malarial disease by the tribal communities of Lesser Himalayas–Pakistan

ETHNOPHARMACOLOGICAL RELEVANCE Malaria is among the most prevalent infectious diseases in the developing countries of world. Estimated number of annual malaria episodes in Pakistan is 1.5 million, but very little is known about medicinal plant species of Pakistan, which have great potential against malarial disease. Present study was aimed to document medicinal plant species used by the local inhabitants of Lesser Himalayas-Pakistan to treat malaria. MATERIALS AND METHODS Data were collected through interviews, questionnaires and contributor observation. A total of 55 informants aged between 25 and 80 years who were familiar with malarial disease participated in the survey. RESULTS A total of 84 plant species belonging to 69 genera and 50 families were recorded to treat malaria. Asteraceae was found as most cited botanical family with (11.9%) representation, followed by Lamiaceae (5.9%), Solanaceae and Verbenaceae (4.7%) and Violaceae (3.5%) respectively. About 60% of the inhabitants prefer herbal treatment by local herbalists or self-treatment with locally available medicinal plant species. Of the plants identified during present investigation against malaria, Azadirachta indica, Swertia chirayita and Swertia ciliata exhibited uppermost frequency of encounter (36.3%) and corresponding PR value 5. About 67.2% of the botanical taxa are reported for the first time in the treatment of malaria. It was observed thatover harvesting is the foremost threat to medicinal plant species of the study area. CONCLUSION Present survey indicates that traditional knowledge about the use of plant species against various diseases and particularly to treat malaria is in decline. Similarly anthropogenic pressure, over exploitation and grazing of the botanical taxa are the major concerns regarding medicinal plant biodiversity loss. Frequently utilized plant species with significant malarial reduction should be authenticated by in vitro and in vivo standard tests.

Comparison of phytochemical profiles and health benefits in fiber and oil flaxseeds (Linum usitatissimum L.).

Flaxseed (Linum usitatissimum L.) is a rich source of nutritive and bioactive compounds. The research evaluated the disparity in phytochemical profiles along with total and cellular antioxidant activities between oil and fiber flaxseeds. There were significant differences in total phenolics, total flavonoids and antioxidant activities among the six cultivars of fiber and oil flaxseed, respectively. Four phytochemical compounds including caffeic acid, p-coumaric acid and ferulic acid, and secoisolariciresinol diglucoside (SDG) were identified and quantified in the cultivars of oil and fiber flaxseed by HPLC analysis. Notably, the average of total phenolic and flavonoid contents, along with total antioxidant activities between fiber and oil flaxseeds were not different significantly; even the cellular antioxidant activity of fiber flaxseed was superior to oil flaxseed. These results suggest that fiber flaxseeds would be valuable candidates as functional products and dietary supplements production owing to the higher bioactive values as well as oil flaxseeds.

Comparative Assessment of Phenolic Content and in Vitro Antioxidant Capacity in the Pulp and Peel of Mango Cultivars

Mango (Mangifera indica L.), also called “the king of fruits”, is one of the most popular fruits in tropical regions. Pulp and peel samples of mango cultivars were analyzed to estimate total phenolic, total flavonoid and total anthocyanin contents. Phenolic acids, hydrophilic peroxyl radical scavenging capacity (hydro-PSC) and oxygen radical scavenging capacity (ORAC) in vitro were also determined. Total phenolics and flavonoid contents were found maximum in the peel of Xiao Tainang and Da Tainang cultivars, respectively, whereas Xiao Tainang also exhibited significant antioxidant capacity. Noteworthy, concentrations of gallic acid, protocatechuic acid, ferulic acid, chlorogenic acid and caffeic acids at 79.15, 64.33, 33.75, 27.19 and 13.62 mg/100 g fresh weight (FW) were quantified for Da Tainang, Xiao Tainang and of Jidan cultivars, respectively. Comparatively, a higher level of phenolics and significant antioxidant capacity in mango peel indicated that it might be useful as a functional food and value-added ingredient to promote human health.

Effect of Light- and Dark-Germination on the Phenolic Biosynthesis, Phytochemical Profiles, and Antioxidant Activities in Sweet Corn (Zea mays L.) Sprouts

Sweet corn is one of the most widely planted crops in China. Sprouting of grains is a new processes to increase the nutritional value of grain products. The present study explores the effects of light on the nutritional quality of sweet corn sprouts. Gene expression of phenolic biosynthesis, phytochemical profiles and antioxidant activity were studied. Two treatments (light and dark) were selected and the morphological structure of sweet corn sprouts, as well as their biochemical composition were investigated to determine the effects of light on the regulation of genes responsible for nutritional compounds. Transcription analyses for three key-encoding genes in the biosynthesis of the precursors of phenolic were studied. Results revealed a negative regulation in the expression of ZmPAL with total phenolic content (TPC) in the light group. TPC and total flavonoid content (TFC) increased during germination and this was correlated with an increase in antioxidant activity (r = 0.95 and 1.0). The findings illustrate that the nutritional value of sweet corn for the consumer can be improved through germination to the euphylla stage.