Li-Yun Lin

Optimization of bioactive compounds in buckwheat sprouts and their effect on blood cholesterol in hamsters.

Nutrient levels in buckwheats that were maximized in day 8 sprouts (D8SP) included total phenolics, quercetin, and l-ascorbic acid, whereas those of oxalic, malic, tartaric, and citric acids, rutin, and gamma-aminobutyric acid (GABA) were found to reach maximum levels on day 10. Ethanolic extract of D8SP (2.5 mg/mL) revealed potent free-radical scavenging (FRS) and antioxidative (ANO) capabilities. However, its Fe2+-chelating capability was only moderate. To further study the hypolipidemic activity of D8SP, 36 Syrian hamsters were grouped into six groups and fed for 28 days, respectively, with (i) control meal, (ii) high fat plus high cholesterol meal, (iii) high fat plus high cholesterol plus 2.5% of buckwheat seeds, (iv) high fat plus high cholesterol plus 25% of buckwheat seeds, (v) high fat plus high cholesterol plus 2.5% of D8SP, and (vi) high fat plus high cholesterol plus 25% of D8SP. High seed meal prominently enhanced body weight gain, whereas high sprout meal exhibited the highest feed efficiency. Ratios of liver/body weight (L/B) were significantly lowered by all BS meals. Although low seed meal reduced serum total cholesterol (TC) levels (p<0.05), its effect was still inferior to the high seed and sprout meals (p<0.01). In contrast, serum triglyceride (TG) levels were lowered only by the high seed and sprout meals (p<0.05). Alternatively, levels of serum low-density lipoprotein cholesterol (LDL-C) were significantly suppressed by all buckwheat meals (p<0.01). Serum high-density lipoprotein cholesterol (HDL-C) levels were increased, however, insignificantly. Nutraceutically more meaningful is that both LDL-C/HDL-C and TC/HDL-C ratios were significantly lowered (p<0.01). Apparently, hepatic TC levels were significantly reduced, whereas hepatic TG levels were totally unaffected. Conclusively, sprouting triggers a variety of nutritional changes in buckwheats. Day 8 sprouts, consisting of high polyphenolic and moderate quercetin contents, are nutraceutically maximized when hypocholesterolemic, hypotriglyceridemic, and antioxidative activities are concerned.

Insulin secretagogue bioactivity of finger citron fruit (Citrus medica L. var. Sarcodactylis Hort, Rutaceae).

Finger citron [Citrus medica L. var. Sarcodactylis Hort, Rutaceae] (FC) fruits, widely cultivated in Japan, the southern provinces of China and Taiwan, are commonly used as functional vegetables and preserved as sweetmeats. Previously we identified the major compounds in essential oils (% in EO) of FC fruits to be d-limonene (51.24), gamma-terpenene (33.71), alpha-pinene (3.40), and beta-pinene (2.88). Documented evidence on its insulin secretion characteristics is still lacking. In parallel to compositional analysis, we performed in vivo the safety, hypoglycemic, and antidiabetic tests in Sprague-Dawley-SPF rats and Wistar DIO rats respectively. By kinetic analysis on the hypoglycemic patterns of the intraperitoneal glucose tolerance (IPGTT) and the insulin-glucose tolerance tests (IGTT), its insulin secretagogue effect was confirmed. In conclusion, FC fruits that concomitantly possess insulin secretagogue and slimming effects would be very beneficial to type 2 diabetes mellitus patients.

Alpinia zerumbet potentially elevates high-density lipoprotein cholesterol level in hamsters

In folkloric plant medicines, Alpinia zerumbet (AZ) has been popularly recognized as an exellent hepatoprotector. To search for a good high-density lipoprotein cholesterol (HDL-C) elevating herbal preparation, we examined AZ for its antioxidant and hypolipidaemic bioactivities, especially its HDL-C elevating activity. AZ seeds contain 0.51% essential oils (SO), which are comprised of monoterpenoids, oxygenated monoterpenoids, sesquiterpenoids, oxygenated sesquiterpenoids, aldehydes, acid, and esters. Gas chromatography/mass spectrometry analysis indicated that most of the monoterpenes and sesquiterpenes were recoverable in pentane eluent, whilst the oxygenated monoterpenoids and sesquiterpenoids remained in ether eluent. The high contents of rutin, quercetin, and polyphenolics in ethanolic extract of AZ seeds exhibit moderate antilipoperoxidative but potent DPPH free radical scavenging bioactivities. Conclusively, both seed powder (SP) and SO are effective hypolipidaemics with amazingly potent HDL-C elevating capabilities. On the basis of hepatoprotectivity, SP is a more feasible hypolipidemic agent as well as a promising HDL-C elevating plant medicine.

Quercetin and ferulic acid aggravate renal carcinoma in long-term diabetic victims

Many phytoantioxidants have therapeutic drawbacks due to their potent prooxidant bioactivity. It is hypothesized that phytoantioxidants (PAO) are beneficial only to the early-stage diabetes mellitus (DM) and will become ineffective once renopathy occurs. Gallic acid, rutin, EGCG, ferulic acid (FA), and quercetin were tried on the streptozotocin (STZ)-induced DM rat model for a 28 week experimental period. All of these PAO were shown to be ineffective for hypoglycemic action. The incidence of cataract (50%), injured glomerules, and renal cell carcinoma (RCC) was very common, among which the most severely affected involved the quercetin- and the FA-treated groups. The tumorigenicity of ferulic acid is still unclear. However, for quercetin, this can be attributted to (i) the prooxidant effect, (ii) the insulin-secretagogue bioactivity, and (iii) the competitive and noncompetitive inhibition on the O-methyltransferase to enhance the estradiol-induced tumorigenesis. Conclusively, quercetin and FA are able to aggravate, if not induce, nephrocarcinoma. It is time to reevaluate the tumorigenic detrimental effect of PAO, especially those exhibiting prooxidant bioactivity.

Sesamin mitigates inflammation and oxidative stress in endothelial cells exposed to oxidized low-density lipoprotein.

Sesamin, a lignan from sesame oil, has been shown to have antihypertensive and antioxidative properties. This study examined the effects of sesamin on oxidized low-density lipoprotein (oxLDL)-induced endothelial dysfunction. Oxidative stress was determined by measuring the generation of intracellular reactive oxygen species (ROS) and by measuring the expression levels of superoxide dismutase (SOD) and endothelial nitric oxide synthase (eNOS). To assess the pro-inflammatory effects of oxLDL, ELISA was used to detect IL-8 expression, endothelin-1 (ET-1) secretion, and nuclear factor-kappaB (NF-kappaB) activation. The expression of adhesion molecules (ICAM-1, VCAM-1, and E-selectin) was examined by flow cytometry. In addition, several apoptotic signaling pathways were also investigated. The data showed that sesamin significantly ameliorated oxLDL-induced ROS generation and SOD-1 inactivation. Sesamin also attenuated the oxLDL-induced activation of NF-kappaB, suggesting that the inhibitory effects of sesamin on IL-8 and ET-1 release, adhesion molecule expression, and the adherence of THP-1 cells were at least partially through the blockade of NF-kappaB activation. Furthermore, sesamin attenuated oxLDL-induced apoptotic features, such as intracellular calcium accumulation and the subsequent collapse of mitochondrial membrane potential, release of cytochrome c, and activation of caspase-3. Results from this study may provide insight into possible molecular mechanisms underlying sesamins beneficial effects against oxLDL-mediated vascular endothelial dysfunction.

Hypolipidemic and antioxidant activity of mountain celery (Cryptotaenia japonica Hassk) seed essential oils.

Mountain celery seed essential oils (MC-E) contained 109 compounds, including mainly nine kinds of monoterpenoids, 31 kinds of of sesquiterpenoids, and 22 kinds of alcohols. A successive gel column adsorption with solvent fractionation yielded four fractionates. The pentane fractionate revealed potent hypolipidemic but poor antioxidant activities. The ether fractionate exhibited strong hypolipidemic activity in addition to excellent 1,1-diphenyl-2-picrylhydrazyl free radical- and superoxide anion-scavenging capabilities. The third acetone fractionate only showed moderate superoxide anion-scavenging activity. Finally, the fourth methanol fractionate having a rather high content of gamma-selinene, 2-methylpropanal, and Z-9-octadecenamide uniquely revealed very strong superoxide anion-scavenging capability. All MC diets except the MC-E-added diet simultaneously exhibited both significant hypolipidemic and high-density lipoprotein-cholesterol (HDL-C)-elevating capabilities. However, all diets totally failed to affect the hepatic phospholipid levels. Conclusively, the MC-E can be fractionated by such a separation technology to produce products uniquely possessing hypolipidemic and HDL-C-elevating activities.

Chemical Synthesis of 9(Z)-Octadecenamide and Its Hypolipidemic Effect: A Bioactive Agent Found in the Essential Oil of Mountain Celery Seeds

The unusual hypolipidemic activity of the methanolic fractionate of the essential oil (EOM) obtained from the mountain celery seed was previously reported. The most enriched 9(Z)-octadecenamide (oleamide) was speculated to be responsible for the relevant bioactivity. Chemically syntheized oleamide (CSO) yielded 85.1% with a purity of 98.6% when identified by RP-HPLC, FTIR, HREIMS, (1)H NMR, and (13)C NMR. CSO was tested for its antioxidative and hypolipidemic bioactivities. Results indicated CSO was potently hypolipidemic with regard to serum TG, TC, LDL-C, LDL-C/HDL-C, and hepatic TG (p < 0.05), but not for serum HDL-C and hepatic TC. In addition, CSO exhibited only poor antioxidative activity, implicating the possibility that the hypolipidemic and antioxidative bioactivity of original EOM was due to another coexisting constituent, probably gamma-selinene. Conclusively, oleamide is a potent hypolipidemic agent as regarding its effects on decreasing serum TG, TC, LDL-C and hepatic TG.

The polyphenolics in the aqueous extract of Psidium guajava kinetically reveal an inhibition model on LDL glycation

Guava [Psidium guajava L. (Myrtaceae)] budding leaf extract (PE) has shown tremendous bioactivities. Previously, we found seven major compounds in PE, i.e., gallic acid, catechin, epicatechin, rutin, quercetin, naringenin, and kaempferol. PE showed a potentially active antiglycative effect in an LDL (low density lipoprotein) mimic biomodel, which can be attributed to its large content of polyphenolics. The glycation and antiglycative reactions showed characteristic distinct four-phase kinetic patterns. In the presence of PE, the kinetic coefficients were 0.000438, 0.000060, 0.000, and −0.0001354 ABS-mL/mg-min, respectively, for phases 1 to 4. Computer simulation evidenced the dose-dependent inhibition model. Conclusively, PE contains a large amount of polyphenolics, whose antiglycative bioactivity fits the inhibition model.

Effect of heat treatments on the essential oils of kumquat (Fortunella margarita Swingle).

Kumquats (Fortunella margarita Swingle) cultivated in Taiwan are eaten raw or made into candied fruit or fruit tea. For the experiments described in this paper, essential oils were obtained from kumquat peels or whole fruit by cold pressing, steam distillation or heating in water at 90°C for 15 min followed by steam distillation. The volatile components contained in the essential oils were identified by direct injection (DI) or headspace-solid phase microextraction (HS-SPME) coupled with gas chromatography (GC). A total of 43 compounds were identified, of which 37 were verified by DI/GC and 31 by HS-SPME/GC. Hot water heating increased the yields of essential oils from both peels and whole fruit. The principal constituents of the oils were similar except for the minor compounds, including linalool, terpinen-4-ol and α-terpineol, the levels of which increased after steam distillation. The whole fruit also contained higher levels of terpene alcohols.

Aqua-culture improved buckwheat sprouts with more abundant precious nutrients and hypolipidemic activity

Nutritional values of buckwheat reach maximum on day 8 sprouting by solid-phase cultivation (BSSC). The precious nutrients surveyed included linolenic acid, total polyphenolics, rutin, quercetin, l-ascorbic acid and γ-aminobutyric acid. To investigate whether a change of cultivation method could improve the nutritional status, we performed aquaculture. By performing chemical, biochemical and animal experiments, we found that maximization of nutrient levels in aquacultured buckwheat sprouts (BSAQ) occurred 2 days earlier than those from BSSC. Simultaneously, their bioactivities were much enhanced, being superior to BSSC regarding antioxidative, free radical scavenging (FRS), anti-low-density lipoprotein lipoperoxidative capabilities and hypolipidemic bioactivity with respect to serum total cholesterol and triglyceride levels in Syrian hamsters. In addition, serum low-density lipoprotein-cholesterol (LDL-C) and high-density lipoprotein-cholesterol (HDL-C) levels and the ratios LDL-C/HDL-C and total cholesterol/HDL-C were all more efficiently suppressed by BSAQ diets. In conclusion, aquaculture is more efficient than the solid-phase cultivation with regard to acceleration and maximization of precious nutrient levels in buckwheat sprouts.