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This study, for the first time, has investigated the relationships between alterations of mangiferin contents in mango leaves at different maturity stages and their antibacterial properties. Leaves were classified into six different maturity stages based on their color: (1) young dark reddish brown, (2) young yellow, (3) young light green, (4) mature green, (5) old dark green, and (6) old yellow leaves. Ethanol extracts were then examined against Gram-positive and Gram-negative bacteria, applying broth dilution and agar well diffusion methods. In addition, we also measured the mangiferin contents in leaves at different stages for the purpose of evaluating how the changes in this phytochemistry value affects their activities against bacteria. The results showed that extracts from leaves at young ages had better antibacterial properties than those from old leaves, as evidenced by the lower minimum inhibitory concentrations and larger inhibitory zones. In addition, we also found that the contents of mangiferin were significantly decreased followed the maturation process. These results suggest that mango leaves at young stages, especially dark reddish brown and young yellow leaves, are preferable for application in bacterial infections and other therapies related to mangiferin’s constituents.

Processing with heat treatment has been reported to alter several therapeutic effects of turmeric. In Vietnamese traditional medicine, turmeric has been long used for bacterial infections, and roasting techniques are sometimes applied with this material. However, there have been no studies investigating the effects of these thermal processes on the plant’s antibacterial properties. Our study was therefore performed to examine the changes that roasting produced on this material. Slices of dried turmeric were further subjected to light-roasting (80 °C in 20 min) or dark-roasting (160 °C in 20 min) processes. Broth dilution and agar-well diffusion methods were applied to examine and compare the effects of ethanol extracts obtained from non-roasted, light-roasted and dark-roasted samples, on a set of 6 gram-positive and gram-negative bacteria. In both investigations, dark-roasted turmeric was significantly less antibacterial than non-roasted and light-roasted materials, as evident by the higher values of minimum inhibitory concentrations and the smaller diameters of induced inhibitory zones. In addition, dark-roasting was also found to clearly reduce curcumin contents, total polyphenol values and antioxidant activities of the extracts. These results suggest that non-roasting or light-roasting might be more suitable for the processing of turmeric materials that are aimed to be applied for bacterial infections.

Vasodilatory effects of mulberry leaf extract (MLE) and its possible underlying mechanisms on porcine basilar artery (PBA) were investigated by measuring changes in isometric tension in vitro. MLE slightly relaxed 60 mM KCl pre-contracted PBA rings (9.4% at 540 μg/mL). A treatment with MLE induced extensive relaxation under pre-contraction with 0.1 μM U-46619 (EC50 = 49.4 μg/mL). Neither endothelial denudation nor treatment with atenolol (10 μM) affected MLE-induced relaxation. Relaxation induced by MLE (540 μg/mL) was significantly attenuated by cimetidine (10 μM). MLE inhibited angiotensin I-induced contraction in endothelium-intact PBA rings (EC50 = 25 μg/mL), similar to captopril. Therefore, the possible mechanisms underlying MLE-induced relaxation in PBA might be mediated through: (1) functional antagonism of thromboxane A2 receptors; (2) suppression of angiotensin I-induced contraction; (3) Ca2+ influx inhibition; (4) stimulation of H2-receptors. Moreover, MLE contained significant amounts of nitrite, nitrate and several phenolic compounds, possibly associated with MLE-induced relaxation.

Phenolic compounds in mulberry leaves harvested from three cultivars (Buriram 60, BR 60; Sakonnakhon, SK; and Khunphai, KH) at different leaf ages (tips, young, and old leaves) were identified and quantified using HPLC-DAD and HPLC-ESI/MS. A total of 13 phenolic compounds, which were mainly as caffeoylquinic acids and flavonol glycosides, were detectable. Predominant phenolic compounds were 5-O-caffeoylquinic acid (3.5–13.1 mg/g dry weight), 4-O-caffeoylquinic acid (1.3–2.4 mg/g dry weight), and quercetin-3-O-rutinoside (1.0–4.4 mg/g dry weight). Qualitative and quantitative differences in phenolic compounds in mulberry leaves were investigated among cultivars and leaf ages. Principal component analysis and hierarchical cluster analysis were used for classification of the mulberry leaves. Based on the similarity of phenolic compounds, mulberry leaves were clustered into three groups: (1) tips of leaves from all cultivars; (2) young and old leaves of mulberry cv. BR 60; (3) young and old leaves of mulberry cv. SK and KH. Therefore, according to phenolic compounds in mulberry leaves, tips of leaves from all cultivars should be intended for production of functional healthy foods.

Vasodilatory effects of mulberry leaf extract (MLE) and its possible underlying mechanisms on porcine basilar artery (PBA) were investigated by measuring changes in isometric tension in vitro . MLE slightly relaxed 60 mM KCl pre-contracted PBA rings (9.4% at 540 μg/mL). A treatment with MLE induced extensive relaxation under pre-contraction with 0.1 μM U-46619 (EC 50 = 49.4 μg/mL). Neither endothelial denudation nor treatment with atenolol (10 μM) affected MLE-induced relaxation. Relaxation induced by MLE (540 μg/mL) was significantly attenuated by cimetidine (10 μM). MLE inhibited angiotensin I-induced contraction in endothelium-intact PBA rings (EC 50 = 25 μg/mL), similar to captopril. Therefore, the possible mechanisms underlying MLE-induced relaxation in PBA might be mediated through: (1) functional antagonism of thromboxane A 2 receptors; (2) suppression of angiotensin I-induced contraction; (3) Ca 2+ influx inhibition; (4) stimulation of H 2 -receptors. Moreover, MLE contained significant amounts of nitrite, nitrate and several phenolic compounds, possibly associated with MLE-induced relaxation. [ABSTRACT FROM AUTHOR]

This study, for the first time, has investigated the relationships between alterations of mangiferin contents in mango leaves at different maturity stages and their antibacterial properties. Leaves were classified into six different maturity stages based on their color: (1) young dark reddish brown, (2) young yellow, (3) young light green, (4) mature green, (5) old dark green, and (6) old yellow leaves. Ethanol extracts were then examined against Gram-positive and Gram-negative bacteria, applying broth dilution and agar well diffusion methods. In addition, we also measured the mangiferin contents in leaves at different stages for the purpose of evaluating how the changes in this phytochemistry value affects their activities against bacteria. The results showed that extracts from leaves at young ages had better antibacterial properties than those from old leaves, as evidenced by the lower minimum inhibitory concentrations and larger inhibitory zones. In addition, we also found that the contents of mangiferin were significantly decreased followed the maturation process. These results suggest that mango leaves at young stages, especially dark reddish brown and young yellow leaves, are preferable for application in bacterial infections and other therapies related to mangiferin's constituents.

Processing with heat treatment has been reported to alter several therapeutic effects of turmeric. In Vietnamese traditional medicine, turmeric has been long used for bacterial infections, and roasting techniques are sometimes applied with this material. However, there have been no studies investigating the effects of these thermal processes on the plant's antibacterial properties. Our study was therefore performed to examine the changes that roasting produced on this material. Slices of dried turmeric were further subjected to light-roasting (80 °C in 20 min) or dark-roasting (160 °C in 20 min) processes. Broth dilution and agar-well diffusion methods were applied to examine and compare the effects of ethanol extracts obtained from non-roasted, light-roasted and dark-roasted samples, on a set of 6 gram-positive and gram-negative bacteria. In both investigations, dark-roasted turmeric was significantly less antibacterial than non-roasted and light-roasted materials, as evident by the higher values of minimum inhibitory concentrations and the smaller diameters of induced inhibitory zones. In addition, dark-roasting was also found to clearly reduce curcumin contents, total polyphenol values and antioxidant activities of the extracts. These results suggest that non-roasting or light-roasting might be more suitable for the processing of turmeric materials that are aimed to be applied for bacterial infections.

Ethnopharmacological Relevance: In Vietnamese traditional herbalism, there are conflicting opinions about the effect of Artemisia vulgaris L. (AVL, English name: mugwort) on hypertension. Some ethnic doctors recommend the use of AVL for treatment of hypertension, whereas others advise against it. The purpose of this study was to clarify the pharmacological characteristics of AVL in isolated arteries to explain the conflicts surrounding the use of AVL for treatment of hypertension., Materials and Methods: We initially performed a functional study using an organ bath system to investigate the effect of AVL extract on isolated porcine basilar artery. We then measured the change in intracellular free Ca(2+) concentration elicited by AVL using cultured smooth muscle cells loaded with the Ca(2+) indicator fluo-4. Finally, using HPLC, we determined the active components in AVL., Results and Discussion: AVL induced vasoconstriction at resting tension, and endothelial removal enhanced this effect significantly. Pretreatment with PD123319 (an AT2 receptor antagonist), Nω-nitro-L-arginine (a nitric oxide synthase inhibitor), or both, also enhanced this effect. AVL-induced contraction was competitively inhibited by methiothepin (a 5-HT1 and 5-HT2 receptor antagonist) in the presence of ketanserin (a 5-HT2 receptor antagonist). Removal of extracellular calcium with nifedipine (an L-type Ca(2+) channel blocker) or ruthenium red (a ryanodine receptor blocker) significantly reduced AVL-induced contraction, whereas losartan (an AT1 receptor antagonist) and diphenhydramine (a H1 receptor antagonist) had no effect on this contraction. AVL increased the intracellular free Ca(2+) concentration in cultured cells, and this increment was inhibited by methiothepin. HPLC analysis revealed that the retention time of the first peak in the AVL profile was similar to that of the 5-HT standard, and that addition of 5-HT to the AVL sample enhanced this peak. On the other hand, AVL induced endothelium-independent relaxation under precontracted conditions with 60mM KCl. Captopril (an angiotensin converting enzyme inhibitor), atenolol (a β1 receptor antagonist) and cimetidine (a H2 receptor antagonist) had no effect on this relaxation. In Ca(2+)-free 60mM KCl-containing solution, pretreatment with AVL significantly inhibited CaCl2-induced contraction., Conclusion: For the first time, the present study has demonstrated that AVL has two opposite effects, contraction and relaxation, on isolated artery, which may help to explain the conflicting indications for AVL in traditional herbalism. 5-HT is a significant factor affecting artery contraction in the presence of AVL., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

The aim of this study was to evaluate, for the first time, the antagonistic effects of Gingko biloba leaf (GB) and Sophora japonica L. flower bud (SJ) extracts on cerebral vasoconstriction in response to KCl, extracellular Ca[Formula: see text], histamine, 5-hydroxytryptamine (5-HT), 9,11-dideoxy-9[Formula: see text],11[Formula: see text]-methanoepoxy prostaglandin (PG) F[Formula: see text](U46619) and bradykinin (BK), in order to explain their traditional application for diseases associated with cerebral vasospasm. Isolated porcine basilar arteries (PBA) and endothelial cells from them were used as the study materials. Neither SJ nor GB had any effect on the contractions induced by KCl and extracellular Ca[Formula: see text]. SJ significantly inhibited the contraction induced by histamine, 5-HT, U46619 and BK, whereas GB inhibited histamine-induced contraction, but had no effects on the contractions induced by 5-HT, U46619 and BK. In the presence of diphenhydramine (a H 1 receptor antagonist), ketanserin (a 5-HT 2 receptor antagonist) and ONO-3708 (a thromboxane (TX) A 2 /PG receptor antagonist), the inhibitory effects of these extracts on the contractions induced by histamine, 5-HT and U46619 were abolished. SJ significantly inhibited the contractions induced by BK and PGF[Formula: see text], but in the presence of ONO-3708 (10[Formula: see text] M) had no effect on them. BK enhanced the production of PGF[Formula: see text] from cultured PBA endothelium cells, and SJ significantly attenuated this enhancement. These results suggest that SJ and GB have a H 1 -antagonistic effect, and that SJ also attenuates cerebral vasoconstriction mediated via 5-HT 2 and TXA 2 /PG receptors. These findings appear to explain why SJ has been used traditionally as a therapeutic medication for cerebral vasospasm after cerebral hemorrhage.