Zanthoxylum Piperitum Research Articles

초피첨가 전통장류의 항균 및 항암활성

초피나무(Z. piperitum) 열매는 다양한 생리활성을 갖고 있으며, 과피 용매추출물은 세균에 대한 강한 항균활성을 갖고 있어, 간장과 된장제조에 초피를 첨가하여 생리활성효과를 조사하였다. 초피를 간장제조에 1%, 2%, 4% 첨가하여 제조하고, 간장추출물을 식중독균(Sta. aureus, Sal. typhimurium, V. parahemolyticus, E. coli 0157:H7)에 대한 항균활성을 조사했다. 초피를 2% 첨가한 간장은 E. coli 0157:H7과 V. parahemolyticuS 의 생육을 각각 70%와 50% 억제했으며, Sal. typhimurium 과 Sta. aureus 에 대한 항균효과는 농도와 간장제조시기에 따라 40% <TEX>${\sim}$</TEX> 60% 의 생육을 억제했다. 초피된장의 용매추출물에서는 약한 항균활성을 확인할 수 있었다. 초피간장의 추출물을 백혈병세포 U-937에 처리하여 caspase-3 활성으로 항암활성을 조사했다. 그 결과 초피의 량을 1%, 2%, 4% 첨가한 간장의 추출물은 초피를 침가하지 않은 간장보다 caspase-3 활성이 각각 4배, 12배, 15배 활성이 증가하는 것이 확인되어졌다. 이는 초피간장의 추출물이 apoptosis를 유도하는 것을 의미하며, 된장의 용매추출물은 caspase-3 활성에 아무런 영향이 없었다. 초피간장 추출물을 처리한 세포의 죽음이 necrosis인지 apoptosis인지 알아보기 위하여 세포내의 DNA fragmentation을 확인한 결과, 초피간장 추출물을 처리한 세포는 DNA 단편화가 형성되어졌다. 초피틀 1% 첨가한 것에서는 fragmentation을 확인하기 힘들었고, 2%와 4%초피를 첨가한 간장추출물은 DNA fragmentation을 강하게 일으켰다. 초피를 첨가한 간장추출물이 caspase를 활성화시키고, DNA fragmentation을 일으키는 apoptosis 기작에 의해 암세포를 죽음으로 유도하는 초피간장의 항암효과를 입증했다. The fruits of Zanthoxylum piperitum are known as having various physiology vitality, and the abstraction ingredient of the pericarp is also known as having strong antibiotic activities against various bacteria. Therefore, this study was carried out to estimate the effect of physiology vitality when the abstraction ingredient of Z. piperitum was added in soy sauce(Chopi-kanjang) and soybean paste(Chopi-doenjang). For the antibiotic activity against the pathogens of sitotoxism such as Staphylococcus aureus, Salmonella typhimurium, Vibrio parahemolyticus, Escherichia coli 0157:H7, the extracts of the Chopi-kanjang was added 1%, 2%, 4% pericarp of Z. piperitum in the manufacturing process of soy source. According to the results, the growth of E. coli 0157:H7 and V. parahemolyticus were respectively inhibited as 70% and 50% by the Chopi-kanjang added 2% of the ingredient. For the antibiotic effects of the aforementioned Chopi-kanjang against Sal. typhimurium and Sta. aureus, the growth of those pathogens was also inhibited between 40% and 60% according to the manufacturing period of Chopi-kanjang. It was confirmed that the antibiotic activity using the mixture of the abstraction ingredient and Chopi-doenjang was lower than those of Chopi-kanjang. In order to estimate the anticancer activity using by caspase-3 activity, the mixture of the abstraction ingredient of the pericarp of Z. piperitum and Chopi-kanjang was treated to leukemia cells. According to the results, the activities of caspase-3 using the mixture added 1%, 2% and 4% of the abstraction ingredient were respectively increased as much as 4, 12, 15 times comparing with the control which was treated with the soy source only. It could be that the mixture of the abstraction ingredient of the pericarp of Z. piperitum and soy source induced apoptosis, and the mixture of the abstraction ingredient and soybean paste had no effect on the activity of caspase-3. In order to find out the death of the aforementioned cells caused by necrosis or apoptosis, DNA fragmentation in the cell was examined. U-937 cells showed apoptotic DNA fragmentation in the incubation with Chopi-kanjang extract.

Hydroxy‐α‐sanshool activates TRPV1 and TRPA1 in sensory neurons

Sanshools are major active ingredients of Zanthoxylum piperitum and are used as food additives in East Asia. Sanshools cause irritant, tingling and sometimes paresthetic sensations on the tongue. However, the molecular mechanism underlying the pungent or tingling sensation induced by sanshools is not known. Because many transient receptor potential (TRP) channels are responsible for the sensations induced by various spices and food additives, we expressed 17 TRP channels in human embryonic kidney (HEK) cells and investigated their activation by hydroxy-alpha-sanshool (HalphaSS) or hydroxy-beta-sanshool (HbetaSS) isolated from Zanthoxylum piperitum. It was found that HalphaSS, but not HbetaSS, depolarized sensory neurons with concomitant firing of action potentials and evoked inward currents. Among 17 TRP channels expressed in HEK cells, HalphaSS caused Ca(2+) influx in cells transfected with TRPV1 or TRPA1, and evoked robust inward currents in cells transfected with TRPV1 or TRPA1. In primary cultured sensory neurons, HalphaSS induced inward currents and Ca(2+) influx in a capsazepine-dependent manner. Moreover, HalphaSS-induced currents and Ca(2+) influx were greatly diminished in TRPV1(-/-) mice. HalphaSS evoked licking behavior when injected into a single hind paw of wild-type mice, but this was much reduced in TRPV1-deficient mice. These results indicate that TRPV1 and TRPA1 are molecular targets of HalphaSS in sensory neurons. We conclude that the activations of TRPV1 and TRPA1 by HalphaSS explain its unique pungent, tingling sensation.

Extraction and Characterization of the Pectic Substances from Japanese Pepper (Zanthoxylum piperitum DC.) Fruit

Pectic substances were extracted from Japanese pepper (Zanthoxylum piperitum DC) fruit with hot diluted HCl (90°C, pH 2.2). The yield of the pectic substances was 8.4% (w/w) based on dry material. The contents of total carbohydrate, anhydrogalacturonic acid, ash, protein, and moisture of the pectic substances were 84.1, 66.9, 3.6, 2.7, and 9.6% (w/w), respectively. The degree of methylation was estimated to be 80.3% by using alcohol oxidase test. This indicated that the pectic substances are high methoxyl pectins and have an ability to form sugar gels. The jelly grade of the pectic substances was estimated to be 130 (USA-SAG) at standard condition. Viscosity-average molecular weight was relatively low (30.3 kDa). When the molecular weight distribution was checked by gel-permeation chromatography on Sepharose CL-4B, the elution profile of the pectic substances was highly polydispersed extending from 40 kDa (or less) to 2000 kDa.

Repellent activity of selected essential oils against Aedes aegypti

Essential oils extracted from ten plant species were screened for repellency against Aedes aegypti mosquitoes. Three oils; Zanthoxylum piperitum, Anethum graveolens and Kaempferia galanga, exerted protection against A. aegypti, with median complete-protection times of 1, 0.5 and 0.25 h, respectively. The protection times were increased significantly by incorporating 10% vanillin. The highest potential was established from Z. piperitum oil + 10% vanillin (2.5 h, range = 1–2.5 h). Mixtures from pairs of the effective oils possessed slight repellency that ranged from 0–0.5 h. None of the oil combinations repelled A. aegypti for longer than their constituent oil alone. With vanillin added, however, each oil mixture provided improved protection, which was approximately equal to oil on its own. GC/MS analysis revealed that the main component of Z. piperitum fruit oil was limonene (37.99%), with minor amounts of sabinene (13.30%) and β-myrcene (7.17%). Repellent testing of stored samples of Z. piperitum fruit oil against A. aegypti demonstrated that repellent activity of those kept at − 20 °C or 4 °C was present for a period of at least 3 months. Therefore, the essential oil of Z. piperitum fruit may prove useful in the development of mosquito repellents as an effective personal protection measure against mosquito bites.

Human Acyl-CoA: Cholesterol Acyltransferase Inhibitory Activities of Aliphatic Acid Amides from Zanthoxylum piperitum DC.

Acyl-CoA: cholesterol acyltransferase (ACAT) plays an important role in the esterification of cholesterol with its substrates, cholesterol and fatty acyl coenzyme A, to facilitate both intracellular storage and intercellular transport. ACAT-1 is more involved in macrophage foam cell formation and ACAT-2 plays a critical role in the cholesterol absorption process in intestinal enterocytes. Three aliphatic acid amides, beta-sanshool (1), gamma-sanshool (2), and hydroxy-beta-sanshool (3), were isolated by bioassay-guided fractionation of the ethanolic extracts of Zanthoxylum piperitum DC. Compounds 1 and 2 inhibited human ACAT-1 and -2 activities with IC50 values of 39.0 and 79.7 microM for 1 and of 12.0 and 82.6 microM for 2, respectively. However, the hACAT-1 and -2 inhibitory activities of compound 3 having hydroxyl group were relatively less than those of compounds 1 and 2. A semi-synthetic compound 4, which has acetyl residue at 2'-OH of compound 3, exhibited the increased hACAT-1 and -2 inhibitory activities with IC50 values of 28.1 and 87.5 microM, respectively.

Fumigant Activity of Plant Essential Oils and Components from Schizonepeta tenuifolia Against Lycoriella ingenua (Diptera: Sciaridae)

Plant essential oils from 21 plant species were tested for their insecticidal activities against larvae of Lycoriella ingenua Dufour (Diptera: Sciaridae) by using a fumigation bioassay. Good insecticidal activity against larvae of L. ingenua was achieved with essential oils of Acorus gramineus Solander, Schizonepeta tenuifolia Briquet, and Zanthoxylum piperitum De Candolle at 25 μg/ml air. S. tenuifolia oil showed the most potent insecticidal activity among the plant essential oils. At 12.5 μg/ml air concentration, S. tenuifolia oil caused 96.6% mortality, but mortality decreased to 60% at 3.125 μg/ml air. Analysis by gas chromatography-mass spectrometry led to identification of three major compounds from S. tenuifolia oil. These three compounds were tested individually for their insecticidal activities against larvae of L. ingenua and compared with the toxicity of dichlorvos. Pulegone was the most toxic, followed by menthone and limonene with LC50 values of 1.21, 6.03, and 15.42 μg/ml, respectively. LC50 of dichlorvos was 8.13 μg/ml. Effects of S. tenuifolia and its components on growth of Pleurotus ostreatus (Jacq. ex Fr.) Kummer also were investigated.

Fumigant Activity of Plant Essential Oils and Components from &lt;I&gt;Schizonepeta tenuifolia&lt;/I&gt; Against &lt;I&gt;Lycoriella ingenua&lt;/I&gt; (Diptera: Sciaridae)

Plant essential oils from 21 plant species were tested for their insecticidal activities against larvae of Lycoriella ingenua Dufour (Diptera: Sciaridae) by using a fumigation bioassay. Good insecticidal activity against larvae of L. ingenua was achieved with essential oils of Acorus gramineus Solander, Schizonepeta tenuifolia Briquet, and Zanthoxylum piperitum De Candolle at 25 microg/ml air. S. tenuifolia oil showed the most potent insecticidal activity among the plant essential oils. At 12.5 microg/ml air concentration, S. tenuifolia oil caused 96.6% mortality, but mortality decreased to 60% at 3.125 microg/ml air. Analysis by gas chromatography-mass spectrometry led to identification of three major compounds from S. tenuifolia oil. These three compounds were tested individually for their insecticidal activities against larvae of L. ingenua and compared with the toxicity of dichlorvos. Pulegone was the most toxic, followed by menthone and limonene with LC50 values of 1.21, 6.03, and 15.42 microg/ml, respectively. LC50 of dichlorvos was 8.13 microg/ml. Effects of S. tenuifolia and its components on growth of Pleurotus ostreatus (Jacq. ex Fr.) Kummer also were investigated.

Polyphenolic Constituent Structures ofZanthoxylum piperitumFruit and the Antibacterial Effects of Its Polymeric Procyanidin on Methicillin-ResistantStaphylococcus aureus

Zanthoxylum piperitum (Rutaceae) is used as a spice and a natural medicine in Japan. Our study found that ZP-CT-A, a polymeric proanthocyanidin purified from the fruit of this species, noticeably decreased the minimum inhibitory concentrations of beta-lactam antibiotics for methicillin-resistant Staphylococcus aureus (MRSA). The structure of ZP-CT-A was characterized on the basis of (13)C NMR and size exclusion chromatographic data and the results of thiolytic degradation. A mechanistic study of the effects of ZP-CT-A indicated that it suppressed the activity of beta-lactamase and largely decreased the stability of the bacterial cell membrane of MRSA, as shown by a reduction in the tolerance of MRSA to low osmotic pressure and high ionic strength solutions.

Sichuan pepper extracts block the PAK1/Cyclin D1 pathway and the growth of NF1-deficient cancer xenograft in mice

There is an increasing evidence that more than 70% of cancers including pancreatic, breast and prostate cancers as well as neurofibromatosis (NF) are highly addicted to abnormal activation of the Ser/Thr kinase PAK1 for their growth. So far FK228 is the most potent among the HDAC (histone deacetylase) inhibitors that block the activation of both PAK1 and another kinase AKT. However, it is still in clinical trials (phase 2) for a variety of cancers (but not for NF as yet), and not available for most cancer/NF patients. Thus, we have been exploring an alternative which is already in the market, and therefore immediately useful for the treatment of those desperate cancer/NF patients. Here we provide the first evidence that extracts of Chinese/ Japanese peppercorns (Zanthoxyli Fructus ) from the plant Zanthoxylum piperitum called “Hua Jiao”/ “Sansho”, block selectively the key kinase PAK1, leading to the down-regulation of cyclin D1. Unlike FK228, these extracts do not inhibit AKT activation at the concentrations that block either cancer growth or PAK1 activation. The Chinese pepper extract selectively inhibits the growth of NF1-deficient malignant peripheral nerve sheath tumor (MPNST) cells, without affecting the growth of normal fibroblasts, and suppresses the growth of NF1-deficient human breast cancer (MDA-MB-231) xenograft in mice. Our data suggest that these peppercorn extracts would be potentially useful for the treatment of PAK1-dependent NF such as MPNST, in addition to a variety of PAK1-dependent cancers including breast cancers.

Effects of Tannins and Related Polyphenols on Methicillin‐Resistant Staphylococcus aureus.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Antioxidant activity of Japanese pepper ( Zanthoxylum piperitum DC.) fruit

Antioxidants were extracted from Japanese pepper ( Zanthoxylum piperitum DC.) fruit and characterized. The antioxidant activity of the methanol extract from Japanese pepper fruit was found to be equal to that of α-tocopherol and stable under heat treatment. The main compounds that gave a significant antioxidant activity from the methanol extract were identified to be hyperoside (quercetin-3- O-galactoside) and quercitrin (quercetin-3- O-rhamnoside) as determined by HPLC, mass spectrometry, UV/Vis spectroscopy, and TLC. Radical-scavenging activities of hyperoside and quercitrin from Japanese pepper fruit were evaluated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. As a result, hyperoside and quercitrin scavenged DPPH radical strongly with IC 50 values of 16 and 18 μM, respectively. These observations show the presence of strong antioxidants, namely hyperoside and quercitrin in Japanese pepper fruit.

Aliphatic acid amides of the fruits of Zanthoxylum piperitum

Six aliphatic acid amides ( 1– 6) were isolated from the pericarp of Zanthoxylum piperitum fruits. MS and NMR spectroscopic investigation revealed that these compounds have a ketone and/or hydroxyl group(s) in the unsaturated aliphatic acid moiety of the structure of the amides. Combinations 3– 4 and 5– 6 are stereoisomers in terms of the relative configurations of their two asymmetric carbons.

Food habits and home range use of Japanese macaques on an island inhabited by deer

Food habits and home range use of a troop of Japanese macaque Macaca fuscata Blyth on Kinkazan Island (9.6 km2), northern Japan, were studied from the spring of 2000 to the winter of 2002. The home range of this troop covers the area where vegetation is modified by foraging of sika deer Cervus nippon Temminck. The core areas of the home ranges of the macaque troop corresponded closely to the distributions of the staple food plants in every season. For example, leaves of Berberis thunbergii DC. and leaves of Zelkova serrata Makino in spring, berries of Berchemia racemosa Sieb. &amp; Zucc. in summer, nuts of Zelkova serrata and Carpinus spp. in the fall of 2000 and winter of 2001, seeds of Torreya nucifera Sieb. &amp; Zucc. in the fall of 2001, and bark of Zanthoxylum piperitum DC. in winter of 2002. Among the staple food plants, Berberis thunbergii and Zanthoxylum piperitum are more abundant on Kinkazan Island than other macaque habitats in northern Japan because they are spiny and unpalatable to sika deer, hence survive under the heavy foraging by the deer. Further, another staple food plant, Berchemia racemosa, a liana, grows abundantly at the edges of Illicium forests. Illicium anisatur is toxic and is not consumed by sika deer. Monkeys of this troop using the unique vegetation induced by sika deer grazing, fed on several plants which are not consumed by monkeys in other areas, and the home range was heavily affected by the distributions of these plants.

Larvicidal Activity of Medicinal Plant Extracts Against Aedes aegypti, Ochlerotatus togoi, and Culex pipiens pallens (Diptera: Culicidae)

The toxicities of methanol extracts from 28 medicinal plant species to early 4th instar larvae of Aedes aegypti, Ochlerotatus togoi {Aedes togoi), and Culex pipiens pollens were determined in the laboratory. Responses varied according to plant and mosquito species. At a concentration of 100 ppm, >90% mortality of the three species was obtained with the extracts of Cinnamomum cassia bark, Illicium verum fruit, Piper nigrum fruit, Zanthoxylum piperitum fruit, and Kaempferia galanga rhizome. P. nigrum fruit extract gave 100% mortality of larvae of Ae. aegypti and O. togoi at 5 ppm and 96% mortality of larvae of C. pipiens pallens at 2.5 ppm. Z. piperitum fruit extract gave 85, 100, and 48% mortality in larvae of Ae. aegypti, O. togoi, and Cx. pipiens pallens at 10 ppm, respectively. The plants described merit further study as potential mosquito larval control agents.

Zanthoxylum piperitum (DC), a potential feeding deterrent for mammals: studies with Microtus ochrogaster (Wagner).

Total extract from the fruit of Szechuan pepper (Zanthoxylum piperitum DC), the volatile components of the extract and a non-volatile fraction containing alkylamides (NVA fraction) are feeding deterrents for rats. The present study investigated the effectiveness of these natural repellents in prairie voles (Microtus ochrogaster Wagner). Two-choice feeding trials were conducted during which food-deprived voles were offered choices between oat-bran wafers. In Experiment 1, 10 voles were given three sets of feeding trials, each 2 h long. Baseline consumption was established during the first set of two trials by offering a choice between two oat-bran wafers dipped in ethanol, the control solvent. During the second set of two trials the voles were given a choice between an oat-bran wafer dipped in ethanol and a wafer dipped in Zanthoxylum extract. During the third set the voles were given a choice between a wafer served on top of a screened dish containing a sample of ethanol and a wafer served on top of a dish containing a sample of extract. In this manner the voles were exposed to volatile compounds emanating from the extract but could not contact it. Wafers dipped in extract were almost completely avoided. The volatile components of extract also significantly reduced food intake. In Experiment 2, habituation to the volatile constituents of extract was examined in 16 Zanthoxylum-naïve voles. Baseline consumption was established by offering two wafers served on top of screened dishes containing ethanol. This was followed by twelve tests during which a choice between a wafer served above a sample of ethanol and a wafer served above a sample of extract was given. The voles failed to habituate to the volatile components of extract, consistently consuming less of the wafers served above extract. In Experiment 3 a dose-response curve to Zanthoxylum extract was established, using 12 stimulus-naive voles. After baseline consumption was established, the animals were given two tests each, presenting a choice between a control wafer and a wafer dipped in a dilution of extract (0.001-100 g liter(-1)). Only concentrations of 10 and 100 g liter(-1) reduced food intake. In Experiment 4 the effects of the non-volatile fraction of extract were compared to those of whole extract. Vegetable oil was used as solvent. Eight stimulus-naïve voles were given two tests with a choice between an oil-dipped and an extract-dipped wafer. A second group of eight voles received two tests with a choice between an oil-dipped and NVA-dipped wafer. Extract-dipped wafers were avoided, but the NVA fraction had no effect on food consumption.

Tyrosinase inhibitor isolated from the leaves of Zanthoxylum piperitum.

Two flavonols, quercetin (1) and quercitrin (2), were isolated from the leaves of Zanthoxylum piperitum. Their structures were established by UV, one- and two-dimensional NMR, and mass spectroscopic methods. Quercetin showed significant inhibition against mushroom tyrosinase with an IC50 value of 3.8 microg/ml, and appeared to inhibit the polyphenol oxidase activity of tyrosinase in a competitive manner (Ki = 10 +/- 0.20 microM) when L-tyrosine was used as a substrate, although it did not inhibit the melanin production of Streptomyces bikiniensis.

초피 과피의 성숙정도에 따른 향기성분의 변화

초피의 성숙과정중 향기성분을 조사하고자, 경상남도 밀양시 제약산 일대에서 2001년 6월 2일, 7월 14일 및 9월 11일에 채취한 초피 과피의 향기성분을 CC-MS로 분석한 결과, 6월 2일에는 52종, 7월 14일에는 47종 및 9월 11일에는 44종이 확인되었다. 각각의 채취시기에 대한 구성성분의 종류를 비교하면 terpene류는 6월 2일과 7월 14일에는 myrcene, <TEX>${\gamma}$</TEX>-terpinene, <TEX>$\alpha$</TEX>-terpinolene, <TEX>$\alpha$</TEX>-phellandrene, <TEX>$\beta$</TEX>-caryophyllene 등 8종이 검출되었으나, 9월 11일에는 <TEX>$\alpha$</TEX>-phellandrene과 <TEX>$\beta$</TEX>-raryophyllene이 검출되지 않았다. Alcohol류는 6월 2일 채취시에는 linalool L, citronellol 등 13종이, 7월 14일과 9월 11일에는 cis-linalool oxide와 piperitol isomer가 추가되어 15종이 검출되었다. Aldyhyde류는 채취시기에 관계없이 citronellal 등 3종이 검출되었으나, 9월 11일에는 citronellal의 함량이 현저히 증가하였으며, ketone류도 cryptone, piperitone 등 5종이 검출되었는데 구성성분의 종류는 채취시기에 관계없이 동일하였으나, 함량의 차이는 있었다. Ester류는 6월 2일에 채취하였을 경우에는 lavandulyl acetate, <TEX>$\alpha$</TEX>-terpinenyl acetate 등 6종이 검출되었으나, 7월 14일과 9월 11일에 채취한 과피에서는 [(E)-6,7-ephoxy-3,7-dimethyl-2-octenyl]ester of acetic acid 가 새로이 검출되어 7종이었다. Hyrocarbon류는 <TEX>$\delta$</TEX>-cadinene, neopentylideneclohexane 등 7종이었는데, 7월 14일과 9월 11일에는 <TEX>$\alpha$</TEX>-muurolene이 추가되어 8종이 검출되었다 초피 과피의 향기성분은 채취시기에 따라서 구성성분의 종류는 물론 농도의 변화가 현저하였다. This study was conducted to estimate volatile compounds in pericarp of Zanthoxylum piperitum DC (Chopi). Chopi which harvested on lune 2, July 14 and September 11 in 2001 was dried at room temperature for one week. Fifty-two, 47, and 44 volatile compounds were analyzed with GC-MS in pericarp harvested on lune 2, July 14 and September 11, respectively. Eight terpenes including myrcene, <TEX>${\gamma}$</TEX>-terpinene, <TEX>$\alpha$</TEX>-terpinolene, <TEX>$\alpha$</TEX>-phellandrene and <TEX>$\beta$</TEX>-caryophyllene were detected in pericarp harvested on tulle 2 and July 14, but not <TEX>$\alpha$</TEX>-phellandrene and <TEX>$\beta$</TEX>-caryophyllene in pericarp harvested on September 11. Thirteen alcohols or terpene alcohols including linalool L and citronellol were detected in pericarp harvested on lune 2, and added cis-linallol oxide and piperitol isomer in pericarp harvested on July 14 and September 11. Three aldehydes or terpene aldehydes were not affected by degree of maturation, but citronellal was increased in pericarp harvested on September 11. Five volatile compounds of ketones containing cryptone and piperitone were detected, and their concentration was changed during maturation. Six esters including lavandulyl acetate and <TEX>$\alpha$</TEX>-terpinenyl acetate were detected in pericarp harvested on lune 2, and [(E)-6,7-ephoxy-3,7-dimethyl-2-octenyl]ester of acetic acid was added in pericarp harvested on July 14 and September 11. Seven hydrocarbons including <TEX>$\delta$</TEX>-cadinene and neopentylidene cyclohexane were detected in pericarp harvested on June 2 and <TEX>$\alpha$</TEX>-muurolene was newly added in pericarp harvested on July 14 and September 11. We suggest that kinds and concentration of volatile compounds in pericarp were remarkably different from those in mature stage.

The inhibitory effects of 12 medicinal plants and their component compounds on lipid peroxidation.

The antioxidative activities of 12 medicinal plants and the compounds isolated from them were investigated using the thiocyanate method to evaluate inhibitory effects on lipid peroxidation in the linoleic acid system. The peroxide levels gradually increased during incubation in the presence of linoleic acid over 3 days, and most of the plants inhibited lipid peroxidation. In particular, of the plants tested, Cudrania tricuspidata, Zanthoxylum piperitum, Houttuynia cordata and Ulmus parvifolia reduced lipid peroxidation more effectively as lipid peroxidation progressed, resulting in inhibition of about 80% relative to the control value by the 3rd day of incubation. In addition, the polyphenols isolated from the plants also showed marked and dose-dependent inhibitory effects on lipid peroxidation. The compounds with the strongest activities were 3,4-dihydroxylbenzoic acid, quercetin, the quercetin glycosides quercetin-3-O-beta-D-galactoside, quercetin-3-O-alpha-L-rhamnoside, quercetin-3-O-beta-D-glucoside and quercetin-3-O-rutinose, catechin, gallic acid, methyl gallate and rosamultin isolated from Zanthoxylum piperitum, Houttuynia cordata, Rosa rugosa and Cedrela sinensis. Moreover, quercetin glycosides showed stronger activity than quercetin, suggesting that glycosylation increases the antioxidative activity of quercetin. Our results indicate that the medicinal plants and their polyphenols show promise as therapeutic agents for various disorders involving free radical reactions.

Study on the inhibitory effects of Korean medicinal plants and their main compounds on the 1,1-diphenyl-2-picrylhydrazyl radical

A 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-generating system was used to evaluate the antioxidant properties of Korean medicinal plants that have been used widely as folk medicines for several disorders, as well as compounds isolated from them. Among the Rosaceae, Rosa rugosa and Rosa davurica showed strong DPPH radical-scavenging activity. The most effective medicinal plant from families other than Rosaceae was Cedrela sinensis, followed in order by Nelumbo nucifera, Eucommia ulmoides, Zanthoxylum piperitum, Cudrania tricuspidata and Houttuynia cordata. These results serve as a good index of the free radical-scavenging activities of Korean medicinal plants. Furthermore, the polyphenols isolated from these plants, procyanidin B-3, (+)-catechin, gallic acid, methyl gallate, quercetin, quercetin-3-O-beta-D-glucoside, quercetin-3-O-beta-galactoside, quercetin-3-O-rutinose and kaempferol, exerted strong DPPH radical-scavenging activity. These results suggest that the Korean medicinal plants and the polyphenols isolated from them that exhibited effective radical-scavenging activity may be promising agents for scavenging free radicals and treating diseases associated with excess free radicals.

Effect of methanol extract of Zanthoxylum piperitum leaves and of its compound, protocatechuic acid, on hepatic drug metabolizing enzymes and lipid peroxidation in rats.

The effect of methanol extract and protocatechuic acid from the leaves of Zanthoxylum piperitum on lipid peroxidation and drug metabolizing enzymes were investigated in the liver of bromobenzene-treated rats. The methanol extract and protocatechuic acid reduced the level of lipid peroxide induced by bromobenzene. The methanol extract and protocatechuic acid reduced the activity of aniline hydroxylase that had been increased by bromobenzene, while did not affect the activities of aminopyrine N-demethylase and glutathione S-transferase. The methanol extract and compound effectively restored the activity of epoxide hydrolase which had been decreased by bromobenzene. These results may suggest that the methanol extract of Z. piperitum and protocatechuic acid prevented lipid peroxidation by reducing the activity of aniline hydroxylase, an epoxide-producing enzyme, and by enhancing the activity of epoxide hydrolase, an epoxide-removing enzyme, in rats that had been intoxicated with bromobenzene.