Piper sarmentosum as an antioxidant on oxidative stress in human umbilical vein endothelial cells induced by hydrogen peroxide

Undescribed Lignanamide and Flavone C-Glucoside Isolated from the Aerial Parts of Piper Samentosum with NO Production Inhibitory Activity in LPS Activated RAW 264.7 Cells

In this study, two undescribed compounds (1 and 2), together with eight known compounds (3-10) were isolated from the aerial parts of Piper samentosum by various chromatography methods. Their chemical structures were determined to be 7'''-oxolyciumamide N (1), vitexin 2''-O-β-D-(6'''-feruloyl)-glucopyranoside (2), 1,2-dihydro-6,8-dimethoxy-7-hydroxy-1-(3,4-dihydroxyphenyl)-N1,N2-bis-[2-(-hydroxyphenyl)ethyl]-2,3-napthalene dicarboamide (3), vitexin 6''-O-β-D-glucopyranoside (4), vitexin 2''-O-α-L-rhamnopyranoside (5), methyl 2-hydroxybenzoate-2-O-β-D-apiofuranosyl-(1→2)-O-β-D-glucopyranoside (6), ficuside G (7), methyl 2-O-β-D-glucopyranosylbenzoate (8), methyl 2,5-dihydroxybenzoate-5-O-β-D-glucopyranoside (9), and 3,7-dimethyloct-1-ene-3,6,7-triol 6-O-β-D-glucopyranoside (10) by spectroscopic data analysis including HR-ESI-MS, 1D-, and 2D-NMR spectra. Compounds 1-5 inhibited nitric oxide production in LPS-stimulated RAW264.7 macrophages with the IC50 values of 27.62, 74.03, 38.54, 70.39, and 44.95 μM, respectively. The NMR data of 9 were firstly reported herein.

Ethnopharmacological analysis based on Thai traditional medicine theory and anti-inflammatory activity of Sa-Tri-Lhung-Klod remedy as a post-partum anti-inflammatory drug

ETHNOPHARMACOLOGICAL RELEVANCE

Sa-Tri-Lhung-Klod (ST) remedy is a Thai traditional remedy used in obstetrics and gynecology to reduce inflammation and nourish the body post-partum. In Thai traditional medicine (TTM), there is a theory of formulating drugs based on the four elements and the tastes of herbs for use in treating diseases.

AIMS OF STUDY

To determine relationships between taste theory and pharmacological properties for the anti-inflammatory effect of ST remedy and its chemical constituent components. To evaluate anti-inflammatory activity and also investigate the HPLC fingerprint of ST extracts.

MATERIALS AND METHODS

ST remedy was extracted by maceration in 95% ethanol (STE) and decoction in distilled water (STW). ST extracts were evaluated for anti-inflammatory activity by nitric oxide inhibitory assay in RAW264.7 cells, carrageenan-induced rat paw edema, and prostaglandin E2 inhibitory assay in inflamed rat paw tissue. In addition, the chemical constituent fingerprints of ST extracts were examined using HPLC.

RESULTS

STE contained seven main chemical compounds, and STW demonstrated only one identifiable chemical compound. The STE and STW displayed potent NO inhibitory activity with an IC50 value of 20.59 ± 0.03 and 52.93 ± 0.90 μg/mL, respectively. Moreover, the STE and STW (at doses of 100 - 400 mg/kg) promoted significant inhibition of inflammation in carrageenan-induced paw edema in rats (20.81 - 38.25%). Additionally, the STE (200 - 400 mg/kg) and STW (100 - 400 mg/kg) significantly reduced PGE2 levels in inflamed rat paw tissue.

CONCLUSION

These findings suggest that the spicy, astringent, sweet, and fragrant taste of the ST remedy used to treat post-partum inflammation encompass constituents with potent anti-inflammatory activity. STE and STW possess anti-inflammatory properties and effectively inhibit the production of NO and PGE2. Results confirm the use of the ST remedy for treating inflammatory diseases in the post-partum period according to TTM knowledge.

Antioxidant Potential of Diosmin and Diosmetin against Oxidative Stress in Endothelial Cells

Phlebotropic flavonoids, including diosmin and its aglycone diosmetin, are natural polyphenols widely used in the prevention and treatment of chronic venous insufficiency (CVI). As oxidative stress plays an important role in the development of pathophysiology of the cardiovascular system, the study aimed to investigate the protective effects of diosmin and diosmetin on hydrogen peroxide (H₂O₂)-induced oxidative stress in endothelial cells. The cells were pretreated with different concentrations of the flavonoid prior to the H₂O₂ exposure. The cell viability, the level of intracellular reactive oxygen species (ROS), the activity of cellular antioxidant enzymes-including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase GPx-and the malondialdehyde (MDA) level were assessed. It was found that the H₂O₂-induced oxidative stress was ameliorated by diosmin/diosmetin in a concentration-dependent manner. The flavonoids restored the activity of cellular antioxidant enzymes and lowered the MDA level upregulated by the H₂O₂ exposure. These results indicate that diosmin and diosmetin may prevent oxidative stress in endothelial cells; therefore, they may protect against the development and progression of oxidative-stress-related disorders.

Hamid A, Ugusman A. Effects of Piper sarmentosum Roxb. on hypertension and diabetes mellitus: A systematic review and meta-analysis

Hypertension and diabetes mellitus are among the most prevalent diseases affecting people from all walks of life. Medicinal herbs have garnered interest as potential agents for the prevention and treatment of diabetes mellitus and hypertension due to their multiple beneficial effects. Piper sarmentosum Roxb. (PS) is an edible medicinal plant that has been traditionally used in Asia for treating hypertension and diabetes mellitus. This review is aimed to provide comprehensive information from the literature on the effects of PS on hypertension and diabetes mellitus. A computerized database search was performed on Scopus, PubMed and Web of Science databases with the following set of keywords: Piper sarmentosum AND diabetes mellitus OR diabetic OR diabetes OR hyperglyc*emia OR blood glucose OR HbA1c OR glycated h*emoglobin OR h*emoglobin A1c OR hyperten* OR blood pressure. A total of 47 articles were screened and 14 articles published between the years 1998 until 2021 were included for data extraction, comprising of six articles on antihypertensive and eight articles on antidiabetic effects of PS. These studies consist of two in vitro studies and eleven in vivo animal studies. Meta-analysis of three studies on hypertension showed that PS versus no treatment significantly lowered the systolic blood pressure with mean difference (MD) -39.84 mmHg (95% confidence interval (CI) -45.05, -34.62; p < 0.01), diastolic blood pressure with MD -26.68 mmHg (95% CI -31.48, -21.88; p < 0.01), and mean arterial pressure with MD -30.56 mmHg (95% CI -34.49, -26.63; p < 0.01). Most of the studies revealed positive effects of PS against hypertension and diabetes mellitus, suggesting the potential of PS as a natural source of antidiabetic and antihypertensive agents.

Impact of Peels Extracts from an Italian Ancient Tomato Variety Grown under Drought Stress Conditions on Vascular Related Dysfunction

Background: Tomato by-products contain a great variety of biologically active substances and represent a significant source of natural antioxidant supplements of the human diet. The aim of the work was to compare the antioxidant properties of a by-product from an ancient Tuscan tomato variety, Rosso di Pitigliano (RED), obtained by growing plants in normal conditions (-Ctr) or in drought stress conditions (-Ds) for their beneficial effects on vascular related dysfunction. Methods: The antioxidant activity and total polyphenol content (TPC) were measured. The identification of bioactive compounds of tomato peel was performed by HPLC. HUVEC were pre-treated with different TPC of RED-Ctr or RED-Ds, then stressed with H₂O₂. Cell viability, ROS production and CAT, SOD and GPx activities were evaluated. Permeation of antioxidant molecules contained in RED across excised rat intestine was also studied. Results: RED-Ds tomato peel extract possessed higher TPC than compared to RED-Ctr (361.32 ± 7.204 mg vs. 152.46 ± 1.568 mg GAE/100 g fresh weight). All extracts were non-cytotoxic. Two hour pre-treatment with 5 µg GAE/mL from RED-Ctr or RED-Ds showed protection from H₂O₂-induced oxidative stress and significantly reduced ROS production raising SOD and CAT activity (* p < 0.05 and ** p < 0.005 vs. H₂O₂, respectively). The permeation of antioxidant molecules contained in RED-Ctr or RED-Ds across excised rat intestine was high with non-significant difference between the two RED types (41.9 ± 9.6% vs. 26.6 ± 7.8%). Conclusions: RED-Ds tomato peel extract represents a good source of bioactive molecules, which protects HUVECs from oxidative stress at low concentration.

Cnidoscolus aconitifolius leaf pellet can manipulate rumen fermentation characteristics and nutrient degradability

Objective

Chaya (Cnidoscolus aconitifolius) leaf has been found to be an important source of protein, vitamins, minerals, as well as phytonutrients. The present study aimed to evaluate the effect of Chaya leaf pellet (CHYP) with various level of crude protein (CP) in the concentrate on rumen fermentation characteristics and nutrient degradability in in vitro gas production technique.

Methods

In an in vitro rumen fermentation study the dietary treatments were arranged according to a 3×5 factorial arrangement in a completely randomized design, consisting of Factor A: three levels of CP of concentrate mixtures (14%, 16%, and 18% CP, respectively) and Factor B: five levels of CHYP supplementation (at 0%, 2%, 4%, 6%, and 8% of dry matter substrates).

Results

The gas production kinetics, fraction (a) and fraction (b) were lower (p<0.05) with an increasing CHYP addition. Additionally, the fraction (a+b) was found to yield a significant interaction (p<0.05) while the fraction (c) was not impacted by CHYP addition. However, in vitro DM degradability was enhanced and interactive (p<0.05), using 16% CP of concentrate with 6% and 8% CHYP, when compared with 18% CP in the non-addition. Additionally, the treatment with higher CP of the concentrate was higher in NH₃-N concentration (p<0.001) and by CHYP supplementation group (p<0.05). Nevertheless, protozoal counts in the rumen were remarkably decreased (p<0.05) with increasing level of CHYP supplementation. Furthermore, rumen C₂ concentration was lower (p<0.05) in the treatments with CHYP supplementation, while C₃ was significantly increased and interactive (p<0.05) between levels of CP and CHYP supplementation especially at 8% CHYP supplementation.

Conclusion

Based on this study, the results revealed CHYP as a promising feed supplement to enhance rumen fermentation and to mitigate methane production. However, in vivo feeding experiments should be subsequently conducted to elucidate the effect of CHYP supplementation on rumen fermentation, as well as ruminant production efficiency.

Piper sarmentosum Roxb. Attenuates Beta Amyloid (Aβ)-Induced Neurotoxicity Via the Inhibition of Amyloidogenesis and Tau Hyperphosphorylation in SH-SY5Y Cells

BACKGROUND

In Alzheimer's disease, accumulation of beta amyloid (Aβ) triggers amyloidogenesis and hyperphosphorylation of tau protein leading to neuronal cell death. Piper sarmentosum Roxb. (PS) is a traditional medicinal herb used by Malay to treat rheumatism, headache and boost memory. It possesses various biological effects, such as anti-cholinergic, anti-inflammatory, anti-oxidant and anti-depressant-like effects.

OBJECTIVE

The present study aimed to investigate neuroprotective properties of PS against Aβ-induced neurotoxicity and to evaluate its potential mechanism of action.

METHODS

Neuroprotective effects of hexane (HXN), dichloromethane (DCM), ethyl acetate (EA) and methanol (MEOH) extracts from leaves (L) and roots (R) of PS against Aβ-induced neurotoxicity were investigated in SH-SY5Y human neuroblastoma cells. Cells were pre-treated with PS for 24 h followed by 24 h of induction with Aβ. The neuroprotective effects of PS were studied using cell viability and cellular reactive oxygen species (ROS) assays. The levels of extracellular Aβ and tau proteins phosphorylated at threonine 231 (pT231) were determined. Gene and protein expressions were assessed using qRT-PCR analyses and western blot analyses, respectively.

RESULTS

Hexane extracts of PS (LHXN and RHXN) protected SH-SY5Y cells against Aβ-induced neurotoxicity, and decreased levels of extracellular Aβ and phosphorylated tau (pT231). Although extracts of PS inhibited Aβ-induced ROS production, it was unlikely that neuroprotective effects were simply due to the anti-oxidant capacity of PS. Further, mechanistic study suggested that the neuroprotective effects of PS might be due to its capability to regulate amyloidogenesis through the downregulation of BACE and APP.

CONCLUSION

These findings suggest that hexane extracts of PS confer neuroprotection against Aβ- induced neurotoxicity in SH-SY5Y cells by attenuating amyloidogenesis and tau hyperphosphorylation. Due to its neuroprotective properties, PS might be a potential therapeutic agent for Alzheimer's disease.

Piper sarmentosum Roxb.: A review on its botany, traditional uses, phytochemistry, and pharmacological activities

ETHNOPHARMACOLOGICAL RELEVANCE

Piper sarmentosum Roxb. (Piperaceae) is a traditional medicinal plant widely distributed in India, Malaysia, Thailand, and the southeastern coastal areas of China including Fujian, Guangdong, and Guizhou. It has been used for centuries for the treatment of wind-cold cough, fever, rheumatism arthralgia, diarrhea dysentery, postpartum foot swelling, stomachache, toothache, diabetes, and traumatic injury.

AIMS OF THE REVIEW

To critically anayze the literature for the botany, traditional uses, phytochemistry, pharmacology, toxicity, and clinical trials of P. sarmentosum in order to provide a scientific consensus for further research and discovery of potential candidate drugs.

MATERIALS AND METHODS

The contents of this review were sourced from electronic databases including PubMed, SciFinder, Web of Science, Science Direct, Elsevier, Google Scholar, Chinese Knowledge On frastructure (CNKI), Wanfang, Chinese Scientific and Technological Periodical Database (VIP), Chinese Biomedical Database (CBM), Cochrane Controlled register of Clinical Trials, Clinical Trials. gov, and Chinese Clinical Trial Registry. Chinese medicine books published over the years were used to elucidate the traditional uses of P. sarmentosum and additional information was also collected from Yao Zhi website (https://db.yaozh.com/).

RESULTS

Phytochemical analyses of the chemical constituents of P. sarmentosum include essential oil, alkaloids, flavonoids, lignans, and steroids. The literature supports the ethnomedicinal uses of P. sarmentosum for the treatment of cold, gastritis, and rheumatoid joint pain, and further confirms its relatively new pharmacological activities, including anti-inflammatory, antineoplastic, and antipyretic activities. Other biological roles such as anti-osteoporosis, antibacterial, antidepressant, anti-atherosclerotic, and hypoglycemic activities have also been reported. However, the methodologies employed in individual studies are limited.

CONCLUSIONS

There is convincing evidence from both in vitro and in vivo studies supporting the traditional use of P. sarmentosum and it is imperative that natural bioactive compounds are examined further. More efforts should be focused on the pharmacodynamic constituents of P. sarmentosum to provide practical basis for quality control, and additional studies are needed to understand the mechanism of their action. Further studies on the comprehensive evaluation of medicinal quality and understandings of serum chemistry, multi-target network pharmacology, and molecular docking technology of P. sarmentosum are of great importance and should be considered.

Ethanolic extract of Betel (Piper betle L.) and Chaphlu (Piper sarmentosum Roxb.) dechlorophyllized using sedimentation process: Production, characteristics, and antioxidant activities

Sedimentation process was used to remove chlorophyll from betel leaf ethanolic extracts (BLEE) and chaphlu leaf ethanolic extracts (CLEE). The influence of water quantity on chlorophyll content, total phenolic content (TPC), and antioxidant activity of the extracts was studied. The sedimentation process showed a remarkable reduction in chlorophyll A, chlorophyll B, and total chlorophyll contents of both extracts. Nevertheless, no differences in chlorophyll content, TPC, and antioxidant activities were observed between dechlorophyllized fractions in both extracts (p > .05). Liquid Chromatography-Mass Spectrometry (LC/MS) profiling showed that the BLEE dechlorophyllized using the extract/water ratio of 1:1 (BLEE-DC1) had higher phenolic compounds than CLEE-DC1. Isovitexin was the most abundant compound identified in the BLEE-DC1 while vitexin 4'-O-galactoside was the most prevalent in CLEE-DC1. When thermal and pH stabilities of the dechlorophyllized extracts were tested, BLEE-DC1 exhibited more heat stability (at 60-100°C for 0-60 min) than CLEE-DC1. Both dechlorophyllized extracts showed optimum antioxidant activities at pH 5.0. PRACTICAL APPLICATIONS: Oxidation process is associated with the numerous human diseases as well as it induces the deteriorative changes in foods, especially those rich in fat or lipid containing high polyunsaturated fatty acids. Numerous synthetic antioxidants have been employed but they may not be safe. Natural antioxidants have gained attention, particularly those from several leaves rich in polyphenols. However, due to the green color caused by chlorophylls, the extract is limited for further applications. Betel leaf ethanolic extract possessing high antioxidant activity could be dechlorophyllized using sedimentation process with the appropriate proportion of water. This green process not only showed the effective removal of chlorophyll, but also increased the proportion of polyphenol in the extract. Greenless betel leaf extract with augmented antioxidant activity can be used as natural additive to replace synthetic counterpart.

Antioxidant and Anti-Inflammatory Properties of Cherry Extract: Nanosystems-Based Strategies to Improve Endothelial Function and Intestinal Absorption

Cherry fruit has a high content in flavonoids. These are important diet components protecting against oxidative stress, inflammation, and endothelial dysfunction, which are all involved in the pathogenesis of atherosclerosis, which is the major cause of cardiovascular diseases (CVD). Since the seasonal availability of fresh fruit is limited, research has been focused on cherry extract (CE), which also possesses a high nutraceutical potential. Many clinical studies have demonstrated the nutraceutical efficacy of fresh cherries, but only a few studies on CE antioxidant and anti-inflammatory activities have been carried out. Here, the results concerning the antioxidant and anti-inflammatory activities of CE are reviewed. These were obtained by an in vitro model based on Human Umbilical Vein Endothelial Cells (HUVEC). To clarify the CE mechanism of action, cells were stressed to induce inflammation and endothelial dysfunction. Considering that antioxidants' polyphenol compounds are easily degraded in the gastrointestinal tract, recent strategies to reduce the degradation and improve the bioavailability of CE are also presented and discussed. In particular, we report on results obtained with nanoparticles (NP) based on chitosan derivatives (Ch-der), which improved the mucoadhesive properties of the chitosan polymers, as well as their positive charge, to favor high cellular interaction and polyphenols intestinal absorption, compared with a non-mucoadhesive negative surface charged poly(lactic-co-glycolic) acid NP. The advantages and safety of different nanosystems loaded with natural CE or other nutraceuticals are also discussed.

Antioxidant Effect of Cocoa By-Product and Cherry Polyphenol Extracts: A Comparative Study

BACKGROUND

Recent studies have highlighted the importance of cherry and cocoa extracts consumption to protect cells from oxidative stress, paying particular attention to cocoa by-products. This study aims to investigate the protective effect of cocoa husk extract (CHE) and cherry extracts (CE) against ROS-induced oxidative stress in Human Umbilical Vein Endothelial Cells (HUVECs).

METHODS

CE and CHE had antioxidant activity characterized by total polyphenols content (TPC). HUVECs were treated for 2 h and 24 h with increasing TPC concentrations of CE and CHE (5-10-25-50-100 µg Gallic Acid Equivalent (GAE)/mL) and then with H2O2 for 1 h. Cell viability and ROS production were evaluated. CE and CHE polyphenols permeability on excised rat intestine were also studied.

RESULTS

CE and CHE showed a similar antioxidant activity (2.5 ± 0.01 mmol Fe2+/100 g FW (fresh weight) and 2.19 ± 0.09 mmol Fe2+/100 g FW, respectively, p > 0.05) whereas CHE had a higher TPC (7105.0 ± 96.9 mg GAE/100 g FW) than CE (402.5 ± 8.4 mg GAE/100 g), p < 0.05. The in vitro viability assay showed that both extracts were non-cytotoxic. CHE resulted in protection against ROS at lower concentrations than CE. CHE showed a 2-fold higher apparent permeability compared to CE.

CONCLUSIONS

CHE represents a high-value antioxidant source, which is interesting for the food and pharmaceutical industries.

Cordycepin attenuates Salivary Hypofunction through the Prevention of Oxidative Stress in Human Submandibular Gland Cells

Xerostomia (dry mouth) is a significant age-related condition. Meanwhile, cordycepin, the natural therapeutic agent, has demonstrated an anti-aging effect. Therefore, the present study aimed to investigate the preventive effects of cordycepin on secretory function in an in vitro model of hydrogen peroxide (H₂O₂)-induced salivary hypofunction. After being exposed to H₂O₂, human submandibular gland (HSG) cells were treated with various concentrations of cordycepin (6.25-50 µM) for 24, 48, and 72h. To evaluate cell proliferation and reactive oxygen species (ROS) generation, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide and 2, 7'-dichlorodihydrofluorescein diacetate assays were performed. The amylase activity was kinetically measured by 2-chloro-p-nitrophenol linked with maltotrioside. The expression of salivary, antioxidant and apoptotic markers at mRNA and protein levels were performed by reverse transcriptase polymerase chain reaction (RT-PCR) and immunofluorescence analysis, respectively. We demonstrated that cordycepin (6.25-25 µM) contributed to significant increases in expression of the salivary marker genes, alpha-amylase 1 (AMY1A) and aquaporin-5 (AQP5), and in amylase secretion without changes in cell viability. Under oxidative stress, HSG cells showed remarkable dysfunction. Cordycepin rescued the protective effects partially by decreasing ROS generation and restoring the expression of the salivary proteins, AMY and AQP5 via anti-oxidant and anti-apoptotic activity. In addition, the amount of amylase that was secreted from HSG cells cultured in cordycepin was increased. In conclusion, cordycepin demonstrated a protective effect on H₂O₂ -induced HSG cells by decreasing ROS generation and upregulating the salivary function markers, AMY1A and AQP5, at both the transcriptional and translational levels.

Effects of Piper sarmentosum extract supplementation on growth performances and rumen fermentation and microflora characteristics in goats

This study was carried out to investigate the effect of diet Piper sarmentosum extract (PSE) on the growth performance, antioxidant properties, rumen fermentation and microflora in goats. Forty Hainan black goats with similar body weight were divided into four groups with supplementation of PSE in the concentrate at 0, 300, 600 and 1,200 mg/kg, respectively, and fed for 56 days. Results showed that average daily gain (ADG) was higher and feed intake/body gain (F/G) was lower in goats fed with PSE at 300 mg/kg (p < .05). The activities of glutathione peroxidase (GSH-Px) and total antioxidant capacity (T-AOC) in the serum of goats differed among treatments and were greatest linearly when PSE was added at 1,200 mg/kg (p < .05). The level of malondialdehyde (MDA) in the serum of goats differed among treatments and was lowest linearly when PSE was added at 1,200 mg/kg (p < .05). The level of protozoal protein in the rumen of goats differed among treatments and was lowest linearly when PSE was added at 1,200 mg/kg (p < .05). The concentrations of ruminal acetic acid and valeric acid and the ratio of acetate to propionate were reduced with PSE supplementation (p < .05). Protozoa, fungi, Ruminococcus flavefaciens and Fibrobacter succinogenes contents differed among treatments and were lowest linearly when PSE was added at 1,200 mg/kg (p < .05). Thus, supplementation of PSE at 300-1,200 mg/kg to goat concentrate is recommended for improving antioxidative ability and rumen efficiency and reducing protozoal content of goat.

Piper sarmentosum Promotes Endothelial Nitric Oxide Production by Reducing Asymmetric Dimethylarginine in Tumor Necrosis Factor-α-Induced Human Umbilical Vein Endothelial Cells

Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of endothelial nitric oxide synthase (eNOS). ADMA is degraded by dimethylarginine dimethylaminohydrolase (DDAH). Elevated levels of ADMA lead to reduction in nitric oxide (NO) production, which is linked to endothelial dysfunction and atherosclerosis. Piper sarmentosum is an herb that has shown stimulation on endothelial NO production by increasing both expression and activity of eNOS. Thus, this study determined whether the positive effect of P. sarmentosum on NO production is related to its modulation on the DDAH-ADMA pathway in cultured human umbilical vein endothelial cells (HUVEC) exposed to tumor necrosis factor-α (TNF-α). HUVEC were divided into four groups: control, treatment with 250 µg/ml of aqueous extract of P. sarmentosum leaves (AEPS), treatment with 30 ng/ml of TNF-α, and concomitant treatment with AEPS and TNF-α for 24 h. After treatments, HUVEC were collected to measure DDAH1 messenger RNA (mRNA) expression using quantitative real-time polymerase chain reaction. DDAH1 protein level was measured using enzyme-linked immunosorbent assay (ELISA), and DDAH enzyme activity was measured using colorimetric assay. ADMA concentration was measured using ELISA, and NO level was measured using Griess assay. Compared to control, TNF-α-treated HUVEC showed reduction in DDAH1 mRNA expression (P < 0.05), DDAH1 protein level (P < 0.01), and DDAH activity (P < 0.05). Treatment with AEPS successfully increased DDAH1 mRNA expression (P < 0.05), DDAH1 protein level (P < 0.01), and DDAH activity (P < 0.05) in TNF-α-treated HUVEC. Treatment with TNF-α caused an increase in ADMA level (P < 0.01) and a decrease in endothelial NO production (P < 0.001). Whereas treatment with AEPS was able to reduce ADMA level (P < 0.01) and restore NO (P < 0.001) in TNF-α-treated HUVEC. The results suggested that AEPS promotes endothelial NO production by stimulating DDAH activity and thus reducing ADMA level in TNF-α-treated HUVEC.

Piper sarmentosum Leaves Aqueous Extract Attenuates Vascular Endothelial Dysfunction in Spontaneously Hypertensive Rats

Piper sarmentosum is a tropical plant in Southeast Asia known for its traditional use in curing various ailments including hypertension. Previous research works have provided evidence for the herb's antihypertensive property. However, the exact mechanisms involved are still in question. The present study investigated the effects of Piper sarmentosum leaves aqueous extract (PSAE) treatment on vascular endothelin system in spontaneously hypertensive rats (SHRs). Four groups of SHRs were treated for 28 consecutive days, with negative and positive control groups receiving distilled water and 3 mg/kg perindopril, respectively. Another two groups are the treatment groups, which received PSAE and combination of 1.5 mg/kg perindopril and PSAE. Weekly measurements of blood pressure showed that PSAE significantly reduced the systolic, diastolic, and mean arterial pressures (P < 0.05) of the rats. PSAE also increased mesenteric artery nitric oxide (NO) level (P < 0.05) and reduced endothelin-1 (ET-1) level (P < 0.05) in the treatment groups. Our results demonstrate that oral administration of PSAE reduced blood pressure in SHRs by reducing the ET-1 level while increasing NO production.

Piper Species: A Comprehensive Review on Their Phytochemistry, Biological Activities and Applications

Piper species are aromatic plants used as spices in the kitchen, but their secondary metabolites have also shown biological effects on human health. These plants are rich in essential oils, which can be found in their fruits, seeds, leaves, branches, roots and stems. Some Piper species have simple chemical profiles, while others, such as Piper nigrum, Piper betle, and Piper auritum, contain very diverse suites of secondary metabolites. In traditional medicine, Piper species have been used worldwide to treat several diseases such as urological problems, skin, liver and stomach ailments, for wound healing, and as antipyretic and anti-inflammatory agents. In addition, Piper species could be used as natural antioxidants and antimicrobial agents in food preservation. The phytochemicals and essential oils of Piper species have shown strong antioxidant activity, in comparison with synthetic antioxidants, and demonstrated antibacterial and antifungal activities against human pathogens. Moreover, Piper species possess therapeutic and preventive potential against several chronic disorders. Among the functional properties of Piper plants/extracts/active components the antiproliferative, anti-inflammatory, and neuropharmacological activities of the extracts and extract-derived bioactive constituents are thought to be key effects for the protection against chronic conditions, based on preclinical in vitro and in vivo studies, besides clinical studies. Habitats and cultivation of Piper species are also covered in this review. In this current work, available literature of chemical constituents of the essential oils Piper plants, their use in traditional medicine, their applications as a food preservative, their antiparasitic activities and other important biological activities are reviewed.

Effects of Supplementation of Piper sarmentosum Leaf Powder on Feed Efficiency, Rumen Ecology and Rumen Protozoal Concentration in Thai Native Beef Cattle

Methane (CH₄) is an end-product of enteric fermentation in cattle [...].

Vulpinic acid, a lichen metabolite, emerges as a potential drug candidate in the therapy of oxidative stress–related diseases, such as atherosclerosis

Vulpinic acid, a lichen compound, has been shown to have many beneficial effects and its medicinal value increases day by day. As in atherosclerosis, endothelial damage is the basis of many diseases. The aim of this study is to investigate the effects of vulpinic acid against oxidative stress damage induced by hydrogen peroxide (H2O2) in endothelial cells. In order to find the IC50 of H2O2 and the protective dose of vulpinic acid, methyl thiazolyldiphenyl tetrazolium bromide (MTT) assays were performed. The amount of reactive oxygen species (ROS) induced by H2O2 and the protective effects of vulpinic acid against ROS were examined by fluorometric DCF-DA kit. The effects of H2O2 and vulpinic acid on actin filaments were determined by tetramethyl rhodamine (TRITC)-phalloidin fluorescence staining. Expression of Tie2 proteins was immunocytochemically analyzed in H2O2- and vulpinic acid-treated cells. After 24 h, the IC50 was found to be 215 μM in HUVECs treated with H2O2. The most effective dose of vulpinic acid against H2O2-associated damage was found to be 15 μM. Vulpinic acid pretreatment was shown to reduce H2O2-induced ROS production significantly ( p < 0.05). It was shown that 215 μM of H2O2 caused actin fragmentation, cell shrinkage, and decrease in actin florescence intensity while vulpinic acid protected the cells from these damages. It was found that Tie2 immunoreactivity was decreased in H2O2-treated groups and vulpinic acid pretreatment reduced the expression of this protein. In conclusion, vulpinic acid decreases H2O2-induced oxidative stress and oxidative stress–related damages in HUVECs. It may be drug candidate in the therapy of atherosclerosis.

Preventive Effect of Naringin on Metabolic Syndrome and Its Mechanism of Action: A Systematic Review

Background

Metabolic syndrome (MetS), which consists of cluster of conditions, hypertension, hyperlipidemia, hyperglycemia, and visceral obesity, is affecting population worldwide. Studies have shown that plant derived flavonoids have the ability to alleviate MetS. Naringin is a type of glycoside flavonoid found in most plant and it plays a critical role in the treatment of MetS due to its antioxidant activity and ability to regulate cytokines.

Methods

A systematic review was done to study the effects of naringin on the metabolic diseases using electronic databases which include Ovid and Scopus using specific descriptors published from the year 2010 till present to provide updated literature on this field. The articles were assessed and chosen based on the criteria in which the mechanisms and effects of naringin on different metabolic diseases were reported.

Results

Thirty-four articles were identified which referred to the studies that correspond to the previously stated criteria. Subsequently after screening for the articles that were published after the year 2010, finally, 19 articles were selected and assessed accordingly. Based on the assessment, naringin could alleviate MetS by reducing visceral obesity, blood glucose, blood pressure, and lipid profile and regulating cytokines.

Conclusions

Naringin is an antioxidant that appears to be efficacious in alleviating MetS by preventing oxidative damage and proinflammatory cytokine release. However, the dosage used in animal studies might not be achieved in human trials. Thus, adequate investigation needs to be conducted to confirm naringin's effects on humans.

In vivo effect of Piper sarmentosum methanolic extract on stress-induced gastric ulcers in rats

INTRODUCTION

Piper sarmentosum (Piperaceae) is traditionally used by Asians to treat numerous common ailments including asthma, fever and gastritis. The aim of the research was to determine and compare the effects of Piper sarmentosum (PS) with omeprazole (OMZ) on gastric parameters in rats exposed to restraint stress.

MATERIAL AND METHODS

The methanolic extract of PS was prepared in the dose of 500 mg/kg. Twenty-eight male Wistar rats were assigned to 4 equal sized groups: two control groups and two treated groups which were supplemented with either PS or OMZ orally at a dose of 500 mg/kg and 20 mg/kg body weight respectively. After 28 days of treatment, one control group, the PS and OMZ group were subjected to a single exposure of water-immersion restraint stress for 3.5 h. After the last exposure to stress, the stomach was excised for evaluation of the parameters.

RESULTS

Oral supplementation of PS was as effective in preventing the formation of gastric lesion when compared with OMZ (p < 0.05). The increased gastric acidity and MDA due to stress was also reduced with supplementation of PS and OMZ. Only PS had the ability to reduce prostaglandin E₂ loss (p = 0.0067) and have the ability to down regulate cyclooxygenase-2 (COX-2) mRNA expression (p = 0.01) with stress exposure.

CONCLUSIONS

Piper sarmentosum possesses a similar protective effect against stress-induced gastric lesions as omeprazole. The protective effect was associated with decreased lipid peroxidation, increased prostaglandin E₂, reduction in gastric acidity and reduction in COX-2 mRNA expression which was altered by stress.

Chitosan-Based Nanoparticles Containing Cherry Extract from Prunus avium L. to Improve the Resistance of Endothelial Cells to Oxidative Stress

Cherries are known for their nutraceutical properties, in particular for their antioxidant ability due to their polyphenol content, which causes a reduction of cardiovascular disease (CVD) risk factors. However, once ingested these molecules are degraded in the Gastrointestinal (GI) tract before reaching the blood, which is the action site. The object of the present work is to evaluate the ability of cherry extract (CE), encapsulated in nanoparticles (NPs) based on different chitosan (Ch) derivatives, to promote a protective effect of human umbilical vein endothelial cells (HUVECs) involved in vascular dysfunction against oxidative stress. CE-loaded NPs based on quaternary ammonium chitosan (NP1) and an S-protected thiolated derivative thereof (NP2) were prepared. The mean particle size (NP1 344.9 ± 17.8, NP2 339.9 ± 68.2 nm), the polydispersity index, the encapsulation efficiency (NP1 78.4 ± 4.5, NP2 79.8 ± 0.6%), and the zeta potential (NP1 14.8 ± 0.3, NP2 15.8 ± 0.5 mV) did not appear to be significantly different. Both NP types improved the CE apparent permeation parameters with respect to the control. Conversely, CE-loaded NP2 protected HUVECs from oxidative stress and reduced reactive oxygen species (ROS) production more than CE-loaded NP1 and free CE. In addition to promoting HUVEC resistance, NP2 could be a useful tool to overcome the problem of cherry seasonality.

Piper sarmentosum Roxb. confers neuroprotection on beta-amyloid (Aβ)-induced microglia-mediated neuroinflammation and attenuates tau hyperphosphorylation in SH-SY5Y cells

ETHNOPHARMACOLOGICAL RELEVANCE

Piper sarmentosum Roxb. (PS), belonging to Piperaceae family, is an edible plant with medicinal properties. It is traditionally used by the Malays to treat headache and boost memory. Pharmacological studies revealed that PS exhibits anti-inflammatory, anti-oxidant, anti-acetylcholinesterase, and anti-depressant-like effects. In view of this, the present study aimed to investigate the anti-inflammatory actions of PS and its potential neuroprotective effects against beta-amyloid (Aβ)-induced microglia-mediated neurotoxicity.

MATERIALS AND METHODS

The inhibitory effects of hexane (L_HXN), dichloromethane (L_DCM), ethyl acetate (L_EA) and methanol (L_MEOH) extracts from leaves of PS on Aβ-induced production and mRNA expression of pro-inflammatory mediators in BV-2 microglial cells were assessed using colorimetric assay with Griess reagent, ELISA kit and real-time RT-PCR respectively. Subsequently, MTT reduction assay was used to evaluate the neuroprotective effects of PS leaf extracts against Aβ-induced microglia-mediated neurotoxicity in SH-SY5Y neuroblastoma cells. The levels of tau proteins phosphorylated at threonine 231 (pT231) and total tau proteins (T-tau) were determined using ELISA kits.

RESULTS

Polar extracts of PS leaves (L_EA and L_MEOH) reduced the Aβ-induced secretion of pro-inflammatory cytokines (IL-1β and TNF-α) in BV-2 cells by downregulating the mRNA expressions of pro-inflammatory cytokines. The inhibition of nitric oxide (NO) production could be due to the free radical scavenging activity of the extracts. In addition, conditioned media from Aβ-induced BV-2 cells pre-treated with L_EA and L_MEOH protected SH-SY5Y cells against microglia-mediated neurotoxicity. Further mechanistic study suggested that the neuroprotective effects were associated with the downregulation of phosphorylated tau proteins.

CONCLUSIONS

The present study suggests that polar extracts of PS leaves confer neuroprotection against Aβ-induced microglia-mediated neurotoxicity in SH-SY5Y cells by attenuating tau hyperphosphorylation through their anti-inflammatory actions and could be a potential therapeutic agent for Alzheimer's disease.

Piper sarmentosum attenuates TNF-α-induced VCAM-1 and ICAM-1 expression in human umbilical vein endothelial cells

Objectives

Inflammation plays a key role in the pathogenesis of atherosclerosis. Piper sarmentosum is an herb with antioxidant and anti-atherosclerotic activities. The aim of this study was to evaluate the anti-inflammatory properties of an aqueous extract of P. sarmentosum (AEPS) in human umbilical vein endothelial cells (HUVECs).

Methods

HUVECs were divided into six groups: control, treatment with 10 ng/ml TNF-α, and co-treatment of 10 ng/ml TNF-α with four different concentrations of AEPS (100, 150, 250, and 300 μg/ml) for 24 h. Subsequently, vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) protein expression, U937 monocyte cells adhesion, and nuclear factor-kappaB (NF-κB) p65 expression in HUVECs were measured.

Results

Treatment of TNF-α-stimulated HUVECs with AEPS at different concentrations resulted in decreased VCAM-1 and ICAM-1 protein expression in a dose-dependent manner. Furthermore, AEPS also inhibited TNF-α-stimulated U937 monocyte cells adhesion to HUVECs. In addition, AEPS reduced TNF-α-induced NF-κB p65 expression in a dose-dependent manner.

Conclusions

The results indicated that AEPS suppressed TNF-α-induced VCAM-1 and ICAM-1 expression NF-κB signaling.

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Piper sarmentosum attenuates VCAM-1 and ICAM-1 expression in TNF-α-induced HUVEC.

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P. sarmentosum inhibits TNF-α-stimulated monocytes adhesion to HUVEC.

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P. sarmentosum reduces TNF-α-induced NF-κB p65 expression in HUVEC.

Effects of Piper sarmentosum extract on the growth performance, antioxidant capability and immune response in weaned piglets

The biological properties of Piper sarmentosum render it a potential substitute for antibiotics in livestock feed. This study evaluated the effects of P. sarmentosum extract (PSE) on the growth performance, antioxidant capability and immune response of weaned piglets. Eighty 21-d-old weaned piglets were selected and randomly allocated to one of four dietary treatments with five replicates of four pigs each. The dietary treatments consisted of a basal diet supplemented with 0 (T0), 50 (T50), 100 (T100) or 200 (T200) mg/kg PSE. The feeding trial lasted 4 weeks. The results revealed that the T50 group had the highest average daily gain (ADG) and average daily feed intake (ADFI) throughout the feeding trial (p < 0.05). Additionally, the T50 group had higher (p < 0.05) serum glutathione peroxidase activity (GSH-Px) and lower (p < 0.05) serum malondialdehyde (MDA) levels than the T0 group at 4 weeks post-weaning (p < 0.05). Serum levels of interleukin-1β (IL-1β) and tumour necrosis factor-α (TNF-α) decreased, while serum levels of interleukin-4 (IL-4), interleukin-10 (IL-10) and transforming growth factor-β (TGF-β) increased by PSE supplementation at 4 weeks post-weaning (p < 0.05). PSE supplementation upregulated the mRNA expression of IL-4, IL-10 and TGF-β and downregulated the mRNA expression of TNF-α, IL-1β and interleukin-6 (IL-6) in the ileal mucosal layer of piglets (p < 0.05). In summary, our study findings revealed that PSE supplementation improved the antioxidant capability, and reduced inflammation, which may be beneficial to weaned piglet health.

Vitamin D protects human endothelial cells from H₂O₂ oxidant injury through the Mek/Erk-Sirt1 axis activation

Endothelium homeostasis alterations govern the pathogenesis of cardiovascular diseases. Several studies show that vitamins anti-oxidant proprieties rescue the endothelial functions adversely affected by oxidative stress in several diseases. We investigated the vitamin D anti-oxidant potential in human endothelial cells exposed to H2O2 oxidative stress. Vitamin D protected endothelial cells against H2O2 oxidative stress counteracting the superoxide anion generation, the apoptosis and blocking the extrinsic caspase cascade by positively controlling phospho-active ERKs level. MEKs/ERKs inhibitor U0126 reverted the vitamin D anti-oxidant effects. Characterizing the vitamin D downstream effector, we found that vitamin D up-regulated SirT-1 and reverted the SirT-1 down-regulation induced by H2O2. ERKs activation by vitamin D strictly correlated with SirT-1 protein accumulation since both MEKs/ERKs inhibition and ERK1/2 silencing decreased SIRT-1. SirT-1 inhibition by Sirtinol reverted the vitamin D anti-oxidant effects. Thus, vitamin D significantly reduced the endothelial malfunction and damage caused by oxidative stress, through the activation of MEKs/ERKs/SirT-1 axis.

Flavonoids of Piper sarmentosum and its cytoprotective effects against oxidative stress

Abnormalities in endothelial cell structure and function may lead to diseases such as thrombosis and atherosclerosis. Oxidative stress plays an important role in the pathogenesis of various cardiovascular diseases including atherosclerosis. Previous studies have shown a relationship between a diet rich in flavonoid and a reduced incidence of cardiovascular diseases. Piper sarmentosum (PS) is a plant with high flavonoid content and it possesses antioxidant and anti-atherosclerotic activities. Therefore this study aimed to investigate the flavonoids present in aqueous extract of PS (AEPS) and its cytoprotective effects in oxidative stress-induced human umbilical vein endothelial cells (HUVEC). AEPS contained high total phenolic content (91.02 ± 0.02 mg QE/g DM) and total flavonoid content (48.57 ± 0.03 mg GAE/g DM). Screening using high performance liquid chromatography (HPLC) technique showed the presence of rutin and vitexin as the main flavonoids in AEPS. HUVEC were exposed to 180 µM H₂O₂ and treated with various concentrations of rutin or vitexin (10 to 400 µM) for 24 hours. Both rutin and vitexin at the concentration of 150-400 µM significantly increased the viability of H₂O₂-induced HUVEC as denoted by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Therefore rutin and vitexin as the main flavonoids present in PS may be involved in the protective effects of PS against oxidative stress.

A review of the literature and latest advances in research of Piper sarmentosum

CONTEXT

Piper sarmentosum Roxb. (Piperaceae) is a traditional medicinal as well as a culinary plant in South East Asian countries, whereby aerial parts of the plant are consumed as a vegetable in various forms and the whole plant or parts are used as folk remedies, alone or in combination with other herbs, to treat various ailments. The plant has extensively been investigated in a broad range of studies to provide scientific evidence for folklore claims or to find new therapeutic uses; however, heretofore, a summary of the data are not available.

OBJECTIVE

In order to describe nutritional and therapeutic potential of P. sarmentosum and summarize scientific evidence that supports traditional claims, a literature review and latest advances in research of the plant are given herein.

MATERIALS AND METHODS

The literature has been retrieved from a number of databases such as Google Scholar, PubMed, Medline, Science Direct and SciFinder. The articles related to synthetic work, ecology and agriculture have been excluded.

RESULTS AND DISCUSSION

The review has not only revealed a number of pharmacological activities supporting the traditional claims but indicates new prospects for the plant. Antiangiogenic activity and toxicity studies suggest the usage of the plant in treating diseases involving neo-vascularization. The available efficacy, safety, pharmacokinetic and stability data urge clinical studies on extracts of the plant.

CONCLUSION

The present review may be helpful to future researchers intending to investigate the plant and natural pharmaceutical industry for preparing evidence-based formulations.

Histological changes in the fracture callus following the administration of water extract of piper sarmentosum (daun kadok) in estrogen-deficient rats

BACKGROUND

The fracture healing is impaired in osteoporosis. Piper sarmentosum is a plant, which contains potent antioxidant, naringenin that may enhance fracture healing. The present histological study aimed to determine the effects of water extract of Piper sarmentosum on the late phase of fracture healing in estrogen-deficient rats.

METHODS

Twenty four female Sprague-Dawley rats (200-250 gm) were obtained. Six rats underwent sham operation and the rest were ovariectomized. Six weeks post-ovariectomy all the rats were fractured at the mid-diaphysis of the right femur and a K-wire was inserted for internal fixation. The sham group was given vehicle (normal saline) and the ovariectomized group was randomly subdivided into three groups: (i) ovariectomized-control group supplemented with vehicle; (ii) ovariectomized+estrogen replacement therapy group treated with estrogen (100 µg/kg/day) and (iii) ovariectomized+Piper sarmentosum group treated with Piper sarmentosum water extract (125 mg/kg). Following six weeks of treatment, the rats were sacrificed and the right femora were harvested for histological assessment of fracture callus.

RESULTS

The ovariectomized-control group showed a significant delay in fracture healing compared to the sham, ovariectomized-estrogen replacement therapy and ovariectomized-Piper sarmentosum groups. The median callus score for the ovariectomized-Piper sarmentosum group was 4.50 (range, 4-5), which was significantly higher than the median callus score 3.50 (range, 3-4) for the ovariectomized-control group (P=0.019). However, there was no significant (P>0.05) difference in the callus score among the sham, ovariectomized-estrogen replacement therapy and ovariectomized-Piper sarmentosum groups groups.

CONCLUSION

Treatment with water extract of Piper sarmentosum proved beneficial in the fracture healing in estrogen-deficient rats.

ROS-induced ZNF580 expression: a key role for H2O2/NF-κB signaling pathway in vascular endothelial inflammation

ZNF580, a newly found C2H2 zinc finger transcription factor, was first described by Zhang (GenBank ID: AF184939). Emerging evidence has suggested that reactive oxygen species (ROS) play an important role in redox-sensitive signal transduction, and the vascular endothelium plays a critical role in the vascular inflammatory response. In this communication, we present evidence for the potential role of ZNF580 in hydrogen peroxide (H2O2)-regulated inflammation-related signaling pathways. In a human endothelial cell hybridoma line (EA.hy926), ZNF580 levels were markedly upregulated with H2O2 stimulation in different concentrations (0-400 μM) and at different time-points (0-6 h). H2O2 promoted the rapid translocation of p65 from the cytoplasm into the nucleus according to immunocytochemistry staining. In subsequent research, inhibition of NF-κB by pyrrolidine dithiocarbamate (PDTC, a selective chemical inhibitor of NF-κB) was shown to block the upregulated expression of ZNF580 that was induced by H2O2. Furthermore, transient transfection of ZNF580 resulted in an increase of the pro-inflammatory cytokine interleukin-8 (IL-8) 3.01±0.05 folds according to real-time RT-PCR and ELISA assays, which also showed significantly enhanced motility of human acute monocytic leukemia cells (THP-1). These results suggest that H2O2 upregulates the expression of ZNF580 via the NF-κB signaling pathway, and overexpression of ZNF580 plays a critical role in augmenting the release of pro-inflammatory cytokine IL-8.

Piper sarmentosum inhibits ICAM-1 and Nox4 gene expression in oxidative stress-induced human umbilical vein endothelial cells

BACKGROUND

Aqueous extract of Piper sarmentosum (AEPS) is known to possess antioxidant and anti-atherosclerotic activities but the mechanism responsible for it remains unclear. In early part of atherosclerosis, nuclear factor-kappa B (NF-κB) induces the expression of cellular adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1), intracellular adhesion molecule-1 (ICAM-1) and E-selectin. NADPH oxidase 4 (Nox4) is the predominant source of superoxide in the endothelial cells whereas superoxide dismutase 1 (SOD1), catalase (CAT) and glutathione peroxidase (GPx) are the antioxidant enzymes responsible for inactivating reactive oxygen species. The present study aimed to investigate the effects of AEPS on the gene expression of NF-κB, VCAM-1, ICAM-1, E-selectin, Nox4, SOD1, CAT and GPx in cultured human umbilical vein endothelial cells (HUVECs).

METHODS

HUVECs were divided into four groups:- control; treatment with 180 μM hydrogen peroxide (H₂O₂); treatment with 150 μg/mL AEPS and concomitant treatment with AEPS and H₂O₂ for 24 hours. Total RNA was extracted from all the groups of HUVEC using TRI reagent. Subsequently, qPCR was carried out to determine the mRNA expression of NF-κB, VCAM-1, ICAM-1, E-selectin, Nox4, SOD1, CAT and GPx. The specificity of the reactions was verified using melting curve analysis and agarose gel electrophoresis.

RESULTS

When stimulated with H₂O₂, HUVECs expressed higher level of ICAM-1 (1.3-fold) and Nox4 (1.2-fold) mRNA expression. However, AEPS treatment led to a reduction in the mRNA expression of ICAM-1 (p < 0.01) and Nox4 (p < 0.05) in the H₂O₂-induced HUVECs. AEPS also upregulated the mRNA expression of SOD1 (p < 0.05), CAT (p < 0.01) and GPx (p < 0.05) in oxidative stress-induced HUVECs. There was no significant change in the mRNA expression of VCAM-1 and E-selectin.

CONCLUSION

The expressional suppression of ICAM-1 and Nox4 and induction of antioxidant enzymes might be an important component of the vascular protective effect of AEPS.

Piper sarmentosum increases nitric oxide production in oxidative stress: a study on human umbilical vein endothelial cells

OBJECTIVE

Nitric oxide produced by endothelial nitric oxide synthase (eNOS) possesses multiple anti-atherosclerotic properties. Hence, enhanced expression of eNOS and increased Nitric oxide levels may protect against the development of atherosclerosis. Piper sarmentosum is a tropical plant with antioxidant and anti-inflammatory activities. This study aimed to investigate the effects of Piper sarmentosum on the eNOS and Nitric oxide pathway in cultured human umbilical vein endothelial cells (HUVECs).

METHODS

HUVECS WERE DIVIDED INTO FOUR GROUPS: control, treatment with 180 microM hydrogen peroxide (H(2)O(2)), treatment with 150 microg/mL aqueous extract of Piper sarmentosum, and concomitant treatment with aqueous extract of PS and H(2)O(2) for 24 hours. Subsequently, HUVECs were harvested and eNOS mRNA expression was determined using qPCR. The eNOS protein level was measured using ELISA, and the eNOS activity and Nitric oxide level were determined by the Griess reaction.

RESULTS

Human umbilical vein endothelial cells treated with aqueous extract of Piper sarmentosum showed a marked induction of Nitric oxide. Treatment with PS also resulted in increased eNOS mRNA expression, eNOS protein level and eNOS activity in HUVECs.

CONCLUSION

Aqueous extract of Piper sarmentosum may improve endothelial function by promoting NO production in HUVECs.