Asian Pacific Journal of Tropical Biomedicine

287-295

Authors: Yucinda YY Khor, Siew-Keah Lee, M Dharmani Devi, Wei Chih Ling

Objective: To investigate the effect of epigallocatechin-3-gallate (EGCG) on endothelial dysfunction in spontaneously hypertensive rats (SHR). Methods: Wistar-Kyoto (WKY) rats and SHR were divided into four groups; WKY control, SHR control and SHR treated with EGCG (50 mg/kg/day) or losartan (10 mg/kg/day). The treatment was given daily for 4 weeks by oral gavage and the blood pressure was monitored by tail-cuff method every 3 days. Acetylcholine-induced endothelium-dependent relaxations were assessed in isolated phenylephrine-precontracted aortic rings at the end of treatment. The vascular levels of reactive oxygen species, nitric oxide, tetrahydrobiopterin, and cyclic guanosine monophosphate were also measured. Moreover, the expression of angiotensin II type 1 (AT1) receptor protein was determined. Results: The systolic blood pressure was significantly decreased in SHR treated with EGCG. The impaired endothelium-dependent relaxation was significantly improved in aortic ring isolated from the EGCG-treated SHR group. EGCG also significantly increased the levels of nitric oxide, tetrahydrobiopterin, and cyclic guanosine monophosphate, while decreasing the level of reactive oxygen species and the protein expression of AT1 receptor in SHR. Conclusions: EGCG attenuates endothelial dysfunction in SHR by decreasing oxidative stress and increasing vascular nitric oxide bioavailability, which may be modulated partly by inhibition of vascular AT1 receptors. An increase in endothelium-dependent relaxation may contribute to a decrease in blood pressure in hypertensive animals.

306-314

Authors: Ya-Nan Shi, Jin-Zhu Su, Juan Wang, Jiang-Qiao Geng

Objective: To evaluate the effect of myricetin on ovalbumin (OVA)-induced allergic rhinitis in mice. Methods: Mice were sensitized and challenged using OVA (5%, 500 mL) intraperitoneally and intranasally, respectively, on an alternative day for 14 days, followed by administration of myricetin (50, 100, and 200 mg/kg) till day 21. Nasal symptoms, biochemical parameters, protein expressions, and histopathology were observed. Results: OVA-induced increased nasal symptoms including rubbing, sneezing, and discharge were significantly reduced by myricetin (100 and 200 mg/kg) (P<0.05). Myricetin also protected against histamine challenge and attenuated elevated serum immunoglobulin E (IgE; total and OVA-specific), total IgG1, and β-hexosaminidase levels, as well as leukotriene C4 and interleukins levels in nasal lavage fluid (P<0.05). Western blot analysis showed that myricetin significantly upregulated the protein expression of T-box expressed in T cells, while downregulating the protein expression of GATA binding protein 3, NF-κB, and 1κВ-α (P<0.05). Additionally, OVA-induced histopathological abberations in the nasal mucosa was markedly ameliorated by myricetin treatment (P<0.05). Conclusions: Myricetin exerts anti-allergic effects against OVA-induced allergic rhinitis via regulating Th1/Th2 balance.

242-249

Authors: Yosra Raziani, Kimia Karami, Hamid Reza Mohammadi, Hossein Mahmoudvand, Mohammad Nabi Moradi, Javad Ghasemian Yadegari

Objective: To assess the effect of oral treatment of methanolic extract of the aerial parts of Astragalus adscendens in streptozotocin-induced diabetic rats. Methods: In order to induce diabetes, rats intraperitoneally received streptozotocin at 65 mg/kg. Sixty adult male Wistar rats were allocated into six groups (10 rats per each) including the healthy control group, the diabetic group as well as the diabetic group treated with Astragalus adscendens methanolic extract at 50, 100, and 200 mg/kg per day or glibenclamide (0.6 mg/kg/day) for 28 d. The effects of Astragalus adscendens methanolic extract on the levels of glucose, insulin, alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, bilirubin, creatinine, urea, uric acid, total protein, albumin, triglyceride, cholesterol, α-amylase, oxidant/antioxidant enzymes, and inflammatory cytokines were evaluated. Real time-PCR was also used for measuring the gene expression of caspase-3, Bcl2, and Bax. Results: The levels of glucose, cholesterol, triglyceride, creatinine, urea, uric acid, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, bilirubin, and malondialdehyde considerably declined (P<0.001) in diabetic rats after treatment with Astragalus adscendens methanolic extract especially at a dose of 200 mg/kg. In addition, treatment with Astragalus adscendens methanolic extract noticeably increased the level of insulin, total protein, and albumin as well as improved the activities of catalase, glutathione peroxidase, and superoxide dismutase, as well as the expression levels of TNF-α, IL-1β, caspase-3, Bcl2 and Bax (P<0.001) compared to the diabetic control group. The extract also inhibited α-amylase in a dose-dependent manner with an IC50 value of 19.6 µg/mL. Conclusions: Astragalus adscendens methanolic extract shows potent antidiabetic, anti-inflammatory, anti-apoptotic, and antioxidant effects in diabetic rats. However, more studies are needed to verify the underlying mechanism of the effect of this plant extract and test its efficacy in clinical trials.

258-267

Authors: Thi Thanh Huong Le, Phu Hung Nguyen, Van Phuong Nguyen, Thy Ngoc Nguyen

Objective: To evaluate the effects of ethanol extract from Ardisia gigantifolia leaves on cell proliferation and cancer stem cell (CSC) number in gastric cancer. Methods: The inhibitory effect of Ardisia gigantifolia extract on the proliferation of MKN45 and MKN74 gastric cancer cells was assessed using 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide assay. Non-adherent culture (3D) model was used to evaluate the effect of the extract on tumorsphere size and number. Moreover, the expression of CD44, ALDH, and p21 was determined by immunofluorescence analysis. Flow cytometric analysis was performed to evaluate cell cycle arrest and the expression of gastric CSC markers CD44 and ALDH. Real-time PCR analysis was also carried out to assess the effect of the extract on the expression of cell cycle-regulated genes. Results: Ardisia gigantifolia extract effectively inhibited cell proliferation with an IC50 of 55.7 µg/mL in MKN45 cells and 123.6 µg/mL in MKN74 cells. The extract also arrested cell cycle in the G0/G1 phase as well as significantly reduced the size and number of tumorspheres. The markedly increased expression of p21 was observed at both mRNA and protein levels in the extract-treated adherent cells and tumorspheres. In addition, Ardisia gigantifolia extract significantly reduced the number of CD44- and/or ALDH-expressing gastric CSC. Conclusions: The development of gastric CSC can be inhibited by the ethanol extract of Ardisia gigantifolia.

195-204

Authors: Vineet Mehta, Priyanka Nagu, Arun Parashar, Manjusha Chaudhary

Objective: To explore the effect of Cassia fistula on collagen II-induced arthritis in rats. Methods: The effect of 250 and 500 mg/kg chloroform and hydroalcoholic extract of Cassia fistula leaf on collagen II-induced arthritis was investigated by evaluating paw volume, arthritis index, spleen index, and biochemical parameters. Histopathological analysis and docking study were also performed. Results: A dose-dependent reduction in paw volume, arthritic index, and spleen index was observed following oral administration of the chloroform and hydroalcoholic extracts. Treatment with Cassia fistula extracts reduced tumor necrosis factor-α, interleukin (IL)-1β, IL-6, prostaglandin E2, aspartate aminotransferase, alanine aminotransferase, total leucocyte count, and erythrocyte sedimentation rate while increasing IL-10 level. In addition, Cassia fistula extracts improved joint architecture, and prevented cartilage and bone destruction. Docking analysis demonstrated that the physcion, 1-octacosanol, 5,3',4'-trihydroxy-6-methoxy-7-O-α-L-rhamnopyranosyl-(1,2)-O-β-D-galactopyranoside and scopoletin may be responsible for the anti-arthritic effect of Cassia fistula. Conclusions: Cassia fistula suppresses the progression of collagen II-induced arthritis by lowering the inflammatory factors, decreasing paw volume and arthritic index, and alleviating joint architecture. However, further studies are required to confirm the bioactive molecule responsible for the anti-arthritic potential of Cassia fistula.

214-221

Authors: Xuan-Hai Do, Trong Nghia Nguyen, Thanh Chung Dang, Thi Thanh Mai Nguyen, Trung Nhan Nguyen, Van Nhat Truong Do, Huu Tho Le, Xuan Hai Nguyen, Hoang Phu Dang, Giang-Linh Nguyen, Dinh-Khanh Hoang, Van-Quan Le, Van-Mao Can

Objective: To investigate the anti-inflammatory and analgesic effects of Solanum procumbens on complete Freund's adjuvant-induced arthritis rat models. Methods: We isolated and identified five compounds in the ethanol-soluble Solanum procumbens extract (SP) with anti-inflammatory effects, including ursolic acid, β-sitosterol, hexadecanoic acid, cis-vaccenic acid, and vanillic acid. Additionally, we investigated the anti-inflammatory effects of SP on rheumatoid arthritis symptoms, including paw volumes, local temperatures, withdrawal latency, and mechanical withdrawal threshold at the hind paw and white blood cell (WBC) number from complete Freund's adjuvant-induced arthritis rat models. Results: We have successfully established a complete Freund's adjuvant-induced arthritis rat model at a low dose (1 mg/mL). SP extract significantly reduced paw volumes (P<0.05), prolonged withdrawal latencies (P<0.05), decreased local temperature, and increased the mechanical withdrawal threshold (P<0.05), but only SP extract at the dose of 300 mg/kg significantly decreased WBC numbers. Conclusions: SP extract could be a potential medication candidate with anti-inflammatory effects for arthritis, but it requires further investigation into the mechanism of the SP and its effectiveness on other models as well as clinical trials.

148-155

Authors: Leila Safaeian, Zahra Haghighatian, Behzad Zolfaghari, Mahdi Amindeldar

Objective: To investigate the effect of Pinus eldarica bark extract on adrenaline-induced myocardial infarction. Methods: Hydroalcoholic extract was prepared using maceration method and its total phenolic content was determined using the Folin-ciocalteu method. Pretreatment was done by oral administration of 100, 200, and 400 mg/kg Pinus eldarica bark extract for 16 days in male Wistar rats. Injection of adrenaline (2 mg/kg, s.c.) was performed on the 15th and 16th days for induction of myocardial infarction. Lead II EEG was recorded. Serum cardiac marker enzymes and antioxidative parameters were evaluated and a histopathological examination of heart tissues was performed. Results: Pretreatment with Pinus eldarica bark extract especially at its high doses significantly lowered the ST-segment elevation, improved heart rate, and decreased RR interval in ECG pattern of rats with adrenaline-induced myocardial infarction. It declined serum markers of heart damage including aspartate aminotransferase, lactate dehydrogenase, and creatine phosphokinase-MB, and also decreased lipid peroxidation marker, and heart weight while raising total antioxidant capacity and considerably improved histopathological alterations of the heart induced by adrenaline. Conclusions: Pinus eldarica bark extract shows beneficial cardioprotective and antioxidant effects against adrenaline-induced myocardial infarction. It can be further explored as a potential treatment for myocardial infarction.

165-175

Authors: Otman El-guourrami, Najoua Salhi, Fatima Zahra Benkhouili, Gokhan Zengin, Mustafa Abdullah Yilmaz, Mouna Ameggouz, Ahmed Zahidi, Lamiaa Rouas, Abdelhakim Bouyahya, Khang Wen Goh, Toong Hai Sam, Long Chiau Ming, Anass Doukkali, Hanane Benzeid

Objective: To assess the acute and subacute toxicity as well as the phytochemical composition of two extracts and three fractions of Ammi majus L. Methods: The aqueous extracts were prepared separately by maceration for 48 h and by infusion for 1 h, while the fractions were prepared by the Soxhlet extractor, successively employing cyclohexane, ethyl acetate, and ethanol. The acute toxicity study was carried out in accordance with the OECD N°423 guideline at a single dose (2000 mg/kg) in mice for 14 days. The subacute toxicity study was performed by a daily oral administration of 250 mg/kg for 10 days and 100 mg/kg doses for 28 days. Phytochemical screening was performed using staining and precipitation reactions, while the chemical characterization of some analytes was detected by HPLC-MS/MS analysis. Results: In the acute toxicity study, no signs of toxicity such as convulsion, salivation, diarrhea, sleep and coma were observed during 30 minutes and 14 days, so the lethal dose was higher than 2000 mg/kg for each extract and fraction. The subacute toxicity results showed that at a dose of 250 mg/kg, 61.10% of the animals died and the rest developed morbidity. On the other hand, at a dose of 100 mg/kg, all the animals were still alive after 28 days, with no morbidity and the biochemical parameters were normal with no abnormalities in the liver, kidneys and pancreas. Phytochemical screening indicated the presence of flavonoids, tannins, coumarins, and free quinones and the absence of alkaloids and anthocyanins. Conclusions: The extracts and fractions of Ammi majus L. are not toxic in the short and long term with a varied chemical composition. Toxicological tests on animals other than rodents and in the long term (more than 28 days) are needed to further confirm the safety of Ammi majus extracts.

184

Authors: none

none

94-103

Authors: Noreafifah Semail, Nik Mohd Noor Nik Zuraina, Yasmin Khairani Muhammad Ismadi, Nurul Iman Mohamad, Azian Harun, Ismail Aziah, Zakuan Zainy Deris

Burkholderia pseudomallei is a causative agent of melioidosis that can infect humans and animals in endemic countries, specifically in Southeast Asia and tropical Australia. A fundamental component for the pathogenesis of Burkholderia pseudomallei is the capability of the bacterium to enter, survive, replicate, and cause disease in a host cell by inducing the host cell fusion. Cell fusion results in multinucleated-giant cell formation, thus enabling the dissemination of Burkholderia pseudomallei intracellularly. cGAS reacts to Burkholderia pseudomallei infection by activating the cGAS-STING pathway and subsequently limiting host’s aberrant cell division and cellular replication by inducing autophagic cell death. In this review, we discuss the host-pathogen interactions between the type Ⅵ secretion system 5 (T6SS-5) of Burkholderia pseudomallei and human cGAS pathway in melioidosis infections. Since T6SS-5 is a main virulent factor in Burkholderia pseudomallei and the cGAS pathway is vital for host immune response, elucidating their functions is important for better understanding the pathogenesis of Burkholderia pseudomallei.

112-120

Authors: Wen-Da Wang, Gang Chen

Objective: To evaluate the antiviral activity of pure compounds against herpes simplex virus type 1 (HSV-1) from the rhizome of Anemarrhena asphodeloides. Methods: Bioassay-guided isolation was conducted to separate the active compound and its chemical structure was elucidated by spectral analysis. In vitro antiviral efficacy of active compound was detected by Cell Counting Kit-8 assay, plaque reduction assay, and fluorescence observation. RT-PCR was used to determine the viral load and the cytokine-related gene expression after HSV-1 infection. In vivo study was also conducted to further determine antiviral efficacy of an active compound against HSV-1. Results: An active compound was isolated and elucidated as mangiferin. Mangiferin significantly inhibited the replication of HSV-1 in Vero cells with a half maximal inhibitory concentration (IC50) of 64.0 mg/L. Time-of-addition and time-of-removal assays demonstrated that mangiferin could effectively inhibit the replication of HSV-1 in the early stage (8 h). UL12, UL42, and UL54 gene expression levels of HSV-1 in the 64 mg/L mangiferin-treated group were markedly reduced as compared with the HSV-1 group (P<0.01). Fluorescence observation showed that mangiferin attenuated the mitochondrial damage maintaining ΔΨm induced by HSV-1 in Vero cells. The expression of inflammatory factors TNF-α, IL- 1β, and IL-6 was remarkably increased in the virus-infected group as compared with that in the normal group (P<0.05), the levels of these inflammatory factors dropped after treatment with mangiferin. Mangiferin significantly decreased the viral load and attenuated the HSV-1-induced up-regulation of TNF-α, IL1β, and IL-6. The relative protection rate of HSV-1-infected mice could reach up to 55.5% when the concentration of mangiferin was 4 g/kg. Conclusions: Mangiferin exhibits promising antiviral activity against HSV-1 in vitro and in vivo and could be a potential antiviral agent for HSV-1.

131-138

Authors: Naglaa M El-Lakkany, Hadeel H Elkattan, Alaa E Elsisi

Objective: To evaluate the efficacy of ponatinib plus gossypol against colorectal cancer HCT-116 and Caco-2 cells. Methods: Cells were treated with ponatinib and/or gossypol at increasing concentrations to evaluate synergistic drug interactions by combination index. Cell viability, FGF19/FGFR4, and apoptotic and autophagic cell death were studied. Results: Ponatinib (1.25-40 μM) and gossypol (2.5-80 μM) monotherapy inhibited HCT-116 and Caco-2 cell viability in a dose- and time-dependent manner. The combination of ponatinib and gossypol at a ratio of 1 to 2 significantly decreased cell viability (P<0.05), with a > 2- and > 4-fold reduction in IC50, respectively, after 24 h and 48 h, as compared to the IC50 of ponatinib. Lower combined concentrations showed greater synergism (combination index<1) with a higher ponatinib dose reduction index. Moreover, ponatinib plus gossypol induced morphological changes in HCT-116 and Caco-2 cells, increased beclin-1 and caspase-3, and decreased FGF19, FGFR4, Bcl-2 and p-Akt as compared to treatment with drugs alone. Conclusions: Gossypol enhances ponatinib's anticancer effects against colorectal cancer cells through antiproliferative, apoptotic, and autophagic mechanisms. This may open the way for the future use of ponatinib at lower doses with gossypol as a potentially safer targeted strategy for colorectal cancer treatment.