Adventitial ablation technique that permits the assessment of adventitial-dependent contribution to microvascular contractile function

Resistance arteries have been implicated as major contributing factor in the sequela of disease conditions such as hypertension and diabetes and as such are a major focus of cardiovascular research. The paracrine influence of the intimal endothelial layer of resistance arteries is well established. Considering the growing body of evidence substantiating a functionally relevant vascular adventitia in this present study we have established a technique which permits determination of the functional influence of the adventitial layer on resistance artery tone. Isolating adventitial-dependent function, analogous to isolating endothelial function, has potentially significant implication for studying the as yet unexplored role of the microvascular adventitial layer in modulating acute vascular contractile function

Evaluasi keselamatan Lactobacillus casei C1 pada tikus Wistar

Pada masa kini, probiotik diambil sebagai makanan tambahan secara meluas untuk kebaikan kesihatan. Namun begitu, masih kurang kajian keselamatan terhadap kebanyakan bakteria probiotik. Tambahan pula, khasiat probiotik amat bergantung pada strain yang digunakan dalam penghasilan produk probiotik. Oleh itu, kajian ini amat penting bagi mengkaji keselamatan pengambilan Lactobacillus casei (Lb. casei) C1 yang baru dipencilkan secara oral. Sebanyak 32 ekor tikus Wistar (WIS) digunakan dalam kajian ketoksikan oral akut (dos tunggal) dan subakut (dos berulangan selama 28 hari). Tikus dibahagikan kepada kumpulan kawalan yang diberi salin penimbal (PBS) dan kumpulan kajian yang diberi Lb. casei C1 (1011 CFU/ml) secara oral. Dalam ketoksikan oral akut, rawatan diberi sekali setiap 24 jam dan dipantau selama 14 hari. Untuk ketoksikan oral subakut, rawatan diberi setiap hari selama 28 hari dan kesan dipantau sepanjang tempoh masa kajian. Berat badan, makanan dan air direkodkan. Kumpulan akut dan subakut dikorbankan pada hari ke-15 dan ke-29. Serum dikumpul untuk menentukan aras protein jumlah, malondialdehid (MDA), alanina aminotransferase (ALT), aspartat aminotransferase (AST), laktat dihidrogenase (LDH) dan kreatinin. Organ pula diambil untuk pemerhatian histologi. Tiada perbezaan yang signifikan (p > 0.05) diperhatikan dalam berat badan, pengambilan makanan dan minuman antara tikus kawalan dan kajian dalam kumpulan ketoksikan oral akut. Bilangan sel darah, aras jumlah protein, MDA, LDH dan kreatinin juga tidak menunjukkan perbezaan yang signifikan antara tikus kawalan dengan kajian. Hasil yang sama juga direkod untuk kumpulan ketoksikan oral subakut kecuali aras ALT dan AST yang menunjukkan perbezaan signifikan (p < 0.05). Tiada perubahan morfologi yang ketara diperhatikan pada organ hepar, ginjal dan ileum tikus kajian berbanding dengan tikus kawalan dalam kedua-dua kumpulan kajian. Kesimpulannya, Lb. casei C1 tidak mempunyai kesan toksik pada tikus Wistar maka ia adalah selamat untuk diambil secara oral

Kesan ekstrak akueus rosel (Hibiscus sabdariffa Linn.) terhadap sperma dan testis tikus diadministrasi nikotin

Penghasilan radikal bebas oleh nikotin dikaitkan dengan kerosakan sistem pembiakan lelaki terutamanya sperma dan testis. Penggunaan rawatan yang berasaskan herba seperti Hibiscus sabdariffa Linn. (HSE) kian meningkat disebabkan kandungan antioksida semula jadi yang tinggi. Oleh itu, kajian ini dijalankan untuk mengkaji kesan ekstrak akueus HSE terhadap kualiti sperma dan tekanan oksidatif testis tikus yang diadministrasi nikotin. Sejumlah 21 ekor tikus jantan Sprague-Dawley dibahagikan secara rawak kepada tiga kumpulan iaitu kumpulan kawalan, nikotin dan nikotin+HSE. Nikotin disuntik secara intraperitoneum pada dos 0.6 mg/kg berat badan manakala HSE diberikan pada dos 100 mg/kg berat badan secara paksaan oral sebelum administrasi nikotin pada setiap hari selama 21 hari berturut-turut. Hasil kajian menunjukkan bilangan, motiliti dan viabiliti sperma lebih tinggi secara signifikan (p<0.05) manakala peratus ketaknormalan morfologi sperma lebih rendah secara signifikan (p<0.05) bagi pada kumpulan nikotin+HSE berbanding kumpulan nikotin. Sementara itu berlakunya penurunan aras malondialdehid (MDA) dan peningkatan aras glutation terturun (GSH) secara signifikan (p<0.05) bagi kumpulan nikotin+HSE berbanding kumpulan nikotin. Pemerhatian histologi mendapati HSE berpotensi melindungi morfologi testis tikus aruhan nikotin. Kesimpulannya, kajian ini menunjukkan bahawa pemberian suplemen ekstrak HSE berpotensi mencegah kerosakan sperma dan testis akibat administrasi nikotin

Dietary UKMR-1 Roselle supplementation prevents nicotine-induced cardiac injury by inhibiting myocardial oxidative stress

UKMR-1, a local variant of mutant Roselle strain (Hibiscus sabdariffa) is enriched with free radical scavenging polyphenols such as anthocyanin, vitamin C and hydroxycitric acid. However, pharmacological actions of UKMR-1 are not fully known. This study was conducted to determine whether supplementation of aqueous UKMR-1 calyx extract was able to protect against nicotine-induced cardiac injury in rats. In this experimental study, healthy male albino rats were randomly allotted into three groups (n=7 per group): control, nicotine and UKMR-1+Nicotine groups. Nicotine (0.6 mg/kg, i.p.) was administered to both nicotine and UKMR-1+Nicotine groups for 28 consecutive days. UKMR-1+Nicotine group also received 100 mg/kg UKMR-1 extract orally via gavage 30 min prior to nicotine injection, daily. UKMR-1+Nicotine group had significantly (p<0.05) higher lactate dehydrogenase (LDH) activity, as well as lower malondialdehyde content in heart tissue homogenate than nicotine group, suggesting its cardio protective activity by inhibition of lipid peroxidation. UKMR-1 also lowered (p<0.05) the blood pressure in nicotine-administered rats. In addition, UKMR-1 significantly (p<0.05) restored activities of cytosolic superoxide dismutase, glutathione peroxidase and glutathione-S-transferase as well as redox balance ratio (GSH:GSSG). In conclusion, UKMR-1 was able to protect against myocardial injury in rat model of nicotine administration possibly by inhibiting oxidative stress

The protective effect of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2) against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes

OBJECTIVES: The aim of this study was to investigate the protective effects of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2) against red blood cell (RBC) membrane oxidative stress in rats with streptozotocin-induced diabetes. METHODS: Forty male Sprague-Dawley rats weighing 230-250 g were randomly divided into four groups (n = 10 rats each): control group (N), roselle-treated control group, diabetic group, and roselle-treated diabetic group. Roselle was administered by force-feeding with aqueous extracts of roselle (100 mg/kg body weight) for 28 days. RESULTS: The results demonstrated that the malondialdehyde levels of the red blood cell membranes in the diabetic group were significantly higher than the levels in the roselle-treated control and roselle-treated diabetic groups. The protein carbonyl level was significantly higher in the roselle-treated diabetic group than in the roselle-treated control group but lower than that in the diabetic group. A significant increase in the red blood cell membrane superoxide dismutase enzyme was found in roselle-treated diabetic rats compared with roselle-treated control rats and diabetic rats. The total protein level of the red blood cell membrane, osmotic fragility, and red blood cell morphology were maintained. CONCLUSION: The present study demonstrates that aqueous extracts of roselle possess a protective effect against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes. These data suggest that roselle can be used as a natural antioxidative supplement in the prevention of oxidative damage in diabetic patients

Tocotrienol-rich Fraction Modulates Cardiac Metabolic Profile changes in Isoprenaline-Induced Myocardial Infarction rats

In myocardial infarction (MI), the occurrence of energy depletion, oxidative stress, and decreased amino acids metabolism alter tissue metabolites. Evidence has shown that tocotrienol-rich fraction (TRF) prevents myocardial injury in MI. However, the protective mechanism at the metabolite level is unknown. Male Sprague-Dawley rats were grouped into control, isoprenaline (ISO)-induced MI (MI), healthy rats receiving 200 mg/kg TRF (200TRF), and MI rats receiving 200 mg/kg TRF (200TRF+MI) groups. TRF was administered via oral gavage daily for 12 weeks followed by intraperitoneal ISO injection (85 mg/kg) for two consecutive days at a 24-hour interval to induce MI. High-performance liquid chromatography was performed to analyze serum α-tocopherol and tocotrienol concentration whereas ultrahigh-performance liquid chromatography-mass spectrometry was used for the untargeted metabolomic study. Serum α-tocopherol but not tocotrienol was increased in the 200TRF (p=0.121) and 200TRF+MI (p<0.05) following TRF supplementation. Multivariate analysis by Orthogonal Projections to Latent Structures Discriminant Analysis showed high predictability of the group comparison models for MI vs control and 200TRF+MI vs MI (cross-validation: Q2 >0.7, R2 Y>0.8, p<0.05). A total of 84 and 37 metabolites [when covariance of p≥|0.05| (magnitude) and p(corr)≥|0.5| (reliability)] were significantly different in the myocardial homogenates of MI vs control and 200TRF+MI vs MI, respectively. MI rats had reduced S-adenosylmethionine and L-cystathionine that might worsen MI by disturbing glutathione metabolism; decreased phosphoribosyl-pyrophosphate and purine salvage process that might impair DNA synthesis, and elevated glucose-6-phosphate suggesting enhanced anaerobic glycolysis possibly for rapid production of energy. Conversely, TRF supplementation reversed the impaired metabolic pathways caused by MI

Tocotrienol-rich fraction modulates cardiac metabolic profile changes in isoprenaline-induced myocardial infarction rats

In myocardial infarction (MI), the occurrence of energy depletion, oxidative stress, and decreased amino acids metabolism alter tissue metabolites. Evidence has shown that tocotrienol-rich fraction (TRF) prevents myocardial injury in MI. However, the protective mechanism at the metabolite level is unknown. Male Sprague-Dawley rats were grouped into control, isoprenaline (ISO)-induced MI (MI), healthy rats receiving 200 mg/kg TRF (200TRF), and MI rats receiving 200 mg/kg TRF (200TRF+MI) groups. TRF was administered via oral gavage daily for 12 weeks followed by intraperitoneal ISO injection (85 mg/kg) for two consecutive days at a 24-hour interval to induce MI. High-performance liquid chromatography was performed to analyze serum α-tocopherol and tocotrienol concentration whereas ultra-high-performance liquid chromatography-mass spectrometry was used for the untargeted metabolomic study. Serum α-tocopherol but not tocotrienol was increased in the 200TRF (p=0.121) and 200TRF+MI (p0.7, R2Y>0.8, p<0.05). A total of 84 and 37 metabolites [when covariance of p≥|0.05| (magnitude) and p(corr)≥|0.5| (reliability)] were significantly different in the myocardial homogenates of MI vs control and 200TRF+MI vs MI, respectively. MI rats had reduced S-adenosylmethionine and L-cystathionine that might worsen MI by disturbing glutathione metabolism; decreased phosphoribosyl-pyrophosphate and purine salvage process that might impair DNA synthesis, and elevated glucose-6-phosphate suggesting enhanced anaerobic glycolysis possibly for rapid production of energy. Conversely, TRF supplementation reversed the impaired metabolic pathways caused by MI

The vasorelaxant effect of Hibiscus sabdariffa linn. Polyphenol-rich extract (HPE) on rat’s isolated aorta

Hibiscus sabdariffa Linn. or also known as roselle which is rich in polyphenols, has been demonstrated to cause lowering of blood pressure in animal and clinical settings. However its exact mechanism of action particularly from polyphenolic compounds is not clearly understood. Therefore, we aimed to determine the effects of H. sabdariffa polyphenol extract (HPE) towards vascular reactivity and its mechanism of action. The HPE was studied on isolated thoracic aortic rings from normal Sprague-Dawley rats, suspended in a 15-ml organ chambers containing Krebs-Henseleit solution. The changes in tension were recorded by isometric transducer connected to data acquisition. HPE relaxed the contraction induced by phenylephrine (PE, 1 μM) in similar pattern for both endothelium-intact and endothelium denuded aortic rings in dose-dependent manner 0.1 ~ 0.9 mg/ml. The pretreatment with atropine (1 μM), a competitive muscarinic antagonist, and propranolol (1 μM), a non-selective beta- blocker did not alter HPE vasorelaxation response. In addition, HPE did not inhibit the contraction induced by extracellular Ca2+ precontracted by PE (1 μM) or KCl (60 mM), in Ca2+ -free solution, suggesting that the relaxation effect of HPE was not via inhibition of calcium channels. In conclusion, HPE demonstrated vasorelaxation effects on rat thoracic aorta although the underlying mechanism is still unknown. The vasorelaxation effect could be via angiotensin type 1 receptor inhibition in the vascular smooth muscle cells or the activation of hyperpolarizing K+ channel

Potential of Hibiscus sabdariffa Linn. polyphenol-rich extract in improving diabetes-induced vascular functional and structural abnormalities in rats

Hibiscus sabdariffa Linn. contains a high concentration of polyphenolic compounds and shows potentials in reducing vascular complications in diabetes mellitus (DM) patients. This study was aimed to determine the ability of H. sabdariffa Linn. polyphenol-rich extract (HPE) in improving vascular endothelial dysfunction and attenuating oxidative stress in type 1 DM. DM was induced in adult male rats and the rats were then divided into three groups; untreated DM (DM); DM with HPE supplementation (DM+HPE); and DM with metformin (DM+MET). Another group of non-diabetic rats served as the normal control group. These rats were left untreated for four weeks before being subjected to the supplementations for another four weeks. The thoracic descending aorta was isolated from the treated and untreated rats to measure the vascular reactivity, oxidative stress, and morphological alterations. The results showed that HPE supplementation significantly reduced the systolic blood pressure (SBP) and mean arterial pressure (MAP) in the DM+HPE group (p<0.05). HPE also showed a tendency to improve endothelium-dependent vasorelaxation compared to the untreated diabetic rats. Rats treated with HPE exhibited a considerable improvement in the activities of antioxidants and significantly attenuated oxidative damage (p<0.05). Histological findings showed that HPE supplementation improved morphological changes in the aorta. In conclusion, HPE supplementation reduces vascular abnormalities in DM condition probably via amelioration of oxidative stress

Pemodelan semula jantung dalam kardiomiopati diabetes: peranan inflamasi, tekanan oksidatif dan apoptosis yang mendasari pembentukan dan perkembangannya

Kardiomiopati diabetes (DCM) merupakan komplikasi kronik diabetes melitus akibat daripada perubahan pada fungsi dan struktur jantung yang diaruh oleh keadaan aras gula darah yang tinggi (hiperglisemia) secara berpanjangan. Walaupun pengawalan hiperglisemia dilakukan dengan komprehensif serta perubahan gaya hidup yang lebih sihat, komplikasi kardiovaskular termasuklah DCM terus menjadi antara punca kematian utama pesakit diabetes. Pembentukan dan perkembangan DCM adalah akibat proses kompensasi melalui pemodelan semula jantung yang melibatkan kematian kardiomiosit hasil daripada kerosakan oksidatif, apoptosis dan inflamasi susulan aruhan hiperglisemia yang tidak terkawal. Walaupun permodelan semula jantung merupakan proses yang penting dalam memulihara struktur dan fungsi jantung, namun dalam keadaan diabetes, rangsangan pemodelan semula jantung yang berpanjangan boleh membawa kepada kemorosotan fungsi yang kekal dan akhirnya menyebabkan kegagalan jantung. Memahami mekanisme yang terlibat dalam pembentukan dan perkembangan DCM adalah sangat penting bagi merangka strategi untuk mengurangkan komplikasi akibat penyakit ini. Oleh itu, dalam kertas ulasan ini, hasil kajian terkini mengenai proses pemodelan semula jantung dalam perkembangan DCM dan mekanisme utama yang mendasari pembentukan dan perkembangannya akan diperjelaskan