PDF(Pubmed)
Abstract：
BACKGROUND: Newcastle Disease Virus (NDV) causes severe economic losses in the poultry industry worldwide. Hence, this study aimed to discover a novel bioactive antiviral agent for controlling NDV. Streptomyces misakiensis was isolated from Egyptian soil and its secondary metabolites were identified using infrared spectroscopy (IR), gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) spectroscopy. The inhibitory activity of bioactive metabolite against NDV were examined. Three experimental groups of 10-day-old specific pathogen-free embryonated chicken eggs (SPF-ECEs), including the bioactive metabolite control group, NDV control positive group, and α-sitosterol and NDV mixture-treated group were inoculated.
RESULTS: α-sitosterol (Ethyl-6-methylheptan-2-yl]-10,13-dimethyl-dodecahydro-1H-cyclopenta[a]phenanthren-3-ol), a secondary metabolite of S. misakiensis, completely inhibited hemagglutination (HA) activity of the NDV strain. The HA activity of the NDV strain was 8 log2 and 9 log2 for 0.5 and 0.75% RBCs, respectively. The NDV HA activity for the two concentrations of RBCs was significantly (P < 0.0001) inhibited after α-sitosterol treatment. There was a significant (P < 0.0001) decrease in the log 2 of HA activity, with values of - 0.500 (75%, chicken RBCs) before inoculation in SPF-ECEs and - 1.161 (50%, RBCs) and - 1.403 (75%, RBCs) following SPF-ECE inoculation. Compared to ECEs inoculated with NDV alone, the α-sitosterol-treated group showed improvement in histological lesion ratings for chorioallantoic membranes (CAM) and hepatic tissues. The CAM of the α-sitosterol- inoculated SPF-ECEs was preserved. The epithelial and stromal layers were noticeably thicker with extensive hemorrhages, clogged vasculatures, and certain inflammatory cells in the stroma layer in the NDV group. However, mild edema and inflammatory cell infiltration were observed in the CAM of the treated group. ECEs inoculated with α-sitosterol alone showed normal histology of the hepatic acini, central veins, and portal triads. Severe degenerative alterations, including steatosis, clogged sinusoids, and central veins, were observed in ECEs inoculated with NDV. Mild hepatic degenerative alterations, with perivascular round cell infiltration, were observed in the treated group.
CONCLUSIONS: To the best of our knowledge, this is the first study to highlight that the potentially bioactive secondary metabolite, α-sitosterol, belonging to the terpene family, has the potential to be a biological weapon against virulent NDV. It could be used for the development of innovative antiviral drugs to control NDV after further clinical investigation.
RESULTS: α-sitosterol (Ethyl-6-methylheptan-2-yl]-10,13-dimethyl-dodecahydro-1H-cyclopenta[a]phenanthren-3-ol), a secondary metabolite of S. misakiensis, completely inhibited hemagglutination (HA) activity of the NDV strain. The HA activity of the NDV strain was 8 log2 and 9 log2 for 0.5 and 0.75% RBCs, respectively. The NDV HA activity for the two concentrations of RBCs was significantly (P < 0.0001) inhibited after α-sitosterol treatment. There was a significant (P < 0.0001) decrease in the log 2 of HA activity, with values of - 0.500 (75%, chicken RBCs) before inoculation in SPF-ECEs and - 1.161 (50%, RBCs) and - 1.403 (75%, RBCs) following SPF-ECE inoculation. Compared to ECEs inoculated with NDV alone, the α-sitosterol-treated group showed improvement in histological lesion ratings for chorioallantoic membranes (CAM) and hepatic tissues. The CAM of the α-sitosterol- inoculated SPF-ECEs was preserved. The epithelial and stromal layers were noticeably thicker with extensive hemorrhages, clogged vasculatures, and certain inflammatory cells in the stroma layer in the NDV group. However, mild edema and inflammatory cell infiltration were observed in the CAM of the treated group. ECEs inoculated with α-sitosterol alone showed normal histology of the hepatic acini, central veins, and portal triads. Severe degenerative alterations, including steatosis, clogged sinusoids, and central veins, were observed in ECEs inoculated with NDV. Mild hepatic degenerative alterations, with perivascular round cell infiltration, were observed in the treated group.
CONCLUSIONS: To the best of our knowledge, this is the first study to highlight that the potentially bioactive secondary metabolite, α-sitosterol, belonging to the terpene family, has the potential to be a biological weapon against virulent NDV. It could be used for the development of innovative antiviral drugs to control NDV after further clinical investigation.
摘要：
背景：新城疫病毒（NDV）在全世界的家禽业中造成严重的经济损失。因此，本研究旨在发现一种新型的生物活性抗病毒剂，用于控制NDV。从埃及土壤中分离出misakiensis链霉菌，并使用红外光谱（IR）鉴定了其次生代谢产物，气相色谱-质谱(GC-MS),和核磁共振（NMR）光谱。研究了生物活性代谢物对NDV的抑制活性。三个10天龄的无特定病原体胚胎鸡蛋（SPF-ECE）的实验组，包括生物活性代谢物对照组，NDV对照阳性组,接种α-谷甾醇和NDV混合治疗组。
结果：α-谷甾醇（乙基-6-甲基庚-2-基]-10,13-二甲基-十二氢-1H-环戊烷[a]菲酚-3-醇），S.misakiensis的次生代谢产物，完全抑制NDV株的血凝（HA）活性。对于0.5和0.75％的RBC，NDV菌株的HA活性分别为8log2和9log2，分别。α-谷甾醇处理后，两种浓度的RBC的NDVHA活性显着受到抑制（P<0.0001）。HA活性的log2有显著降低(P<0.0001),值为-0.500(75%，鸡红细胞)接种前在SPF-ECE和-1.161(50%，红细胞）和-1.403（75%，RBCs)在SPF-ECE接种后。与单独接种NDV的ECE相比，α-谷甾醇治疗组的绒毛尿囊膜（CAM）和肝组织的组织学病变评分有所改善。α-谷甾醇-接种的SPF-ECE的CAM被保存。上皮和基质层明显较厚，有大量出血，血管阻塞,NDV组间质中的某些炎症细胞。然而,在治疗组的CAM中观察到轻度水肿和炎性细胞浸润。单独接种α-谷甾醇的ECE显示肝腺泡的正常组织学，中央静脉,和门户三合会。严重的退行性改变,包括脂肪变性,阻塞的正弦曲线，和中央静脉，在接种NDV的ECE中观察到。轻度肝脏退行性改变，血管周围圆形细胞浸润，在治疗组中观察到。
结论：据我们所知，这是第一项强调潜在生物活性次级代谢产物的研究，α-谷甾醇,属于萜烯家族，有可能成为对抗强毒NDV的生物武器。经过进一步的临床研究，可用于创新抗病毒药物的开发，以控制NDV。
结果：α-谷甾醇（乙基-6-甲基庚-2-基]-10,13-二甲基-十二氢-1H-环戊烷[a]菲酚-3-醇），S.misakiensis的次生代谢产物，完全抑制NDV株的血凝（HA）活性。对于0.5和0.75％的RBC，NDV菌株的HA活性分别为8log2和9log2，分别。α-谷甾醇处理后，两种浓度的RBC的NDVHA活性显着受到抑制（P<0.0001）。HA活性的log2有显著降低(P<0.0001),值为-0.500(75%，鸡红细胞)接种前在SPF-ECE和-1.161(50%，红细胞）和-1.403（75%，RBCs)在SPF-ECE接种后。与单独接种NDV的ECE相比，α-谷甾醇治疗组的绒毛尿囊膜（CAM）和肝组织的组织学病变评分有所改善。α-谷甾醇-接种的SPF-ECE的CAM被保存。上皮和基质层明显较厚，有大量出血，血管阻塞,NDV组间质中的某些炎症细胞。然而,在治疗组的CAM中观察到轻度水肿和炎性细胞浸润。单独接种α-谷甾醇的ECE显示肝腺泡的正常组织学，中央静脉,和门户三合会。严重的退行性改变,包括脂肪变性,阻塞的正弦曲线，和中央静脉，在接种NDV的ECE中观察到。轻度肝脏退行性改变，血管周围圆形细胞浸润，在治疗组中观察到。
结论：据我们所知，这是第一项强调潜在生物活性次级代谢产物的研究，α-谷甾醇,属于萜烯家族，有可能成为对抗强毒NDV的生物武器。经过进一步的临床研究，可用于创新抗病毒药物的开发，以控制NDV。
