Vijayakumar Saravanan, Kumari Shobha, Ranjan Ravi, Kumar Ashish, Kumar Vikash, Vedika Sonali, Pandey Krishna, Singh Pritam Narayan, Alti Dayakar
ICMR-National Centre for Disease Informatics and Research, Bengaluru, India.
ICMR-Rajendra Memorial Research Institute of Medical Sciences, Patna, India.
Int Immunopharmacol. 2025 Jul 28;163:115283. doi: 10.1016/j.intimp.2025.115283.
Leishmaniasis continues to pose a significant global health challenge, exacerbated by the increasing resistance to current therapeutic agents such as miltefosine and amphotericin B. This growing resistance highlights the urgent need for alternative treatment strategies. In this context, phytomedicine has emerged as a promising avenue for novel antileishmanial therapies. In our previous study, the crude extract derived from neem (Azadirachta indica) leaves exhibited notable antileishmanial activity. Subsequent analysis using LC-MS/MS enabled the identification of bioactive constituents within the active fraction, including azadiradione (AZD), a drug with potential therapeutic effects unexplored against leishmaniasis.
AZD exhibited dose-dependent growth inhibition along with structural disruption and DNA fragmentation in promastigotes with an IC of 17.09 μM. In silico docking and simulation with AZD identified Leishmania peroxidases (e.g., ascorbate peroxidase and tryparedoxin peroxidase) as probable molecular targets, with subsequent downregulation of their expression confirmed in vitro. The CC on human macrophages (MФs) and EC on intracellular amastigotes were determined as 56.32 μM and 11.67 μM for AZD, respectively. The dose-dependent reduction in MФs' infectivity demonstrates the drug potential of AZD against the pathogenic stage of Leishmania. However, the selectivity index (SI) of AZD was calculated as 4.83, indicating a moderate Leishmania-specific drug potential of AZD. The decrease in IL-10, IL-1β, and arginase expression and the increase in IL-12 and iNOS expression reinforce the immunoregulatory potential of AZD in favour of the host. Further investigations are required to optimize the dosage and improve the selectivity of AZD before proposing it for the treatment of Leishmania infection.
This study demonstrated the novel findings related to the drug potential of AZD with defined Leishmania targets and host protective cytokine response. Studies on animal models may deliver further insights into its therapeutic potential.
利什曼病仍然是一项重大的全球健康挑战，对当前治疗药物（如米替福新和两性霉素B）的耐药性不断增加，使这一挑战更加严峻。这种日益增长的耐药性凸显了对替代治疗策略的迫切需求。在此背景下，植物医学已成为新型抗利什曼病治疗方法的一个有前景的途径。在我们之前的研究中，从印楝（Azadirachta indica）叶中提取的粗提物表现出显著的抗利什曼病活性。随后使用液相色谱 - 串联质谱（LC - MS/MS）进行分析，能够鉴定出活性组分中的生物活性成分，包括印楝二酮（AZD），一种对利什曼病潜在治疗作用尚未被探索的药物。
AZD在无鞭毛体中表现出剂量依赖性生长抑制以及结构破坏和DNA片段化，半数抑制浓度（IC）为17.09 μM。与AZD进行的计算机对接和模拟确定利什曼过氧化物酶（如抗坏血酸过氧化物酶和锥虫硫氧还蛋白过氧化物酶）为可能的分子靶点，随后在体外证实了它们的表达下调。AZD对人巨噬细胞（MФs）的半数细胞毒性浓度（CC）和对细胞内无鞭毛体的半数有效浓度（EC）分别测定为56.32 μM和11.67 μM。MФs感染性的剂量依赖性降低证明了AZD对利什曼原虫致病阶段的药物潜力。然而，AZD的选择性指数（SI）计算为4.83，表明AZD具有中等程度的利什曼原虫特异性药物潜力。白细胞介素 - 10（IL - 10）、白细胞介素 - 1β（IL - 1β）和精氨酸酶表达的降低以及白细胞介素 - 12（IL - 12）和诱导型一氧化氮合酶（iNOS）表达的增加，增强了AZD对宿主有利的免疫调节潜力。在将AZD用于治疗利什曼原虫感染之前，需要进一步研究以优化其剂量并提高其选择性。
本研究证明了与AZD的药物潜力相关的新发现，确定了利什曼原虫靶点和宿主保护性细胞因子反应。对动物模型的研究可能会进一步深入了解其治疗潜力。
