Makhwitine John P, Kumalo Hezekiel M, Ndlovu Sizwe I, Mkhwanazi Nompumelelo P
Discipline of Medical Microbiology, School of Laboratory Medicine and Medical Sciences, College of Health Science, University of KwaZulu-Natal, Durban 4000, South Africa.
Drug Research and Innovation Unit, Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Science, University of KwaZulu-Natal, Durban 4000, South Africa.
Microorganisms. 2023 May 26;11(6):1404. doi: 10.3390/microorganisms11061404.
The continuous burden of human immunodeficiency virus-1 in Sub-Saharan Africa, coupled with the inability of antiretroviral agents to eradicate HIV-1 from viral reservoirs, the potential risks of drug resistance development, and the development of adverse effects, emphasizes the need to develop a new class of HIV-1 inhibitors. Here, we cultivated four endophytic fungal isolates from a medicinal plant, with the addition of small epigenetic modifiers, sodium butyrate, and valproic acid, to induce the expression of biosynthetic gene clusters encoding active secondary metabolites with probable anti-HIV activities. We identified a non-toxic crude extract of the endophytic fungus treated with sodium butyrate to possess significantly greater anti-HIV activity than the untreated extracts. P03MB2 showed anti-HIV activity with an IC of 0.6024 µg/mL compared to untreated fungal crude extract (IC 5.053 µg/mL) when treated with sodium butyrate. The profile of secondary metabolite compounds from the bioactive, partially purified extracts were identified by gas chromatography-mass spectrometry (GC-MS), and more bioactive compounds were detected in treated P03MB2 fractions than in untreated fractions. Pyrrolo[1,2-a]pyrazine-1,4-dione, hexahydro (13.64%), cyclotrisiloxane, hexamethyl (8.18%), cyclotetrasiloxane, octamethyl (7.23%), cyclopentasiloxane, decamethyl (6.36%), quinoline, 1,2-dihydro-2,24-trimethyl (5.45%), propanenitrile (4.55%), deca-6,9-diene (4.55%), dibutyl phthalate (4.55%), and silane[1,1-dimethyl-2-propenyl)oxy]dimethyl (2.73%) were the most abundant compounds. These results indicate that treatment of endophytic fungi with small epigenetic modifiers enhances the secretion of secondary metabolites with stronger anti-HIV-1 properties, acknowledging the feasibility of epigenetic modification as an innovative approach for the discovery of cryptic fungal metabolites which can be developed into therapeutic compounds.
人类免疫缺陷病毒1型在撒哈拉以南非洲地区持续肆虐，加之抗逆转录病毒药物无法从病毒储存库中根除HIV-1、存在产生耐药性的潜在风险以及出现不良反应，这些都凸显了开发新型HIV-1抑制剂的必要性。在此，我们从一种药用植物中培养了4种内生真菌分离株，并添加了小的表观遗传修饰剂丁酸钠和丙戊酸，以诱导编码可能具有抗HIV活性的活性次级代谢产物的生物合成基因簇的表达。我们发现，用丁酸钠处理的内生真菌的无毒粗提物比未处理的粗提物具有显著更强的抗HIV活性。与未处理的真菌粗提物（IC50为5.053 µg/mL）相比，P03MB2在用丁酸钠处理后显示出抗HIV活性，IC50为0.6024 µg/mL。通过气相色谱-质谱联用（GC-MS）鉴定了生物活性部分纯化提取物中的次级代谢产物化合物谱，与未处理的部分相比，在处理后的P03MB2组分中检测到了更多的生物活性化合物。吡咯并[1,2-a]吡嗪-1,4-二酮，六氢（13.64%）、环三硅氧烷，六甲基（8.18%）、环四硅氧烷，八甲基（7.23%）、环五硅氧烷，十甲基（6.36%）、喹啉，1,2-二氢-2,2,4-三甲基（5.45%）、丙腈（4.55%）、癸-6,9-二烯（4.55%）、邻苯二甲酸二丁酯（4.55%）和硅烷[1,1-二甲基-2-丙烯基）氧基]二甲基（2.73%）是含量最丰富的化合物。这些结果表明，用小的表观遗传修饰剂处理内生真菌可增强具有更强抗HIV-1特性的次级代谢产物的分泌，这认可了表观遗传修饰作为发现可开发成治疗化合物的隐秘真菌代谢产物的创新方法的可行性。
