Ravilla Jahnavi, Rajendran Soundaram, Basavaraj Vidya M, Satheeshan Greeshma, Narayanan Janakiraman, Venkatesh Thejaswini, Sundaram Gopinath M
Department of Molecular Nutrition, CSIR-Central Food Technological Research Institute, Mysuru 570020, Karnataka, India.
Department of Biochemistry and Molecular Biology, Central University of Kerala, Kasaragod 671320, Kerala, India.
Antioxidants (Basel). 2025 Jun 12;14(6):717. doi: 10.3390/antiox14060717.
Gamma oryzanol (GO) is a natural anti-oxidant found in rice bran with potential health benefits. Conventional isolation of GO from rice bran requires the use of non-eco-friendly solvents such as acetone, ethyl acetate and hexane due to its low aqueous solubility. Further, nanoencapsulation of GO is required for the enhancement of stability and bioavailability. Plant-derived nanovesicles (PDNVs) are natural/intrinsic exosome-mimetic vesicles isolated from edible plants using green methods. Washed/soaked rice water (SRW) is often discarded as waste prior to cooking rice. However, traditional knowledge indicates its health-promoting anti-oxidant benefit, probably contributed by the presence of GO. Herein, for the first time, we isolated PDNVs from SRW by the cost-effective Polyethylene glycol 6000(PEG) precipitation method and demonstrated the presence of GO in PDNVs. In our initial screen, PDNVs were isolated from both rice grains (RGs) as well as the SRW of four different rice varieties, in which we identified the copious presence of GO in black RGs and brown SRW PDNVs. Both RG and SRW PDNVs were non-toxic to keratinocytes. SRW PDNVs displayed distinct cellular uptake mechanisms compared to RG PDNVs in human keratinocytes. Compared to native GO, brown SRW PDNVs containing GO displayed superior anti-oxidant activity in HaCaT keratinocytes, likely due to its enhanced cellular uptake. Overall, we describe here a waste-to-wealth green approach using an economical PEG method for the extraction of GO in bioavailable form. Given that oxidative stress is a driving factor for inflammation and related diseases, SRW PDNVs provide an affordable natural formulation for the treatment of diseases with underlying oxidative stress and inflammation.
γ-谷维素（GO）是一种存在于米糠中的天然抗氧化剂，对健康具有潜在益处。由于GO在水中的溶解度较低，传统上从米糠中分离GO需要使用丙酮、乙酸乙酯和己烷等不环保的溶剂。此外，为了提高稳定性和生物利用度，需要对GO进行纳米封装。植物源纳米囊泡（PDNVs）是使用绿色方法从可食用植物中分离出的天然/内在的外泌体模拟囊泡。淘米水（SRW）在煮饭之前通常作为废物丢弃。然而，传统知识表明它具有促进健康的抗氧化益处，这可能是由于GO的存在。在此，我们首次通过经济高效的聚乙二醇6000（PEG）沉淀法从SRW中分离出PDNVs，并证明了PDNVs中存在GO。在我们的初步筛选中，从四种不同水稻品种的稻谷（RGs）以及SRW中都分离出了PDNVs，我们发现黑色RGs和棕色SRW PDNVs中大量存在GO。RG和SRW PDNVs对角质形成细胞均无毒。在人类角质形成细胞中，SRW PDNVs与RG PDNVs相比表现出不同的细胞摄取机制。与天然GO相比，含有GO的棕色SRW PDNVs在HaCaT角质形成细胞中表现出优异的抗氧化活性，这可能是由于其细胞摄取增强。总体而言，我们在此描述了一种变废为宝的绿色方法，即使用经济的PEG方法以生物可利用的形式提取GO。鉴于氧化应激是炎症和相关疾病的驱动因素，SRW PDNVs为治疗具有潜在氧化应激和炎症的疾病提供了一种经济实惠的天然制剂。
