Effects on Steroid 5-Alpha Reductase Gene Expression of Thai Rice Bran Extracts and Molecular Dynamics Study on SRD5A2

Abstract

Steroid 5-alpha reductases (SRD5As) are responsible for the conversion of testosterone to dihydrotestosterone, a potent androgen, which is the aetiologic factor of androgenetic alopecia. This study aimed to compare the SRD5A gene expression suppression activity exerted by Thai rice bran extracts and their components and investigate the interactional mechanism between bioactive compounds and SRD5A2 using molecular dynamics (MD) simulation. Bran of Oryza sativa cv. Tubtim Chumphae (TRB), Yamuechaebia Morchor (YRB), Riceberry (RRB), and Malinil Surin (MRB), all rice milling by-products, was solvent-extracted. The ethanolic extract of TRB had the highest sum of overall bioactive compounds (γ-oryzanol; α-, β-, and γ-tocopherol; phenolics; and flavonoids). Among all extracts, TRB greatly downregulated the expression of SRD5A1, SRD5A2, and SRD5A3; there were no significant differences between TRB and finasteride regarding SRD5A suppression. The linear relationship and principal component analysis supported that the α-tocopherol content was correlated with the SRD5A suppression exerted by TRB. Furthermore, MD simulation demonstrated that α-tocopherol had the highest binding affinity towards SRD5A2 by interacting with residues Phe118 and Trp201. Our findings indicate that α-tocopherol effectively downregulates the expression of SRD5A genes and inhibits SRD5A2 activity, actions that are comparable to standard finasteride. TRB, a source of α-tocopherol, could be developed as an anti-hair loss product.

Antioxidation, Anti-Inflammation, and Regulation of SRD5A Gene Expression of Oryza sativa cv. Bue Bang 3 CMU Husk and Bran Extracts as Androgenetic Alopecia Molecular Treatment Substances

“…Many studies provided evidence that supports the hair-growth-promoting efficacy of herbal extracts and their bioactive compounds via the inhibition of 5α-reductase activity [ 9 , 56 , 57 , 58 , 59 ]. Only a few studied the downregulation of SRD5A expression, and reduction in the protein translation of 5α-reductase enzymes.…”

“…Only a few studied the downregulation of SRD5A expression, and reduction in the protein translation of 5α-reductase enzymes. DU-145 has been used as in vitro model to investigate the effects of substances on 5α-reductase activity and SRD5A expression [ 55 , 56 , 60 , 61 , 62 ]. Thus, this study evaluated the effect of BB3CMU-H and BB3CMU-RB on SRD5A1 , SRD5A2 , and SRD5A3 expression, as shown in Figure 2 .…”

“…However, SRD5A1 was slightly suppressed by BB3CMU-RB, with a fold change of 0.76 ± 0.01 compared with the control group. Tocopherols and γ-oryzanol were identified to diminish the mRNA expressions of SRD5A1 , SRD5A2 , and SRD5A3 [ 56 ]. Furthermore, it was established that linoleic acid, enriched in rice bran extract, was responsible for the downregulation of SRD5A1 expression [ 60 ].…”

Recovery of Polyphenolic Fraction from Arabica Coffee Pulp and Its Antifungal Applications

“…However, the chemical profile of the extract was not reported. Phytochemical extracts are known to exhibit antimicrobial activity from a wide variety of secondary metabolite compositions [ 49 , 53 ]. Crude extract from plants might be a good candidate for an antifungal agent.…”

“…The chemometric multivariate has been used to comprehend the relationships between bioactive ingredients and biological activities by many studies [ 53 , 54 , 55 ]. The score plot relationship of the polyphenols and the biological activities are illustrated in Figure 5 .…”