[Advancements in virtual screening techniques for study of enzyme inhibitor compounds].

Enzymes are closely associated with the onset and progression of numerous diseases, making enzymes a primary target in innovative drug development. However, the challenge remains in identifying compounds that exhibit potent inhibitory effects on the target enzymes. With the continuous expansion of the total number of natural products and increasing difficulty in isolating and enriching new compounds, traditional high-throughput screening methods are finding it increasingly challenging to meet the demands of new drug development. Virtual screening, characterized by its high efficiency and low cost, has gradually become an indispensable technology in drug development. It represents a prominent example of the integration of artificial intelligence with biopharmaceuticals and is an inevitable trend in the rapid development of innovative drug screening in the future. Therefore, this article primarily focused on systematically reviewing the recent applications of virtual screening technology in the development of enzyme inhibitors and explored the prospects and advantages of using this technology in developing new drugs, aiming to provide essential theoretical insights and references for the application of related technologies in the field of new drug development.

Preparation of S-iron-enriched yeast using siderophores and its effect on iron deficiency anemia in rats.

Efforts to obtain organic trace elements have been made, including yeast enrichment and transformation, but the application of yeast for this purpose is restricted by poor tolerance and low enrichment. Siderophores play an important role in iron transport. Thus, the role of siderophores in iron transport under high-iron conditions and the application of siderophores in the enrichment of elements was explored. The results showed that some siderophores from iron-tolerant strains promoted yeast growth and increased its intracellular iron content. Among them, siderophore TZT-12 (from LK1110) was the best for promoting yeast growth and iron conversion. The siderophore-iron-enriched yeast (S-iron-enriched yeast) effectively restored the iron concentration, and an iron concentration of 59.40 mg/g was obtained by adding TZT-12. Iron deficiency anemia in rats was significantly mitigated with S-iron-enriched yeast compared with ferrous sulfate. These findings provide a new perspective on the preparation of organic trace elements for supplementation or food fortification.

Application of enzyme-assisted extraction of baicalin from Scutellaria baicalensis Georgi.

Endophytes may depend on degrading the plant cell wall with cellulases for their survival. Therefore, cellulase produced by endophytes may be useful in releasing the active ingredient of medicinal plants. Scutellaria baicalensis Georgi is a traditional Chinese medicinal plant widely used in China and baicalin is one of its main active ingredients. In this study, fresh S. baicalensis Georgi was used to isolate endophytes, Congo red staining was used to screen cellulase-producing strains, and HPLC was used to determine the content of baicalin in S. baicalensis Georgi. As a result, a highly active strain of endophyte capable of the extraction of high levels of baicalin was obtained. The strain was named HG-5 and identified as Bacillus sp. Scanning electron microscopy analysis confirmed that the enzyme better promotes the dissolution of plant active ingredients. After optimizing the enzyme production and extraction processes, we found that when compared with the traditional extraction method, the baicalin yield was increased 79.31% after extraction with the HG-5 enzyme. The current study provides a novel approach and method for the use of endophyte cellulase to improve the extraction of compounds from medicinal plants.

A new mixed inhibitor of adenosine deaminase produced by endophytic Cochliobolus sp. from medicinal plant seeds.

Medicinal plants have been studied for potential endophytic interactions and numerous studies have provided evidence that seeds harbor diverse microbial communities, not only on their surfaces but also within the embryo. Adenosine deaminase (ADA) is known as a potential therapeutic target for the treatment of lymphoproliferative disorders and cancer. Therefore, in this study, 20 types of medicinal plant seeds were used to screen endophytic fungi with tissue homogenate and streak. In addition, 128 morphologically distinct endophyte strains were isolated and their ADA inhibitory activity determined by a spectrophotometric assay. The strain with the highest inhibitory activity was identified as Cochliobolus sp. Seven compounds were isolated from the strain using a chromatography method. Compound 3 showed the highest ADA inhibitory activity and was identified as 5-hydroxy-2-hydroxymethyl-4H-pyran-4-one, based on the results of 1H and 13C NMR spectroscopy. The results of molecular docking suggested that compound 3 binds to the active site and the nonspecific binding site of the ADA. Furthermore, we found that compound 3 is a mixed ADA inhibitor. These results indicate that endophytic strains are a promising source of ADA inhibitors and that compound 3 may be a superior source for use in the preparation of biologically active ADA inhibitor compounds used to treat cancer.

Reynoutria Japonica from Traditional Chinese Medicine: A Source of Competitive Adenosine Deaminase Inhibitors for Anticancer.

BACKGROUND: Adenosine deaminase (ADA) is an important enzyme in purine metabolism and is known as a potential therapeutic target for the treatment of lymphoproliferative disorders and cancer. Traditional Chinese Herbal Medicine (TCHM) is widely used alone or in combination with chemotherapy to treat cancer, due to its ability to deliver a broad variety of bioactive secondary metabolites as promising sources of novel organic natural agents. OBJECTIVE: In the present study, 29 varieties of medicinal plants were screened for the presence of ADA inhibitors. RESULTS: Extracts from Reynoutria japonica, Glycyrrhiza uralensis, Lithospermum erythrorhizon, Magnolia officinalis, Gardenia jasminoides, Stephania tetrandra, Commiphora myrrha, Raphanus sativus and Corydalis yanhusuo demonstrated strong ADA inhibition with rates greater than 50%. However, Reynoutria japonica possessed the highest ADA inhibitory activity at 95.26% and so was used in our study for isolating the ADA inhibitor to be further studied. Eight compounds were obtained and their structures were identified. The compound H1 had strong ADA inhibitory activity and was deduced to be emodin by 1H and 13C-NMR spectroscopic analysis with an IC50 of 0.629 mM. The molecular docking data showed that emodin could bind tightly to the active site of ADA. Our results demonstrated that emodin displayed a new biological activity which is ADA inhibitory activity with high cytotoxic activity against K562 leukemia cells. The bioactivity of cordycepin was significantly increased when used in combination with emodin. CONCLUSION: Emodin may represent a good candidate anti-cancer therapy and adenosine protective agent.

A novel enzyme-assisted approach for efficient extraction of Z-ligustilide from Angelica sinensis plants.

Endophytes coexist with plants, in part, due to cellulase that allow saccharification of plant cell walls. The cellulase enzymes found in naturally occurring endophytes may exhibit stronger activity and more specificity than commercially available cellulase for enzyme-assisted extraction of compounds from medicinal plant materials. In order to identify endophytes with high cellulase activity, we screened endophytes taken from different parts of Angelica sinensis using the Congo red staining method. We identified three strains with higher cellulase activity. Of the 3 strains identified, No.Lut1201 increased the yield of extracted Z-ligustilide 2 fold compared to commercially available cellulase (Ningxia Sunson) using a cellulase-assisted extraction method and traditional extraction methods. Scanning electron microscopy clearly demonstrated that the cellulase extracted from endophytes enhance cell wall polysaccharide degradation as well as Z-ligustilide extraction from Radix Angelica sinensis (RAS). The current study provides a new method and ideas of using cellulase of endophytes for improving the extraction of compounds from medicinal plants.

Effects of Fe-YM1504 on iron deficiency anemia in rats.

Iron deficiency anemia (IDA) is one of the most serious forms of malnutrition. It is possible that some strains present in the natural environment possess a higher tolerance to inorganic iron and a higher ability to convert and accumulate iron compared with Saccharomyces cerevisiae wild-type strain. In the present study, the strain no. YM1504, able to grow in an iron-rich environment, was used as a potential organic iron supplement, and its efficacy in alleviating IDA in rats was investigated. Sixty female weanling Sprague-Dawley rats were randomly divided into a normal control group fed with a standard diet and a model group fed with an iron-deficient diet to create the IDA model. After the model was established, IDA rats were further randomly divided into five subgroups: the IDA group, the ferrous sulfate (FeSO4) group and Fe-YM1504 low-, medium- or high-dose groups receiving different concentrations of Fe-YM1504 supplements. Our results showed that Fe-YM1504 has an effective restorative function by returning the hemoglobin (Hb), hematocrit (HCT), mean corpuscular hemoglobin (MCH), mean corpuscular volume (MCV), serum iron (SI), total iron binding capacity (TIBC), serum ferritin (SF), etc. in IDA animals to the normal level. Moreover, malondialdehyde and the enzyme activities of superoxide dismutase and glutathione peroxidase in both plasma and liver homogenate were improved. Finally, compared with the FeSO4 group, the Fe-YM1504 middle-dose was more effective in alleviating IDA and fewer side effects were observed. The present study indicated that iron-enriched strain no. YM1504 might play a significant role in ameliorating IDA rats and might be exploited as a new iron supplement.

Higher Bioavailability of Organic Bound Zinc from High Zinc-Enriched Fungi.

The organic forms of trace elements are considered more bioavailable than the inorganic forms. Although yeast can enrich metal elements and convert inorganic zinc to organic species, its tolerability and transforming capacity are limited. It would therefore be very interesting to look for higher conversion and accumulation in zinc fungi to obtain organic bound zinc from the natural environment. In this paper, potato dextrose agar (PDA) medium containing 800 µg/mL zinc was used for initial screening, with twenty-two fungal strains that tolerated high zinc isolated from the natural environment, and one strain (No.LZ-1108) growing well at a zinc (II) concentration of 10,000 µg/mL. According to morphological analysis, 18S rDNA sequence analysis, and biophysical and biochemical characteristics, No.LZ-1108 was tentatively identified as Fusarium oxysporum. Using atomic absorption spectrometry, the zinc content in the No.LZ-1108 cells was found to be 6.7 mg/g dry cell. After oral administration to rats at a dose of 10 mg Zn (II)/kg body weight, the area under the plasma concentration-time curve (AUC) and the maximum zinc blood concentration (Cmax) of No.LZ-1108 and zinc gluconate were 8.10 g/L.min and 4.28 g/L.min, 23.72 µg/mL and 6.23 µg/mL, respectively. The AUC of No.LZ-1108 was significantly higher than those of zinc gluconate (P<0.05), and the mean relative bioavailability of AUC(test)/AUC(zinc gluconate) was 190 %, which showed that the bound zinc in No.LZ-1108 was more bioavailable than zinc gluconate. The present study reports an interesting alternative to developing zinc-based supplements from a natural source of zinc.