Natural compound glycyrrhetinic acid protects against doxorubicin-induced cardiotoxicity by activating the Nrf2/HO-1 signaling pathway

BACKGROUND

As one of the most classic antineoplastic agents, doxorubicin (Dox) is extensively used to treat a wide range of cancers. Nevertheless, the clinical outcomes of Dox-based therapies are severely hampered due to the significant cardiotoxicity. Glycyrrhetinic acid (GA) is the major biologically active compound of licorice, one of the most well-known food additives and medicinal plants in the world. We previously demonstrated that GA has the potential capability to protect mice from Dox-induced cardiac injuries. However, the underlying cardioprotective mechanism remains unexplored.

PURPOSE

To investigate the cardioprotective benefits of GA against Dox-induced cardiotoxicity and to elucidate its mechanisms of action.

STUDY DESIGN/METHODS

H9c2 cardiomyoblasts and AC16 cardiomyocytes were used as the cell models in vitro. A transgenic zebrafish model and a 4T1 mouse breast cancer model were applied to explore the cardioprotective effects of GA in vivo.

RESULTS

In vitro, GA inhibited Dox-induced cell death and LDH release in H9c2 and AC16 cells without affecting the anti-cancer effects of Dox. GA significantly alleviated Dox-induced ROS generation, mitochondrial dysfunction, and apoptosis in H9c2 cells. Moreover, GA abolished the expression of pro-apoptotic proteins and restored Nrf2/HO-1 signaling pathway in Dox-treated H9c2 cells. On the contrary, Nrf2 knockdown strongly abrogated the cardioprotective effects of GA on Dox-treated H9c2 cells. In vivo, GA attenuated Dox-induced cardiac dysfunction by restoring stroke volume, cardiac output, and fractional shortening in the transgenic zebrafish embryos. In a 4T1 mouse breast cancer model, GA dramatically prevented body weight loss, attenuated cardiac dysfunction, and prolonged survival rate in Dox-treated mice, without compromising Dox's anti-tumor efficacy. Consistently, GA attenuated oxidative injury, reduced cardiomyocytes apoptosis, and restored the expressions of Nrf2 and HO-1 in Dox-treated mouse hearts.

CONCLUSION

GA protects against Dox-induced cardiotoxicity by suppressing oxidative stress, mitochondrial dysfunction, and apoptosis via upregulating Nrf2/HO-1 signaling pathway. These findings could provide solid evidence to support the further development of GA as a feasible and safe adjuvant to Dox chemotherapy for overcoming Dox-induced cardiotoxicity.

Effects of different cooking methods on volatile flavor compounds, nutritional constituents, and antioxidant activities of Clitocybe squamulosa

To explore a scientific and reasonable cooking method for Clitocybe squamulosa, four cooking methods (boiling, steaming, microwaving, and frying) were applied to C. squamulosa, and the effects of different cooking methods on volatile flavor compounds, nutritional constituents, and antioxidant activities in C. squamulosa were systematically investigated. The results showed that 54, 53, 61, 63, and 49 volatile flavor compounds were detected in raw, boiled, steamed, microwaved, and fried samples, respectively. Large differences in volatile flavor compounds between the four cooking and raw samples were determined by using relative odor activity values (ROAV) and principal component analysis (PCA). In addition, steaming and microwaving could protect the nutrients of C. squamulosa, reduce losses during the cooking process and improve the color of cooked products compared to boiling and frying cooking methods. Meanwhile, cooking treatment exerted different effects on the antioxidant activity of C. squamulosa, and the antioxidant activity of C. squamulosa was the highest after microwave cooking treatment. This research can provide a theoretical basis for the cooking, processing and utilization of C. squamulosa and other wild edible fungi.

The uniqueness and superiority of energy utilization in yaks compared with cattle in the highlands: A review

Yaks living on the Qinghai-Tibetan Plateau for a long time have evolved a series of mechanisms to adapt to the unique geographical environment and climate characteristics of the plateau. Compared with other ruminants, yaks have higher energy utilization and metabolic efficiency. This paper presents possible mechanisms responsible for the efficient energy utilization, absorption and metabolism resulting from the unique evolutionary process of yaks. It is hoped that the information discussed in this review will give a better insight into the uniqueness and superiority of yaks in regards to energy metabolism and utilization compared with cattle and open new avenues for the targeted regulation of energy utilization pathways of other ruminants.

Purification, Characterization, and Immobilization of a Novel Protease-Resistant α-Galactosidase from Oudemansiella radicata and Its Application in Degradation of Raffinose Family Oligosaccharides from Soymilk

α-galactosidase (EC 3.2.1.22) are glycosidases that catalyze the hydrolysis of α-1,6-linked D-galactosyl residues of different substrates, which has been widely applied in the food industry. Oudemansiella radicata is a kind of precious edible medicinal mushroom, which is a healthy, green, and safe food-derived enzyme source. In this study, a novel acidic α-galactosidase was purified from the dry fruiting bodies of O. radicata by ion-exchange chromatography and gel filtration, and designated as ORG (O. radicata α-galactosidase). ORG was further immobilized to obtain iORG by the sodium alginate–chitosan co-immobilization method. Then, the characterization of free and immobilized enzymes and their potential application in the removal of the RFOs from soymilk were investigated. The results showed that ORG might be a 74 kDa heterodimer, and it exhibited maximum activity at 50 °C and pH 3.0, whereas iORG showed maximum activity at 50 °C and pH 5.5. In addition, iORG exhibited higher thermal stability, pH stability, storage stability, and a better degradation effect on raffinose family oligosaccharides (RFOs) in soymilk than ORG, and iORG completely hydrolyzed RFOs in soymilk at 50 °C within 3 h. Therefore, iORG might be a promising candidate in the food industry due to its excellent stability, high removal efficiency of RFOs from soymilk, and great reusability.

Effect of the ratio of dietary metabolizable energy to nitrogen content on production performance, serum metabolites, rumen fermentation parameters, and bacterial diversity in yaks

This study examined the effect of the ratio of dietary metabolizable energy (MJ) to nitrogen (g) content (ME:N) on average daily gain (ADG), blood biochemical indices, rumen fermentation parameters, and rumen bacterial community in yaks. Thirty-six male yaks, aged 2–3 years, were divided into three groups and received a ME:N ratio of 0.42 (HY), 0.36 (MY,) or 0.32 (LY) MJ/g. Dry matter intake ranged between 3.16 and 3.63 kg/d and was lesser (p < 0.001) in the LY group than the other two groups. ME intake increased (p < 0.001) with an increase in the ME:N ratio, while N intake did not differ among groups. The ADG was 660 g/day for the MY group, which was higher (p < 0.005) than the 430 g/day in the LY group, while the HY group gained 560 g/day and did not differ from the other two groups. Feed intake to ADG ratio ranged between 5.95 and 7.95, and numerically was highest in the LY group and lowest in the MY group. In general, the concentration of ruminal total volatile fatty acids (p < 0.03) and molar proportions of propionate (p < 0.04), increased, while the molar proportion of acetate (p < 0.005) and the acetate:propionate ratio decreased (p < 0.001) with a decrease in the ME:N ratio. The molar proportion of butyrate did not differ among groups (p = 0.112). Group MY had higher ruminal NH₃-N content than group HY and had a higher serum glucose content but lower urea content, lactate dehydrogenase, and creatine kinase content than group LY. In ruminal bacteria at the phylum level, the relative abundance of Firmicutes (F) was greater and of Bacteroidetes (B) was lesser, while the F:B ratio was greater in group MY than in groups HY an LY. We concluded that the yaks consuming the diet containing a ME:N ratio of 0.36 MJ/g had the best performance of the three groups.

Effects of Sparassis latifolia neutral polysaccharide on immune activity via TLR4-mediated MyD88-dependent and independent signaling pathways in RAW264.7 macrophages

Background

Sparassis latifolia (S. latifolia) is a precious edible fungus with multiple biological activities. To date, no study has been investigated the underlying molecular mechanism of immunoregulation caused by the neutral polysaccharide of S. latifolia.

Materials and methods

To investigate immunomodulatory mechanism of S. latifolia neutral polysaccharide (SLNP), SLNP was obtained from S. latifolia and its structure, immune receptors and regulation mechanism were studied.

Results

S. latifolia neutral polysaccharide consisted of arabinose, galactose, glucose, xylose, and mannose with a molar ratio of 6:12:63:10:5. SLNP was a pyran polysaccharide with a relative molecular weight of 3.2 × 105 Da. SLNP promoted the proliferation of RAW264.7, which further induced the secretions of nitric oxide, TNF-α, IL-6, and IFN-β, and upregulated the immune receptor TLR4 expression. Moreover, SLNP increased remarkably the levels of TRAF6, IRF3, JNK, ERK, p38, and p38 mRNA and protein mediated by TLR4.

Conclusion

S. latifolia neutral polysaccharide regulated the immune function of RAW264.7 through MyD88-dependent and -independent signaling pathways mediated by TLR4 receptor, which suggests that SLNP is a new immunomodulator.

Colon-specific delivery of isoliquiritigenin by oral edible zein/caseate nanocomplex for ulcerative colitis treatment

Although a natural anti-inflammatory ingredient, isoliquiritigenin (ISL), plays an effective role in ulcerative colitis (UC) treatment, a series of drawbacks still limit its clinical application, including the poor solubility, instability in gastrointestinal tract, and rapid elimination rate of ISL. Zein-based NPs display the benefits on drug loading and delivery, whereas with the poor stability. In this study, an edible nano-system composed by zein/caseinate complex was fabricated for the colon-targeting delivery of ISL, to improve its colon retention and anti-UC effects. The optimized ISL loaded zein/caseinate NPs (ISL@NPs) were prepared by single-factor design by anti-solvent precipitation method, and then characterized. The improved cellular uptake of ISL@NPs on NCM460 and RAW 264.7 cells was evaluated in vitro. The colon tissue permeability and retention capacity in vivo, and the anti-UC efficacy of ISL@NPs in DSS-induce UC were implemented. As a result, ISL@NPs with the high drug loading efficiency of 9.39% ± 0.26%, the average particle diameter of 137.32 ± 2.54 nm, exhibited the pH-sensitive stability in the different simulated gastrointestinal buffer. Compared with free ISL, ISL@NPs showed significantly higher cellular uptake ability in NCM460 and RAW 264.7 cells. Based on in vivo imaging system, zein/caseinate NPs showed the prolonged colonic retention and the enhanced penetration into the colonic epithelium. Finally, the oral administration of ISL@NPs could effectively alleviate the UC-related symptoms, down-regulate the production of pro-inflammatory factors, and reduce the infiltration of macrophages and neutrophils in colon tissues. In this study, an oral colon-specific nano-system, composed with the natural compound and edible materials, was developed as the promising alternatives in the prevention and treatment of UC.

Quality assessment and Q-markers discovery of Tongsaimai tablet by integrating serum pharmacochemistry and network pharmacology for anti-atherosclerosis benefit

Background

The limited therapeutic outcomes of atherosclerosis (AS) have allowed, traditional Chinese medicine has been well established as an alternative approach in ameliorating AS and associated clinical syndromes. Clinically, Tongsaimai tablet (TSMT), a commercial Chinese patent medicine approved by CFDA, shows an obvious therapeutic effect on AS treatment. However, its effective mechanism and quality control still need thorough and urgent exploration.

Methods

The mice were orally administered with TSMT and their serum was investigated for the absorbed compounds using serum pharmacochemistry via the UPLC-Q-Exactive Orbitrap/MS analysis was employed to investigate these absorbed compounds in serum of mice orally administrated with TSMT. Based on these absorbed prototype compounds in serum derived from TSMT, a component-target-disease network was constructed using network pharmacology strategy, which elucidated the potential bioactive components, effective targets, and molecular mechanisms of TSMT against AS. Further, the screened compounds from the component-target network were utilized as the quality control (QC) markers, determining multi-component content determination and HPLC fingerprint to assess quality of nine batches of TSMT samples.

Results

A total of 164 individual components were identified in TSMT. Among them, 29 prototype compounds were found in serum of mice administrated with TSMT. Based on these candidate prototype components, 34 protein targets and 151 pathways related to AS were predicted, and they might significantly exhibit potential anti-AS mechanisms via synergistic regulations of lipid regulation, shear stress, and anti-inflammation, etc. Five potentially bioactive ingredients in TSMT, including Ferulic acid, Liquiritin, Senkyunolide I, Luteolin and Glycyrrhizic acid in quantity not less than 1.2798, 0.4716, 0.5419, 0.1349, 4.0386 mg/g, respectively, screened from the component-target-pathway network. Thereby, these indicated that these five compounds of TMST which played vital roles in the attenuation of AS could serve as crucial marker compounds for quality control.

Conclusions

Overall, based on the combination of serum pharmacochemistry and network pharmacology, the present study firstly provided a useful strategy to establish a quality assessment approach for TSMT by screening out the potential anti-AS mechanisms and chemical quality markers.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-022-00658-9.