Targeting TRPV1 and TRPA1: A feasible strategy for natural herbal medicines to combat postoperative ileus.

Under physiological or pathological conditions, transient receptor potential (TRP) channel vanilloid type 1 (TRPV1) and TRP ankyrin 1 (TRPA1) possess the ability to detect a vast array of stimuli and execute diverse functions. Interestingly, increasing works have reported that activation of TRPV1 and TRPA1 could also be beneficial for ameliorating postoperative ileus (POI). Increasing research has revealed that the gastrointestinal (GI) tract is rich in TRPV1/TRPA1, which can be stimulated by capsaicin, allicin and other compounds. This activation stimulates a variety of neurotransmitters, leading to increased intestinal motility and providing protective effects against GI injury. POI is the most common emergent complication following abdominal and pelvic surgery, and is characterized by postoperative bowel dysfunction, pain, and inflammatory responses. It is noteworthy that natural herbs are gradually gaining recognition as a potential therapeutic option for POI due to the lack of effective pharmacological interventions. Therefore, the focus of this paper is on the TRPV1/TRPA1 channel, and an analysis and summary of the processes and mechanism by which natural herbs activate TRPV1/TRPA1 to enhance GI motility and relieve pain are provided, which will lay the foundation for the development of natural herb treatments for this disease.

Flavonoids regulate tumor-associated macrophages - From structure-activity relationship to clinical potential (Review).

In recent years, the strategy for tumor therapy has changed from focusing on the direct killing effect of different types of therapeutic agents on cancer cells to the new mainstream of multi-mode and -pathway combined interventions in the microenvironment of the developing tumor. Flavonoids, with unique tricyclic structures, have diverse and extensive immunomodulatory and anti-cancer activities in the tumor microenvironment (TME). Tumor-associated macrophages (TAMs) are the most abundant immunosuppressive cells in the TME. The regulation of macrophages to fight cancer is a promising immunotherapeutic strategy. This study covers the most comprehensive cognition of flavonoids in regulating TAMs so far. Far more than a simple list of studies, we try to dig out evidence of crosstalk at the molecular level between flavonoids and TAMs from literature, in order to discuss the most relevant chemical structure and its possible relationship with the multimodal pharmacological activity, as well as systematically build a structure-activity relationship between flavonoids and TAMs. Additionally, we point out the advantages of the macro-control of flavonoids in the TME and discuss the potential clinical implications as well as areas for future research of flavonoids in regulating TAMs. These results will provide hopeful directions for the research of antitumor drugs, while providing new ideas for the pharmaceutical industry to develop more effective forms of flavonoids.

The antihypertensive potential of flavonoids from Chinese Herbal Medicine: A review.

With the coming of the era of the aging population, hypertension has become a global health burden to be dealt with. Although there are multiple drugs and procedures to control the symptoms of hypertension, the management of it is still a long-term process, and the side effects of conventional drugs pose a burden on patients. Flavonoids, common compounds found in fruits and vegetables as secondary metabolites, are active components in Chinese Herbal Medicine. The flavonoids are proved to have cardiovascular benefits based on a plethora of animal experiments over the last decade. Thus, the flavonoids or flavonoid-rich plant extracts endowed with anti-hypertension activities and probable mechanisms were reviewed. It has been found that flavonoids may affect blood pressure in various ways. Moreover, despite the substantial evidence of the potential for flavonoids in the control of hypertension, it is not sufficient to support the clinical application of flavonoids as an adjuvant or core drug. So the synergistic effects of flavonoids with other drugs, pharmacokinetic studies, clinical trials and the safety of flavonoids are also incorporated in the discussion. It is believed that more breakthrough studies are needed. Overall, this review may shed some new light on the explicit recognition of the mechanisms of anti-hypertension actions of flavonoids, pointing out the limitations of relevant research at the current stage and the aspects that should be strengthened in future researches.

Chemical composition and pharmacological mechanism of Qingfei Paidu Decoction and Ma Xing Shi Gan Decoction against Coronavirus Disease 2019 (COVID-19): In silico and experimental study.

The Coronavirus Disease 2019 (COVID-19) pandemic has become a huge threaten to global health, which raise urgent demand of developing efficient therapeutic strategy. The aim of the present study is to dissect the chemical composition and the pharmacological mechanism of Qingfei Paidu Decoction (QFPD), a clinically used Chinese medicine for treating COVID-19 patients in China. Through comprehensive analysis by liquid chromatography coupled with high resolution mass spectrometry (MS), a total of 129 compounds of QFPD were putatively identified. We also constructed molecular networking of mass spectrometry data to classify these compounds into 14 main clusters, in which exhibited specific patterns of flavonoids (45 %), glycosides (15 %), carboxylic acids (10 %), and saponins (5 %). The target network model of QFPD, established by predicting and collecting the targets of identified compounds, indicated a pivotal role of Ma Xing Shi Gan Decoction (MXSG) in the therapeutic efficacy of QFPD. Supportively, through transcriptomic analysis of gene expression after MXSG administration in rat model of LPS-induced pneumonia, the thrombin and Toll-like receptor (TLR) signaling pathway were suggested to be essential pathways for MXSG mediated anti-inflammatory effects. Besides, changes in content of major compounds in MXSG during decoction were found by the chemical analysis. We also validate that one major compound in MXSG, i.e. glycyrrhizic acid, inhibited TLR agonists induced IL-6 production in macrophage. In conclusion, the integration of in silico and experimental results indicated that the therapeutic effects of QFPD against COVID-19 may be attributed to the anti-inflammatory effects of MXSG, which supports the rationality of the compatibility of TCM.

FT-IR and FT-Raman fingerprints of flavonoids - A review.

Flavonoids are secondary metabolites commonly found in plants. They are known for their antioxidant properties, are part of the defense mechanisms of plants and are responsible for the pigmentation of fruit and flowers petals. Consumption foods rich in flavonoids in the daily diet brings a number of pro-health benefits - for example blood pressure regulation, delaying the aging process or anti-cancer effect. These compounds in synthetic or natural form are also used in pharmacy. The profile of flavonoid compounds can be quickly, accurately and easy determine in the test sample by using the infrared and Raman spectroscopy. Those methods are successfully used in the food and pharmaceutical industries. Spectroscopy methods allow us to determine the chemical structure of these compounds. This review describes and compares differences between the spectroscopic spectra of individual compounds with the chemical structure for the flavonoids subgroups: flavones, isoflavones, flavanones, flavonols and anthocyanins.

Electrosynthesis of three-dimensional nanoporous nickel on screen-printed electrode used for the determination of narirutin in citrus wastewater.

In this study, an electrochemical sensor was designed for the detection of narirutin using three-dimensional nanostructured porous nickel on screen-printed electrode (3DnpNi/SPE). The modified electrode was successfully synthesized by the dynamic hydrogen bubble template method. The 3DnpNi/SPE was characterized by spectroscopic, microscopic, and electrochemical methods. The results showed that the 3DnpNi/SPE presents good electrocatalytic activity for the oxidation of narirutin. The quantification of narirutin was conducted by differential pulse voltammetry, which showed a wide concentration range (1.0 × 10-7 - 1.0 × 10-5 mol L-1), with low detection limit (3.9 × 10-8 mol L-1), and excellent sensitivity (0.31 A L mol-1). The proposed electrode was applied toward the determination of narirutin in yellow water sample from the citrus industry, where it presented a good degree of accuracy. The 3DnpNi/SPE showed repeatability, long-term stability, and selectivity. The results obtained showed agreement with those obtained by HPLC/DAD method. Chemical compounds studied in this article.

Simultaneous determination of 14 bioactive citrus flavonoids using thin-layer chromatography combined with surface enhanced Raman spectroscopy.

Citrus flavonoids consist of diverse analogs and possess various health-promoting effects dramatically depending on their chemical structures. Since different flavonoids usually co-exist in real samples, it's necessary to develop rapid and efficient methods for simultaneous determination of multiple flavonoids. Thin layer chromatography combined with surface enhanced Raman spectroscopy (TLC-SERS) was established to simultaneously separate and detect 14 citrus flavonoids for the first time. These target compounds could be characterized and discriminated when paired with SERS at 6-500 times greater the sensitivity than TLC alone. TLC-SERS exhibited high recovery rates (91.5-121.7%) with relative standard deviation lower than 20.8%. Moreover, the established TLC-SERS method was successfully used to simultaneously detect multiple flavonoids in real samples, which exhibited comparable accuracy to high performance liquid chromatography with shorter analytical time (10 vs 45 min). All the results demonstrated that this could be a promising method for simultaneous, rapid, sensitive and accurate detection of flavonoids.

Effects of polyphenols on crystallization of amorphous sucrose lyophiles.

The crystallization of amorphous sucrose in food products can greatly affect the quality of foods. This study investigated the effects of polyphenols on the crystallization of amorphous sucrose lyophiles. Monoglycosylated, polyglycosylated, and aglycones with differing polyphenol backbones were studied, in addition to bulk food ingredients containing a high concentration of polyphenols. Solutions containing sucrose with and without polyphenols (1 and 5%) were lyophilized, stored in RH-controlled desiccators, and analyzed by x-ray diffraction. Moisture sorption studies, Karl Fischer titration, and differential scanning calorimetry were also completed. Polyphenol addition delayed sucrose crystallization by up to 6.4x compared to the control. Structure played the most significant role in efficacy of polyphenols in delaying sucrose crystallization, more than Tg or hygroscopicity. Glycosylated polyphenols were more effective than aglycones, polyphenols with (2,1) glycosidic linkages were more effective than those with (6,1) linkages, and bulk food ingredients were the most effective at delaying sucrose crystallization.

Impact of extraction processes on phytochemicals content and biological activity of Citrus × clementina Hort. Ex Tan. leaves: New opportunity for under-utilized food by-products.

Plants are a rich source of natural bioactive compounds with a wide range of applications in the food and pharmaceutical industries. Citrus × clementina leaves extracts and essential oils may be a potential candidate for formulation of products characterized by hypoglycaemic, antioxidant and anti-browning properties. C. × clementina leaves collected in three different areas in Calabria (South Italy) were extracted by Soxhlet apparatus, maceration, Ultrasound assisted maceration, and hydrodistillation. Hesperidin, tangeritin, and sinensetin were identified by HPLC-DAD analysis as dominant constituents of the extracts. The absence of coumarins and furanocoumarins was demonstrated. GC-MS analyses of essential oils evidenced the presence of sabinene, linalool, and (E)-ß-ocimene as main compounds. Based on RACI and GAS values calculated by the integration of data obtained by DPPH, ABTS, FRAP and ß-carotene bleaching methods, hydroalcoholic extract obtained by Ultrasound assisted maceration of the leaves collected in Corigliano Calabro showed the highest antioxidant activity. Ultrasound assisted hydroalcoholic extract of Cetraro leaves revealed the highest α-amylase inhibitory activity (IC50 of 64.37 µg/ml). Promising results of C. × clementina extracts as tyrosinase inhibitors were also obtained. To evaluate the relationship between identified compounds and bioactivity PCA was performed. Taking into account results obtained by this study, C. × clementina leaves that were considered Citrus-by-products could be utilized for formulation of food additives, nutraceuticals and functional foods.

Nobiletin, sinensetin, and tangeretin are the main perpetrators in clementines provoking food-drug interactions in vitro.

For clementine juice, previous data indicate a possible food-drug interaction with substrates of key enzymes responsible for drug metabolism (i.e. cytochrome P450 [CYP] 3A4, CYP1A2). However, which compounds in clementine juice are responsible for these effects are unknown. Therefore, we aimed to identify the compounds in clementine juice provoking metabolic enzyme inhibition or induction. The results demonstrated that the flavonoid fraction of clementine juice provoked induction of several genes and inhibition of both CYP3A4 and CYP1A2, matching effects observed with whole clementine juice. CYP1A2 inhibition and induction can most likely be attributed to nobiletin, sinensetin, and tangeretin. Tangeretin was the only compound causing CYP3A4 induction while CYP3A4 inhibition was most likely the result of additive or synergistic effects caused by several compounds. Thus, whenever evaluating the clinical relevance of clementine interactions, flavonoid contents should be reported because these might explain differences between cultivars and harvests.

Effective-component compatibility of Bufei Yishen formula II inhibits mucus hypersecretion of chronic obstructive pulmonary disease rats by regulating EGFR/PI3K/mTOR signaling.

ETHNOPHARMACOLOGICAL RELEVANCE: The effective-component compatibility of Bufei Yishen formula I (ECC-BYF I), a combination of 10 compounds, including total ginsenosides, astragaloside IV, icariin, and paeonol, etc., is derived from Bufei Yishen formula (BYF). The efficacy and safety of ECC-BYF I is equal to BYF. However, the composition of ECC-BYF I needs to be further optimized. Based on the beneficial effects of BYF and ECC-BYF I on chronic obstructive pulmonary disease (COPD), this study aimed to optimize the composition of ECC-BYF I and to explore the effects and mechanisms of optimized ECC-BYF I (ECC-BYF II) on mucus hypersecretion in COPD rats. MATERIALS AND METHODS: ECC-BYF I was initially optimized to six groups: optimized ECC-BYF I (OECC-BYF I)-A~F. Based on a COPD rat model, the effects of OECC-BYF I-A~F on COPD rats were evaluated. R-value comprehensive evaluation was used to evaluate the optimal formula, which was named ECC-BYF II. The changes in goblet cells and expression of mucins and the mRNA and proteins involved in the epidermal growth factor receptor/phosphoinositide-3-kinase/mammalian target of rapamycin (EGFR/PI3K/mTOR) pathway were evaluated to explore the effects and mechanisms of ECC-BYF II on mucus hypersecretion. RESULTS: ECC-BYF I and its six optimized groups, OECC-BYF I-A~F, had beneficial effects on COPD rats in improving pulmonary function and lung tissue pathology, reducing inflammation and oxidative stress, and improving the protease/anti-protease imbalance and collagen deposition. R-value comprehensive evaluation found that OECC-BYF I-E (paeonol, icariin, nobiletin, total ginsenoside, astragaloside IV) was the optimal formula for improving the comprehensive effects (lung function: VT, MV, PEF, EF50, FVC, FEV 0.1, FEV 0.1/FVC; histological changes: MLI, MAN; IL-1ß, IL-6, TNF-α, MMP-9, TIMP-1, T-AOC, LPO, MUC5AC, Collagen I and Collagen III). OECC-BYF I-E was named ECC-BYF II. Importantly, the effect of ECC-BYF II showed no significant difference from BYF and ECC-BYF I. ECC-BYF II inhibited mucus hypersecretion in COPD rats, which manifested as reducing the expression of MUC5AC and MUC5B and the hyperplasia rate of goblet cells. The mRNA and protein expression levels of EGFR, PI3K, Akt, and mTOR were increased in COPD rats and were obviously downregulated after ECC-BYF II administration. CONCLUSION: ECC-BYF II, which consists of paeonol, icariin, nobiletin, total ginsenoside and astragaloside IV, has beneficial effects equivalent to BYF and ECC-BYF I on COPD rats. ECC-BYF II significantly inhibited mucus hypersecretion, which may be related to the regulation of the EGFR/PI3K/mTOR pathway.

Potential of benzophenones and flavanones to modulate the bitter intensity of Cyclopia genistoides herbal tea.

Variation in the bitter taste of Cyclopia genistoides (honeybush) herbal tea and reported modulation between its major xanthones, mangiferin and isomangiferin, prompted further investigation into the potential modulatory effects of honeybush phenolics. Combinations of crude benzophenone (BF)-, xanthone (XF)-, and flavanone (FF)-rich fractions and their major individual phenolic compounds were analysed by descriptive sensory analysis. The fractions were prepared from a bitter, hot water extract of green C. genistoides. Fraction BF, which is below the bitter threshold (intensity 10 on 100-point scale), enhanced the bitter intensity of XF and FF slightly (p < 0.05), although none of the major individual benzophenones retained this bitter enhancing effect. On the contrary, 3-ß-d-glucopyranosyl-4-ß-d-glucopyranosyloxyiriflophenone, the major benzophenone in BF, significantly (p < 0.05) decreased the bitter taste of XF, at a low concentration, whereas FF suppressed the bitter intensity of XF and mangiferin, the major xanthone present in XF. Hesperidin, however, had no effect on the bitter intensity of XF. In contrast, (2S)-5-[α-L-rhamnopyranosyl-(1→2)-ß-d-glucopyranosyloxy]-naringenin, the major compound of FF, significantly (p < 0.05) enhanced the bitter taste of XF when added at concentrations comparable to that of 'fermented' honeybush tea infusions. The concentration-dependence of these bitter taste interactions may be responsible for the variable bitter intensity of C. genistoides herbal tea.

Membrane selection and optimisation of tangential flow ultrafiltration of Cyclopia genistoides extract for benzophenone and xanthone enrichment.

Ultrafiltration of Cyclopia genistoides extract was optimised to increase its benzophenone and xanthone content as quantified using HPLC-DAD. Regenerated cellulose (RC) and polyethersulphone membranes with molecular weight cut-offs of 10 and 30 kDa were evaluated in terms of compound enrichment, permeate flux and permeate yield, using dead-end ultrafiltration. Compound enrichment was subsequently optimised using the 10 kDa RC membrane and tangential flow ultrafiltration (TFU). The effect of extract composition on compound enrichment, due to natural variation in the source material, was assessed using extracts from different batches of plant material (n = 11). Transmembrane pressure and feed flow rate affected (p < 0.05) process efficiency (mean permeate flux, compound enrichment and membrane fouling). TFU achieved ≥20% enrichment of the target compounds, proving its suitability for preparation of a nutraceutical extract of C. genistoides.

Development of a sensitive monoclonal antibody-based indirect competitive enzyme-linked immunosorbent assay for analysing nobiletin in citrus and herb samples.

Nobiletin, a polymethoxyflavone mainly found in citrus fruits, have been reported to exhibit various beneficial biological activities for human health. It is an important bioactive compound in traditional Chinese medicine, Pericarpium Citri Reticulatae and Fructus Aurantii. To detect the contents of nobiletin in citrus and herb samples, we developed an indirect competitive enzyme-linked immunosorbent assay (icELISA) based on monoclonal antibodies. It possessed a median inhibition concentration (IC50) of 2.43 ±â€¯0.19 ng/mL and a working range of 0.52-12.3 ng/mL. The assay exhibited the average recoveries of 72.5-85.3% in citrus peel, pulp and juice samples. Moreover, eleven citrus cultivars samples and four herb samples were also detected by the icELISA. The nobiletin content varied in different citrus cultivars samples and herb samples, which were confirmed by the ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS). These results indicated that the developed immunoassay was suitable for detecting nobiletin in citrus and herb samples.

Efficiency of four different dietary preparation methods in extracting functional compounds from dried tangerine peel.

Dried tangerine peel (DTP) is an excellent plant resource that has been used as ingredients for both food and traditional Chinese medicine. In this study, the efficiency of four different dietary preparation methods (i.e. soaking, boiling, steaming, and ethanol extraction) in extraction of functional compounds (i.e. flavonoids and essential oil constituents) from DTP was evaluated systematically for the first time. To conduct a comprehensive evaluation of the extraction of the functional compounds, a synthetic evaluation model based on a weighting method was established. The optimum conditions of each dietary preparation method (e.g., time, temperature, solid-liquid ratio, etc.) were determined by response surface methodology. Ethanol extraction showed the best extraction efficiency, followed by soaking, boiling, and steaming. Additionally, different DTP extracts were shown to be clearly distinguished by electronic eye and electronic tongue. This research provides essential findings for the effective dietary instruction of DTP consumption.

Bitter profiling of phenolic fractions of green Cyclopia genistoides herbal tea.

The bitter taste of Cyclopia genistoides infusions is unacceptable to consumers, who are used to the slightly sweet taste of the herbal teas produced from other Cyclopia species. Bitter taste intensities of crude phenolic fractions of a bitter hot water extract of C. genistoides were determined by a trained panel to identify the fraction contributing most to the bitter taste. Fractions, enriched in benzophenones (B), xanthones (X) and flavanones (F), and each tested at their infusion equivalent concentration (IEC) scored 5, 31 and 13 (on a 100-point scale), respectively. Fraction B, containing mostly iriflophenone glucosides, was perceived as not bitter. The major xanthone in fraction X, mangiferin, was significantly (p < 0.05) more bitter than its regio-isomer, isomangiferin, at equal concentration. A mixture of isomangiferin and mangiferin at their IECs was significantly (p < 0.05) less bitter than the mangiferin solution alone, indicating bitter suppression by isomangiferin.

Optimization of low power ultrasound-assisted extraction of phenolic compounds from mandarin (Citrus reticulata Blanco cv. Sainampueng) peel.

Mandarin peel is a good source of phenolic compounds, which can be extracted by the ultrasound-assisted extraction (UAE) method. This research was to optimize the UAE conditions for maximum mandarin peel extract (MPE) relating to the extract yield, total phenolic content and the content of a mandarin peel rich flavonoid, hesperidin, using a response surface method comparing with the maceration extraction (MAE) method. The results showed that the selected factors (temperature, time and power) have a significant influence on the extraction yield, total phenolic content and hesperidin content. The extraction at 48°C and 56.71W for 40min was considered the optimal UAE condition since it provided the maximum yield (26.52%), total phenolic (15,263.32mgEq gallic/100g DW) and hesperidin (6435.53mg/100g DW). At the same extraction temperature and time, UAE showed greater extraction efficiency than MAE with 1.77 times higher yield than that of MAE.

Anti-angiogenic effects of Qingdu granule on breast cancer through inhibiting NFAT signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Qingdu granule (QDG), a traditional Chinese herbal prescription, had anti-tumor effect on breast cancer. However the underlying mechanism of QDG was unclear. THE AIM OF THIS STUDY: The present study aimed to investigate whether QDG could inhibit angiogenesis of breast cancer via acting on nuclear factor of activated T-cells (NFAT) signaling pathway. This was implicated in human umbilical vein endothelial cells (HUVECs) in vitro and breast cancer xenograft model in vivo. MATERIALS AND METHODS: The VEGF165 (15.58 ng/mL) induced human umbilical vein endothelial cells (HUVECs) were treated with serum samples containing tamoxifen (TAM), tacrolimus (FK506), or QDG with three dosages. The migration and canalization capacities of HUVECs were evaluated by transwell migration and tube formation assay. In 72 h-cultured HUVECs, The gene expression, protein amount, and nuclear translocation of NFATc3 were measured. The anti-tumor and anti-angiogenic effects of QDG in vivo were investigated in breast cancer xenograft model. The serum VEGF levels, microvessel density, and protein expressions (immunohistochemistry and western blot) of VEGF, VEGFR2 and NFATc3 were detected. RESULTS: The results showed that, QDG significantly inhibited HUVEC migration and tube formation. It downregulated NFATc3 gene expression, decreased NFATc3 protein amount, and reduced the ratio of NFATc3 nuclear translocation in HUVECs. In breast cancer xenograft model, QDG treatment significantly suppressed tumor growth, inhibited VEGF release, and decreased microvessel density. QDG reduced protein expressions of VEGF, VEGFR2 and NFATc3. CONCLUSION: The results suggested that QDG showed anti-angiogenic effects of breast cancer both in vitro and in vivo. The mechanism might be partially associated with inhibiting NFAT signaling pathway.

Simultaneous characterization of chemical structures and bioactivities of citrus-derived components using SERS barcodes.

Rapid detection of bioactive components in food has attracted great attention. Herein, we report a novel method through surface-enhanced Raman spectroscopy (SERS) spectra based barcodes for simultaneous characterization of chemical structures and bioactivities of nine citrus components for the first time. SERS barcodes were successfully used to characterize and discriminate all the components with high sensitivity down to 40-60ng. Importantly, SERS barcodes exhibited the 'identity' characteristics. Beyond the molecular structure information, bioactivity information can also be read from the barcodes according to the bioactivity assay and structure-activity relationship. Hence, a simple and intuitive SERS barcoding approach used for simultaneous characterization of chemical structures and bioactivities was established. With a large database of barcodes, there is high potential that the SERS barcoding approach could be further developed to be a rapid, simple and effective foodomics-like approach for bioactive compound identification from a complex food matrix.

Development and characterization of an α-l-rhamnosidase mutant with improved thermostability and a higher efficiency for debittering orange juice.

The glycoside hydrolase, α-l-rhamnosidase, could remove the bitter taste of naringin from citrus juices. However, most α-l-rhamnosidases are easily deactivated at high temperatures, limiting the practice in debittering citrus juices. The V529A mutant of the α-l-rhamnosidase r-Rha1 from Aspergillus niger JMU-TS528 was developed with improved thermostability using directed evolution technology and site-directed mutagenesis. The enzyme mutant had a half-live of thermal inactivation T(1/2) of 1.92 h, 25.00 min, and 2 min at 60, 65, and 70 °C, respectively. In addition, it had improved substrate affinity and better resistance to the inhibition of glucose. The improved substrate affinity was related to its lowered binding energy. Most significantly, the naringin content was reduced to below the bitter taste threshold by treatment with 75 U/mL of the mutant during the preheating process of orange juice production. The comprehensive results indicate that thermostability improvement could promote the practical value of α-l-rhamnosidase in citrus juice processing.