Inhibitory effect of Epimedium extract on S-adenosyl-l-homocysteine hydrolase and biomethylation

A systematic review of traditional uses, phytochemistry, pharmacology and toxicity of Epimedium koreanum Nakai

ETHNOPHARMACOLOGICAL RELEVANCE

Epimedium koreanum Nakai (E. koreanum), a member of the genus Epimedium in the family Berberidaceae, is a well-known and well-liked traditional herb used as a "kidney tonic". For thousands of years, it has been utilized for renal yang deficiency, impotence, spermatorrhea, impotence, weakness of tendons and bones, rheumatic paralysis and discomfort, numbness, and constriction.

AIM OF THE STUDY

The paper aims to comprehensively in-depth, and methodically review the most recent research on the traditional uses, phytochemistry, pharmacology, and toxicity of E. koreanum.

MATERIALS AND METHODS

Scientific databases including Web of Science, PubMed, Google Scholar, Elsevier, Springer, ScienceDirect, Baidu Scholar, and CNKI and medicine books in China were searched for relevant information on E. koreanum.

RESULTS

In traditional uses, E. koreanum is frequently used to treat various diseases like erectile dysfunction, infertility, rheumatoid arthritis, osteoporosis, asthma, kidney-yang deficiency syndrome, etc. To date, more than 379 compounds have been discovered from various parts of E. koreanum, including flavonoids, lignans, organic acids, terpenoids, hydrocarbons, dihydrophenanthrene derivatives, alkaloids, and others. Research has revealed that the compounds and crude extracts have a wide range of pharmacological effects on the reproductive, cardiovascular, and nervous systems, as well as anti-osteoporosis, anti-tumor, antioxidant, anti-inflammatory, immunomodulatory, hepatoprotective, and antiviral properties. Besides, the crude extracts show potential hepatotoxicity.

CONCLUSION

Based on recent domestic and international research investigations, E. koreanum contains a wealth of chemical components with pronounced pharmacological activities. Its traditional uses are numerous, and the majority of these traditional uses have been supported by contemporary pharmacological investigations. Crude extracts, on the other hand, can result in hepatotoxicity. Therefore, additional in vivo and in vitro experimental research on the pharmacology and toxicology of E. koreanum are required in the future to assess its safety and efficacy. This will give a firmer scientific foundation for its safe application and the development of new drugs in the future.

Potential of Icariin–Glucosamine Combination in the Treatment of Osteoarthritis by Topical Application: Development of Topical Formulation and In Vitro Permeation Study

The aim of this study was to develop a topically applied formulation with the potential to alleviate arthritis ailments. A combination of two active ingredients, icariin from Epimedium L. (Species: Epimedium Koreanum) extract as a potential promoter of chondrogenesis and glucosamine sulfate as a precursor of cartilage tissues, was tested. In permeation studies, the potential for skin permeation of both substances was confirmed; however, the in vitro release test did not accurately reflect the degree of skin permeation. The in vitro release of icariin was at a level of 15.0–19.0% for the plant-extract-derived icariin and 29.0–35.0% for the pure substance. The level of glucosamine sulfate release was 38.4% (on average). For icariin of both origins, the release results were higher than those obtained via oral administration (about 12.0%), which shows the potential superiority of topical application. In addition, the physicochemical parameters that affect the in vitro release and performance of topical formulations were addressed. This preliminary research and permeation analysis of the formulation produced a promising picture of its prospects regarding arthritis treatment, although further investigation is needed.

The effect of total flavonoids of Epimedium on granulosa cell development in laying hens

To investigate the impact of total flavonoids of Epimedium (TFE) on the development of follicles of laying hens, 3 types of follicles including primary, prehierarchical, and preovulatory follicles were selected to obtain the follicular granulosa cells cultured in vitro. First, extraction of TFE was conducted by alcohol-soluble and ultrasonic methods. The effects of TFE on activity and proliferation of follicular granulosa cells were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and measuring the expression of proliferating cell nuclear antigen mRNA through real-time quantitative polymerase chain reaction, and the expression of the follicle-stimulating hormone receptor, luteinizing hormone receptor, steroidogenic acute regulatory protein, and cytochrome P450 family 11 subfamily A member 1 mRNA was detected to study the functions of TFE affecting the differentiation and hormone secretion by granulosa cells. The results showed that TFE significantly improved the proliferation of 3 types of granulosa cells and promoted the differentiation of granulosa cells and accelerated the conversion of primary follicles to prehierarchical follicles. Total flavonoids of Epimedium played an important role in promoting progesterone secretion by prehierarchical and preovulatory granulosa cells. The results indicated that TFE could promote proliferation and differentiation of follicular granulosa cells and improve hormone secretion and follicle development, which provided reference data for TFE used as a feed additive or safe Chinese veterinary medicine to promote the laying rate.

Epimedium koreanum Extract and Its Flavonoids Reduced Atherosclerotic Risk via Suppressing Modification of Human HDL

Atherosclerosis is the key factor responsible for cardiovascular events, which is a major cause of morbidities and mortalities worldwide. It is well known that high-density lipoprotein (HDL) oxidation and glycation increases the risk for atherosclerosis. Epimedium koreanum has been used as a traditional oriental medicine for treating erectile dysfunction, kidney diseases, osteoporosis, and breast cancer. However, no reports on the effects of E. koreanum on HDL modification exist. In this study, we investigated the inhibitory effects of E. koreanum extract and its eight flavonoids, which are: (1) anhydroicaritin 3-O-rhamnoside, (2) β-anhydroicaritin, (3–5) epimedins A-C, (6) epimedoside A, (7) icariin, and (8) des-O-methyl-β-anhydroicaritin, against HDL modification. HDLs obtained from pooled human plasma samples were incubated in vitro with E. koreanum extract or each compound in the presence of copper sulfate or fructose. The HDL modifications were evaluated by measuring generation of conjugated dienes, production of thiobarbituric acid reactive substances, change in electrophoretic mobility of apoA-I, advanced glycation end products formation, and apoA-I aggregation. Consequently, E. koreanum extract and compound 8 suppressed HDL modification through inhibition of lipid peroxidation, apoA-I aggregation, negative charge increase, and AGEs formation. In particular, compound 8 showed more potent inhibitory effect on HDL modification than the extracts, suggesting its protective role against atherosclerosis via inhibition of HDL oxidation and glycation.

Effect of drying processes on prenylflavonoid content and antioxidant activity of Epimedium koreanum Nakai

Epimedium koreanum Nakai is a famous Chinese herbal medicine for the treatment of impotence, osteoporosis, immune suppression and cardiovascular diseases. Drying is the most common and fundamental procedure in post-harvest processing of E. koreanum, which contributes to the variations of flavonoid content, especially prenylflavonoids, the bioactive components. In present study, effect of drying processes on flavonoid content and antioxidant activity were investigated. High performance liquid chromatography coupled with diode-array detection and electrospray ionization quadrupole time-of-flight tandem mass spectrometry methods were employed. Twenty seven compounds were identified and 11 of them, including eight prenylflavonoids and three other types of flavonoids, were further quantified. The antioxidant activity of E. koreanum was evaluated by the 2,2-diphenyl-1-picrylhydrazyl free radical scavenging method. The results showed that content of the eight prenylflavonoids exhibited significant variations after different drying processes, especially icariin and baohuoside I. The variation tendency of antioxidant activity was positively correlated with the content of total flavonoid, afzelin and icariin.

Rapid measurement of epimedin A, epimedin B, epimedin C, icariin, and moisture in Herba Epimedii using near infrared spectroscopy

In this work, near infrared (NIR) spectroscopy was used in combination with chemometrics to determine the epimedin A, epimedin B, epimedin C, icariin, and moisture contents of Herba Epimedii. The variable selection method genetic algorithm (GA) and regression tool support vector machine (SVM) were used to improve the model performance. Four different calibration models, namely Full-PLS, GA-PLS, Full-SVM, and GA-SVM, were established, and their performances in terms of prediction accuracy and model robustness were systemically studied and compared. In conclusion, the performances of the models based on the efficient variables selected through GA were better than those based on full spectra, and the nonlinear models were superior over the linear models. In addition, the GA-SVM model demonstrated the optimal performance in predicting five quality parameters (viz. epimedin A, epimedin B, epimedin C, icariin, and moisture). For GA-SVM, the determination coefficient (R_p²), root-mean-square error (RMSEP), and residual predictive deviation (RPD) for the prediction set were 0.9015, 0.0268%, and 2.20 for epimedin A; 0.9089, 0.0656%, and 3.08 for epimedin B; 0.9056, 0.1787%, and 3.18 for epimedin C; 0.8192, 0.0657%, and 2.26 for icariin; and 0.9367, 0.2062%, and 4.12 for moisture, correspondingly. Results indicated that NIR spectroscopy coupled with GA-SVM calibration can be used as a reliable alternative strategy to measure the epimedin A, epimedin B, epimedin C, icariin, and moisture contents of Herba Epimedii because this technique is fast, economic, and nondestructive compared with traditional chemical methods.

Determination of Five Major 8-Prenylflavones in Leaves of Epimedium by Solid-Phase Extraction Coupled with Capillary Electrophoresis

A simple, accurate and reproducible method which is based on the capillary electrophoresis, coupled with solid-phase extraction, has been developed for simultaneous determination of multiple 8-prenylflavones from Chinese Herba Epimedii. In this study, the author has mainly illustrated the experimental process and research results of five major components including epimedin C, icariin, diphylloside A, epimedoside A and icarisoside A that have been extracted and identified from Herba Epimedii for the first time. Experimental conditions have been optimized to achieve the best separation efficiency for the following factors: the buffer pH, buffer concentration and applied voltage. The experiment can be conducted through two separable stages: the first stage is to obtain the crude extracts through the solid-phase extraction; and the second stage is to further separate five major components by using the capillary electrophoresis. The separation of the five components and the analysis of the experiment are relatively fast and can be completed within 20 min. The concentration ranges of the construction of standard curves of five major 8-prenylflavones are 32.0-395.0, 23.4-292.0, 42.1-526.0, 18.8-233.5 and 29.7-371.0 µg mL(-1) respectively, which have showed acceptable linearity with a correlation coefficient, r ≥ 0.999. The coefficient varies within 2.0% for both intra- and inter-days tests. The recoveries of five components range from 92.3 to 104.1%. The relative standard deviations of recoveries of five components range from 1.2 and 2.8%. This new method will facilitate the extraction and expedite the determination of medical components from Herba Epimedii.

Application of near infrared spectroscopy for the rapid determination of epimedin A, B, C and icariin in Epimedium

More efficient and parsimonious models based on CARS-PLSR are obtained compared with the full-spectrum PLSR ones for the determination of epimedin A, B, C and icariin in Epimedium.

Fast quality control of Herba Epimedii by using Fourier transform infrared spectroscopy

Herba Epimedii is a well-known traditional Chinese medicine (TCM) having the effect of nourishing the kidney and strengthening the 'Yang'. Its primary effective constituents are considered to be the 8-prenyl flavonols, which can be assorted into 4'-methoxyl-prenylflavonols (MPFs) and 4'-hydroxyl-prenylflavonols (HPFs), according to the group (methoxyl or hydroxyl) located at 4' in their structures. The Fourier transform infrared spectroscopy (FT-IR) has been widely used in the researches of TCMs. In the present study, the FT-IR was attempted to be applied in the quality control of Herba Epimedii. We compared the IR spectra of 17 pure flavonoids, of which eight were derived from Herba Epimedii, and found a characteristic absorption peak at 1259+/-1 cm(-1), corresponding to the MPFs, the major 8-prenyl flavonols in the aerial parts of the Epimedium species. This peak could also be found in the IR spectra of both the herbal samples and their 70% ethanol extracts. Moreover, the intensity of this peak was in the direct correlation with the total content of MPFs. The correlation values, representing the semblance of two spectra, of the IR spectrum of herbal sample and icariin, in the range of 1280-1200 cm(-1), had been established to be a good index for the quality control of the herbs. Accordingly, a correlation value of not less than 0.50 could be used as the essential screening criteria for the herbs. The FT-IR could be used for the fast and effective quality control of Herba Epimedii.

Simultaneous extraction of epimedin A, B, C and icariin from Herba Epimedii by ultrasonic technique

An ultrasonic-assisted extraction (UAE) procedure of epimedin A, epimedin B, epimedin C and icariin from Herba Epimedii was developed. The effects of ethanol concentration, ratio of liquid to solid, UAE time, extraction temperature and number of extraction cycles on the extraction yields of the four flavonoids from Herba Epimedii were investigated. The optimal UAE condition was found using orthogonal test: 50% (v/v) ethanol solution, liquid:solid ratio of 30 ml/g, ultrasonication duration 30 min, extraction temperature 50 degrees C and three extraction cycles. The UAE method showed a high reproducibility. Epimedin A, B, C and icariin in the crude extract exhibited photodegradation under ultraviolet irradiation. This UAE method was shown to be highly efficient compared with the conventional Soxhlet extraction and boiling extraction. The effect of ultrasound on cell destruction was examined by scanning electron microscopy. The contents of epimedin A, B, C and icariin in the leaves of 20 Epimedium species were determined using high-performance liquid chromatographic method following UAE method.