Antioxidant, antihyperuricemic and xanthine oxidase inhibitory activities of Hyoscyamus reticulatus

Antibacterial effect of Asphodelus fistulosus aqueous and ethanolic crude extracts on gram positive and gram negative bacteria

Abstract Asphodelus fistulosus (A. fistulosus) is a wild plant grows in Jordan. Traditionally, it is used to treat different medical conditions and diseases such as respiratory ailments, against burns and dermatomucosal infections.This study aims to find out the effects of A. fistulosus aqueous and ethanolic crude extracts on Staphylococcus aureus(S. aureus) as gram positive bacteria and Escherichia coli (E. coli) as gram negative bacteria and to investigate which one will be affected either by aqueous and/or ethanolic crude extracts of A. fistulosus shooting parts that were collected from Jerash in the north of Jordan. Agar well diffusion method was used to evaluate the antibacterial activity of the crude extracts. In addition, MIC (minimum inhibitory concentration) as well as MBC (minimum bactericidal concentration) were determined against both types of bacteria. The results showed that flower aqueous extract of A. fistulosus was very effective against E. coli (20.0 ± 0.50) mm and caused a (14.0 ± 0.50) mm inhibition to S. aureus. The ethanolic extract of stem was very effective cauesed a (19.0 ± 0.50) mm inhibition in both bacterial species. Respectively, both S. aureus and E. coli were inhibited by ethanolic and aqueous extracts (mixture1 and mixture2) (15.0 ± 0.00 mm and 10.5 ± 0.50 mm). The highest antimbacterial activity was observed for the leaves aqueous extract against E.coli (0.06120 mg/mL). The obtained MIC values from A. fistulosus parts extracts demonstrated antibacterial activity ranged between 7.606 and 0.06120 mg/mL. The highest antimicrobial activity was recorded in the leaves aqueous extract against E. coli.The MBC value of stem aqueous extract was 5.00 mg/mL against both S. aureus and E. coli. On the other hand, ethanolic and aqueous extracts of the leaves gave MBC values 5.00 mg/mL, and 0.156 mg/mL, respectively, against E. coli.Based on the results of this study, it can be concluded that there is good inhibitory effect of aqueous and ethanolic of A. fistulosus shooting parts extracts on growth of E. coli and S. aureus. Adding to that, stem ethanolic extract has the most effective against S. aureus while aqueous extract of flower has the most effective against E. coli.So, it is recommended to have further future studies on the A. fistulosus shooting parts crude extract bioactive components and the mechanism of how these constituents affect these types of bacteria.

Simple assay for quantifying xanthine oxidase activity

This paper reports a sensitive method for assaying xanthine oxidase (XO) enzyme activity. XO produces hydrogen peroxide (H₂O₂) and superoxide anion radicals (O₂^•-), promoting the development of oxidative stress-related diseases, and is inhibited by various plant extracts. XO activity is quantified by incubating enzyme samples with an appropriate xanthine concentration as the substrate. The proposed method requires XO activity to be quantified based on H₂O₂ generation using a 3,3',5,5'-tetramethylbenzidine (TMB)-H₂O₂ system catalyzed by cupric ions. After a 30-minute incubation at 37 °C, sufficient cupric ion and TMB amounts are added. The assay produces optical signals that can be visually recognized or detected with a UV-visible spectrometer. A direct correlation was found between XO activity and the absorbance at 450 nm of the resulting di-imine (dication) yellow product. The proposed method uses sodium azide to prevent catalase enzyme interference. The new assay's function was confirmed using the TMB-XO assay and a Bland-Altman plot. The resulting correlation coefficient was 0.9976. The innovative assay was relatively precise and comparable to the comparison protocols. In conclusion, the presented method is very efficient at measuring XO activity.

Isolation and Identification of Constituents Exhibiting Antioxidant, Antibacterial, and Antihyperuricemia Activities in Piper methysticum Root

The aqueous extract of kava (Piper methysticum) root is known as a traditional beverage for daily intake in the Western Pacific Islands, such as Fiji, Tonga, and Vanuatu, to induce relaxation and health-beneficial effects. In this study, the antioxidant, anti-hyperuricemia, and antibacterial properties of kava root were investigated through the isolation and purification of bioactive compounds in ten fractions separated by column chromatography (CC). They included six flavonoids, 5-hydroxy-4',7-dimethoxyflavanone (C1), matteucinol (C2), isosakuranetin (C3), 5,7- dimethoxyflavanone (C4), 2',4'-dihydroxy-6'-methoxydihydrochalcone (in MC5) and alpinetin (C10), and seven kavalactones, 5,6-dehydrokawain (DK) (in MC5 and C6), kavain (in MC7), yangonin (in MC7 and C8), dihydro-5,6-dehydrokavain (DDK) (in MC9), 7,8-dihydromethysticin (in MC9), dihydromethysticin (in MC9), methysticin (in MC9). The chemical structures of the compounds were illustrated by the analyses of gas chromatography-mass spectrometry (GC-MS), electrospray ionization-mass spectrometry (ESI-MS), nuclear magnetic resonance (¹H and ¹³C-NMR), and X-ray diffraction. The evaluation of the free radical scavenging activity of the isolated substances via the DPPH and ABTS assays revealed that C3 (IC₅₀: ABTS = 76.5; DPPH = 74.8 µg/mL) possessed the strongest antioxidant property. In terms of anti-hyperuricemia activity evaluated via the xanthine oxidase inhibitory in vitro assay, the compound C10 was the most promising inhibitor, revealing an IC₅₀ of 134.52 µg/mL. The two kavalactone mixtures in MC5 and a pure compound C6 inhibited the growth of bacteria Listeria monocytogenes, while MC7 can constrain the development of Klebsiella pneumoniae. This is the first study to isolate, purify, and identify the flavonoids isosakuranetin, 2',4'-dihydroxy-6'-methoxydihydrochalcone and alpinetin in kava root and report their pharmaceutical potential. The identified bioactive compounds showed potent antioxidant, anti-hyperuricemia, and antibacterial activity and thus can enhance the value of beverages and foods derived from kava root.

Phytochemical Variability, In Vitro and In Vivo Biological Investigations, and In Silico Antibacterial Mechanisms of Mentha piperita Essential Oils Collected from Two Different Regions in Morocco

The objective of this work is to explore the phytochemical profile of Mentha piperita essential oils (MPEO) collected from two different Moroccan regions using gas chromatography-mass spectrophotometer (GC-MS) and to investigate their antioxidant, anti-inflammatory, antidiabetic and, antimicrobial effects using in vivo and in vitro assays. The chemical constituent of MPEO from the Azrou zone is dominated by carvone (70.25%), while MPEO from the Ouazzane zone is rich in Menthol (43.32%) and Menthone (29.4%). MPEO from Ouezzane showed higher antioxidant activity than EO from Azrou. Nevertheless, EO from Ouezzane considerably inhibited 5-Lipoxygenase (IC50 = 11.64 ± 0.02 µg/mL) compared to EO from Azro (IC50 = 23.84 ± 0.03 µg/mL). Both EOs from Azrou and Ouazzane inhibited the α-amylase activity in vitro, with IC50 values of 131.62 ± 0.01 µg/mL and 91.64 ± 0.03 µg/mL, respectively. The EOs were also tested for minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The discdiffusion test revealed that MPEOs from both regions have significant antibacterial efficacy, and MPEOs from the north region showed the highest effect. The gram-positive bacteria were the most susceptible organisms. The MIC concentrations were in the range of 0.05 to 6.25 mg/mL, and the MBC concentrations were within 0.05-25.0 mg/mL. The MBC/MIC index indicated that MPEO has strong bactericidal effects.

Optimization of the Extraction Conditions and Biological Evaluation of Dendropanax morbifera H. Lev as an Anti-Hyperuricemic Source

Dendropanax morbifera H. Levis a medicinal plant native to South Korea, East Asia, and South America. Among some 75 species, one species grows in Korea. In previous studies, D. morbifera extracts with anti-oxidant, anti-inflammatory, anti-complementary and anti-cancer activities were reported. The present study aims to investigate optimization of extraction and evaluation of anti-hyperuricemic effects of D. morbifera leaf and the phytochemicals contained therein. Ethanol and hexane extract were found to display the best xanthine oxidase inhibition among six types of solvent and water extract. The antioxidant effect of the ethanol extract was superior to that of the hexane extract. The DPPH radical scavenging effect of the ethanol and hexane extracts were 81.52 ± 1.57% and 2.69 ± 0.16. The reducing power of the ethanol and hexane extracts were 9.71 ± 0.15 and 0.89 ± 0.01 mg/g equivalent of gallic acid. Total phenols of the ethanol and hexane extracts were 6.53 ± 0.16 and 0.63 ± 0.001 mg/g equivalent of gallic acid. In addition, we compared the two marker compounds from D. morbifera, chlorogenic acid and rutin, which were determined in the ethanol extract at 0.80 ± 0.03% and 0.52 ± 0.01%, respectively. We found that the ethanol extracts showed better xanthine oxidase inhibition than hexane extracts. Especially, ethanol extracts showed higher antioxidant activity than hexane extracts. Based on these results, we selected the ethanol extract as an effective xanthine oxidase inhibitor and confirmed whether ethanol extracts showed xanthine oxidase inhibition in animal experiments. The in vivo mouse study demonstrated that ethanol extract of D. morbifera leaf at the dose of 300 mg/kg could inhibit blood/hepatic xanthine oxidase activity and this result shows that the xanthine oxidase inhibitory activity in vitro is reproduced in vivo. The present study showed that ethanol extract was optimal xanthine oxidase inhibitor which can be applied to prevent diseases related to hyperuricemia.

Antihyperuricemic and xanthine oxidase inhibitory activities of Tribulus arabicus and its isolated compound, ursolic acid: In vitro and in vivo investigation and docking simulations

BACKGROUND

Hyperurecemia is usually associated with gout and various metabolic arthritis disorders. Limited medications are available to manage such conditions. This study aimed to isolate the triterpenes constituent of the plant and to assess xanthine oxidase (XO) inhibitory and antihyperuricemic activities of Tribulus arabicus ethanolic extract, its fractions and the isolated compound using in vitro and in vivo approaches.

METHODS

The ethanolic extract, fractions; n-hexane, chloroform and n-butanol and the isolated compound (ursolic acid) were evaluated in vitro for their XO inhibitory activity. Those that demonstrated significant activity were further evaluated for their antihyperuricemic activity on potassium oxonate-induced hyperuricemia in mice.

RESULTS

The ethanolic extract was found to be safe up to 5000 mg/kg. The extract and its n-hexane fraction exhibited significant inhibitory activity on XO, whilst only a modest reduction in the enzymatic activity was noticed with n-butanol and chloroform fractions. Furthermore, administration of the ethanolic extract at low and high doses significantly reduced serum urate levels in mice by 31.1 and 64.6% respectively. The isolated active constituent, ursolic acid, showed potent XO inhibition activity (Half maximal inhibitory concentration, IC50 = 10.3 μg/mL), and significantly reduced uric acid level in vivo by 79.9%. Virtually, the binding mode of ursolic acid with XO was determined using molecular docking simulations.

CONCLUSIONS

The activity of the ethanolic extract of T. arabicus and its n-hexane fraction can be attributed to the isolated compound, ursolic acid. Ursolic acid has good hypouricemic activity and therefore has high potential to be used for the treatment of gout and hyperuricemia-related diseases.

l-Arginine and allopurinol supplementation attenuates inflammatory mediators in human osteoblasts-osteoarthritis cells

This study investigated the synergistic effects of l-arginine and allopurinol on antioxidant and inflammatory mediators in human osteoblasts-osteoarthritis (HOb-OA) cells. The cells were treated with allopurinol (50-150 mg/kg bwt) and l-arginine (50-150 mg/kg bwt) for 72 h. Cell viability, catalase, superoxide dismutase (SOD), glutathione peroxidase (Gpx), reduced glutathione (GSH), lipid peroxidation, and the inflammatory markers interleukin 6 (IL-6), interleukin 1β (IL-1β), nuclear factor κB (NF-κB) and tumor necrosis factor alpha (TNF-α) were measured. The combined supplementation with allopurinol and l-arginine increased catalase, SOD, GSH, and Gpx, while it decreased lipid peroxidation, IL-6, IL-1β, and TNF-α. While TNF-α, IL-6, IL-1β, and NF-κB mRNA and protein expression were higher in control HOb-OA cells, the combined supplementation with allopurinol and l-arginine substantially reduced their expression in HOb-OA cells by >40%. In summary, combined supplementation with allopurinol and l-arginine might be very effective in osteoarthritis. A search for therapeutic agents that inhibit inflammation could help to prevent and manage osteoarthritis. However, further studies need to determine the biochemical and molecular mechanisms of these agents in osteoarthritis.

Optimization of Ultrasonic-Assisted Extraction for Pinocembrin from Flos populi Using Response Surface Methodology

In this study, the ultrasound-assisted extraction (UAE) was used for extraction of pinocembrin from Flos populi. Based on the results of the single-factor experiment, four independent parameters, including ethanol concentration (40–80 %), extraction temperature (50–70 °C), extraction time (25–45 min) and electrical acoustic intensity (40.8–81.5 W/m2) were further investigated using response surface methodology (RSM) coupled with Box-Behnken design. The experimental data were fitted to the quadratic response surface model using multiple regression analysis with high adjusted determination coefficient value (R 2) of 0.9697. The highest yield (134.2 ± 1.53 mg/g) of pinocembrin was obtained under the optimal conditions (ethanol concentration of 68 %, extraction temperature of 69 °C, extraction time of 42 min and electrical acoustic intensity of 66.81 W/cm2), which agreed to the predicted value of 132.9 mg/g. Moreover, the comparison between the UAE and reflux extraction also showed the suitability of UAE for pinocembrin from Flos populi.

Hypouricemic effect of the methanol extract from Prunus mume fruit in mice

CONTEXT

The fruit of the Prunus mume Sieb. et Zucc (Rosaceae) is used as a health food or medicinal material in traditional herb medicine for a long time in Eastern Asian countries.

OBJECTIVE

Our present study investigated the hypouricemic effect of the methanol extract from P. mume fruit (MPMF) in mice with potassium oxonate-induced hyperuremia.

MATERIALS AND METHODS

Effect of MPMF (35, 70 and 140 mg/kg, p.o.) administrated for 7 days on the serum, liver, urinary uric acid levels and liver xanthine oxidase (XO) activity were assessed in mice.

RESULTS

Hyperuricemic mice induced by potassium oxonate demonstrated an elevation in serum and liver uric acid levels (11.0 mg/dL and 0.52 mg/g tissue) and a reduction in urinary uric acid levels (49.9 mg/dL). Oral administration of 140 mg/kg MPMF for 7 days reversed the abnormalities in serum, liver and urinary uric acid levels (7.1 mg/dL, 0.37 mg/g tissue and 69.7 mg/dL, respectively). In addition, 70 and 140 mg/kg MPMF (3.1 and 2.9 nmol/min per mg protein) inhibited liver XO activity compared with hyperuricemic mice (3.9 nmol/min per mg protein).

DISCUSSION AND CONCLUSION

The results indicated that the beneficial hypouricaemic effect of MPMF may be mediated, at least in part, by inhibiting XO activity in the liver. Our study suggests that P. mume and its extracts may have a considerable potential for development as an anti-gout agent for clinical application.

Xanthine oxidase inhibitory activity of the methanolic extracts of selected Jordanian medicinal plants

Background:

The search for novel xanthine oxidase (XO) inhibitors with a higher therapeutic activity and fewer side effects are desired not only to treat gout but also to combat various other diseases associated with the XO activity. At present, the potential of developing successful natural products for the management of XO-related diseases is still largely unexplored. In the present study, we have screened the methanolic extracts of various Jordanian medicinal plants for their XO inhibitory activities using an optimized protocol.

Materials and Methods:

The methanolic extracts of 23 medicinal plants, belonging to 12 families, were tested in vitro, at 200 μg/ml concentrations, for their XO inhibitory potential. The dose-dependent inhibition profiles of the most active plants were further evaluated by estimating the IC₅₀ values of their corresponding extracts.

Results:

Six plants were found most active (% inhibition more than 39%). These plants are Salvia spinosa L. (IC₅₀ = 53.7 μg/ml), Anthemis palestina Boiss. (168.0 μg/ml), Chrysanthemum coronarium L. (199.5 μg/ml), Achillea biebersteinii Afansiev (360.0 μg/ml), Rosmarinus officinalis L. (650.0 μg/ml), and Ginkgo biloba L. (595.8 μg/ml). Moreover, four more plants, namely Lavandula angustifolia Mill. (28.7% inhibition), Helianthemum ledifolium (L.) Mill. (28.4%), Majorana syriaca (L.) Kostel. (25.1%), and Mentha spicata L. (22.5%) showed a XO inhibitory activity in the range of 22–30%.

Conclusion:

The study showed that many of the tested plant species are potential sources of natural XO inhibitors that can be developed, upon further investigation, into successful herbal drugs for treatment of gout and other XO-related disorders.