Free Radical Scavenging, Anti-Infectious, and Toxicity Activities from Stenochlaena palustris (Burm.f.) Bedd. Extracts.

Stenochlaena palustris (Burm.f.) Bedd. (Blechnaceae) or Kelakai is a traditional medicinal plant found in the Indonesian islands of Borneo and Sumatra. It has been used to treat wound healing, infection, and diabetes. This study looked into the free radical scavenging activity, antiplasmodial activity, toxicity, and antibacterial activity against pathogenic bacteria. The species' aerial part was extracted with methanol, followed by a liquid-liquid extraction against (n-hexane, dichloromethane, and ethyl acetate). The extracts' free radical scavenging activities were determined using DPPH and NO radicals. The antiplasmodial and toxicity assays were conducted using two Plasmodium falciparum strains (3D7 and W2) and the brine shrimp lethality test. In addition, antibacterial activity was determined using the well diffusion method. The results revealed that ethyl acetate depicted potential activities toward the assay. The ethyl acetate showed potential free radical scavenging activities with an IC50 value of 51.63 ± 0.46 µg/mL (DPPH) and 60.03 ± 0.65 µg/mL (NO). The antiplasmodial activities showed that the ethyl acetate had potential activities among the extracts with an IC50 value of 11.06 ± 0.45 µg/mL. However, all the extracts demonstrated nontoxic toward Artemia salina with LC50 > 1000 µg/mL. Furthermore, the ethyl acetate demonstrated intermediate susceptibility against B. cereus ATCC 10876, V. parahaemolyticus ATCC 17802, L. monocytogenes ATCC 7644, and S. Typhimurium ATCC 14028 at a concentration of 500 µg/disc. According to these findings, the ethyl acetate extract of S. palustris (Burm.f.) Bedd is a promising source of natural antioxidants and antiplasmodial agents.

Spiroisoxazoline Inhibitors of Acetylcholinesterase from Pseudoceratina verrucosa. Quantitative Chiroptical Analysis of Configurational Heterogeneity, and Total Synthesis of (±)-Methyl Purpuroceratate C.

Examination of the MeOH extract of the sponge, Pseudoceratina cf. verrucosa, Berquist 1995 collected near Ningaloo Reef, Western Australia for selective acetylcholinesterase (AChE) inhibitors, yielded five new bromotyrosine alkaloids, methyl purpuroceratates A and B (1b and 2b), purpuroceratic acid C (3a), and ningalamides A and B (4 and 5). The structures of 1-4 share the dibromo-spirocyclohexadienyl-isoxazoline (SIO) ring system found in purealidin-R, while ketoxime 5 is analogous to ianthelline and purpurealidin I. The planar structures of all five compounds were obtained from analysis of MS, 1D and 2D NMR data, and the absolute configuration of the spiroisoxazoline (SIO) unit was assigned by electronic circular dichroism (ECD) and comparison with standards prepared by total synthesis of methyl purpuroceratate C, (±)-3b. Compound 4 is the most complex SIO described, to date. The configuration of the homoserine module (C) in 4 was ascertained, after acid hydrolysis, by derivatization of an l-tryptophanamide derivative based on Marfey's reagent. Chiral-phase HPLC, with comparison to synthetic standards, revealed that most SIOs isolated from P. cf. verrucosa were configurationally heterogeneous; some, essentially racemic. Chiral-phase HPLC, with UV-ECD detection, is demonstrated as a superlative method for configurational assignment and quantitation of the enantiomeric composition of SIOs. Two SIOs─aerophobin-1 and aplysinamisine II─emerged as selective inhibitors of AChE over butyrylcholinesterase (BuChE, IC50 ratio >10), while aplysamine-2 moderately inhibited both cholinesterases (ChEs, IC50, (AChE) 0.46 µM; IC50, (BuChE) 1.03 µM). SIO alkaloids represent a potential new structural manifold for lead-discovery of new therapeutics for treatment of Alzheimer's disease.

Cytotoxicity and Antiplasmodial Properties of Different Hylocereus polyrhizus Peel Extracts.

BACKGROUND Dragon fruit (Hylocereus polyrhizus) is one of the most common fruits in tropical countries, including Indonesia. The unique deep purple-colored pulp of the fruit is eaten whole and consumed as juice. However, the inedible thick peel is wasted, causing environmental issues. In this study, the toxic, cytotoxic, and antiplasmodium activity from various extract of H. polyrhizus peels were examined. MATERIAL AND METHODS We evaluated the cytotoxicity and antiplasmodial properties of the various peel extracts by using different organic solvents.The extraction of the peels was conducted using maceration to obtain pigment, n-hexane, dichloromethane, and ethyl acetate extracts. The toxicity of the extract was assessed using the brine shrimp lethality test, followed by WST assay to test in vitro cytotoxic properties and in vitro antiplasmodial properties in 2 Plasmodium falciparum strains (3D7 and W2). RESULTS The n-hexane, dichloromethane, and ethyl acetate extracts depicted various levels of activity, whereas the pigment extract did not show any activities. However, dichloromethane demonstrated a high toxicity level with LC50 of 10.32±0.13 µg/mL and a weak cytotoxic level against SK-OV-3 cell lines (IC50 of 560.86±0.63 µg/mL). Moreover, the dichloromethane and n-hexane extracts showed high and promising antiplasmodial activity with IC50 2.13±0.42 and 6.51±0.49 µg/mL, respectively. CONCLUSIONS The dichloromethane extract demonstrated high antiplasmodial activity. Our observations have elucidated the cytotoxic and antiplasmodial activity of the peel of dragon fruits and can be used as a foundation for further research into the isolation and bioactivity of secondary metabolites.

Phytochemical studies on the Australian native plant species Acacia pycnantha and Jacaranda mimosifolia D.Don.

In ongoing investigations into colours in Nature, the chemical constituents from the flowers of Acacia pycnantha and Jacaranda mimosifolia D.Don grown in Australia are reported. Eight known secondary metabolites were isolated from the A. pycnantha flower including isosalipurposide (7) which may be responsible for their distinctive colouration. Nine secondary metabolites were isolated from the J. mimosifolia D.Don flower including the new phenylethanoid ß-D-glucopyranose (10). All isolated compounds were inactive against bacteria tested at concentration of 32 µg/mL.

Phenolic compounds characterization and biological activities of Citrus aurantium bloom.

Citrus plants are known to possess beneficial biological activities for human health. In addition, ethnopharmacological application of plants is a good tool to explore their bioactivities and active compounds. This research was carried out to evaluate the phenolic and flavonoid analysis, antioxidant properties, anti inflammatory and anti cancer activity of Citrus aurantium bloom. The total phenolics and flavonoids results revealed that methanolic extract contained high total phenolics and flavonoids compared to ethanolic and boiling water extracts. The obtained total phenolics value for methanolic Citrus aurantium bloom extract was 4.55 ± 0.05 mg gallic acid equivalent (GAE)/g dry weight (DW), and for total flavonoids it was 3.83 ± 0.05 mg rutin equivalent/g DW. In addition, the RP-HPLC analyses of phenolics and flavonoids indicated the presence of gallic acid, pyrogallol, syringic acid, caffeic acid, rutin, quercetin and naringin as bioactive compounds. The antioxidant activity of Citrus aurantium bloom were examined by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay and the ferric reducing/antioxidant potential (FRAP). The free radical scavenging and ferric reducing power activities were higher for the methanolic extract of Citrus aurantium bloom at a concentration of 300 µg/mL, with values of 55.3% and 51.7%, respectively, as compared to the corresponding boiling water and ethanolic extracts, but the activities were lower than those of antioxidant standards such as BHT and α-tocopherol. Furthermore, the anti-inflammatory result of methanolic extract showed appreciable reduction in nitric oxide production of stimulated RAW 264.7 cells at the presence of plant extract. Apart from that, the anticancer activity of the methanolic extract was investigated in vitro against human cancer cell lines (MCF-7; MDA-MB-231), human colon adenocarcinoma (HT-29) and Chang cell as a normal human hepatocyte. The obtained result demonstrated the moderate to appreciable activities against all cell line tested and the compounds present in the extracts are non-toxic which make them suitable as potential therapeutics.

Antioxidant, anti-inflammatory and cytotoxicity of Phaleria macrocarpa (Boerl.) Scheff Fruit.

BACKGROUND: Phaleria macrocarpa (Scheff.) Boerl (Thymelaceae) originates from Papua Island, Indonesia and grows in tropical areas. The different parts of the fruit of P. macrocarpa were evaluated for antioxidant, anti-inflammatory, and cytotoxic activities. METHODS: Phaleria macrocarpa fruit were divided into pericarp, mesocarp and seed. All parts of the fruit were reflux extracted with methanol. The antioxidant activity of the extracts were characterized in various in vitro model systems such as FTC, TBA, DPPH radical, reducing power and NO radical. Anti-inflammatory assays were done by using NO production by macrophage RAW 264.7 cell lines induced by LPS/IFN-γ and cytotoxic activities were determined by using several cancer cell lines and one normal cell line RESULTS: The results showed that different parts (pericarp, mesocarp, and seed) of Phaleria macrocarpa fruit contain various amount of total phenolic (59.2 ± 0.04, 60.5 ± 0.17, 47.7 ± 1.04 mg gallic acid equivalent/g DW) and flavonoid compounds (161.3 ± 1.58, 131.7 ± 1.66, 35.9 ± 2.47 mg rutin equivalent/g DW). Pericarp and mesocarp showed high antioxidant activities by using DPPH (71.97%, 62.41%), ferric reducing antioxidant power (92.35%, 78.78%) and NO scavenging activity (65.68%, 53.45%). Ferric thiocyanate and thiobarbituric acid tests showed appreciable antioxidant activity in the percentage hydroperoxides inhibitory activity from pericarp and mesocarp in the last day of the assay. Similarly, the pericarp and mesocarp inhibited inducible nitric oxide synthesis with values of 63.4 ± 1.4% and 69.5 ± 1.4% in macrophage RAW 264.7 cell lines induced by LPS/IFN-γ indicating their notable anti-inflammatory potential. Cytotoxic activities against HT-29, MCF-7, HeLa and Chang cell lines were observed in all parts. CONCLUSIONS: These results indicated the possible application of P. macrocarpa fruit as a source of bioactive compounds, potent as an antioxidant, anti inflammatory and cytotoxic agents.

Flavonoid analyses and antimicrobial activity of various parts of Phaleria macrocarpa (Scheff.) Boerl fruit.

Phaleria macrocarpa (Scheff.) Boerl (Thymelaceae) is commonly known as 'Crown of God', 'Mahkota Dewa', and 'Pau'. It originates from Papua Island, Indonesia and it grows in tropical areas. Empirically, it is potent in treating the hypertensive, diabetic, cancer and diuretic patients. It has a long history of ethnopharmacological usage, and the lack of information about its biological activities led us to investigate the possible biological activities by characterisation of flavonoids and antimicrobial activity of various part of P. macrocarpa against pathogenic bacteria and fungi. The results showed that kaempferol, myricetin, naringin, and rutin were the major flavonoids present in the pericarp while naringin and quercetin were found in the mesocarp and seed. Furthermore, the antibacterial activity of different parts of P. macrocarpa fruit showed a weak ability to moderate antibacterial activity against pathogenic tested bacteria (inhibition range: 0.93-2.17 cm) at concentration of 0.3 mg/disc. The anti fungi activity was only found in seed extract against Aspergillus niger (1.87 cm) at concentration of 0.3 mg/well. From the results obtained, P. macrocarpa fruit could be considered as a natural antimicrobial source due to the presence of flavonoid compounds.

Bioactive compounds, antioxidant, xanthine oxidase inhibitory, tyrosinase inhibitory and anti-inflammatory activities of selected agro-industrial by-products.

Evaluation of abundantly available agro-industrial by-products for their bioactive compounds and biological activities is beneficial in particular for the food and pharmaceutical industries. In this study, rapeseed meal, cottonseed meal and soybean meal were investigated for the presence of bioactive compounds and antioxidant, anti-inflammatory, xanthine oxidase and tyrosinase inhibitory activities. Methanolic extracts of rapeseed meal showed significantly (P < 0.01) higher phenolics and flavonoids contents; and significantly (P < 0.01) higher DPPH and nitric oxide free radical scavenging activities when compared to that of cottonseed meal and soybean meal extracts. Ferric thiocyanate and thiobarbituric acid tests results showed rapeseed meal with the highest antioxidant activity (P < 0.01) followed by BHT, cotton seed meal and soybean meal. Rapeseed meal extract in xanthine oxidase and tyrosinase inhibitory assays showed the lowest IC(50) values followed by cottonseed and soybean meals. Anti-inflammatory assay using IFN-γ/LPS stimulated RAW 264.7 cells indicated rapeseed meal is a potent source of anti-inflammatory agent. Correlation analysis showed that phenolics and flavonoids were highly correlated to both antioxidant and anti-inflammatory activities. Rapeseed meal was found to be promising as a natural source of bioactive compounds with high antioxidant, anti-inflammatory, xanthine oxidase and tyrosinase inhibitory activities in contrast to cotton and soybean meals.

Evaluation of Crocus sativus L. stigma phenolic and flavonoid compounds and its antioxidant activity.

Saffron (Crocus sativus L.) belongs to the Iridaceae family. The stigma of saffron has been widely used as spice, medicinal plant, and food additive in the Mediterranean and Subtropical countries. Recently, attention has been paid to the identification of new sources of safe natural antioxidants for the food industry. The antioxidant activities of spices are mainly attributed to their phenolic and flavonoid compounds. Saffron is one of the spices believed to possess antioxidant properties, but information on its antioxidant activity and phenolic, flavonoids compound are rather limited, therefore this research was carried out to evaluate the antioxidant activity of saffron stigmas extracted with different solvents. The phenolic and flavonoid compounds of saffron were also examined using reversed phase (RP)-HPLC. Results showed that saffron stigma possess antioxidant activity. The free radical scavenging and ferric reducing power activities were higher for the methanolic extract of saffron stigma at a concentration of 300 µg/mL, with values of 68.2% and 78.9%, respectively, as compared to the corresponding boiling water and ethanolic extracts, but the activities were lower than those of antioxidant standards such as BHT and α-tocopherol. The obtained total phenolics value for methanolic saffron extract was 6.54 ± 0.02 mg gallic acid equivalent (GAE)/g dry weight (DW), and for total flavonoids, 5.88 ± 0.12 mg rutin equivalent/g DW, which were also higher than values obtained from the ethanolic and boiling water extracts. In addition, the RP-HPLC analyses indicated the presence of gallic acid and pyrogallol as two bioactive compounds. In summary, saffron stigmas showed antioxidant activity and methanol appeared to be the best solvent to extract the active components, among which the presence of gallic acid and pyrogallol might contribute towards the stigma's antioxidant properties. Hence, saffron stigma could be applied as a natural antioxidant source for industrial purposes.