Stink bean (Parkia speciosa) empty pod: a potent natural antidiabetic agent for the prevention of pancreatic and hepatorenal dysfunction in high fat diet/streptozotocin-induced type 2 diabetes in rats.

The present study investigated the effect of polyphenol-rich extract of Parkia speciosa (PPS) against pancreatic and hepatorenal dysfunction in high-fat diet (HFD)/streptozotocin (STZ)-induced diabetes. Diabetic rats were treated with PPS (100 and 400 mg/kg) and glibenclamide. The results revealed that diabetic rats displayed marked hyperglycaemia, hyperlipidaemia, hypoinsulinemia as well as alterations in serum renal and kidney function markers. Furthermore, diabetic rats showed significant increase in hepatorenal level of malonaldehyde as well as suppression of antioxidant enzyme activities. Whereas, diabetic rats that received PPS displayed marked attenuation in most of the aforementioned parameters compared to the untreated diabetic rats. Additionally, histological examination revealed restoration of histopathological alterations of the pancreas, liver, and kidney of PPS treated diabetic rats. In conclusion, the results demonstrated that PPS could decrease serum lipids and blood glucose level, enhance insulin level and hepatorenal antioxidant capacity, as well as ameliorate hepatorenal dysfunction in rats.

Parkia speciosa Hassk. Empty Pod Extract Prevents Cardiomyocyte Hypertrophy by Inhibiting MAPK and Calcineurin-NFATC3 Signaling Pathways.

Cardiac hypertrophy is an early hallmark during the clinical course of heart failure. Therapeutic strategies aiming to alleviate cardiac hypertrophy via the mitogen-activated protein kinase (MAPK)/calcineurin-nuclear factor of activated T-cells (NFAT) signaling pathway may help prevent cardiac dysfunction. Previously, empty pod ethanol crude extract of Parkia speciosa Hassk was shown to demonstrate protective effects against cardiomyocyte hypertrophy. Therefore, the current study aimed to investigate the effects of various fractions of the plant ethanol extract on the MAPK/NFAT signaling pathway in angiotensin II (Ang II)-induced cardiomyocyte hypertrophy. Simultaneous treatment with ethyl acetate (EA) fraction produced the most potent antihypertrophic effect evidenced by the reduced release of B-type natriuretic peptide (BNP). Subsequently, treatment with the EA fraction (6.25, 12.5, and 25 µg/mL) prevented an Ang II-induced increase in cell surface area, hypertrophic factors (atrial natriuretic peptide and BNP), reactive oxygen species, protein content, and NADPH oxidase 4 expression in the cells. Furthermore, EA treatment attenuated the activation of the MAPK pathway and calcineurin-related pathway (GATA-binding protein 4 and NFATC3), which was similar to the effects of valsartan (positive control). Our findings indicate that the EA fraction prevents Ang II-induced cardiac hypertrophy by regulating the MAPK/calcineurin-NFAT signaling pathway.

Parkia speciosa Hassk. Empty Pod Extract Alleviates Angiotensin II-Induced Cardiomyocyte Hypertrophy in H9c2 Cells by Modulating the Ang II/ROS/NO Axis and MAPK Pathway.

Cardiac hypertrophy is characteristic of heart failure in patients who have experienced cardiac remodeling. Many medicinal plants, including Parkia speciosa Hassk., have documented cardioprotective effects against such pathologies. This study investigated the activity of P. speciosa empty pod extract against cardiomyocyte hypertrophy in H9c2 cardiomyocytes exposed to angiotensin II (Ang II). In particular, its role in modulating the Ang II/reactive oxygen species/nitric oxide (Ang II/ROS/NO) axis and mitogen-activated protein kinase (MAPK) pathway was examined. Treatment with the extract (12.5, 25, and 50 µg/ml) prevented Ang II-induced increases in cell size, NADPH oxidase activity, B-type natriuretic peptide levels, and reactive oxygen species and reductions in superoxide dismutase activity. These were comparable to the effects of the valsartan positive control. However, the extract did not significantly ameliorate the effects of Ang II on inducible nitric oxide synthase activity and nitric oxide levels, while valsartan did confer such protection. Although the extract decreased the levels of phosphorylated extracellular signal-related kinase, p38, and c-Jun N-terminal kinase, valsartan only decreased phosphorylated c-Jun N-terminal kinase expression. Phytochemical screening identified the flavonoids rutin (1) and quercetin (2) in the extract. These findings suggest that P. speciosa empty pod extract protects against Ang II-induced cardiomyocyte hypertrophy, possibly by modulating the Ang II/ROS/NO axis and MAPK signaling pathway via a mechanism distinct from valsartan.

Assessment and comparison of phytochemical constituents and biological activities of bitter bean (Parkia speciosa Hassk.) collected from different locations in Malaysia.

BACKGROUND: Parkia speciosa seeds are a common ingredient in Malay cuisine with traditional interest because of its medicinal importance and content of health-promoting phytochemicals. This study evaluated the phytochemical constituents and biological activities (antioxidant and antibacterial activities) of Parkia speciosa Hassk seeds collected from three different regions of Malaysia (Perak, Negeri Sembilan and Johor). Phytochemical constituents (total flavonoid and total phenolic) were measured using the spectrophotometric method, and individual flavonoids and phenolic acids were identified using ultra-high-performance liquid chromatography. Ferric reducing antioxidant potential (FRAP) assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay we used in order to evaluation of antioxidant activities. Disc diffusion method was employed for the evaluation of antibacterial activity of extracts against Gram-positive and Gram-negative bacterial strains. RESULTS: The primary screening of phytochemicals showed that P. speciosa seeds contain alkaloids, terpenoids, flavonoids, and phenolics. Samples collected from Perak contained the highest levels of the phytochemical constituents, with highest DPPH and FRAP activity followed by Negeri sembilan and Johor. From the identified compounds, quercetin and gallic acid were identified as the most abundant compounds. Seeds collected from the Perak location exhibited potent antibacterial activity, against both Gram-positive and Gram-negative bacteria strains. Staphylococcus aureus and Bacillus subtilis were recorded as the bacterial strains most sensitive to P. speciosa seed extracts. Correlation analysis showed that flavonoid compounds are responsible for the antioxidant activities of the P. speciosa seeds studied, while antibacterial activity showed a high correlation with the levels of gallic acid. CONCLUSIONS: Parkia speciosa seed grown in Perak exhibit the highest concentrations of phytochemicals, as well as the highest biological activity. It may also be recommended for the food industry to use seeds from this area for their products, which are going to compete in the expanding functional food markets.

Green synthesis of silver nanoparticles using extract of Parkia speciosa Hassk pods assisted by microwave irradiation.

This paper reports an investigation of the microwave-assisted synthesis of silver nanoparticles (Ag NPs) using extract of stinky bean (Parkia speciosa Hassk) pods (BP). The formation of Ag NPs was identified by instrumental analysis consists of UV-vis spectrophotometry, Fourier-transform infrared (FTIR) spectrophotometry, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and particle size analysis. Furthermore, Ag NPs were used as antibacterial agents against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The results indicate rapid formation of Ag NPs during microwave irradiation with similar properties to those obtained through the aging method. In general, the use of microwave irradiation yields larger particles, and it is affected by volume ratio of the extract to the AgNO3 solution. The prepared materials demonstrated antibacterial activity.

Organosulfide profile and hydrogen sulfide-releasing capacity of stinky bean (Parkia speciosa) oil: Effects of pH and extraction methods.

Stinky beans (Parkia speciosa) were hydrodistilled and solvent-extracted and the oil obtained was analyzed by GC-MS/FID. Nine cyclic and one acyclic organosulfides were identified comprising 36% of total volatiles. Solvent extracts contained significantly (p < 0.05) higher total organosulfides (680 ppm) as compared to distilled oil (444 ppm). The concentrations of organosulfides are highly dependent on the pH values of the matrix, with control sample (pH 5.40) giving the highest total organosulfides (424 ppm) followed by that of pH 7.0 (234 ppm), pH 9.0 (195 ppm), and pH 3.0 (152 ppm). The H2S-releasing capacity, expressed as diallyl trisulfide equivalents (DATS-E in mmol DATS/g), corresponded well with the differences in organosulfide concentrations as affected by pH with control having the highest value (24.35) followed pH 7.0 (7.27), pH 9.0 (3.27), and pH 3.0 (1.80). We conclude that stinky bean oil is a potent H2S-releasing agent that could have health-beneficial properties.

Differential pollen placement on an Old World nectar bat increases pollination efficiency.

BACKGROUND AND AIMS: Plant species that share pollinators are potentially subject to non-adaptive interspecific pollen transfer, resulting in reduced reproductive success. Mechanisms that increase pollination efficiency between conspecific individuals are therefore highly beneficial. Many nocturnally flowering plant species in Thailand are pollinated by the nectar bat Eonycteris spelaea (Pteropodidae). This study tested the hypothesis that plant species within a community reduce interspecific pollen movement by placing pollen on different areas of the bat's body. METHODS: Using flight cage trials, pollen transfer by E. spelaea was compared between conspecific versus heterospecific flowers across four bat-pollinated plant genera. Pollen from four locations on the bat's body was also quantified to determine if pollen placement varies by plant species. KEY RESULTS: It was found that E. spelaea transfers significantly more pollen between conspecific than heterospecific flowers, and that diverse floral designs produce significantly different patterns of pollen deposition on E. spelaea. CONCLUSIONS: In the Old World tropics, differential pollen placement is a mechanism that reduces competition among bat-pollinated plant species sharing a common pollinator.

Extraction of antioxidative and antihypertensive bioactive peptides from Parkia speciosa seeds.

Antioxidative and antihypertensive bioactive peptides were successfully derived from Parkia speciosa seed using alcalase. The effects of temperature (25 and 50 °C), substrate-to-enzyme ratio (S/E ratio, 20 and 50), and incubation time (0.5, 1, 2 and 5h) were evaluated based on 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and angiotensin-converting enzyme (ACE) assays. Bioactive peptide extracted at a hydrolysis condition of: temperature=50 °C, S/E ratio=50 and incubation time=2h, exhibited the highest DPPH radical scavenging activity (2.9 mg GAE/g), reducing power (11.7 mM) and %ACE-inhibitory activity (80.2%). The sample was subsequently subjected to fractionation and the peptide fraction of <10 kDa showed the strongest bioactivities. A total of 29 peptide sequences from peptide fraction of <10 kDa were identified as the most potent contributors to the bioactivities. These novel bioactive peptides were suggested to be beneficial to nutraceutical and food industries.