Bee pollen (BP) is full of useful nutrients and phytochemicals.Its chemical components and bioactivities depend mainly on the type of floral pollen.
Monofloral BP from
L.,
,
L.,
,
, and
were ...harvested. Crude extraction and partition were performed to yield solvent-partitioned extracts of each BP. Total phenolic content (TPC) was assayed by the Folin-Ciocalteu method, while the flavonoid content (FC) was measured by the aluminium chloride colorimetric method. Antioxidant capacity was measured by the (i) 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, (ii) 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) scavenging activity and its Trolox equivalent antioxidant capacity (TEAC), and (iii) ferric reducing antioxidant power (FRAP). All samples were tested for lipoxygenase inhibitory (LOXI) activity. The most active sample was enriched by silica gel 60 column chromatography (SiG60-CC) and high performance liquid chromatography (HPLC), observing the chemical pattern of each fraction using thin layer chromatography. Chemical structure of the most active compound was analyzed by proton nuclear magnetic resonance and mass spectrometry.
Dichloromethane (DCM)-partitioned BP extracts of
L. and
(DCMMBP) showed a very high TPC, while DCMMBP had the highest FC. In addition, DCMMBP had the strongest DPPH and ABTS radical scavenging activities (as a TEAC value), as well as FRAP value. Also, DCMMBP (60 µg/mL) gave the highest LOXI activity (78.60 ± 2.81%). Hence, DCMMBP was chosen for further enrichment by SiG60-CC and HPLC. Following this, the most active fraction showed higher antioxidant andLOXI activities with an EC
for DPPH and ABTS of 54.66 ± 3.45 µg/mL and 24.56 ± 2.99 µg/mL (with a TEAC value of 2,529.69 ± 142.16 µmole TE/g), respectively, and a FRAP value of 3,466.17 ± 81.30 µmole Fe
/g and an IC
for LOXI activity of 12.11 ± 0.36 µg/mL. Triferuloyl spermidines were revealed to be the likely main active components.
TPC, FC, and spermidine derivatives played an important role in the antioxidant and antilipoxygenase activities in
bee pollen.
Bee pollen (BP) is full of nutrients and phytochemicals, and so it is widely used as a health food and alternative medicine. Its composition and bioactivity mainly depend on the floral pollens. In ...this work, BP collected by
with different monoculture flowering crops (BP1-6) were used. The types of floral pollen in each BP were initially identified by morphology, and subsequently confirmed using molecular phylogenetic analysis. Data from both approaches were consistent and revealed each BP to be monofloral and derived from the flowers of
L.,
L.,
,
,
, and
for BP1 to BP6, respectively. The crude extracts of all six BPs were prepared by sequential partition with methanol, dichloromethane (DCM), and hexane. The crude extracts were then tested for the
(i)
-amylase inhibitory, (ii) acetylcholinesterase inhibitory (AChEI), and (iii) porcine pancreatic lipase inhibitory (PPLI) activities in terms of the percentage enzyme inhibition and half maximum inhibitory concentration (IC
). The DCM partitioned extract of
.
BP (DCMXBP) had the highest active
-amylase inhibitory activity with an IC
value of 1,792.48 ± 50.56 µg/mL. The DCM partitioned extracts of
.
L. BP (DCMCBP) and
BP (DCMMBP) had the highest PPLI activities with an IC
value of 458.5 ± 13.4 and 500.8 ± 24.8 µg/mL, respectively), while no crude extract showed any marked AChEI activity. Here, the
PPLI activity was focused on. Unlike
.
L. BP, there has been no previous report of
BP having PPLI activity. Hence, DCMMBP was further fractionated by silica gel 60 column chromatography, pooling fractions with the same thin layer chromatography profile. The pooled fraction of DCMMBP2-1 was found to be the most active (IC
of 52.6 ± 3.5 µg/mL), while nuclear magnetic resonance analysis revealed the presence of unsaturated free fatty acids. Gas chromatography with flame-ionization detection analysis revealed the major fatty acids included one saturated acid (palmitic acid) and two polyunsaturated acids (linoleic and linolenic acids). In contrast, the pooled fraction of DCMMBP2-2 was inactive but pure, and was identified as naringenin, which has previously been reported to be present in
.
L. Thus, it can be concluded that naringenin was compound marker for
BP. The fatty acids in BP are nutritional and pose potent PPLI activity.
The essential function of melanin is to protect our skin against harmful environmental factors. However, excessive melanin production can cause undesirable hyperpigmentation issues, such as freckles ...and melasma. Although several compounds are used to control melanin production by inhibiting tyrosinase (TYR), their efficacy is limited by skin-related adverse effects and cytotoxicity concerns. Consequently, searching for new natural compounds with an effective TYR inhibitor (TYR-I) activity but less harmful effects continues. Plant-based natural extracts are an alternative that are in great demand due to their safety and diverse biological properties. This study assessed ten isolated plant compounds for their TYR-I activities using an in vitro mushroom TYR inhibition assay. Among these compounds, piperine (400 μM) demonstrated the highest TYR-I activity, with a potency of 36.27 ± 1.96 %. Hence, this study examined the effect of piperine on melanogenesis in melanocyte stimulating hormone-treated B16F10 melanoma cells and using kojic acid as a positive reference. Cell viability was evaluated through the standard 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Measurements of cellular TYR activity and melanin content were performed and related to changes in the transcriptional expression levels of melanogenesis-related genes, assessed via quantitative real-time reverse transcriptase (RT-q)PCR analysis. The results revealed that piperine at a concentration of 44 μM significantly reduced cellular TYR activity by 21.51 ± 2.00 % without causing cytotoxicity. Additionally, at the same concentration, piperine significantly decreased the intracellular melanin content by 37.52 ± 2.53 % through downregulating transcription levels of TYR and TYR-related protein 1 (TRP-1) but not TRP-2. Kojic acid, at a concentration of 1407 μM, induced a significant decrease in the melanin content and cellular TYR activity by suppressing all three melanogenesis-related genes. These findings suggest that piperine has potential as a potent depigmenting agent.
Bee pollen, one of the economic bee products, is widely known as a nutritional food with many bioactivities that depend on many such factors as bee species, plant source and biogeography. For this ...study, bee pollen was collected from
, harvested from the flowers of mimosa (
L.) in the Chiang Mai province, Thailand. The sample was extracted in methanol (MeOH) and then sequentially partitioned with hexane, dichloromethane (DCM) and MeOH in order to isolate compounds depending on their polarities. The obtained extracts were then tested for their antioxidant and anti-tyrosinase activities through 1,1-diphyenyl-2-picrylhydrazyl (DPPH) assay and for/through inhibition of mushroom tyrosinase extract, respectively. The DCM partitioned extract of mimosa flower bee pollen (DCMMBP) provided the highest antioxidant activity, with an effective concentration at 50% (EC
) of 192.1 μg/mL, and was further fractionated by silica gel 60 column chromatography and Sephadex LH20 size exclusion chromatography. All fractions were tested for their antioxidant activity and analyzed for the chemical structure through nuclear magnetic resonance (NMR). The most active fraction (EC
of 121.3 μg/mL) was a mixture of compounds, but the isolated flavonoid, naringenin, had a negligible antioxidant activity. In contrast, all three partitioned extracts and pooled fractions after silica gel 60 column chromatography provided no anti-tyrosinase activity (IC
of > 500 μg/mL) and a very low percentage of tyrosinase inhibition (0–2.99 ± 3.18%), compared to kojic acid (IC
of 8.58 μg/mL and tyrosinase inhibition of 74.2 ± 1.25%).
Gastric cancer is a global health concern, but current treatment with chemotherapy and surgery is often inadequate, prompting the exploration of alternative treatments. Propolis is a natural ...substance collected by bees known for its diverse properties linked to floral sources. The Dichloromethane Partitioned Extract (DPE) from Tetragonula laeviceps propolis, in Bankha district, Thailand was previously shown to possess significant cytotoxicity against KATO-III gastric cancer cells, while showing lower cytotoxicity toward WI-38 normal fibroblast cells. Here, the DPE was further fractionated by column chromatography, identified active fractions, and subjected to structural analysis using nuclear magnetic resonance spectroscopy. Cytotoxicity against KATO-III cells was reevaluated, and programmed cell death was analyzed using flow cytometry. Expression levels of cancer-related genes were measured using quantitative real-time reverse transcriptase PCR. Cardol C15:2 (compound 1) and mangiferolic acid (MF; compound 2) were discovered in the most active fractions following structural analysis. MF exhibited strong cytotoxicity against KATO-III cells (IC50 of 4.78–16.02 μg/mL), although this was less effective than doxorubicin (IC50 of 0.56–1.55 μg/mL). Morphological changes, including decreased cell density and increased debris, were observed in KATO-III cells treated with 30 μg/mL of MF. Significant induction of late-stage apoptosis and necrosis, particularly at 48 and 72 h, suggested potential DNA damage and cell cycle arrest, evidenced by an increased proportion of sub-G1 and S-phase cells. Doxorubicin, the positive control, triggered late apoptosis but caused more necrosis after 72 h. Furthermore, MF at 30 μg/mL significantly increased the expression level of COX2 and NFκB genes linked to inflammation and cell death pathways. This upregulation was consistent at later time points (48 and 72 h) and was accompanied by increased expression of CASP3 and CASP7 genes. These findings suggest MF effectively induces cell death in KATO-III cells through late apoptosis and necrosis, potentially mediated by upregulated inflammation-related genes.
Propolis is a natural product produced by bees and has antioxidant properties that depend on the local flora and the bee species. Propolis from two dominant stingless bee species in Thailand, ...Tetragonula laeviceps and Tetragonula pegdeni were collected from four locations in Ratchaburi province and one location in Chiangmai province, with different dominant plants at each location. Samples were extracted in methanol (MeOH) and sequentially partitioned with hexane, dichloromethane (DCM), and MeOH. All partitioned extracts were examined by three antioxidant methods: 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and ferric reducing ability (FRAP) assays. For the DPPH, the MeOH-partitioned extract of T. laeviceps from Bankha district (MPE7) was the most active 50% effective concentration (EC
50
) of 75.62 µg/mL), while the DCM-partitioned extract of T. pegdeni from Suan phueng district (DPE2) was the most active in the ABTS and FRAP assays (EC
50
of 22.06 µg/mL and 10.23 mM/g, respectively). DPE2 also showed the highest phenolic and flavonoid contents (98.94 µg gallic acid equivalents/mg dry weight and 286.07 µg quercetin equivalents/mg, respectively). High performance liquid chromatography analysis revealed the identification and quantification of 12 phenolic compounds, with the highest concentration of vitexin in MPE7 and MPE5. Interestingly, kaempferol (5.16 µg/mg) was only detected in DPE2. The different antioxidant properties among sites are expected due to the specific flora in each location. Furthermore, the bioactivity of propolis extracts differs significantly between bee species in a similar location, suggesting that they have different flora preferences. These results verify the potential of extracts to effectively scavenge radicals.
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