Bee products have long been used in traditional medicine.The raw materials,crude extracts and purified active compounds from them have been found to exhibil interesting bioactivities,such as ...antimicrobial,anti-inflammatory and antioxidant activities.In addition,they have been widely used in the treatment of many immune-related diseases,as well as in recent times in the treatment of tumors.Bee product peptides induce apoptotic cell death in vitro in several transformed(cancer) human cell lines,including those derived from renal,lung,liver,prostate,bladder and lymphoid cancers.These bioactive natural products may.therefore,prove to be useful as part of a novel targeted therapy for some types of cancer,such as prostate and breast cancer.This review summarizes the current knowledge regarding the in vivo and in vitro potential of selective bee products against tumor cells.
European honeybee, Apis mellifera, produces α-glucosidase (HBGase) that catalyzes the cleavage of an α-glycosidic bond of the non-reducing end of polysaccharides and has potential applications for ...malt hydrolysis in brewing industry. Characterized by their substrate specificities, HBGases have three isoforms including HBGase II, which prefers maltose to sucrose as a substrate. Previous study found that the catalytic efficiency of maltose hydrolysis of N226P mutant of HBGase II was higher than that of the wild type (WT), and the catalytic efficiency of maltose hydrolysis of WT was higher than those of H227Y and N226P-H227Y mutants. We hypothesized that N226P mutation probably caused maltose to bind with better affinity and position/orientation for hydrolysis than WT, while H227Y and N226P-H227Y mutations caused maltose to bind with worse affinity and position/orientation for hydrolysis than WT. Using this hypothesis, we performed molecular dynamics on the catalytically competent binding conformations of maltose/WT, maltose/N226P, maltose/H227Y, and maltose/N226P-H227Y complexes to elucidate effects of N226P and H227Y mutations on maltose binding in HBGase II active site. Our results reasonably support this hypothesis because the N226P mutant had better binding affinity, higher number of important binding residues, strong and medium hydrogen bonds as well as shorter distance between atoms necessary for hydrolysis than WT, while the H227Y and N226P-H227Y mutants had worse binding affinities, lower number of important binding residues and strong hydrogen bonds as well as longer distances between atoms necessary for hydrolysis than WT. Moreover, results of binding free energy and hydrogen bond interaction of residue 227 support the role of H227 as a maltose preference residue, as proposed by previous studies. Our study provides important and novel insight into how N226P and H227Y mutations affect maltose binding in HBGase II active site. This knowledge could potentially be used to engineer HBGase II to improve its efficiency.
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.
Objective:To screen crude extracts of propolis,bee pollen and honey from four stingless bee speciesTrigona incisa(T.incisa),Timia apicalis,Trigona fuso-baltata and Trigona filscibasis)native to East ...Kalimantan.Indonesia for cytotoxic activity against five human cancer cell lines(HepG2,SW620,ChaGo-1,KATO-Ⅲand BT474).Methods:All samples were extracted with methanol,and then subpartitioned with n-hexane and ethyl acetate.Each crude extract was screened at 20μg/mL for in vitro cytotoxicity against the cell lines using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Tn addition,four previously shown bioactive components from propolis(apigenin,cafieic acid phenyl ester,kaempferol and naringenin)and two chemotherapeutic drugs(doxorubicin and 5-fluorouracil)were used to evaluate the sensitivity of the cell lines.Results:Overall,crude extracts from propolis and honey had higher cytotoxic activities than bee pollen,but the activity was dependent upon the extraction solvent,bee species and cell line.Propolis extracts from T.incisa and Tarda apicalis showed the highest and lowest cytotoxic activity,respectively.Only the HepG2 cell line was broadly sensitive to the honey extracts.For pure compounds,doxorubicin was the most cytotoxic,the four propolis compounds the least,but the ChaGo-I cell line was sensitive to kaempferol at 10μg/mL and KATO-Ⅲwas sensitive to kaempferol and apigenin at 10μg/mL,.All pure compounds were effective against the BT474 cell line.Conclusions:Propolis from f,incisa and Trigona fusco-balteata contain an in vitro cytotoxic activity against human cancer cell lines.Further study is required,including the isolation and characterization of the active antiproliferative agent(s).
Ovarian cancer is the fifth main cause of pre-senescent death in women. Although chemotherapy is generally an efficient treatment, its side effects and the occurrence of chemotherapeutic resistance ...have prompted the need for alternative treatments. In this study, α-mangostin and apigenin were evaluated as possible anticancer alternatives to the chemotherapeutic drug doxorubicin, used herein as a positive control. The ovarian adenocarcinoma cell line SKOV-3 (ATCC No. HTB77) was used as model ovarian cancer cells, whereas the skin fibroblast line CCD-986Sk (ATCC No. CRL-1947) and lung fibroblast line WI-38 (ATCC No. CCL-75) were used as model untransformed cells. Apigenin and doxorubicin inhibited the growth of SKOV-3 cells in a dose- and time-dependent manner. After 72 hr exposure, doxorubicin was mostly toxic to SKOV-3 cells, whereas apigenin was toxic to SKOV-3 cells but not CCD-986Sk and WI-38 cells. α-Mangostin was more toxic to SKOV-3 cells than to CCD-986Sk cells. A lower cell density, cell shrinkage, and more unattached (floating round) cells were observed in all treated SKOV-3 cells, but the greatest effects were observed with α-mangostin. With regard to programmed cell death, apigenin caused early apoptosis within 24 hr, whereas α-mangostin and doxorubicin caused late apoptosis and necrosis after 72 hr of exposure. Caspase-3 activity was significantly increased in α-mangostin-treated SKOV-3 cells after 12 hr of exposure, whereas only caspase-9 activity was significantly increased in apigenin-treated SKOV-3 cells at 24 hr. Both α-mangostin and apigenin arrested the cell cycle at the G
2
/M phase, but after 24 and 48 hr, respectively. Significant upregulation of
BCL2
(apoptosis-associated gene) and
COX2
(inflammation-associated gene) transcripts was observed in apigenin- and α-mangostin-treated SKOV-3 cells, respectively. α-Mangostin and apigenin are therefore alternative options for SKOV-3 cell inhibition, with apigenin causing rapid early apoptosis related to the intrinsic apoptotic pathway, and α-mangostin likely being involved with inflammation.
Malassezia globosa, a lipophilic pathogen, is known to be involved in various chronic skin diseases. Unfortunately, the available treatments have unwanted side effects and microbial drug resistance ...is evolving. As the antimicrobial activity of propolis is outstanding, this study aimed to examine the potential of propolis from the stingless bee Geniotrigona thoracica against the yeast. Anti-M. globosa growth activity was ascertained in agar well diffusion and broth microdilution assays and the inhibitory concentration value at 50 % (IC50) was determined. Since the yeast cannot synthesize its own fatty acids, extracellular lipase is important for its survival. Here, anti-M. globosa extracellular lipase activity was additionally investigated by colorimetric and agar-based methods. Compared to the crude hexane and crude dichloromethane extracts, the crude methanol partitioned extract (CMPE) exhibited the best anti-M. globosa growth activity with an IC50 of 1.22 mg/mL. After CMPE was further enriched by silica gel column chromatography, fraction CMPE1 (IC50 of 0.98 mM or 184.93 μg/mL) presented the highest activity and was later identified as methyl gallate (MG) by nuclear magnetic resonance analysis. Subsequently, MG was successfully synthesized and shown to have a similar activity, and a minimal fungicidal concentration of 43.44 mM or 8.00 mg/mL. However, lipase assay analysis suggested that extracellular lipase might not be the main target mechanism of MG. This is the first report of MG as a new anti-Malassezia compound. It could be a good candidate for further developing alternative therapeutic agents.
Honey from the European honeybee, Apis mellifera, is produced by α-glucosidases (HBGases) and is widely used in food, pharmaceutical, and cosmetic industries. Categorized by their substrate ...specificities, HBGases have three isoforms: HBGase I, II and III. Previous experimental investigations showed that wild-type HBGase III from Apis mellifera (WT) preferred sucrose to maltose as a substrate, while the Y227H mutant (MT) preferred maltose to sucrose. This mutant can potentially be used for malt hydrolysis because it can efficiently hydrolyze maltose. In this work, to elucidate important factors contributing to substrate specificity of this enzyme and gain insight into how the Y227H mutation causes substrate specificity change, WT and MT homology models were constructed, and sucrose/maltose was docked into active sites of the WT and MT. AMBER14 was employed to perform three independent molecular dynamics runs for these four complexes. Based on the relative binding free energies calculated by the MM-GBSA method, sucrose is better than maltose for WT binding, while maltose is better than sucrose for MT binding. These rankings support the experimentally observed substrate specificity that WT preferred sucrose to maltose as a substrate, while MT preferred maltose to sucrose, suggesting the importance of binding affinity for substrate specificity. We also found that the Y227H mutation caused changes in the proximities between the atoms necessary for sucrose/maltose hydrolysis that may affect enzyme efficiency in the hydrolysis of sucrose/maltose. Moreover, the per-residue binding free energy decomposition results show that Y227/H227 may be a key residue for preference binding of sucrose/maltose in the WT/MT active site. Our study provides important and novel insight into the binding of sucrose/maltose in the active site of Apis mellifera HBGase III and into how the Y227H mutation leads to the substrate specificity change at the molecular level. This knowledge could be beneficial in the design of this enzyme for increased production of desired products.
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.
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