Albizia lebbeck suppresses histamine signaling by the inhibition of histamine H1 receptor and histidine decarboxylase gene transcriptions

A Comprehensive Insight into the Phytochemical, Pharmacological Potential, and Traditional Medicinal Uses of Albizia lebbeck (L.) Benth

Background. Albizialebbeck is a deciduous tree having tremendous medicinal utilities, for example, respiratory, skin, gastrointestinal, oral disorders, eye, urinary, genital, anorectal, inflammatory, and neurological disorders, and venereal diseases. Several studies have been undertaken on the medicinal and traditional values of A. lebbeck. Objective. The detailed information about its medicinal uses and pharmacological implications is highly scattered and distributed in different data sources. Hence, the study was conducted to supply an inclusive review of its ethnomedicinal uses, phytochemicals, and the available pharmacological attributes supporting its efficiency in traditional medicine. Method. Literature surveys were conducted on this medicinal plant via search engines like Google Scholar, PubMed, and Science Direct, and obtained information up to December 2020 has been assessed and analyzed for this study. Results. Systematic investigation revealed that A. lebbeck consists of various phytochemicals, including major alkaloids, flavonoids, saponins, and terpenoids. Its crude extract, fraction, and bioactive compounds exhibited potent adulticidal, antiallergic, anticancer, anticonvulsant, antidiabetic, antidiarrheal, anti-inflammatory, antimicrobial, antinociceptive, antioxidant, antiparasitic, antipyretic, antivenom, estrogenic, neuroprotective, nootropic, ovicidal, and wound healing activities. Conclusions. This study proposes that A. lebbeck remains a rich source of phytochemicals with various biological activities which possess outstanding therapeutic benefits to humanity across the world. However, studies are required to estimate the potential side effects. Moreover, mechanistic physiognomies of the isolated compounds with known bioactivities are quite limited; thus, forthcoming research needs to focus on the mechanisms of these active phytochemicals to facilitate their potential enrolling for drug discovery.

Anti-anaphylactic potential of benzoylpaeoniflorin through inhibiting HDC and MAPKs from Paeonia lactiflora

Guided by cell-based anti-anaphylactic assay, eighteen cage-like monoterpenoid glycosides (1-18) were obtained from the bioactive fraction of P. lactiflora extract. Among these, compounds 1, 5, 6, 11, 12, 15, and 17 significantly reduced the release rate of β-HEX and HIS without or with less cytotoxicity. Furthermore, the most potent inhibitor benzoylpaeoniflorin (5) was selected as the prioritized compound for the study of action of mechanism, and its anti-anaphylactic activity was medicated by dual-inhibiting HDC and MAPK signal pathway. Moreover, molecular docking simulation explained that benzoylpaeoniflorin (5) blocked the conversion of L-histidine to HIS by occupying the HDC active site. Finally, in vivo on PCA using BALB/c mice, benzoylpaeoniflorin (5) suppressed the IgE-mediated PCA reaction in antigen-challenged mice. These findings indicated that cage-like monoterpenoid glycosides, especially benzoylpaeoniflorin (5), mainly contribute to the anti-anaphylactic activity of P. lactiflora by dual-inhibiting HDC and MAPK signal pathway. Therefore, benzoylpaeoniflorin (5) may be considered as a novel drug candidate for the treatment of anaphylactic diseases.

The Natural Products Targeting on Allergic Rhinitis: From Traditional Medicine to Modern Drug Discovery

More than 500 million people suffer from allergic rhinitis (AR) in the world. Current treatments include oral antihistamines and intranasal corticosteroids; however, they often cause side effects and are unsuitable for long-term exposure. Natural products could work as a feasible alternative, and this study aimed to review the efficacies and mechanisms of natural substances in AR therapies by examining previous literature. Fifty-seven studies were collected and classified into plants, fungi, and minerals decoction; clinical trials were organized separately. The majority of the natural products showed their efficacies by two mechanisms: anti-inflammation regulating diverse mediators and anti-oxidation controlling the activity of nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) pathway stimulated by reactive oxygen species (ROS). The main AR factors modified by natural products included interleukin (IL)-4, IL-5, IL-13, interferon-gamma (IFN-γ), tumor necrosis factor-α (TNF-α), cyclooxygenase 2 (COX-2), and phospho-ERK1/2 (p-ERK1/2). Although further studies are required to verify their efficacies and safeties, natural products can significantly contribute to the treatment of AR.

Effects of narrow-band UVB on nasal symptom and upregulation of histamine H1 receptor mRNA in allergic rhinitis model rats

BACKGROUND

Phototherapy with narrow-band ultraviolet B (narrow-band UVB) is clinically effective treatment for atopic dermatitis. In the present study, we examined the effects of intranasal irradiation with narrow-band UVB on nasal symptom, upregulation of histamine H1 receptor (H1R) gene expression and induction of DNA damage in the nasal mucosa of allergic rhinitis (AR) model rat.

METHODS

AR model rats were intranasally irradiated with 310 nm of narrow-band UVB. Nasal mucosal levels of H1R mRNA were measured using real-time quantitative reverse transcriptase (RT)-PCR. DNA damage was evaluated using cyclobutane pyrimidine dimer (CPD) immunostaining.

RESULTS

In toluene 2,4-diisocyanate (TDI)-sensitized rats, TDI provoked sneezes and H1R gene expression in the nasal mucosa. Intranasal pre-irradiation with 310 nm narrow-band UVB at doses of 600 and 1400, but not 200 mJ/cm2 significantly inhibited the number of sneezes and upregulation of H1R gene expression provoked by TDI. CPD-positive cells appeared in the nasal mucosa after intranasal narrow-band UVB irradiation at a dose of 1400, but not 200 and 600 mJ/cm2. The suppression of TDI-provoked sneezes and upregulation of H1R gene expression lasted 24 hours, but not 48 hours, after narrow-band UVB irradiation with a dose of 600 mJ/cm2.

CONCLUSIONS

Intranasal pre-irradiation with narrow-band UVB dose-dependently inhibited sneezes and upregulation of H1R gene expression of the nasal mucosa in AR model rats, suggesting that the inhibition of nasal upregulation of H1R gene expression suppressed nasal symptom. The suppression after narrow-band UVB irradiation at a dose of 600 mJ/cm2 was reversible without induction of DNA damage. These findings indicated that low-dose narrow-band UVB phototherapy could be effectively and safely used for AR treatment in a clinical setting.

LEVEL OF EVIDENCE

NA.

The ethnopharmacology, phytochemistry, pharmacology and toxicology of genus Albizia: A review

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Albizia (Leguminosae) comprises about 150 species and some species have been used for the treatment of rheumatism, stomachache, cough, diarrhea, and wounds in traditional and local medicine. The aim of the review: This review article documents and critically assesses the current status of the traditional uses, phytochemistry, pharmacology, and toxicology of the Albizia species.

MATERIALS AND METHODS

All provided literatures on the Albizia species were searched using the electronic databases (e.g. Web of Science, Elsevier, Springer, PubMed, ACS, CNKI, Google Scholar, and Baidu Scholar), books, and theses with keywords of 'Albizia' and 'Albizzia'.

RESULTS

Albizia species have been used for melancholia, insomnia, wounds, fever, abscesses, diabetes, headache, stomachache, diarrhea, cough, rheumatism, snake bite, malaria, and parasitic infection in traditional and local medicine. These plants mainly contain triterpenoid saponins, flavonoids, lignanoids, alkaloids, phenolic glycosides, etc. Albizia species have been demonstrated to possess various pharmacological activities. Among them, the antidiabetic, anti-inflammatory, antifertility, antianxiety, antidepressant, and anti-fever properties are consistent with the traditional and local applications of the Albizia species.

CONCLUSIONS

The traditional and local uses of Albizia species have been partially demonstrated by the pharmacological investigation. However, some traditional applications have not been assessed scientifically due to incomplete methodologies and ambiguous findings. Moreover, no clinical evidences support the health benefits of these plants. The systematic and comprehensive preclinical studies and clinical trials are still required to verify the pharmacological activities, clinical efficacy, and safety of Albizia species.

Molecular Modelling, Synthesis and Evaluation of Flavone and Flavanone Scaffolds as Anti-inflammatory Agents

OBJECTIVE

The objective of the study was to develop new Cyclooxygenase-2 inhibitors as anti-inflammatory agents from the synthetic route.

MATERIALS AND METHODS

The 2-phenyl-4H-chromen-4-one and 2-phenyl-2,3-dihydro-4H-chromenone hybrids were synthesised and characterised by using UV, IR, ¹H-NMR, and mass spectrometry. An attempt was made for consolidated lead flavones and flavanones scaffolds by determining ADME/ T properties. Molecular docking simulations were performed by using Autodock.4 to understand the binding interaction over the targeted enzyme Cyclooxygenase-2. The titled compounds were evaluated for various in-vitro models for antioxidant and anti-inflammatory activities and based upon the IC₅₀ values, the selected compounds were screened for in vivo anti-inflammatory activity by both acute and chronic models.

RESULTS AND DISCUSSION

Twenty titled compounds were synthesised and elucidated their structure for confirmation of their functional groups by various spectroscopic techniques. Among the synthesized compounds, flavone derivatives such as HFc (7-hydroxy-3-(4-methoxy phenyl)-4H-chromen-4- one), HF_d (2-(2,4-di methoxy-phenyl)-7-hydroxy-4H-chromen-4-one) and HFe (7-hydroxy-2- (thiophen-2-yl)-4H-chromen-4-one) produced higher potency. Flavanone derivatives HFAc (7- hydroxy-2-(4-hydroxy-3-methoxy phenyl)-2,3-dihydro-4H-chromen-4-one), HFAb (7-hydroxy-2-(4- methoxy phenyl)-2,3-dihydro-4H-chromen-4-one) and HFA_d (7-hydroxy-2-(thiophen-2-yl)-2,3- dihydro-4H-chromen-4-one) showed significant anti-inflammatory activity compared to the standard COX-2 inhibitors.

CONCLUSION

The flavone and flavanone scaffolds possess their excellent inhibitory action over the Cyclooxygenase-2 and act as a potential anti-inflammatory agent. The results of computational studies were also significantly correlated and concluded that those naturally mimicking flavonoid analogues were tremendous candidates to fight against the inflammatory diseases in drug discovery.

Lycium europaeum Linn as a source of polysaccharide with in vitro antioxidant activities and in vivo anti-inflammatory and hepato-nephroprotective potentials

ETHNOPHARMACOLOGICAL RELEVANCE

Lycium europaeum Linn. is widely used to treat the burning of the skin and well-known as a medicinal plant having various biological activities.

AIMS OF THE STUDY

The purpose of the present study is to characterize the polysaccharide from L. europaeum L. leaves (LEP) and to explore its antioxidant, anti-inflammatory and hepato-nephroprotective properties.

MATERIALS AND METHODS

The structural and functional characteristics of LEP were investigated using X-ray diffraction techniques (XRD), Scanning Electron Microscopy (SEM), and FT-IR Spectroscopy. The antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl and hydrogen peroxide scavenging assays. Hepato-renal effects were studied using CCl₄ and cisplatin-induced liver and kidney injuries in mice, respectively. Anti-inflammatory activity was assessed on carrageenan-induced paw edema.

RESULTS

The LEP showed an interesting water-holding capacity and effective foaming and emulsifying properties. XRD analysis suggested that LEP form a semi-crystalline polymer with an amorphous structure. FT-IR profile showed the presence of pyranose ring in LEP. SEM and helix-coil transition analyses indicated that LEP had a lamellar structure with angular edges and didn't present a triple helical conformation in solution. In vitro, LEP indicated significant concentration-dependent antioxidant activity. In vivo, LEP treatment significantly reduced the effects of CCl₄ intoxication on serum liver biomarkers (AST, ALT, LDH, and GGT) and the effect of cisplatin on serum renal biomarkers (urea, blood urea nitrogen, creatinine, and uric acid). Meanwhile, LEP diminishes significantly the effect of CCl₄ and cisplatin on the level of lipid peroxidation in liver and kidney tissues, respectively. Additionally, the normal histological structure of liver and kidney was restored after treatment with the polysaccharide. LEP possessed a significant anti-inflammatory activity on acute inflammation induced by carrageenan in mice.

CONCLUSION

Overall, the findings of this study support the traditional use of L. europaeum L. This plant may also be used as a good agent for protection against inflammatory diseases and hepato-renal injuries in patients with cancer.

Chemical Composition and Antioxidant, Analgesic, and Anti-Inflammatory Effects of Methanolic Extract of Euphorbia retusa in Mice

Plants provide an alternative source to manage different human disorders due to various metabolites. The aim of this study is to investigate the phytochemical constituents of the methanolic extracts of Euphorbia retusa and to evaluate their antioxidant, anti-inflammatory, and analgesic activities. The phytochemical results obtained by HPLC and by chemical assay reactions have revealed the richness of the methanolic extract of E. retusa in active compounds, in particular polyphenols, flavonoids, and tannins. The methanolic extract shows significant antioxidant activities in vitro, in the DPPH and the FRAP assays. The antinociceptive activity was evaluated using acetic acid and hot-plate models of pain in mice. The anti-inflammatory activity was evaluated by carrageenan-induced paw edema. Oral pretreatment with the methanolic extract of E. retusa (200 mg/kg) exhibited a significant inhibition of pain induced either by acetic acid or by the heating plate and in a manner comparable to the standard drug paracetamol. E. retusa significantly reduced paw edema starting from the 3rd hour after carrageenan administration by increasing the activity of antioxidant enzymes (SOD, CAT, and GPx) in liver and paw tissues and decreasing the levels of MDA. These results may confirm the interesting potential of this plant as a treatment of various inflammatory and pain diseases.

Pinocembrin, a novel histidine decarboxylase inhibitor with anti-allergic potential in in vitro

Pinocembrin (5, 7- dihydroxy flavanone) is the most abundant chiral flavonoid found in propolis, exhibiting antioxidant, antimicrobial and anti-inflammatory properties. However, the effect of Pinocembrin on allergic response is unexplored. Thus, current study aimed at investigating the effects of Pinocembrin on IgE-mediated allergic response in vitro. A special emphasis was directed toward histidine decarboxylase (HDC) and other pro-allergic and pro-inflammatory mediators. Preliminary studies, using a microbiological model of Klebsiella pneumoniae, provided first evidences that suggest Pinocembrin as a potential thermal stable inhibitor for HDC. Applying docking analysis revealed possible interaction between Pinocembrin and mammalian HDC. In vitro studies validated the predicted interaction and showed that Pinocembrin inhibits HDC activity and histamine in IgE-sensitized RBL-2H3 in response to dinitrophenol (DNP)-bovine serum albumin (BSA) stimulation. In addition, Pinocembrin mitigated the damage in the mitochondrial membrane, formation of cytoplasmic granules and degranulation as indicated by lower β-hexoseaminidase level. Interestingly, it reduced range of pro-inflammatory mediators in the IgE-mediated allergic response including tumor necrosis factor (TNF)-α, interleukin (IL)-6, nitric oxide (NO), inducible NO synthase (iNOS), phosphorylation of inhibitory kappa B (IкB)-α, prostaglandin (PGE)-2 and cyclooxygenase (COX)-2. In conclusion, current study suggests Pinocembrin as a potential HDC inhibitor, and provides the first evidences it is in vitro anti-allergic properties, suggesting Pinocembrin as a new candidate for natural anti-allergic drugs.

Evaluation of the anti-inflammatory activity of the aqueous and ethanolic extracts of the leaves of Albizzia lebbeck in rats

Albizzia lebbeck Benth. (Mimosaceae) is a medicinal tree used to treat several inflammatory ailments in the Indian traditional Ayurvedic system of medicine. The aim of the present study was to evaluate the possible anti-inflammatory activity of the aqueous (AE) and ethanolic (EE) extracts of the leaves of A. lebbeck to support the ethnopharmacological claims. The study was carried out using Wistar rats (100-150 g). The AE and EE were prepared using the Soxhlet extraction process. The anti-inflammatory activity of the AE and EE of the leaves of A. lebbeck were studied using carrageenan-induced paw edema and cotton pellet-induced granuloma models. The AE and EE of the leaves of A. lebbeck at doses of 50, 100, and 200 mg/kg p.o. (oral administration) showed a dose-dependent and significant (p < 0.05) inhibition of carrageenan-induced hind paw edema with maximum percentage inhibition (PI) values of 22.34, 30.85, 39.36 and 22.53, 32.98, 42.55, respectively. The AE and EE at doses of 50, 100, 200 mg/kg p.o. significantly (p < 0.05) inhibited granuloma formation with PI values of 19.07, 27.57, 38.55 and 23.93, 32.23, 42.33, respectively. The AE and EE of the leaves of A. lebbeck showed significant (p < 0.05) anti-inflammatory activity.

Disruption of Heat Shock Protein 90 (Hsp90)-Protein Kinase Cδ (PKCδ) Interaction by (-)-Maackiain Suppresses Histamine H1 Receptor Gene Transcription in HeLa Cells

The histamine H1 receptor (H1R) gene is an allergic disease sensitive gene, and its expression level is strongly correlated with the severity of allergic symptoms. (-)-Maackiain was identified as a Kujin-derived anti-allergic compound that suppresses the up-regulation of the H1R gene. However, the underlying mechanism of H1R gene suppression remains unknown. Here, we sought to identify a target protein of (-)-maackiain and investigate its mechanism of action. A fluorescence quenching assay and immunoblot analysis identified heat shock protein 90 (Hsp90) as a target protein of (-)-maackiain. A pull-down assay revealed that (-)-maackiain disrupted the interaction of Hsp90 with PKCδ, resulting in the suppression of phorbol 12-myristate 13-acetate (PMA)-induced up-regulation of H1R gene expression in HeLa cells. Additional Hsp90 inhibitors, including 17-(allylamino)-17-demethoxygeldanamycin, celastrol, and novobiocin also suppressed PMA-induced H1R gene up-regulation. 17-(Allylamino)-17-demethoxygeldanamycin inhibited PKCδ translocation to the Golgi and phosphorylation of Tyr(311) on PKCδ. These data suggest that (-)-maackiain is a novel Hsp90 pathway inhibitor. The underlying mechanism of the suppression of PMA-induced up-regulation of H1R gene expression by (-)-maackiain and Hsp90 inhibitors is the inhibition of PKCδ activation through the disruption of Hsp90-PKCδ interaction. Involvement of Hsp90 in H1R gene up-regulation suggests that suppression of the Hsp90 pathway could be a novel therapeutic strategy for allergic rhinitis.

Maackiain is a novel antiallergic compound that suppresses transcriptional upregulation of the histamine H1 receptor and interleukin-4 genes

Kujin contains antiallergic compounds that inhibit upregulation of histamine H1 receptor (H1R) and interleukin (IL)-4 gene expression. However, the underlying mechanism remains unknown. We sought to identify a Kujin-derived antiallergic compound and investigate its mechanism of action. The H1R and IL-4 mRNA levels were determined by real-time quantitative RT-PCR. To investigate the effects of maackiain in vivo, toluene-2,4-diisocyanate (TDI)-sensitized rats were used as a nasal hypersensitivity animal model. We identified (-)-maackiain as the responsible component. Synthetic maackiain showed stereoselectivity for the suppression of IL-4 gene expression but not for H1R gene expression, suggesting distinct target proteins for transcriptional signaling. (-)-Maackiain inhibited of PKCδ translocation to the Golgi and phosphorylation of Tyr(311) on PKCδ, which led to the suppression of H1R gene transcription. However, (-)-maackiain did not show any antioxidant activity or inhibition of PKCδ enzymatic activity per se. Pretreatment with maackiain alleviated nasal symptoms and suppressed TDI-induced upregulations of H1R and IL-4 gene expressions in TDI-sensitized rats. These data suggest that (-)-maackiain is a novel antiallergic compound that alleviates nasal symptoms in TDI-sensitized allergy model rats through the inhibition of H1R and IL-4 gene expression. The molecular mechanism underlying its suppressive effect for H1R gene expression is mediated by the inhibition of PKCδ activation.

Ethnomedicinal plants used to treat skin diseases by Tharu community of district Udham Singh Nagar, Uttarakhand, India

ETHNOPHARMACOLOGICAL RELEVANCE

Tharu community is the largest primitive indigenous community of the Uttarakhand, India. In this article we have scientifically enumerated medicinal plants and herbal preparations used by the Tharu community to treat various skin diseases, and discussed dermatological properties of these plants in the light of previous ethnomedicinal, microbiological, pharmacological, toxicological, phytochemical and clinical studies.

MATERIALS AND METHODS

Ethnomedicinal survey was conducted in different villages of Tharu community located in district Udham Singh Nagar, Uttarakhand, India. Ethnomedicinal information on plants used to treat various skin diseases was collected from 122 individuals (93 males and 29 females), including 35 experienced herbal practitioners and 87 local villagers. For each of the recorded plant species the use value (UV) and fidelity level (FL) was calculated. The informant consensus factor (Fic) was also calculated to find out the homogeneity in the information given by the informants.

RESULTS

A total of 90 plant species belonging to 86 genera and 48 families were used by the Tharu community to treat various skin diseases viz., wounds (38 spp.), boils (32 spp.), cuts (18 spp.), leprosy (11 spp.), eczema (10 spp.), itching (7 spp.), ringworm (5 spp.), burns (4 spp.), leucoderma (4 spp.), cracked heels (2 spp.), dandruff (3 spp.), body infection (2 spp.), chilblains (2 spp.), hair fall (2 spp.) and toes infection (2 spp.). Information on botanical name, family, vernacular name, ailments treated, mode and dose of herbal preparations, UV and FL values are provided for each of the recorded species. According to UV value most preferred plant species used to treat skin diseases by Tharu community was Ricinus communis L. followed by Tridax procumbens (L.) L., Azadirachta indica A. Juss., Ageratum conyzoides and Allium cepa L.

CONCLUSIONS

The present study has revealed significant information on various medicinal plants used to treat skin diseases by Tharu community. Literature review has confirmed most of the claims made by the Tharu community regarding treatment of various skin diseases by the reported plants. The literature review has also revealed that products from very few of the reported plants are available in market, while most of the reported plants are still under preclinical or clinical trials. There are various known phytochemicals, and antibiotic, antibacterial, antiviral and antifungal agents present in these plants which may be synthesized or transformed to make pharmaceuticals. Some of the reported plants have shown promising results in preclinical trails and there is a need of clinical trials to see their safety and efficacy in treating various skin diseases. These plants may be targeted for development of new medicines, ointments or drugs for the treatment of skin diseases. However further toxicological, preclinical and clinical studies are needed to validate claims about little worked out plant species reported in the present study viz., Sida cordata (Burm. F.) Borss. Waalk., Millettia extensa (Benth.) Baker, Caesulia axillaris Roxb., Ehretia laevis Roxb., Vanda tessellate (Roxb.) Hook. Ex G.Don. and Eualaliopsis binata (Retz.) C.E. Hubb. Further studies on these plants are recommended to assess their potential in development of new skin care products.

Quercetin inhibits transcriptional up-regulation of histamine H1 receptor via suppressing protein kinase C-δ/extracellular signal-regulated kinase/poly(ADP-ribose) polymerase-1 signaling pathway in HeLa cells

It has been reported that the histamine H1 receptor (H1R) gene is up-regulated in patients with allergic rhinitis and H1R expression level strongly correlates with the severity of allergy symptoms. Accordingly compounds that suppress the H1R gene expression are promising as useful anti-allergic medications. Recently, we demonstrated that histamine or phorbol-12-myristate-13-acetate (PMA) stimulation induced the up-regulation of H1R gene expression through the protein kinase Cδ (PKCδ)/extracellular signal-regulated kinase/poly(ADP-ribose) polymerase-1 signaling pathway in HeLa cells expressing H1R endogenously. Quercetin is one of the well-characterized flavonoids and it possesses many biological activities including anti-allergic activity. However, effect of quercetin on H1R signaling is remained unknown. In the present study, we examined the effect of quercetin on histamine- and PMA-induced up-regulation of H1R gene expression in HeLa cells. We also investigated its in vivo effects on the toluene-2,4-diisocyanate (TDI)-sensitized allergy model rats. Quercetin suppressed histamine- and PMA-induced up-regulation of H1R gene expression. Quercetin also inhibited histamine- or PMA-induced phosphorylation of Tyr(311) of PKCδ and translocation of PKCδ to the Golgi. Pre-treatment with quercetin for 3weeks suppressed TDI-induced nasal allergy-like symptoms and elevation of H1R mRNA in the nasal mucosa of TDI-sensitized rats. These data suggest that quercetin suppresses H1R gene expression by the suppression of PKCδ activation through the inhibition of its translocation to the Golgi.