1,5-Diphenylpent-3-en-1-ynes and methyl naphthalene carboxylates from Lawsonia inermis and their anti-inflammatory activity

New Triterpenoids and Anti-Inflammatory Constituents from Glinus oppositifolius

Three new triterpenoids-spergulagenin B (1), spergulagenin C (2), and spergulagenin D (3)-were isolated from the aerial part of Glinus oppositifolius, along with 17 known compounds (4-20). The structures of these new compounds were identified by spectroscopic and MS analyses. Compounds 3, 5, 19, and 20 were evaluated for inhibition of nitric oxide production in LPS-stimulated RAW 264.7 cells with IC₅₀ values of 17.03, 18.21, 16.30, and 12.64 μM, respectively. Compounds 3, 5, and 20 exhibited inhibitory effects on LPS-induced nitric oxide production in RAW 264.7 cells with IC₅₀ values of 18.35 ± 1.34, 17.56 ± 1.41, and 14.27 ± 1.29 μM, respectively.

Lawsonia inermis Extract-Loaded Cellulose Acetate Nanofibrous Wound Dressings Alleviate Wound Inflammation Through PI3K/AKT/NFκB Signaling Pathway: A Preclinical Investigation

In this research, we aimed to combine the principles of herbal medicine and tissue engineering to develop a bioactive wound dressing. The nanofibrous scaffolds were produced via electrospinning of cellulose acetate/Lawsonia inermis extract (LIE) solution. The developed constructs were studied regarding their interaction with fibroblast cells and their various physicochemical and biological properties. The wound healing potential of the prepared dressings was studied on a rat model skin wound. In vitro studies showed that cellulose acetate scaffolds loaded with 3% LIE had the highest cell protection capacity under oxidative stress and promoted the fibroblast cells proliferation. Therefore, this group was used for wound healing assay. In vivo study showed that LIE-loaded wound dressings had the highest epithelial thickness, collagen deposition, and angiogenesis scores. Gene expression analysis showed that wounds treated with cellulose acetate/LIE wound dressings upregulated VEGF, b-FGF, and collagen type 2 genes. While, NFK-β and TNF-a genes expressions were significantly reduced by these dressings. This study implies that local delivery of LIE via cellulose acetate scaffolds can alleviate inflammation and increase the expression of pro-healing genes.

Flavonoids as inhibitors of human neutrophil elastase

Elastase is a proteolytic enzyme belonging to the family of hydrolases produced by human neutrophils, monocytes, macrophages, and endothelial cells. Human neutrophil elastase is known to play multiple roles in the human body, but an increase in its activity may cause a variety of diseases. Elastase inhibitors may prevent the development of psoriasis, chronic kidney disease, respiratory disorders (including COVID-19), immune disorders, and even cancers. Among polyphenolic compounds, some flavonoids and their derivatives, which are mostly found in herbal plants, have been revealed to influence elastase release and its action on human cells. This review focuses on elastase inhibitors that have been discovered from natural sources and are biochemically characterised as flavonoids. The inhibitory activity on elastase is a characteristic of flavonoid aglycones and their glycoside and methylated, acetylated and hydroxylated derivatives. The presented analysis of structure-activity relationship (SAR) enables the determination of the chemical groups responsible for evoking an inhibitory effect on elastase. Further study especially of the in vivo efficacy and safety of the described natural compounds is of interest in order to gain better understanding of their health-promoting potential.

Pain-relieving effects of Lawsonia inermis on neuropathic pain induced by chronic constriction injury

The aim of this study was to determine the role of Lawsonia inermis (L. inermis) extract in the chronic constriction injury (CCI)-induced neuropathic pain. Following CCI surgery, L. inermis extract (250 mg/kg and 500 mg/kg) and gabapentin (100 mg/kg) were administered intraperitoneally for 14 consecutive days. Heat hyperalgesia and allodynia were assessed by radiant heat, aceton drop, and von frey filament tests, respectively. Rat pain behaviors were evaluated on -1sh, 3rd, 5th, 7th, 10th and 14th days post CCI surgery. At the end of the study, the spinal levels of malondialdehyde (MDA), total thiol, IL1-β, and TNF-α were estimated. Treatment of L. inermis extract reversed the decreased level of thiol and the elevation of MDA level in the spinal cord of CCI rats. Besides, L. inermis extract treatment decreased the elevation of inflammatory markers including IL1-β, and TNF-α in the spinal cord of CCI rats. These results indicated that L. inermis has potential neuroprotective effects against CCI induced neuropathic pain due to its anti-oxidant, and anti-inflammatory effects.

One-pot synthesis of new alkyl 1-naphthoates bearing quinoline, pyranone and cyclohexenone moieties via metal-free sequential addition/oxidation reactions

A mild and one-pot synthetic pathway was successfully developed for the synthesis of new naphthoate-based scaffolds containing quinoline, pyranone and cyclohexenone moieties via a multistep reaction between acenaphthoquinone and various 1,3-diketones in the presence of different primary aliphatic and benzylic alcohols. This reaction proceeds via a sequential addition/oxidation mechanistic process including a metal-free addition step of acenaphthoquinone and 1,3-diketones followed by the H₅IO₆-mediated C–C oxidative cleavage of the corresponding vicinal diols at room temperature. The alcohols play a dual role, as the reaction solvent as well as the nucleophile, to conduct the reaction process toward naphthoate formation. All alkyl naphthoate derivatives prepared in this work are new compounds and were definitively characterized using ¹H-NMR, ¹³C-NMR and HRMS analysis, while X-ray crystallography was carried out for one of the products. The synthesis of a naphthalene-based nucleus attached to heterocyclic moieties is noteworthy to follow in the near future for diverse applications in biology, medicine, metal complex design, and semiconductor and optical materials.

Various new alkyl 1-naphthoates bearing quinoline, pyranone and cyclohexenone moieties were successfully synthesized by a one-pot sequential addition/oxidation process.

Morphological, Biochemical, and Climatological Analysis of Three Moroccan Henna Verities

In this study, we aimed to evaluate planted Henna in three sites in Morocco, namely, Alnif, Tafraoute Sidi Ali, and Tazzarine. Morphometric study shows that Tafraoute Sidi Ali Henna variety has highest geometric and weight parameters (length of 27.48 mm, width of 10.92 mm, specific mass of 25.1 mg/leaf, leaf area of 51, 53 mm², and rib's number of 9.41) when compared to Alnif and Tazzarine varieties. On the other hand, biochemical analysis shows that Tazzarine Henna variety, in the first rank, is characterized by high levels of total sugars (11.27 g/100 g), reducing sugars (5.59 g/100 g), proteins (4.4 g/100g), lipids (3.05 g/100g), phenolic compounds (31.9 g/100 g), flavonoids (5.68 g/100 g), and tannins (5.5 g/100 g). Chromatographic study shows that Tazzarine Henna variety is rich in monocyclic and polycyclic phenolic compounds. Climatic conditions analysis shows that the morphometric and biochemical diversity is related to hydrous and thermal profiles of studied sites. As a conclusion of this work, we can recommend the use of morphometric analysis and phytochemical and chromatographic analysis to determine the quality of Henna in Morocco and elsewhere.

Virtual Screening, Docking, Synthesis and Bioactivity Evaluation of Thiazolidinediones as Potential PPARγ Partial Agonists for Preparation of Antidiabetic Agents

Background:

Peroxisome proliferator-activated receptor gamma (PPARγ) is one of the key targets of insulin resistance research, in addition to being ligand-activated transcription factors of the nuclear hormone receptor superfamily with a leading role in adiposeness activation and insulin sensitivity. They regulate cholesterol and carbohydrate metabolism through direct actions on gene expression. Despite their therapeutic importance, there are dose limiting side effects associated with PPARγ drug treatments, thus a new generation of safer PPARγ drugs are being actively sought after treatment.

Methods:

In this study, we used computer aided drug design to screen new series of PPARγ ligands, and synthesized a series of potential thiazolidinedione derivatives such as 5,7- dibenzyloxybenzyl-3-hydroxymethyl-4H-coumarin-4-ketone, using 4-steps to synthesize the target compounds and built streptozotocin (STZ) induced insulin resistance rat model to measure their antidiabetic activity.

Results:

We found that 10 mg/kg concentration of compound 0701C could significantly decrease blood glucose and serum PPARγ, serum insulin levels in insulin resistance model rat.

Conclusion:

We would conclude that compound 0701C might serve as a potential PPARγ partial agonist.

Copper-Catalyzed Regioselective and Stereoselective Coupling of Grignard Reagents with Pent-1-en-4-yn-3-yl Benzoates: A Shortcut to ( Z) -1,5-Disubstituted Pent-3-en-1-ynes from Accessible Starting Materials

Copper-catalyzed coupling of Grignard reagents with pent-1-en-4-yn-3-yl benzoates occurs regioselectively at the terminal alkenyl carbon rather than the alkynyl site, leading to the stereoselective formation of unexpected ( Z) -1,5-disubstituted pent-3-en-1-ynes without generation of the initially expected alkenyl allene products. By using easily accessible starting materials, this reaction can provide direct access to thermodynamically unfavorable Z-configured enynes, which widely exist in many bioactive natural products, such as the anti-inflammatory components in henna.

Study of the anti-allergic and anti-inflammatory activity of Brachychiton rupestris and Brachychiton discolor leaves (Malvaceae) using in vitro models

Background

Brachychiton rupestris and Brachychiton discolor (Malvaceae) are ornamental trees native to Australia. Some members of Brachychiton and its highly related genus, Sterculia, are employed in traditional medicine for itching, dermatitis and other skin diseases. However, scientific studies on these two genera are scarce. Aiming to reveal the scientific basis of the folk medicinal use of these plants, the cytotoxicity, anti-inflammatory and anti-allergic activities of Brachychiton rupestris and Brachychiton discolor leaves extracts and fractions were evaluated. Also, phytochemical investigation of B. rupestris was performed to identify the compounds exerting the biological effect.

Methods

Extracts as well as fractions of Brachychiton rupestris and Brachychiton discolor were tested for their cytotoxicity versus hepatoma HepG2, lung A549, and breast MDA-MB-231 cancer cell lines. Assessment of the anti-allergic activity was done using degranulation assay in RBL-2H3 mast cells. Anti-inflammatory effect was tested by measuring the suppression of superoxide anion production as well as elastase release in fMLF/CB-induced human neutrophils. Phytochemical investigation of the n-hexane, dichloromethane and ethyl acetate fractions of B. rupestris was done using different chromatographic and spectroscopic techniques.

Results

The tested samples showed no cytotoxicity towards the tested cell lines. The nonpolar fractions of both B. rupestris and B. discolor showed potent anti-allergic potency by inhibiting the release of β-hexosaminidase. The dichloromethane fraction of both species exhibited the highest anti-inflammatory activity by suppressing superoxide anion generation and elastase release with IC₅₀ values of 2.99 and 1.98 μg/mL, respectively for B. rupestris, and 0.78 and 1.57 μg/mL, respectively for B. discolor. Phytochemical investigation of various fractions of B. rupestris resulted in the isolation of β-amyrin acetate (1), β-sitosterol (2) and stigmasterol (3) from the n-hexane fraction. Scopoletin (4) and β-sitosterol-3-O-β-D-glucoside (5) were obtained from the dichloromethane fraction. Dihydrodehydrodiconiferyl alcohol 4-O-β-D-glucoside (6) and dihydrodehydrodiconiferyl alcohol 9-O-β-D-glucoside (7) were separated from the ethyl acetate fraction. Scopoletin (4) showed anti-allergic and anti-inflammatory activity.

Conclusions

It was concluded that the nonpolar fractions of both Brachychiton species exhibited anti-allergic and anti-inflammatory activities.

Electronic supplementary material

The online version of this article (10.1186/s12906-018-2359-6) contains supplementary material, which is available to authorized users.

Naphthalene, a versatile platform in medicinal chemistry: Sky-high perspective

Naphthalene, a cytotoxic moiety, is an extensively explored aromatic conjugated system with applications in various pathophysiological conditions viz. anticancer, antimicrobial, anti-inflammatory, antiviral, antitubercular, antihypertensive, antidiabetic, anti-neurodegenerative, antipsychotic, anticonvulsant, antidepressant. Naphthalene epoxides and naphthoquinones are most reactive metabolites of naphthalene and are responsible for the covalent interaction with cysteine amino acid of cellular proteins for cytotoxic nature. Many naphthalene derived bioactive phytoconstituents are present in nature including podophyllotoxins (Etoposide, teniposide), bis-ANS 82, Rifampicin, Justiprocumin A, B, Patentiflorin A. The naphthalene-based molecules, viz. Naphyrone, tolnaftate, naftifine, nafcillin, terbinafine, propranolol, nabumetone, nafimidone, naproxen, duloxetine, lasofoxifene, bedaquiline etc. have also been approved by FDA and are being marketed as therapeutics. Thus, the naphthalene scaffold emerges as an important building block in drug discovery owing to its broad spectrum of biological activities through varying structural modifications. This review incorporates the pharmacological aspects of different types of chemically modified naphthalene-based molecules along with their activity profile. This compiled information may serve as a benchmark for the alteration of existing ligands to design novel potent molecules with lesser side effects.

Anti-invasive Activity of Lawsonia inermis Branch and Its Potential Target Protein

The methanolic extract from the branch of Lawsonia inermis was found to inhibit the invasion of HT1080 cells strongly. The extract and its EtOAc- and 1-BuOH-soluble fractions strongly inhibited the enzyme activities and the secretions of MMPs from HT1080 cells. We, therefore, tried to examine and estimate the active constituents among the constituents isolated. However, there are no active compound among the isolated compounds. Next, we tried to identify the selective binding protein of whole constituents of their extracts. As a result, ribosomal protein S18 (RPs S18, human), 60S ribosomal protein L18 isoform 1 (60S RPs L18 i1, human) and eukaryotic elongation factor 2 (eEF2, human) were detected as their selective binding and potential target proteins. To confirm that the proteins are target proteins or not, we examined the effects of their proteins on synthesis of MMPs using siRNA method. With the treatment of siRNA for RPs S18, 60S RPs L18 i1 and eEF2 proteins, the MMP-2 protein synthesis were downregulated in HT1080 cells. MMP-9 productions were also downregulated with the treatment of siRNA for RPs S18 and eEF2. From the results, we reached a conclusion that the extract was considered to have the potential to inhibit the production of MMPs proteins via inhibition of RPs S18 and eEF2 proteins, leading to inhibit the invasion in HT1080 cells.

Luteolin attenuates neutrophilic oxidative stress and inflammatory arthritis by inhibiting Raf1 activity

Neutrophils play a significant role in inflammatory tissue injury. Activated neutrophils produce reactive oxygen species (ROS), release proteases, and form neutrophil extracellular traps (NETs), significantly affecting the pathogenesis of inflammatory arthritis. We examined the therapeutic effects of luteolin, a flavone found in many plants, in neutrophilic inflammation and on acute inflammatory arthritis. Luteolin significantly inhibited superoxide anion generation, ROS production, and NET formation in human neutrophils. The increase in elastase release, CD11b expression, and chemotaxis was also inhibited by luteolin. Luteolin significantly suppressed phosphorylation of extracellular signal-regulated kinase (Erk) and mitogen-activated protein kinase kinase-1 (MEK-1), but not c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK). Analysis of the molecular mechanism further revealed that luteolin acts as a Raf-1 inhibitor. In mice with complete Freund's adjuvant-induced arthritis, luteolin ameliorated neutrophil infiltration as well as the thickness of paw edema and ROS production. In conclusion, in addition to its known ROS scavenging effect, this study is the first to provide evidence that luteolin diminishes human neutrophil inflammatory responses by inhibiting Raf1-MEK-1-Erk. Our results focused on the importance of neutrophil activation in inflammatory tissue injury and offer opportunities for the development of luteolin's therapeutic potential to attenuate neutrophilic inflammatory diseases.

Two new unsaturated fatty acids from the whole plant of Pothos chinensis

Two new unsaturated fatty acids, (Z)-octadec-13-en-11-ynoic acid (1) and (Z)-octadec-16-en-12,14-diynoic acid (2), along with six known compounds were isolated from the whole plant of Pothos chinensis. The structures of these compounds were elucidated by detailed spectroscopic analysis, including 1D and 2D NMR data. Compound 2 showed moderate antibacterial activity against Staphylococcus aureus.

New Benzenoid Derivatives and Other Constituents from Lawsonia inermis with Inhibitory Activity against NO Production

Three new benzenoid derivatives, lawsoinermone (1), inermidioic acid (2), and inermic acid (3) have been isolated from the aerial part of Lawsonia inermis, together with 11 known compounds (4-14). The structures of three new compounds were determined through spectroscopic and MS analyses. Compounds 1, 4-6, 13 and 14 were evaluated for inhibition of nitric oxide production in LPS-stimulated product of nitrite in RAW 264.7 cells with IC₅₀ values of 6.12, 16.43, 18.98, 9.30, 9.30 and 14.90 μg/mL, respectively.

Characterization of Antileishmanial Compounds from Lawsonia inermis L. Leaves Using Semi-High Resolution Antileishmanial Profiling Combined with HPLC-HRMS-SPE-NMR

This work describes an analytical platform based on semi-high-resolution antileishmanial profiling combined with hyphenation of high-performance liquid chromatography – high-resolution mass spectrometry – solid-phase extraction – nuclear magnetic resonance spectroscopy, i.e., semiHR-antileishmanial assay/HPLC-HRMS-SPE-NMR. The platform enables fast pinpointing of HPLC peaks representing Leishmania tropica inhibitors in complex matrices, with subsequent structural identification of targeted inhibitors. Active analytes were cumulatively trapped on SPE cartridges and the structures elucidated by analysis of NMR spectra obtained in the HPLC-HRMS-SPE-NMR mode. This led to the identification of six known compounds 2,4,6-trihydroxyacetophenone-2-O-β-D-glucopyranoside (1), lalioside (2), luteolin-4′-O-β-D-glucopyranoside (3), apigenin-4′-O-β-D-glucopyranoside (4), luteolin (5), and apigenin (6). IC₅₀ of the active compounds were determined with luteolin being the most potent inhibitor with an IC₅₀ value of 4.15 μg/ml. The platform proved to be an efficient method for the identification of L. tropica inhibitors.

Naphthohydroquinones, naphthoquinones, anthraquinones, and a naphthohydroquinone dimer isolated from the aerial parts of Morinda parvifolia and their cytotoxic effects through up-regulation of p53

Five unknown compounds, morindaparvins C-G, consisting of naphthohydroquinones, a naphthoquinone, an anthraquinone, and a naphthohydroquinone dimer, together with three known quinones and seven other known compounds, were isolated from the aerial parts of Morinda parvifolia. The structures of morindaparvins C, D, E, F, and G were elucidated on the basis of spectroscopic or X-ray diffraction analysis as methyl 4-hydroxy-1,6-dimethoxy-naphthalene-2-carboxylate, methyl 4,8-dihydroxy-1-methoxy-naphthalene-2-carboxylate, 3-amino-6-methoxy-2-methoxycarbonyl-1,4-naphthoquinone, 1,4-dihydroxy-7-hydroxymethyl-anthraquinone, and dimethyl 1,1'-dihydroxy-4,4',7,7'-tetramethoxy-2,2'-binaphthalene-3,3'-dicarboxylate, respectively. Naphthoquinones and naphthohydroquinone dimers were previously unknown in the genus Morinda. In addition, the compounds were tested for cytotoxicity against four human cancer cell lines HeLa, A2780, Ketr3 and MCF-7 and their effects on p53-activated transcription. Three naphthoquinones had moderate cytotoxic effects with IC50 values ranging from 1.51 to 9.56 μM, through up-regulation of p53 transcriptional activity.

New Diphenol and Isocoumarins from the Aerial Part of Lawsonia inermis and Their Inhibitory Activities against NO Production

Lawsonia inermis Linn (Lythraceae), also known as henna, is a small shrub or tree distributed throughout Taiwan’s Lanyu Island, in North Africa, and in Australia. Its leaves are used as a folk medicine for the treatment of external hemorrhage and fingernail abscesses. Investigation of the ethyl acetate (EtOAc)-soluble fractions from methanol extract of the aerial part of Lawsonia inermis has led to the isolation of a new diphenol, (Z)-4,4′-(prop-1-ene-1,3-diyl)diphenol (1), two new isocoumarin carbonates, inermiscarbonates A (2) and B (3), and six known compounds, 4′-hydroxyflavanone (4), apigenine (5), kampferol (6), luteolin (7), quercetin (8), and (-)-catechin (9). Their structures were determined by detailed analysis of spectroscopic data and comparison with the data of known analogues. Compounds 1 and 4–9 were evaluated for the inhibition of nitric oxide production in lipopolysaccharide (LPS)-stimulated product of nitrite in RAW 264.7 cells with IC₅₀ values of 5.63, 15.72, 8.67, 6.67, 6.17, 7.61, and 14.52 μg/mL, respectively.

Ellagitannins modulate the inflammatory response of human neutrophils ex vivo

BACKGROUND

Tannin-rich plant materials are commonly used in the traditional medicine as external anti-inflammatory, antioxidant and antimicrobial agents. Plant extracts containing significant quantities of tannins are often used in the prevention and treatment of oral cavity diseases such as periodontosis or gingivitis. The contribution of pure ellagitannins to the observed anti-inflammatory activity of tannin-rich remedies is still not resolved.

PURPOSE

The aim of the present study the study was to establish if ellagitannins and their precursor - pentagalloylglucose (1) can modulate the inflammatory response of ex-vivo stimulated neutrophils.

METHODS

Human neutrophils were isolated from the buffy coats obtained from healthy volunteers. Neutrophils were cultivated with or without tested compounds. The influence of ellagitannins and 1 on the production and release of pro-inflammatory factors such as elastase, reactive oxygen species, interleukin-8, tumour necrosis factor alpha (TNF-α) and metalloproteinase-9 was evaluated using ELISA sets or chemical methods. The effect on surface expression of toll like receptor 4 (TLR-4) and apoptosis was also checked using flow cytometry.

RESULTS

The results showed that ellgitannins modulate the inflammatory response of human neutrophils by the inhibition of production and release of chosen cytokines and pro-inflammatory enzymes. By the induction of TNF-α ellagitannins enhance neutrophil apoptosis, which is of interest in the case of chronic inflammation within oral cavity. Ellagitannins also decrease the surface expression of TLR-4 in activated neutrophils.

CONCLUSION

The results support the traditional use of tannin-rich products in the prevention and treatment of oral cavity diseases. The present study proves the substantial contribution of ellagitannins to the anti-inflammatory activity of tannin-rich medicinal plant materials.

Antagonism of human formyl peptide receptor 1 with natural compounds and their synthetic derivatives

Formyl peptide receptor 1 (FPR1) regulates a wide variety of neutrophil functional responses and plays an important role in inflammation and the pathogenesis of various diseases. To date, a variety of natural and synthetic molecules have been identified as FPR1 ligands. Here, we review current knowledge on natural products and natural product-inspired small molecules reported to antagonize and/or inhibit the FPR1-mediated responses. Based on this literature, additional screening of selected commercially available natural compounds for their ability to inhibit fMLF-induced Ca(2+) mobilization in human neutrophils and FPR1 transfected HL-60 cells, and pharmacophore modeling, natural products with potential as FPR1 antagonists are considered and discussed in this review. The identification and characterization of natural products that antagonize FPR1 activity may have potential for the development of novel therapeutics to limit or alter the outcome of inflammatory processes.

Bioactive 6S-styryllactone constituents of Polyalthia parviflora

Parvistones A-E (1-5), five new styryllactones possessing a rare α,β-lactone moiety and a 6S configuration, were isolated from a methanolic extract of Polyalthia parviflora leaves. The structures and the absolute configuration of the isolates were elucidated using NMR spectroscopy, specific rotation, circular dichroism, and X-ray single-crystal analysis. Compounds 8, 9, 11, and 12 were isolated for the first time. The results were supported by comparing the data measured to those of 6R-styryllactones. Moreover, a plausible biogenetic pathway of the isolated compounds was proposed. The structure-activity relationship of the compounds in an in vitro anti-inflammatory assay revealed the 6S-styryllactones to be more potent than the 6R derivatives. However, the effect was opposite regarding their cytotoxic activity. In addition, 6S-styrylpyrones isolated showed more potent anti-inflammatory and cytotoxic activity when compared to the 1S-phenylpyranopyrones obtained.

Lawsonia inermis L. (henna): ethnobotanical, phytochemical and pharmacological aspects

ETHNOPHARMACOLOGICAL RELEVANCE

The use of Lawsonia inermis L. (henna) for medicinal and cosmetic purposes is inextricably linked to ancient and modern cultures of North Africa and Asia. Literature and artwork indicates that Lawsonia inermis played an important holistic role in the daily lives of some ancient cultures, providing psychological and medicinal benefits, as well as being used for personal adornment. Although henna was historically applied to the hands and feet to protect against fungal pathogens and to hair to combat lice and dandruff, other traditional uses include the treatment of liver and digestive disorders, reduction of tissue loss in leprosy, diabetic foot disorders and ulcers.

PHYTOCHEMISTRY

Almost 70 phenolic compounds have been isolated from various parts of the plant. Naphthaquinones, which include the dyeing principle lawsone, have been linked to many of the pharmacological activities. The terpene, β-ionone is largely responsible for the pungent odour of the essential oil isolated from the flowers. In addition to other volatile terpenes, some non-volatile terpenoids, a single sterol, two alkaloids and two dioxin derivatives have also been isolated from the plant.

BIOACTIVITY

Henna is a pharmacologically important plant with significant in vitro and in vivo biological activities. Although a myriad of pharmacological activities have been documented, the antioxidant and antimicrobial activities are the most thoroughly investigated. Some incidents of adverse reactions following application to the skin have been reported, but these are mainly confined to cases involving individuals with glucose-6-phosphate dehydrogenase deficiency and reactions to adulterants added to henna products.

CONCLUSIONS

Adulteration of henna is very common and may have resulted in unwarranted scientific findings. Phytochemical profiling studies of the plant, which are crucial for the establishment of proper quality control protocols, are lacking and hamper the development of medicinal products. Although many in vitro studies have been conducted to evaluate the pharmacological activities and many in vivo studies have focussed on the toxicity of extracts, more in vivo studies to validate pharmacological activities are needed. The roles of specific compounds and their synergies have not been comprehensively investigated.

Antioxidant and anti-inflammatory flavonol glucuronides from Polygonum aviculare L

A series of 11 flavonol glucuronides were isolated from the herb of Polygonum aviculare L. (Ph.Eur) of which 8 were reported for the first time from the Polygonum species. Three acetylated kaempferol and isorhamnetin glucuronides were isolated from a natural source for the first time. All compounds, including the new ones, were characterized using 1D and 2D NMR spectra as well as high resolution mass spectrometry. The influence of all isolated compounds on the production of reactive oxygen species, as well as on elastase release by human neutrophils, was evaluated in in vitro studies. The results showed that all investigated compounds at physiologically achievable concentrations within the range of 0.5-10 μM significantly inhibited the production of reactive oxygen species as well as elastase release in human neutrophils model and should be considered as responsible for anti-inflammatory activity of the P. aviculare herb. The chemotaxonomic value of isolated compounds was also discussed.