Natural Products and Inflammation

Anti-inflammatory Principles of the Plant Family Amaryllidaceae

There is considerable interest in the utilisation of plants against inflammation. Over 50 species of the plant family Amaryllidaceae are known for such usage in traditional medicine. This review was undertaken to identify the chemical principles responsible for these anti-inflammatory effects. It describes the findings from in vitro, in vivo and in silico studies, as well as the probes made on the mechanisms of action. The literature search returned over 600 hits, of which around 130 were chosen for their relevance to the text. Over 140 compounds have thus far been screened for anti-inflammatory effects. These were mostly isoquinoline alkaloids but also included other classes of secondary metabolites such as chromones, flavonoids and triterpenoids. In vitro studies were carried out in mononuclear cells such as lymphocytes, monocytes, neutrophils and macrophages, against which no serious side effects were observed. The constituents were also effective against inflammation induced by physical and chemical stimuli in a variety of murine test subjects. Chief among the compounds were the isoquinoline alkaloids lycorine and narciclasine, which displayed potent effects against pain, swelling, asthma and arthritis, amongst others. From a mechanistic perspective, several of the compounds were shown to mediate in inflammatory pathways, notably via the modulation of both pro-inflammatory (such as NF-κB, TNF-α and IL-1) and anti-inflammatory (such as IL-10 and TGF-β) factors. Useful insights also emerged from active-site docking studies of some of the compounds. The Amaryllidaceae affords a rich and diverse platform for the discovery of potential anti-inflammatory drugs.

Anti-inflammatory effects of the plant family Amaryllidaceae

ETHNOPHARMACOLOGICAL RELEVANCE

Members of the plant family Amaryllidaceae are widely recorded in traditional systems of medicine. Their usage for inflammatory conditions is most prominent, with substantive evidence emerging from several locations around the world.

AIM OF THE STUDY

This survey was undertaken to identify such plant taxa, highlight the countries from which they originate and afford details of the ailments against which they are utilized. The undertaking also sought to establish the in vitro and in vivo activities of Amaryllidaceae plant extracts in inflammation-based assays. Furthermore, it set out to unravel the molecular mechanisms used to explain these effects.

MATERIALS AND METHODS

Over six-hundred articles were identified in searches carried out on SciFinder, Scopus, ScienceDirect, PubMed and Google Scholar. These were condensed to around 170 that formulated the basis of the text. The keyword engaged was 'Amaryllidaceae' in conjunction with 'inflammation' or 'anti-inflammatory', as well as the names of individual genera combined with the latter two.

RESULTS

Fifty-one species from thirty-five countries were identified for their uses against inflammation. Twenty-four of such conditions were discernible, of which their applicability in wound healing and pain management was most conspicuous. The utilization of all plant parts was apparent, preparations of which were used primarily via topical application. Extracts of seventy-three species (from twenty-three genera) were examined in nearly thirty inflammation-based assays where their activities in vitro and in vivo were shown to be significant. They were effective in vivo against pain and swelling as well as wound healing, without detriment towards test subjects. The in vitro studies were carried out mainly in mononuclear cells such as macrophages, leukocytes, lymphocytes and neutrophils against which their cytotoxic effects were seen to be minimal. The modes of operation were shown to involve modulation of both pro-inflammatory (such as NF-κB, TNF-α, IL-6, IFN-γ, COX and NO) and anti-inflammatory (such as IL-10) factors.

CONCLUSIONS

The Amaryllidaceae is showcased as a platform highly conducive towards studies in the inflammation arena. Potent activities in instances were observed via in vitro and in vivo models of study, bolstered by the significant amounts of information emerging from traditional forms of medicine. It is conceivable that the family may yield future anti-inflammatory chemotherapeutics, particularly those related to its alkaloid principles.

LC-QToF chemical profiling of Euphorbia grantii Oliv. and its potential to inhibit LPS-induced lung inflammation in rats via the NF-κB, CY450P2E1, and P38 MAPK14 pathways

Acute lung injury (ALI) is a life-threatening syndrome that causes high morbidity and mortality worldwide. The aerial parts of Euphorbia grantii Oliv. were extracted with methanol to give a total methanolic extract (TME), which was further fractionated into dichloromethane (DCMF) and the remaining mother liquor (MLF) fractions. Biological guided anti-inflammatory assays in vitro revealed that the DCMF showed the highest activity (IC50 6.9 ± 0.2 μg/mL and 0.29 ± 0.01 μg/mL) compared to. celecoxib (IC50 of 88.0 ± 1 μg/mL and 0.30 ± 0.01 μg/mL) on COX-1 and COX-2, respectively. Additionally, anti-LOX activity was IC50 = 24.0 ± 2.5 μg/mL vs. zileuton with IC50 of 40.0 ± 0.5 μg/mL. LC-DAD-QToF analysis of TME and the active DCMF resulted in the tentative identification and characterization of 56 phytochemical compounds, where the diterpenes were the dominated metabolites. An LPS-induced inflammatory model of ALI (10 mg/kg i.p) was used to assess the anti-inflammatory potential of DCMF in vivo at dose of 200 mg/kg and 300 mg/kg compared to dexamethasone (5 mg/kg i.p). Our treatments significantly reduced the pro-inflammatory cytokines (TNF-α, IL-1, IL-6, and MPO), increased the activity of antioxidant enzymes (SOD, CAT, and GSH), decreased the activity of oxidative stress enzyme (MDA), and reduced the expression of inflammatory genes (p38.MAPK14 and CY450P2E1). The western blotting of NF-κB p65 in lung tissues was inhibited after orally administration of the DCMF. Histopathological study of the lung tissues, scoring, and immunohistochemistry of transforming growth factor-beta 1 (TGF-β1) were also assessed. In both dose regimens, DCMF of E. grantii prevented further lung damage and reduced the side effects of LPS on acute lung tissue injury.

Bilobalide attenuates lipopolysaccharide‑induced HepG2 cell injury by inhibiting TLR4‑NF‑κB signaling via the PI3K/Akt pathway

Inflammation is involved in the pathological process underlying a number of liver diseases. Bilobalide (BB) is a natural compound from Ginkgo biloba leaves that was recently demonstrated to exert hepatoprotective effects by inhibiting oxidative stress in the liver cancer cell line HepG2. The anti-inflammatory activity of BB has been reported in recent studies. The major objective of the present study was to investigate whether BB could attenuate inflammation-associated cell damage. HepG2 cells were cultured with lipopolysaccharide (LPS) and BB, and cell damage was evaluated by measuring cell viability using MTT assay. The activity of the NF-κB signaling pathway was assessed by measuring the levels of IκBα, NF-κB p65, phosphorylated (p)-IκBα, p-p65, p65 DNA-binding activity and inflammatory cytokines IL-1β, IL-6 and TNF-α. A toll-like receptor (TLR)4 inhibitor (CLI-095) was used to detect the involvement of TLR4 in cell injury caused by LPS. In addition, the PI3K/Akt inhibitor LY294002 was applied to explore the involvement of the PI3K/Akt axis in mediating the effects of BB. The results demonstrated that LPS induced HepG2 cell injury. LPS also elevated the levels of p-IκBα, p-p65, p65 DNA-binding activity and inflammatory cytokines. However, CLI-095 significantly attenuated the LPS-induced cell damage and inhibited the activation of NF-κB signaling. BB also dose-dependently attenuated the LPS-induced cell damage, activation of NF-κB signaling and TLR4 overexpression. Furthermore, it was observed that LY294002 diminished the cytoprotective effects of BB on cell injury, TLR4 expression and NF-κB activation. These findings indicated that BB could attenuate LPS-induced inflammatory injury to HepG2 cells by regulating TLR4-NF-κB signaling.

The inhibitory role of stigmasterol on tumor growth by inducing apoptosis in Balb/c mouse with spontaneous breast tumor (SMMT)

BACKGROUND

Breast cancer is one of the most common types of cancer in women worldwide. Anti-apoptotic activity of cancer cells is considered the main reason for drug resistance in BC which reduces the 5-year survival rate of patients and is still considered the main obstacle for cancer therapy. Stigmasterol (SS) is natural phytosterols compound in the plant which has been proved to play an important role to lower cholesterol and inducing anti-inflammatory, and anticancer properties.

METHODS

In this, study, we aimed to evaluate the effect of SS on the expression of anti-apoptotic genes (Bcl-2 and BCL-XL), and also evaluate its effects on cell apoptosis and cell viability using MCF-7 cell line as well as evaluating its effect on tumor growth of spontaneous breast tumor (SMMT) in vivo.

RESULT

SS significantly decreased the expression of Bcl-2 and BCL-XL genes (*P < 0.05), induced apoptosis, and reduced cell proliferation in MCF-7 cell lines. Our in vivo study also indicated that SS could inhibit tumor size after treatment with (0, 10, 20 µM) compared to the normal control.

CONCLUSION

SS can be suggested as a potential agent in BC cancer treatment or as an adjuvant based on its ability to decrease the expression of Bcl-2 and BCL-XL genes and induce apoptosis.

Anti-Neuroinflammatory Potential of Polyphenols by Inhibiting NF-κB to Halt Alzheimer's Disease

Alzheimer's disease (AD) is an irrevocable chronic brain disorder featured by neuronal loss, microglial accumulation, and progressive cognitive impairment. The proper pathophysiology of this life-threatening disorder is not completely understood and no exact remedies have been found yet. Over the last few decades, research on AD has mainly highlighted pathomechanisms linked to a couple of the major pathological hallmarks, including extracellular senile plaques made of amyloid-β (Aβ) peptides, and intracellular neurofibrillary tangles (NFTs) made of tau proteins. Aβ can induce apoptosis, trigger an inflammatory response, and inhibit the synaptic plasticity of the hippocampus, which ultimately contributes to reducing cognitive functions and memory impairment. Recently, a third disease hallmark, the neuroinflammatory reaction that is mediated by cerebral innate immune cells, has become a spotlight in the current research area, assured by pre-clinical, clinical, and genetic investigations. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), a cytokine producer, is significantly associated with physiological inflammatory proceedings and thus shows a promising candidate for inflammation- based AD therapy. Recent data reveal that phytochemicals, mainly polyphenol compounds, exhibit potential neuroprotective functions and these may be considered as a vital resource for discovering several drug candidates against AD. Interestingly, phytochemicals can easily interfere with the signaling pathway of NF-κB. This review represents the anti-neuroinflammatory potential of polyphenols as inhibitors of NF-κB to combat AD pathogenesis.

Jaceosidin: A Natural Flavone with Versatile Pharmacological and Biological Activities

Nature always remains an inexhaustible source of treasures for mankind. It remains a mystery for every challenge until the completion of the challenge. While we talk about the complicated health issues, nature offers us a great variety of chemical scaffolds and their various moieties packed in the form of natural products e.g., plants, microorganisms (fungi, algae, protozoa), and terrestrial vertebrates and invertebrates. This review article is an update about jaceosidin, a bioactive flavone, from genus Artemisia. This potentially active compound exhibits a variety of pharmacological activities including anti-inflammatory, anti-oxidant, anti-bacterial, antiallergic and anti-cancer activities. The bioactivities and the therapeutic action of jaceosidin, especially the modulation of different cell signaling pathways (ERK1/2, NF-κB, PI3K/Akt and ATM-Chk1/2) which become deregulated in various pathological disorders, have been focused here. The reported data suggest that the bioavailability of this anti-cancer compound should be enhanced by utilizing various chemical, biological and computational techniques. Moreover, it is recommended that researchers and scientists should work on exploring the mode of action of this particular flavone to precede it further as a potent anti-cancer compound.

Borneol protects against cerulein-induced oxidative stress and inflammation in acute pancreatitis mice model

Borneol is a commonly used flavouring substance in traditional Chinese medicine, which possesses several pharmacological activities including analgesic, antiinflammatory, and antioxidant properties. The aim of this study was to investigate the effects of borneol on cerulein-induced acute pancreatitis (AP) model. Swiss albino mice were pretreated with borneol (100 and 300 mg/kg) daily for 7 days, before six consecutive injections of cerulein (50 μg/kg/hr, intraperitoneally). The protective effect of borneol was studied by biochemical, enzyme linked immunosorbent assay, histological, immunoblotting, and immunohistochemical analysis. Oral administration of borneol significantly attenuated pancreatic damage by reducing amylase, lipase levels and histological changes. Borneol attenuated cerulein-induced oxidative-nitrosative stress by decreasing malondialdehyde, nitrite levels, and elevating reduced glutathione levels. Pancreatic inflammation was ameliorated by inhibiting myeloperoxidase activity and pro-inflammatory cytokine (Interleukins and TNF-α) levels. Furthermore, borneol administration significantly increased nuclear factor E2-related factor 2 (Nrf2), superoxide dismutase (SOD1) expression and reduced phospho-NF-κB p65 expression. Treatment with borneol significantly inhibited TNF-α, IL-1β, IL-6, and inducible nitric oxide synthase expression in cerulein-induced AP mouse model. Together, these results indicate that borneol which is currently used as US-FDA approved food adjuvant has the potential to attenuate cerulein-induced AP possibly by reducing the oxidative damage and pancreatic inflammation by modulating Nrf2/NF-κB pathway.

Germacrone: A Potent Secondary Metabolite with Therapeutic Potential in Metabolic Diseases, Cancer and Viral Infections

Natural products, an infinite reserve of bioactive molecules, will continue to serve humans as an important source of therapeutic agents. Germacrone is a bioactive natural compound found in the traditional medicinal plants of family Zingiberaceae. This multifaceted chemical entity has become a point of focus during recent years due to its numerous pharmacological applications, e.g., anticancer, anti-inflammatory, antiviral, antioxidant, anti-adipogenic, anti-androgenic, antimicrobial, insecticidal, and neuroprotective. Germacrone is an effective inducer of cell cycle arrest and apoptosis in various cancers (breast, brain, liver, skin, prostate, gastric, and esophageal) via modulation of different cell signaling molecules and pathways involved in cancer proliferation. This is the first report highlighting the wide spectrum of pharmacological activities exhibited by germacrone. The reported data collected from various shreds of evidences recommend that this multifaceted compound could serve as a potential drug candidate in the near future.

Natural Compounds Therapeutic Features in Brain Disorders by Experimental, Bioinformatics and Cheminformatics Methods

BACKGROUND

Synthetic compounds with pharmaceutical applications in brain disorders are daily designed and synthesized, with well first effects but also seldom severe side effects. This imposes the search for alternative therapies based on the pharmaceutical potentials of natural compounds. The natural compounds isolated from various plants and arthropods venom are well known for their antimicrobial (antibacterial, antiviral) and antiinflammatory activities, but more studies are needed for a better understanding of their structural and pharmacological features with new therapeutic applications.

OBJECTIVES

Here we present some structural and pharmaceutical features of natural compounds isolated from plants and arthropods venom relevant for their efficiency and potency in brain disorders. We present the polytherapeutic effects of natural compounds belonging to terpenes (limonene), monoterpenoids (1,8-cineole) and stilbenes (resveratrol), as well as natural peptides (apamin, mastoparan and melittin).

METHODS

Various experimental and in silico methods are presented with special attention on bioinformatics (natural compounds database, artificial neural network) and cheminformatics (QSAR, drug design, computational mutagenesis, molecular docking).

RESULTS

In the present paper we reviewed: (i) recent studies regarding the pharmacological potential of natural compounds in the brain; (ii) the most useful databases containing molecular and functional features of natural compounds; and (iii) the most important molecular descriptors of natural compounds in comparison with a few synthetic compounds.

CONCLUSION

Our paper indicates that natural compounds are a real alternative for nervous system therapy and represents a helpful tool for the future papers focused on the study of the natural compounds.

Effects of ginseng supplementation on selected markers of inflammation: A systematic review and meta-analysis

The present meta-analysis was performed to evaluate the efficacy of ginseng administration on serum level of inflammatory biomarkers. We performed a systematic search of all available randomized controlled trials (RCTs) conducted up to June 2018 in the following electronic databases: PubMed, Scopus, Cochrane, and Google Scholar. RCTs that investigated the effect ginseng supplementation on high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were included for final analysis. A total of seven RCTs were included in the meta-analysis. Results indicated significant reduction in IL-6 (mean difference [MD]: -0.265 pg/ml, 95% CI [-0.396, -0.135], p < .001) and TNF-α (MD: -2.471 pg/ml, 95% CI [-2.904, -2.039], p < .001) and no significant change in hs-CRP (MD: -0.125 mg/L, 95% CI [-0.597, 0.347], p = .604). Although there was publication bias across studies, trim and fill analysis showed that results from unpublished studies could not change the results for CRP. However, removing one study in sensitivity analysis did reveal a significant reduction in CRP. We conclude that ginseng supplementation significantly lowered IL-6 and TNF-α but did not significantly lower CRP. However, these findings were not robust, because they showed sensitivity for CRP and IL-6, and future long-term well-designed dose-escalating trials are required.

Anti-inflammatory effect of aerial bulblets of Dioscorea japonica Thunb extract through inhibition of NF-κB and MAPK signalling pathway in RAW 264.7

BACKGROUND

Yam (Dioscorea japonica Thunb) is a well-known health food in Korea and is widely distributed in the temperate and tropical regions. Although various medical effects of yam have been demonstrated, there is little current knowledge on the efficacy of Youngyeoja (YYJ; the aerial bulblets of the yam plant), their physiological effects, and their mechanism of action.

METHODS

To investigate the anti-inflammatory effects of YYJ, we examined the level of inflammatory mediators in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells treated with YYJ extract. Nitric oxide (NO) and prostaglandin E2 (PGE2) levels were determined using enzyme-linked immunosorbent assays. Expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were evaluated using real-time polymerase chain reaction and western blotting. In addition, activation of nuclear factor-kappaB (NF-κB) and mitogen-activated protein kinase (MAPK) was detected using western blotting.

RESULTS

Treatment of macrophages with LPS markedly induced the production of NO and PGE2. YYJ treatment inhibited the induction of inflammatory mediators and the expression of iNOS and COX-2. More importantly, LPS-induced phosphorylation of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor (IκB) was suppressed by treatment with YYJ, suggesting YYJ inhibited NF-κB activation. Furthermore, YYJ inhibited the LPS-induced phosphorylation of MAPKs.

CONCLUSION

YYJ was shown to have a potent anti-inflammatory effect in LPS-stimulated RAW 264.7 cells, which may be attributed to its inhibitory effect on NF-κB and MAPK activation, consequently blocking the production of inflammatory factors. Therefore, these results suggest that the YYJ extracts could be used as anti-inflammatory agents.