Potential anti-inflammatory and antioxidant effects of Citrus aurantium essential oil against carbon tetrachloride-mediated hepatotoxicity: A biochemical, molecular and histopathological changes in adult rats

Therapeutic potential of the linalool against cadmium-induced testicular tissue damage

Cadmium (Cd) is a heavy metal that has harmful effects and is one of the contaminants found in the environment. Cd exposure causes important pathophysiological processes, such as reproductive toxicity. Linalool (Lnl) is a monoterpene, a component of essential oils known to be produced synthetically. Additionally, Lnl has many important beneficial effects, such as anti-inflammatory and antioxidant effects. The objective of this study is to determine whether Lnl has a healing impact in opposition to testicular tissue damage due to Cd exposure. In the study, 28 male rats were divided at random into four equal groups (n = 7). No treatment was applied to the control group. CdCl2 was applied intraperitoneally to the Cd group at a dose of 3 mg/kg for the first 7 days of the trial. For the Cd + Lnl group, 3 mg/kg CdCl2 was applied intraperitoneally for the first 7 days of the trial, and 100 mg/kg/day Lnl was applied. Upon completion of all applications, the rats were sacrificed and blood samples and testicular tissue were taken. Cd exposure caused histopathological changes, oxidative stress, inflammation, and an increase in apoptotic cells in testicular tissue. However, Cd altered endocrine hormones in the hypothalamic-pituitary-gonad axis. However, Lnl application against Cd exposure was able to regulate the negativity caused by Cd in both testicular tissue and endocrine hormone levels. In conclusion, Lnl may be a potential therapeutic strategy against Cd-induced reproductive toxicity. We believe that Lnl has a high potential for further studies to determine its detailed mechanisms of action and cellular signaling pathways.

Mandarin peel ethanolic extract attenuates diclofenac sodium induced hepatorenal toxicity in rats by mitigating oxidative stress and inflammation

Nonsteroidal anti-inflammatory drugs (NSAIDs) constitute approximately one-third of the global pharmaceutical market and are the first drugs of choice when treating fever and pain. Furthermore, among NSAIDs, the use of diclofenac sodium (DS) is preferred as it is a strong inhibitor of cyclooxygenase enzyme. However, despite its strong efficacy, DS is known for its potential to cause hepatorenal damage. Currently, to mitigate the adverse effects of certain drugs, medically effective agricultural products are often preferred as they are inexpensive, effective and safe. One such agricultural product-mandarin-is noteworthy for its high phenolic contents. The purpose of the present study was to assess the efficacy of mandarin peel ethanolic extract (MPEE) in protecting against hepatorenal damage induced by DS. Four groups (six/group) of adult male albino rats received oral administration of physiological saline (control group), DS (10 mg/kg body weight), MPEE (200 mg/kg body weight), and DS + MPEE for 7 days. Rats in the DS group showed increased serum levels of ALT, AST, ALP, BUN, CRE, and UA. Furthermore, the hepatic and renal tissue levels of MDA, TNF-α and IL-1β increased, whereas those of GSH, SOD, GP-x and IL-10 decreased (p < 0.05). Investigation of MPEE in terms of its effects on biochemical, oxidative and inflammatory parameters, it exerted protective and healing effects. Therefore, MPEE can be used to ameliorate DS-induced hepatorenal damage.

Hepatoprotective effects of Niudali (Callerya speciosa) root aqueous extracts against tetrachloromethane-induced acute liver injury and inflammation

Niudali (Callerya speciosa) is commonly grown in southeastern regions of China and consumed as a food ingredient. Although Niudali root extracts showed various biological activities, the hepatoprotective effects of Niudali root phytochemicals are not fully studied. Herein, we prepared two Niudali root aqueous extracts, namely, c and Niudali polysaccharides-enriched extract (NPE), and identified an alkaloid, (hypaphorine) in NEW. The hepatoprotective effects of NWE, NPE, and hypaphorine were evaluated in an acute liver injury model induced by carbon tetrachloride (CCl4) in mice. Pathohistological examination and blood chemistry assays showed that treatment of NWE, NPE, and hypaphorine alleviated CCl4-induced liver damage by lowering the liver injury score (by 75.51%, 80.01%, and 41.22%) and serum aspartate and alanine transaminases level (by 63.24%, 85.22%, and 49.74% and by 78.73%, 80.08%, and 81.70%), respectively. NWE, NPE, and hypaphorine also reduced CCl4-induced hepatic oxidative stresses in the liver tissue by decreasing the levels of malondialdehyde (by 40.00%, 51.25%, and 28.75%) and reactive oxygen species (by 30.22%, 36.14%, and 33.54%) while increasing the levels of antioxidant enzymes including superoxide dismutase (by 21.36%, 21.64%, and 8.90%), catalase (by 22.13%, 33.33%, and 5.39%), and glutathione (by 84.87%, 90.65%, and 80.53%), respectively. Mechanistic assays showed that NWE, NPE, and hypaphorine alleviated liver damage by mediating inflammatory biomarkers (e.g., pro-inflammatory cytokines) via the signaling pathways of mitogen-activated protein kinases and nuclear factor-κB. Findings from our study extend the understanding of Niudali's hepatoprotective effects, which is useful for its development as a dietary intervention for liver inflammation.

Targeting NF-κB pathway for the anti-inflammatory potential of Bhadradarvadi kashayam on stimulated RAW 264.7 macrophages

Macrophage-arbitrated inflammation is associated with the regulation of rheumatoid arthritis (RA). Low risk and better efficiency are steered herbal drugs more credible than conventional medicines in RA management. Bhadradarvadi (BDK) concoction has been traditionally used for rheumatism in Ayurveda. However, the mechanisms at the molecular level are still elusive. This study was designed to inspect the process of immunomodulation and anti-inflammatory properties of BDK in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages for the first time. BDK concoction was prepared and evaluated with the stimulated murine macrophage-like RAW 264.7 cell lines. TNF-α, IL6, and PGE2 were quantified by ELISA. The normalization of the fold change in the expression of the target gene mRNA was done by comparing the values of the β-actin housekeeping gene using the 2-ΔΔCt comparative cycle threshold. The expression of TNF-α, IL6, iNOS, and COX-2 in the RAW 264.7 macrophage cells was analyzed using flow cytometry. Our results showed that BDK (150-350 μl/ml) treatment significantly decreased the inflammatory cytokines (TNF-α, and IL-6) and inflammatory mediators (PGE2) in LPS-stimulated RAW 264.7 macrophage cells. The pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) expression, inflammatory enzymes (iNOS and COX-2), and NF-κBp65 were significantly downregulated at transcriptome level in LPS-stimulated RAW 264.7 macrophage cells. The flow cytometry analysis revealed that BDK treatment diminished the TNF-α, IL-6, iNOS, and COX-2 expression at the proteome level, as well as obstruction of NF-κB-p65 nuclear translocation was observed by immunofluorescence analysis in LPS-stimulated RAW 264.7 macrophage cells. Collectively, BDK can intensely augment the anti-inflammatory activities via inhibiting the NF-κB signaling pathway trigger for treating autoimmune disorders including RA.

Progress of research on the role of active ingredients of Citri Reticulatae Pericarpium in liver injury

BACKGROUND

Liver is a vital organ responsible for metabolizing and detoxifying both endogenous and exogenous substances in the body. However, it is susceptible to damage from chemical and natural toxins. The high incidence and mortality rates of liver disease and its associated complications impose a significant economic burden and survival pressure on patients and their families. Various liver diseases exist, including cholestasis, viral and non-viral hepatitis, fatty liver disease, drug-induced liver injury, alcoholic liver injury, and severe end-stage liver diseases such as cirrhosis, hepatocellular carcinoma (HCC), and cholangiocellular carcinoma (CCA). Recent research has shown that flavonoids found in Citri Reticulatae Pericarpium (CRP) have the potential to normalize blood glucose, cholesterol levels, and liver lipid levels. Additionally, these flavonoids exhibit anti-inflammatory properties, prevent oxidation and lipid peroxidation, and reduce liver toxicity, thereby preventing liver injury. Given these promising findings, it is essential to explore the potential of active components in CRP for developing new drugs to treat liver diseases.

OBJECTIVE

Recent studies have revealed that flavonoids, including hesperidin (HD), hesperetin (HT), naringenin (NIN), nobiletin (NOB), naringin (NRG), tangerine (TN), and erodcyol (ED), are the primary bioactive components in CRP. These flavonoids exhibit various therapeutic effects on liver injury, including anti-oxidative stress, anti-cytotoxicity, anti-inflammatory, anti-fibrosis, and anti-tumor mechanisms. In this review, we have summarized the research progress on the hepatoprotective effects of HD, HT, NIN, NOB, NRG, TN, ED and limonene (LIM), highlighting their underlying molecular mechanisms. Despite their promising effects, the current clinical application of these active ingredients in CRP has some limitations. Therefore, further studies are needed to explore the full potential of these flavonoids and develop new therapeutic strategies for liver diseases.

METHODS

For this review, we conducted a systematic search of three databases (ScienceNet, PubMed, and Science Direct) up to July 2022, using the search terms "CRP active ingredient," "liver injury," and "flavonoids." The search data followed the PRISMA standard.

RESULTS

Our findings indicate that flavonoids found in CRP can effectively reduce drug-induced liver injury, alcoholic liver injury, and non-alcoholic liver injury. These therapeutic effects are mainly attributed to the ability of flavonoids to improve liver resistance to oxidative stress and inflammation while normalizing cholesterol and liver lipid levels by exhibiting anti-free radical and anti-lipid peroxidation properties.

CONCLUSION

Our review provides new insights into the potential of active components in CRP for preventing and treating liver injury by regulating various molecular targets within different cell signaling pathways. This information can aid in the development of novel therapeutic strategies for liver disease.

Investigation of the phytochemical composition and remedial effects of southern grape hyacinth (Muscari neglectum Guss. ex Ten.) plant extract against carbon tetrachloride-induced oxidative stress in rats

We aimed to determine the phytochemical contents of the aerial part M. neglectum aerial part (MAP) and M. neglectum bulb (MB) ethanolic extract of Muscari neglectum and to investigate their protective effects on gastric damage induced by carbon tetrachloride (CCl₄) in rats. After the toxicity testing, 42 female Wistar albino rats were divided into 7 groups, Control, MAP, MB, CCl₄, CCl₄ + MAP, CCl₄ + MB, and CCl₄ + Silymarin groups. At the end of the experiment, the serum biochemical parameters, antioxidant defense enzymes, and malondialdehyde (MDA) contents in the stomach tissue were evaluated to determine the antioxidant role of the M. neglectum extracts. According to the gas chromatography-mass spectroscopy, fatty acid analysis, octadecadienoic, and 9,12,15 octadecatrienoic fatty acids were found as major fatty acids in the MAP, whereas 9,12 octadecadienoic and octadecanoic acids were the major fatty acids in the MB. According to the liquid chromatography-tandem mass spectrometry, quinic acid, fumaric acid, gentisic acid, caffeic acid, kaempferol, and apigenin were found in the MAP, while quinic acid, fumaric acid, caffeic acid, and kaempferol were found in the MB. The total phenolic and flavonoid contents in the extract were determined in the MAP and MB. The MAP and MB extracts generally caused a statistically significant decrease in the MDA content and increase in the antioxidant parameters in the stomach tissue. It was concluded that MAP and MB extracts may have antioxidant and gastric protective effects due to the phytochemical content of M. neglectum.HighlightsAccording to LC-MS/MS results, quinic acid, fumaric acid, chemferol, apigenin, and caffeic acid were determined as major compounds in M. neglectum extracts.According to GC-MS results, octadecadienoic, octadecatrienoic, and octadecanoic methyl esters were the major fatty acids of the M. neglectum extracts.The M. neglectum extracts regulated the levels of stomach damage and biochemical parameters.The M. neglectum extracts extract might have pharmaceutical-nutritional potential.

Immunomodulatory effect of Linalool (Lin) against CCl4 -induced hepatotoxicity and oxidative damage in rats

The current study explored the hepatoprotective and immunomodulatory effects of Linalool (Lin) against carbon tetrachloride (CCl₄ )-induced toxicity in mice. Four study groups (n = 8 each) were used: (1) a negative control group and (2) a toxicity control group (single dose of CCl₄ administered on day 14 as 1 mL/kg of CCL₄ in 1% olive oil). Intraperitoneally (i.p.)), and two experimental groups where mice were treated with either (3) Lin (25 mg/kg b.w., orally, daily for 15 days) or (4) pretreated with Lin (25 mg/kg b.w., orally, daily for 14 days) and intoxicated with CCl₄ (1 mL/kg of CCL₄ in 1% olive oil. i.p.) on day 14. The levels of the anti-inflammatory cytokine interleukin 10 (IL-10), the proinflammatory cytokines TNF-α, IL-6, and TGF-1β, and the histopathology of the liver were assessed. According to our findings, IL-10 concentrations were significantly increased in Lin-treated groups, while other cytokine levels were marked by a considerable decrease in the toxicity model group (CCl₄ -treated group). Histopathological examinations of liver tissues showed that the Lin-treated groups had an almost normal structure. The current findings showed that Lin could inhibit CCl₄ -induced liver injury in mice, which warrants further investigation of Lin as a potential protective and therapeutic agent against hepatotoxicity.

Identification of hepatoprotective traditional Chinese medicines based on the structure–activity relationship, molecular network, and machine learning techniques

The efforts focused on discovering potential hepatoprotective drugs are critical for relieving the burdens caused by liver diseases. Traditional Chinese medicine (TCM) is an important resource for discovering hepatoprotective agents. Currently, there are hundreds of hepatoprotective products derived from TCM available in the literature, providing crucial clues to discover novel potential hepatoprotectants from TCMs based on predictive research. In the current study, a large-scale dataset focused on TCM-induced hepatoprotection was established, including 676 hepatoprotective ingredients and 205 hepatoprotective TCMs. Then, a comprehensive analysis based on the structure–activity relationship, molecular network, and machine learning techniques was performed at molecular and holistic TCM levels, respectively. As a result, we developed an in silico model for predicting the hepatoprotective activity of ingredients derived from TCMs, in which the accuracy exceeded 85%. In addition, we originally proposed a material basis and a drug property-based approach to identify potential hepatoprotective TCMs. Consequently, a total of 12 TCMs were predicted to hold potential hepatoprotective activity, nine of which have been proven to be beneficial to the liver in previous publications. The high rate of consistency between our predictive results and the literature reports demonstrated that our methods were technically sound and reliable. In summary, systematical predictive research focused on the hepatoprotection of TCM was conducted in this work, which would not only assist screening of potential hepatoprotectants from TCMs but also provide a novel research mode for discovering the potential activities of TCMs.

Bio-Stimulating Effect of Natural Polysaccharides from Lobularia maritima on Durum Wheat Seedlings: Improved Plant Growth, Salt Stress Tolerance by Modulating Biochemical Responses and Ion Homeostasis

Bioactivities of polysaccharides derived from halophyte plants have gained attention in recent years. The use of biostimulants in agriculture is an innovative method of dealing with environmental stressors affecting plant growth and development. Here, we investigated the use of natural polysaccharides derived from the halophyte plant Lobularia maritima (PSLm) as a biostimulant in durum wheat seedlings under salt stress. Treatment with polysaccharide extract (0.5, 1, and 2 mg/mL PSLm) stimulated in vitro wheat growth, including germination, shoot length, root length, and fresh weight. PSLm at 2 mg/mL provided tolerance to plants against NaCl stress with improved membrane stability and low electrolyte leakage, increased antioxidant activities (catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD)), enhanced leaf chlorophyll fluorescence, proline, and total sugar contents, decreased lipid peroxidation (MDA), and reactive oxygen species (H₂O₂) levels, and coordinated the efflux and compartmentation of intracellular ions. The expression profile analyses of ten stress-related genes (NHX1, HKT1.4, SOS1, SOD, CAT, GA20-ox1, GA3-ox1, NRT1.1, NRT2.1, and GS) using RT-qPCR revealed the induction of several key genes in durum wheat growing in media supplemented with PSLm extract, even in unstressed conditions that could be related to the observed tolerance. This study revealed that PSLm extract contributes to salt tolerance in durum wheat seedlings, thereby enhancing their reactive oxygen species scavenging ability, and provided evidence for exploring PSLm as a plant biostimulant for sustainable and organic agriculture.

Thiamine Demonstrates Bio-Preservative and Anti-Microbial Effects in Minced Beef Meat Storage and Lipopolysaccharide (LPS)-Stimulated RAW 264.7 Macrophages

This study assessed the anti-inflammatory effect of thiamine (TA) in lipopolysaccharide-stimulated RAW264.7 cells and also assessed the preservative properties of TA in minced beef. TA demonstrated a concentration-dependent antimicrobial effect on microbial contaminants. Inhibition zones and MIC from the effect of TA on the tested bacterial strains were respectively within the ranges 15−20 mm and 62.5−700 µg/mL. TA significantly (p < 0.05) decreased all the pro-inflammatory factors [(nitric oxide (NO), prostaglandin E2 (PGE2), TNF-α, IL-6, IL-1β, and nuclear factor-κB (NF-κB)] monitored relative to LPS-stimulated RAW264.7 cells. TA inhibited the expression of both iNOS and COX-2. In minced beef flesh, the growth of Listeria monocytogenes was inhibited by TA. TA improved physicochemical and microbiological parameters of stored minced beef meat compared to control. Principal component analyses and heat maps elucidate the quality of the tested meats.

Antioxidant and hepatoprotective effects of novel heteropolysaccharide isolated from Lobularia maritima on CCl4‐induced liver injury in rats

The aim of the present study was to investigate the extraction and the characterization of a novel heteropolysaccharide from Tunisian halophyte Lobularia maritima (LmPS). We were also interested in its antioxidant, anti‐inflammatory, and hepatoprotective effects on carbon tetrachloride (CCl₄)‐induced liver injury in rats. LmPS physicochemical properties were evaluated by thin‐layer chromatography (TLC), high‐performance liquid chromatography (HPLC), thermogravimetric analysis (TGA), and UV absorption. According to TLC and HPLC results, LmPS was a heteropolysaccharide composed of glucose, galactose, and xylose. Its molecular weight was 130.62 kDa. This heteropolysaccharide was characterized by a significant antioxidant potential and was efficient against oxidative stress and CCL₄‐induced hepatotoxicity in rat Wistar models (n = 8) treated with a single dose of LmPS 250 mg/kg of body weight. This was evidenced by a significant increase in serum marker enzymes specially aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH). The cytokines released after stimulation of rats with LmPS showed high anti‐inflammatory profiles with an increased rate of interleukine‐10 (IL‐10) with 0.03 pg/mL compared to animals treated only with CCl₄. On the contrary, we noticed a decrease of the other cytokines (tumor necrosis factor α: TNF‐α, interleukine‐6: IL‐6, transforming growth factor beta 1: TGF‐β1) with average concentration values of <0.2, 0.1, and 0.04 pg/mL, respectively. Besides, histopathological examinations revealed that CCl₄ causes acute liver damage, characterized by extensive hepatocellular necrosis, vacuolization, and inflammatory cell infiltration, as well as DNA fragmentation. LmPS administration at a dose of 250 mg/kg resulted in a significant hepatoprotection, evidenced by a reduction of CCl₄‐induced oxidative damage for all tested markers. These findings eagerly confirmed that LmPS was effective in the protection against CCl₄‐induced hepatotoxicity and genotoxicity. It, therefore, suggested a potential therapeutic use of this polysaccharide as an alternative medicine for patients with acute liver diseases.

Concentration of Potentially Toxic Elements in Vegetable Oils and Health Risk Assessment: a Systematic Review and Meta-analysis

The present study evaluates the concentration of potentially toxic elements (PTEs), including Pb, Cd, As, Fe, Zn, Cu, and Ni, in vegetable oils through a meta-analytic approach. The published studies in relation to the concentrations of PTEs in vegetable oils were retrieved from major international databases such as PubMed, Scopus, Web of Science, and Embase followed by meta-analysis. Moreover, the health risk assessment was evaluated using total target hazard quotient (TTHQ) by a Monte Carlo simulation (MCS) model. According to the results of 51 articles included among 958 retrieved studies, the concentrations of the PTEs were as follows: Cd ≈As (0.110 mg/kg) > Pb (0.086 mg/kg) in cottonseed, canola, and olive oil and Fe (12.964 mg/kg) > Zn (1.044 mg/kg) > Ni (0.893 mg/kg) > Cu (0.264 mg/kg) in cottonseed, olive, and soybean for trace elementals, respectively. Based on the continent type, the higher concentration of Cd, As, and Pb was related to PAHO (American region) and AFRO (African region), and the higher concentrations of Fe, Zn, Cu, and Ni were observed in WPRO (Western Pacific Region), EMRO (Eastern Mediterranean Region), and AFRO. On the other hand, non-carcinogenic health risk assessment of the PTEs indicated that there was a different risk pattern in various countries, and the TTHQ level in adult groups was lower than 1. It can be concluded that the consumption of vegetable oils is safe and does not pose risk to the health of consumers.

Citrus aurantium L. Active Constituents, Biological Effects and Extraction Methods. An Updated Review

Citrus genus is a prominent staple crop globally. Long-term breeding and much hybridization engendered a myriad of species, each characterized by a specific metabolism generating different secondary metabolites. Citrus aurantium L., commonly recognized as sour or bitter orange, can exceptionally be distinguished from other Citrus species by unique characteristics. It is a fruit with distinctive flavor, rich in nutrients and phytochemicals which possess different health benefits. This paper presents an overview of the most recent studies done on the matter. It intends to provide an in-depth understanding of the biological activities and medicinal uses of active constituents existing in C. aurantium. Every plant part is first discussed separately with regards to its content in active constituents. All extraction methods, their concepts and yields, used to recover these valuable molecules from their original plant matrix are thoroughly reported.

Cannabinoid Type-2 Receptor Agonist, JWH133 May Be a Possible Candidate for Targeting Infection, Inflammation, and Immunity in COVID-19

The COVID-19 pandemic, caused by SARS-CoV-2, is a deadly disease affecting millions due to the non-availability of drugs and vaccines. The majority of COVID-19 drugs have been repurposed based on antiviral, immunomodulatory, and antibiotic potential. The pathogenesis and advanced complications with infection involve the immune-inflammatory cascade. Therefore, a therapeutic strategy could reduce infectivity, inflammation, and immune modulation. In recent years, modulating the endocannabinoid system, particularly activation of the cannabinoid type 2 (CB2) receptor is a promising therapeutic target for modulation of immune-inflammatory responses. JWH133, a selective, full functional agonist of the CB2 receptor, has been extensively studied for its potent anti-inflammatory, antiviral, and immunomodulatory properties. JWH133 modulates numerous signaling pathways and inhibits inflammatory mediators, including cytokines, chemokines, adhesion molecules, prostanoids, and eicosanoids. In this study, we propose that JWH133 could be a promising candidate for targeting infection, immunity, and inflammation in COVID-19, due to its pharmacological and molecular mechanisms in numerous preclinical efficacy and safety studies, along with its immunomodulatory, anti-inflammatory, organoprotective, and antiviral properties. Thus, JWH133 should be investigated in preclinical and clinical studies for its potential as an agent or adjuvant with other agents for its effect on viremia, infectivity, immune modulation, resolution of inflammation, reduction in severity, and progression of complications in COVID-19. JWH133 is devoid of psychotropic effects due to CB2 receptor selectivity, has negligible toxicity, good bioavailability and druggable properties, including pharmacokinetic and physicochemical effects. We believe that JWH133 could be a promising drug and may inspire further studies for an evidence-based approach against COVID-19.

A Review of the Potential Use of Pinene and Linalool as Terpene-Based Medicines for Brain Health: Discovering Novel Therapeutics in the Flavours and Fragrances of Cannabis

"Medicinal cannabis" is defined as the use of cannabis-based products for the treatment of an illness. Investigations of cannabis compounds in psychiatric and neurological illnesses primarily focus on the major cannabinoids, cannabidiol (CBD) and Δ9-tetrahydrocannabinol (Δ9-THC), which are hypothesised to benefit multiple illnesses manifesting cognitive impairment, neurodegeneration and neuro-inflammation, as well as chronic pain, epilepsy and post-traumatic stress disorder, respectively. The cannabis plant contains >500 compounds, including terpenes responsible for the flavour and fragrance profiles of plants. Recently, research has begun providing evidence on the potential use of certain plant-derived terpenes in modern medicine, demonstrating anti-oxidant, anti-inflammatory, and neuroprotective effects of these compounds. This review examined the effects of two key terpenes, pinene and linalool, on parameters relevant to neurological and psychiatric disorders, highlighting gaps in the literature and recommendations for future research into terpene therapeutics. Overall, evidence is mostly limited to preclinical studies and well-designed clinical trials are lacking. Nevertheless, existing data suggests that pinene and linalool are relevant candidates for further investigation as novel medicines for illnesses, including stroke, ischemia, inflammatory and neuropathic pain (including migraine), cognitive impairment (relevant to Alzheimer's disease and ageing), insomnia, anxiety, and depression. Linalool and pinene influence multiple neurotransmitter, inflammatory and neurotrophic signals as well as behaviour, demonstrating psycho-activity (albeit non-intoxicating). Optimising the phytochemical profile of cannabis chemovars to yield therapeutic levels of beneficial terpenes and cannabinoids, such as linalool, pinene and CBD, could present a unique opportunity to discover novel medicines to treat psychiatric and neurological illnesses; however, further research is needed.

A Review of Research Progress on Agathis dammara and its Application Prospects for Cardiovascular Diseases and Fatty Liver Disease

Cardiovascular diseases and fatty liver disease have become the leading causes of death in modern society. However, the currently existing drugs do not solve all issues related to these diseases; thus, it is expected that more potential drugs for clinical use will be developed. Undeniably, natural products have attracted increasing attention. It is of great significance to identify effective active monomer components for drug discovery and disease prevention. As a pure natural product, Agathis dammara (AD) has antioxidant, hypolipidemic, hypoglycemic, antitumor, and anti-inflammatory activities. However, at present, there are few reports regarding the effects of AD on chronic inflammatory cardiovascular diseases, such as aneurysm, atherosclerosis, myocardial ischemia-reperfusion injury, and cardiac hypertrophy and liver diseases such as fatty liver disease. AD and products derived from it have a very broad application prospect for cardiovascular diseases and fatty liver disease.

Novel non-specific lipid-transfer protein (TdLTP4) isolated from durum wheat: Antimicrobial activities and anti-inflammatory properties in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages

Lipid transfer proteins (LTP) are members of the family of pathogenesis-related proteins (PR-14) that play a key role in plant defense mechanisms. In this study, a novel gene TdLTP4 encoding an antifungal protein from wheat (cv. Om Rabiaa) was cloned, overexpressed in Escherichia coli BL-21 (DE3) and enriched using ammonium sulfate fractionation. The TdLTP4 fusion protein was then tested against a panel of pathogens, food-borne and spoilage bacteria and fungi in order to evaluate the antimicrobial properties. TdLTP4 was applied to 0.5 μg/mL LPS-induced RAW 264.7 macrophages in vitro at different concentrations (5, 10, 20, 50 and 100 μg/mL). Levels of nitric oxide (NO), pro-inflammatory cytokines interleukin (IL)-1β (IL-1 β), interleukin (IL)-6 (IL-6), tumor necrosis factor (TNF-α) and anti-inflammatory cytokine IL-10 in the supernatant fraction were measured using enzyme-linked immunosorbent assay (ELISA). Expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) were detected via Western blot. The inhibition zones and minimal inhibitory concentration (MIC) values of bacterial strains were in the range of 14-26 mm and 62.5-250 μg/mL, respectively. Moreover, a remarkable activity against several fungal strains was revealed. TdLTP4 (5-100 μg/mL) decreased the production of NO (IC₅₀ = 4.32 μg/mL), IL-6 (IC₅₀ = 11.52 μg/mL), IL-1β (IC₅₀ = 7.87 μg/mL) and TNF-α (IC₅₀ = 8.66 μg/mL) by lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. TdLTP4 could modulate the macrophages inflammatory mode by causing reduction in iNOS and COX-2. According to these findings, TdLTP4 fusion protein could be used as natural anti-inflammatory and antimicrobial agent in food preservation and human health.

Protocatechuic acid protects against hepatorenal toxicities in rats exposed to Furan

Furan formed in processed food is hepatotoxic and likely carcinogenic in humans. We investigated protocatechuic acid (PCA) protective role in rats' hepatorenal function treated with furan. Rats were grouped and treated as follows: Control, PCA (50 mg/kg), furan alone (8 mg/kg), furan + PCA1 (25 + 8 mg/kg), and furan + PCA2 (50 + 8 mg/kg). Upon sacrifice, evaluation of hepatorenal function, oxidative stress status, reactive oxygen and nitrogen species (RONS), lipid peroxidation (LPO), myeloperoxidase (MPO) activity, among nitric oxide (NO) levels were performed. Cytokine levels (IL-10, IL-1ß, TNF-alpha), Caspase 3 and 9 activities, and histopathological examination were also assessed. We found that the final body and relative liver weights changed significantly (p < 0.05) in treated groups. Hepatic transaminases, urea, and creatinine increased (p < 0.05) in furan only treated group, and reduced in PCA co-treated groups. The furan-induced decrease in antioxidant status increased RONS, and LPO levels were alleviated (p < 0.05) by PCA co-treatment. Furthermore, furan-mediated increase in NO, IL-1ß, TNF-alpha levels, MPO, Cas-3, and 9 activities and suppressed IL-10 levels was reversed accordingly in rats' kidney and liver co-treated with PCA. The extent of furan-mediated hepatorenal lesions was lessened in PCA co-treated rats. Our findings suggest that PCA protects against oxido-inflammatory pathways, enhanced caspases 3 and 9 activations induced by furan in rat hepatorenal system.

Insights into the chemical composition and bioactivities of citrus peel essential oils

Citrus peel (CP), a by-product of the citrus fruit processing, comprises nearly forty to fifty percent of the fruit portion. Interestingly, the essential oil (EO) is primarily concentrated in the peel portion of the citrus fruit. Extraction of CP essential oil (CPEO) is an effective way of utilizing the citrus fruit processing waste. The CPEO can be more efficiently recovered from CP waste by improving the efficiency of conventional extraction processes. The main components of CPEO include monoterpenes, sesquiterpenes and their oxygenated derivatives. Specifically, limonene is the major oil component identified in the peel of different citrus species. The health promoting biological activities of CPEO are functioning as antioxidant, anti-inflammatory, analgesic, antimicrobial and anticancer agents, thereby can be used as a source of functional components and preservatives for the development of nutritionally safe newer food products. This paper provides an in-depth knowledge about the chemical constituents and bioactivities of EOs extracted from peels of different citrus species.

LC-MS-based identification of bioactive compounds and hepatoprotective and nephroprotective activities of Bignonia binata leaves against carbon tetrachloride-induced injury in rats

The chemical profiling of the main phytoconstituents of total ethanolic extract (TEE) and its different fractions of Bignonia binata leaves was dereplicated using liquid chromatography-high resolution-electrospray ionisation-mass spectrometry (LC-HR-ESI-MS), revealed the presence of various classes of secondary metabolites; eight phenylethanoids, two flavonoidal glycosides and two iridoids. Moreover, the hepatoprotective and nephroprotective activities of the TEE and its different fractions were investigated in carbon tetrachloride (CCl₄)-intoxicated rats and were compared with those of silymarin-treated group, revealing the highest potency of the EtOAc group, followed by the aqueous one in improving the CCl₄-induced alterations in several biochemical parameters. Besides, EtOAc and aqueous fractions exhibited the most inhibition of CCl₄-induced inflammatory mediators and improving the changes in the histopathological structures of the liver and kidney. In addition, the EtOAc fraction demonstrated the highest total phenolic content, whereas TEE showed the highest amount of total flavonoid content.

Can limonene be a possible candidate for evaluation as an agent or adjuvant against infection, immunity, and inflammation in COVID-19?

Coronavirus disease (COVID-19) caused by novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an ongoing pandemic and presents a public health emergency. It has affected millions of people and continues to affect more, despite the tremendous social preventive measures. The therapeutic strategy relies on suppressing infectivity and inflammation, along with immune modulation. The identification of candidate drugs effective for COVID-19 is crucial, thus many natural products including phytochemicals are also being proposed for repurposing and evaluated for their potential in COVID-19. Among numerous phytochemicals, limonene (LMN), a dietary terpene of natural origin has been recently showed to target viral proteins in the in-silico studies. LMN is one of the main compounds identified in many citrus plants, available and accessible in diets and well-studied for its therapeutic benefits. Due to dietary nature, relative safety and efficacy along with favorable physicochemical properties, LMN has been suggested to be a fascinating candidate for further investigation in COVID-19. LMN showed to modulate numerous signaling pathways and inhibits inflammatory mediators, including cytokines, chemokines, adhesion molecules, prostanoids, and eicosanoids. We hypothesized that given the pathogenesis of COVID-19 involving infection, inflammation, and immunity, LMN may have potential to limit the severity and progression of the disease owing to its immunomodulatory, anti-inflammatory, and antiviral properties. The present article discusses the possibilities of LMN in SARS-CoV-2 infections based on its immunomodulatory, anti-inflammatory, and antiviral properties. Though, the suggestion on the possible use of LMN in COVID-19 remains inconclusive until the in-silico effects confirmed in the experimental studies and further proof of the concept studies. The candidature of LMN in COVID-19 treatment somewhat appear speculative but cannot be overlooked provided favorable physiochemical and druggable properties. The safety and efficacy of LMN are necessary to be established in preclinical and clinical studies before making suggestions for use in humans.

Ameliorative Effect of Linalool in Cisplatin-Induced Nephrotoxicity: The Role of HMGB1/TLR4/NF-κB and Nrf2/HO1 Pathways

BACKGROUND

The monoterpene linalool is a well-known essential oil component produced by several aromatic plants. Cisplatin is a widely used anticancer drug that produces many side effects, particularly nephrotoxicity. Here, we aimed to inspect linalool's protective activity against cisplatin-induced nephrotoxicity and explore part of the underlying mechanisms.

METHODS

Male Wistar rats were given linalool (50 and 100 mg/kg/day orally) for 15 days; then challenged with cisplatin (8 mg/kg) on the 12th day. Renal function parameters, oxidative stress, inflammatory and apoptotic markers, and toll-like receptor pathway gene, and protein expressions were investigated. Histopathology, immunohistochemistry, and cell-line mediated cytotoxicity assays were conducted.

RESULTS

Linalool ameliorated kidney function after cisplatin challenge and managed all oxidation system parameters including GSH, SOD, CAT, MDA, NADPH, and particularly the Nrf2-mediated pathway markers. Linalool decreased TLR4, MYD88 and TRIF gene and protein expressions; diminished related inflammatory mediators such as TNF-α, IL-1β, IL-6, and NF-κB; and down-regulated HMBG1. Linalool mitigated cisplatin-induced apoptotic markers such as caspase 3, caspase 9, and Bax expression, and boosted the anti-apoptotic Bcl2 expression. Linalool potentiated the cytotoxic effect of cisplatin when investigated on HeLa and PC3 human cancer cell lines.

CONCLUSION

Linalool could protect against cisplatin-induced kidney function and tissue damage.

Biological Properties of a Citral-Enriched Fraction of Citrus limon Essential Oil

Lemon essential oil (LEO) is a well-known flavoring agent with versatile biological activities. In the present study, we have isolated and characterized four citral-enriched fractions of winter LEO. We reported that in murine and human macrophages the pre-treatment with a mix of these fractions (Cfr-LEO) reduces the expression of the pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 induced by LPS. In addition, Cfr-LEO counteracts LPS-induced oxidative stress, as shown by the increase in the GSH/GSSG ratio in comparison to cells treated with LPS alone. Overall, the results reported here encourage the application of EO fractions, enriched in citral, in the nutraceutical industry, not only for its organoleptic properties but also for its protective action against inflammation and oxidative stress.

Anticonvulsant Essential Oils and Their Relationship with Oxidative Stress in Epilepsy

Epilepsy is a most disabling neurological disorder affecting all age groups. Among the various mechanisms that may result in epilepsy, neuronal hyperexcitability and oxidative injury produced by an excessive formation of free radicals may play a role in the development of this pathology. Therefore, new treatment approaches are needed to address resistant conditions that do not respond fully to current antiepileptic drugs. This paper reviews studies on the anticonvulsant activities of essential oils and their chemical constituents. Data from studies published from January 2011 to December 2018 was selected from the PubMed database for examination. The bioactivity of 19 essential oils and 16 constituents is described. Apiaceae and Lamiaceae were the most promising botanical families due to the largest number of reports about plant species from these families that produce anticonvulsant essential oils. Among the evaluated compounds, β-caryophyllene, borneol, eugenol and nerolidol were the constituents that presented antioxidant properties related to anticonvulsant action. These data show the potential of these natural products as health promoting agents and use against various types of seizure disorders. Their properties on oxidative stress may contribute to the control of this neurological condition. However, further studies on the toxicological profile and mechanism of action of essential oils are needed.

Essential oil from halophyte Lobularia maritima: protective effects against CCl4-induced hepatic oxidative damage in rats and inhibition of the production of proinflammatory gene expression by lipopolysaccharide-stimulated RAW 264.7 macrophages

The present study evaluates the chemical profiling of the essential oil of a halophyte, L. maritima (LmEO), and its protective potential against CCl4-induced oxidative stress in rats. Forty compounds have been identified in LmEO. The major components are α-pinene (3.51%), benzyl alcohol (8.65%), linalool (22.43%), pulegone (3.33%), 1-phenyl butanone (7.33%), globulol (4.32%), γ-terpinene (6.15%), terpinen-4-ol (4.31%), α-terpineol (3.9%), ledol (3.59%), epi-α-cadinol (3.05%) and α-cadinol (4.91%). In comparison with the CCl4-intoxicated group, LmEO treatment resulted in decreased liver serum marker enzymes, decreased lipid peroxidation and increased antioxidant enzyme levels, with overall further amelioration of oxidative stress. The administration of LmEO to CCl4-treated rats at a dose of 250 mg kg-1 body weight significantly reduced the toxic effects and the oxidative stress on the liver, thus validating the traditional medicinal claim of this plant. Moreover, the anti-inflammatory activity of LmEO was evaluated in lipopolysaccharide-stimulated murine RAW 264.7 cells. Our oil could modulate the inflammatory mode of the macrophages by causing reduction in iNOS and COX2 enzymes as well as in IL-1β, IL-6, and TNF-α cytokine levels. These findings suggest that LmEO exerts anti-inflammatory effects by regulating the expression of inflammatory cytokines.

Anti-inflammatory effects of linalool on ovalbumin-induced pulmonary inflammation

Linalool is a natural product present in fruits and aromatic plants with biological activities. Researchers have reported that the inhalation of linalool exerts anti-inflammatory activities. In this study, we examined the therapeutic effects of linalool on airway inflammation and mucus overproduction in mice with allergic asthma. Oral administration of linalool significantly inhibited the levels of eosinophil numbers, Th2 cytokines and immunoglobulin E (IgE) caused by ovalbumin (OVA) exposure. Linalool exerted preventive effects against the influx of inflammatory cells and mucus hypersecretion in the lung tissues. Linalool also dose-dependently decreased the levels of inducible nitric oxide synthase (iNOS) expression and protein kinase B (AKT) activation in the lung tissues. Linalool effectively downregulated the activation of mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-κB) caused by OVA exposure. Furthermore, linalool exerted inhibitory effect on OVA-induced airway hyperresponsiveness (AHR). In the in vitro study, the increased secretion of MCP-1 was attenuated with linalool treatment in lipopolysaccharide (LPS)-stimulated H292 airway epithelial cells. In conclusion, linalool effectively exerts a protective role in OVA-induced airway inflammation and mucus hypersecretion, and its protective effects are closely related to the downregulation of inflammatory mediators and MAPKs/NF-κB signaling.