Current Insights on Bioactive Molecules, Antioxidant, Anti-Inflammatory, and Other Pharmacological Activities of Cinnamomum camphora Linn.

C. camphora is a renowned traditional Unani medicinal herb and belongs to the family Lauraceae. It has therapeutic applications in various ailments and prophylactic properties to prevent flu-like epidemic symptoms and COVID-19. This comprehensive appraisal is to familiarize the reader with the traditional, broad applications of camphor both in Unani and modern medicine and its effects on bioactive molecules. Electronic databases such as Web of Science, PubMed, Google Scholar, Scopus, and Research Gate were searched for bioactive molecules, and preclinical/clinical research and including 59 research and review papers up to 2022 were retrieved. Additionally, 21 classical Unani and English herbal pharmacopeia books with ethnomedicinal properties and therapeutic applications were explored. Oxidative stress significantly impacts aging, obesity, diabetes mellitus, depression, and neurodegenerative diseases. The polyphenolic bioactive compounds such as linalool, borneol, and nerolidol of C. camphora have antioxidant activity and have the potential to remove free radicals. Its other major bioactive molecules are camphor, cineole, limelol, safrole, limonene, alpha-pinene, and cineole with anti-inflammatory, antibacterial, anxiolytic, analgesic, immunomodulatory, antihyperlipidemic, and many other pharmacological properties have been established in vitro or in vivo preclinical research. Natural bioactive molecules and their mechanisms of action and applications in diseases have been highlighted, with future prospects, gaps, and priorities that need to be addressed.

Modulation of transient receptor potential (TRP) channels by plant derived substances used in over-the-counter cough and cold remedies.

BACKGROUND: Upper respiratory tract infections (URTIs) impact all age groups and have a significant economic and social burden on society, worldwide. Most URTIs are mild and self-limiting, but due to the wide range of possible causative agents, including Rhinovirus (hRV), Adenovirus, Respiratory Syncytial Virus (RSV), Coronavirus and Influenza, there is no single and effective treatment. Over-the-counter (OTC) remedies, including traditional medicines and those containing plant derived substances, help to alleviate symptoms including inflammation, pain, fever and cough. PURPOSE: This systematic review focuses on the role of the major plant derived substances in several OTC remedies used to treat cold symptoms, with a particular focus on the transient receptor potential (TRP) channels involved in pain and cough. METHODS: Literature searches were done using Pubmed and Web of Science, with no date limitations, using the principles of the PRISMA statement. The search terms used were 'TRP channel AND plant compound', 'cough AND plant compound', 'cough AND TRP channels AND plant compound', 'cough AND P2X3 AND plant compound' and 'P2X3 AND plant compound' where plant compound represents menthol or camphor or eucalyptus or turpentine or thymol. RESULTS: The literature reviewed showed that menthol activates TRPM8 and may inhibit respiratory reflexes reducing irritation and cough. Menthol has a bimodal action on TRPA1, but inhibition may have an analgesic effect. Eucalyptus also activates TRPM8 and inhibits TRPA1 whilst down regulating P2X3, aiding in the reduction of cough, pain and airway irritation. Camphor inhibits TRPA1 and the activation of TRPM8 may add to the effects of menthol. Activation of TRPV1 by camphor, may also have an analgesic effect. CONCLUSIONS: The literature suggests that these plant derived substances have multifaceted actions and can interact with the TRP 'cough' receptors. The plant derived substances used in cough and cold medicines have the potential to target multiple symptoms experienced during a cold.

Synthesis and Antiviral Properties of Camphor-Derived Iminothiazolidine-4-Ones and 2,3-Dihydrothiazoles.

A set of heterocyclic products was synthesized from natural (+)-camphor and semi-synthetic (-)-camphor. Then, 2-Imino-4-thiazolidinones and 2,3-dihydrothiazoles were obtained using a three-step procedure. For the synthesized compounds, their antiviral activity against the vaccinia virus and Marburg virus was studied. New promising agents active against both viruses were found among the tested compounds.

Camphor, Artemisinin and Sumac Phytochemicals as inhibitors against COVID-19: Computational approach.

Covid-19 is an emerging infectious disease caused by coronavirus SARS-CoV-2. Due to the rapid rise in deaths resulted from this infection all around the world, the identification of drugs against this new coronavirus is an important requirement. Among the drugs that can fight this type of infection; natural products are substances that serve as sources of beneficial chemical molecules for the development of effective therapies. In this study, Camphor, Artemisinin and 14 Sumac phytochemicals were docked in the active site of SARS-CoV-2 main protease (PDB code: 6LU7). We have also performed molecular dynamic simulation at 100 ns with MM-GBSA/PBSA analysis for the structures with the best affinity in the binding site of the studied enzyme (Hinokiflavone and Myricetin) after docking calculations to consider parameters like RMSD, covariance, PCA, radius of gyration, potential energy, temperature and pressure. The result indicates that Hinokiflavone and Myricetin are the structures with best affinity and stability in the binding site of the studied enzyme and they respect the conditions mentioned in Lipinski's rule and have acceptable ADMET proprieties; so, these compounds have important pharmacokinetic properties and bioavailability, and they could have more potent antiviral treatment of COVID-19 than the other studied compounds.

Neuroprotective role of camphor against ciprofloxacin induced depression in rats: modulation of Nrf-2 and TLR4.

BACKGROUND: Depression affects people feeling to be anxious, worried, and restless. They also lose interest in activities, concentrating and appetite, they finally may attempt suicide. Depression is the second chronic disease, as a source of the global burden of disease, after heart disease. Its prevalence elevated seven times during the COVID-19. AIM: The current study was designed to evaluate camphor neuroprotective role against rats' ciprofloxacin-induced depression. MATERIALS AND METHODS: Depression was induced by administration of ciprofloxacin (50 mg/kg; orally) for 21 days. Wister albino male rats were divided into five groups. Group I (normal control): rats were given normal saline. Group II: rats received camphor (10 mg/kg; i.p.) for 21 days. Group III (depression control): rats received ciprofloxacin only. Groups IV and V: rats received camphor (5 and 10 mg/kg; i.p.) for 21 days concurrent with ciprofloxacin. Behavior tests as forced swimming test, activity cage, and rotarod were estimated. Oxidative stress and antioxidant biomarkers as malondialdehyde (MDA), nitric oxide (NO), catalase, and nuclear factor erythroid 2-related factor 2 (Nrf-2) besides inflammatory biomarkers as Toll-like receptor 4 (TLR4) and tumor necrosis factor alpha (TNF-α) as well as neurotransmitters were determined. Finally, histopathological examination was done. RESULTS: Camphor increased catalase and Nrf-2 activities, decreased NO, MDA, TNF-α, TLR4 serum levels, and elevating brain contents of serotonin, dopamine, gamma-amino butyric acid (GABA) and P190-RHO GTP protein with normal neuronal cells of the frontal cortex. CONCLUSION: Camphor has neuroprotective effect via modulation of Nrf-2 and TLR4 against ciprofloxacin-induced depression in rats.