Natural Products Journal, The - Volume 13, Issue 6, 2023

Nigella sativa L. (Ranunculaceae) is one of the most widely used traditional therapeutic plants. It possesses important classes of bioactive compounds, among which thymoquinone, as the major bioactive component of the essential oil, has attracted noteworthy attention due to its active role in treating various disorders. N. sativa can induce a wide range of pharmacological functions, including anti-oxidative stress responses, antidiabetic, anticancer, cell apoptosis, increased membrane permeability, immunomodulatory, analgesic, antimicrobial, anti-inflammatory, spasmolytic, bronchodilatory, hepato-protective, renal protective, gastro-protective, and antioxidant properties. The seeds of N. sativa, commonly known as black seed or black cumin, show many potential pharmacological roles and are utilized in folk (herbal) medicine all over the world for the treatment and prevention of a various range of diseases and conditions, including asthma, cancers, inflammatory situations, type 2 diabetes mellitus disorders, bacterial and viral infections, and dyslipidemia. This review outlines the main pharmacological properties of N. sativa and its components due to their potential wide applications for a large variety of human diseases. The seeds constitute fixed and essential oils, proteins, alkaloids and saponin. Much of the biological function of the seeds has been demonstrated to be due to thymoquinone. Beneficial influences of the seeds application and thymoquinone might be contributed to their cytoprotective and antioxidant functions and their effect on immune response and some inflammatory mediators.

Immunologists have long considered inflammation to be a two-edged sword. Short-term inflammation can be beneficial, but long-term chronic inflammation is damaging. Obesity, type 2 diabetes (T2D), and cancer have recently been added to the never-ending list of inflammatory diseases. The nuclear transcription factor peroxisome proliferator-activated receptor gamma (PPAR-γ) is involved in inflammation and obesity. Clinicians employed PPAR-γ agonists, both synthetic and natural, to treat disorders such as obesity and T2D without fully understanding the biochemical features and potential adverse effects. This is one of the reasons for the controversy surrounding the thiazolidinedione class of medicines, including rosiglitazone and pioglitazone. Nonetheless, various natural PPAR-γ ligands, including endogenous physiological ligands, are discovered regularly around the world. This review aims to summarise the physiochemical properties and possible antiinflammatory actions of ligands discovered in nature. Future research in this area should be supported in order to find improved commercial PPAR-γ ligand anti-inflammatory products.

Delivery of therapeutics using synthetic polymers is challenging due to toxicity, immunogenicity and impaired bioavailability following administration. However, natural polymers are being explored as safe for their use as a substitute for synthetic polymers. In the past three decades, the biomaterials like starches have been applied to impart an imperative role in delivering therapeutics. There is an increased focus on finding new sources of starches and their modifications. Hence, the derivatization of starches has become necessary to achieve desired properties. The modifications to native starch systems are being investigated to improve solubility, stability, bioavailability, etc., of an incorporated drug(s) and lower-down induced toxicities. All these requirements have led to the use of modified starches in the drug delivery of bioactive component(s). This review explores the current state of knowledge about starch structure and chemical modification methods from perspectives. It integrates aspects of its use in developing drug delivery devices like tablets, hydrogel, and patches. The information provided in this review may be applied as a reference for future chemically modified starch as excipients in drug carrier studies.

Due to its accuracy and expert-authenticated validation mechanism, DNA barcoding technology is advocated to be superior to existing methods of species identification. While DNA barcoding is generally viewed as valuable innovation in herbal materials authentication, the acceptability and accessibility issues pose a barrier to its uptake into the global herbal regulatory framework. We explore the current status of DNA barcoding technology for quality assurance of herbal materials/ products (HM/P) and the challenges of its formal adoption into multi-level policy. We discuss the adulteration problem in the HM/P value chain, provide an overview of DNA barcoding technology features, and highlight the current use of DNA barcoding from the perspective of four key stakeholders, i.e., epistemic group, international bodies, governments, and market agents, practicing DNA barcoding technology in the HM/P value chain. The discussion also includes the status of DNA barcoding in the control system of HM/P in the US, EU, and China, and provides some recommendations on how the application of DNA barcoding as quality control/assurance can be deployed in the HM/P value chain.

Pectins are polysaccharides that have a sequence that is similar to that of plant cell membranes that are predominantly made up of galacturonic acid units, and their concentration, morphology, and molecular mass vary. Tissue engineering is a multidisciplinary field that examines natural replacement for the injured tissue to heal or preserve its function, and it involves using scaffolds, cells, and biomolecules. Biocompatible, biodegradable, and permeable scaffolds are required. The study aims to find the potential of pectin/pectin derivative scaffolds for tissue engineering applications.

Introduction: Acanthamoeba is a ubiquitous and parasitic protozoan capable of causing serious human infections, resulting in blindness and even death. Seaweeds are abundant and widely known for their antimicrobial properties. This study aims to unveil the anti-amoebic potential of two Malaysian red seaweeds, Gracilaria changii and Gracilaria salicornia on Acanthamoeba castellanii. Methods: Water, methanol and ethyl acetate extracts of G. changii and G. salicornia were tested against A. castellanii. Liquid chromatography-mass spectrometry (LC-MS) analysis was carried out to identify the compounds responsible for the anti-amoebic effect. Results: Methanol extract of G. salicornia showed significant growth inhibition of 22% in A. castellanii trophozoites. Cytotoxicity of these extracts was shown to be minimal in human keratinocyte cells through cell viability assay. Conclusion: Data from LC-MS revealed 14 compounds with reported biological activities. These findings suggest the use of G. changii and G. salicornia as potential sources of anti-amoebic compounds.

Background: Zika virus (ZIKV) infection is a public health concern and currently there is no specific therapeutic or approved vaccine. Resveratrol (RESV), a natural antiviral compound, has been shown to possess antiviral properties against ZIKV and other viral infections, but the mechanisms of action against ZIKV remain unknown. Objective: This study aimed to investigate the role of the high mobility group box 1 protein (HMGB1) in the underlying anti-ZIKV mechanisms of RESV. Methods: HMGB1 protein expression and ZIKV replication in both the RESV-treated wildtype (WT) and HMGB1-knockdown (shHMGB1) Huh7 cells were analyzed using ELISA, immunofluorescence assay, immunoblot assay, focus-forming assay and qRT-PCR. HMGB1’s role was explored by evaluating the changes in the type-1 interferon (IFN) response genes using the qRT-PCR and immunoblot assays. Results: The treatment of the ZIKV-infected WT Huh7 cells with RESV significantly reduced ZIKV titers by >90% (P < 0.001) at 48 and 72 hr pi in a dose-dependent manner and inhibited ZIKV-induced HMGB1 translocation (P < 0.001), resulting in nuclear HMGB1 accumulation. Compared to the WT Huh7 cells, shHMGB1 Huh7 cells without RESV treatment showed a significant increase in the infectious virus titers and RNA with a maximum rise of 74% (P < 0.001) and 65% (P < 0.01), respectively. RESV treatment of the ZIKV-infected WT Huh7 cells significantly increased the MxA (one of the classical interferon-stimulated genes, ISGs) and IFN-β levels (P < 0.05). The treatment of the infected shHMGB1 Huh7 cells with RESV showed a less effective antiviral response (P > 0.05) and did not cause changes in the expressions of MxA and IFN-β. Conclusion: RESV possesses therapeutic activity against ZIKV infection and the mechanism of action is mainly attributed to HMGB1 nuclear retention, which could upregulate the type-1 IFN and ISGs.