Inhibitory Effect of Lithospermic Acid on the HIV-1 Nucleocapsid Protein

Inhibitory mechanism of lithospermic acid on the fibrillation of type 2 diabetes associated islet amyloid polypeptide

The abnormal fibrillation of a 37-residue peptide hormone human islet amyloid polypeptide (hIAPP) is linked with type 2 diabetes (T2D). Pang et al. depicted a prominent role of lithospermic acid (LA) in blocking hIAPP fibrillation and alleviating the hIAPP aggregates-induced cytotoxicity. LA is a polyphenolic compound present in extra virgin olive oil with therapeutic properties. Despite its notable inhibitory effect on hIAPP fibrillation, the inhibition mechanism remains unclear. Here, molecular dynamics (MD) simulations have been utilized to shed light on the putative binding mechanism and inhibitory mechanism of LA against hIAPP fibrillation. The molecular docking predicted favourable binding (-7.1 kcal/mol) of LA with hIAPP. Interestingly, LA increases the helix content in hIAPP and blocks the conformational transition to the aggregation-competent conformations. The conformational clustering and hydrogen bond analyses depicted that LA formed hydrogen bonds with Asn21 of hIAPP, which play an important role in hIAPP aggregation. LA binds favourably to hIAPP (ΔGbinding = -49.62 ± 3.34 kcal/mol) with a major contribution from the van der Waals interactions. The MD simulations highlighted that LA dramatically interfered with the intrapeptide interactions and inhibited sampling of aggregation-competent β-sheet conformations in hIAPP via hydrogen bonds through its hydroxyl groups, van der Waals interactions with hIAPP residues, thus blocking hIAPP aggregation to β-sheet rich cytotoxic fibrillar aggregates. The MD simulations illuminated specific interactions between hIAPP and LA, which will benefit in developing new chemical entities against hIAPP fibrillation.

Lithospermic acid inhibits dengue virus infection through binding with envelope proteins

The dengue virus has emerged as a global pandemic, highlighting the urgent need for the immediate development of antiviral therapeutics. Lithospermum erythrorhizon, a medicinal plant commonly used in China for various ailments including viral infections, inflammation, rheumatism, and cancer, showed promising antiviral properties in our research. Specifically, both the ethanol extract of Lithospermum erythrorhizon and its active component, lithospermic acid, demonstrated significant inhibitory effects on Dengue virus (DENV) replication in Vero cells, with EC50 values of 6.50 μg/mL(95 % CI: 2.25 to 18.98)and 15.00 μM(95 % CI: 12.13 to 18.07), respectively. Notably, lithospermic acid exhibited potent antiviral activity across multiple cell lines against DENV, impeding virus replication and specifically impeding the expression of viral E and NS3 proteins during the early stages of DENV infection. Experimental assays involving RNase digestion and sucrose density gradient analysis confirmed that lithospermic acid did not directly inactivate DENV but rather interfered with viral processes. Furthermore, the compound was found to bind to the E protein of DENV, effectively inhibiting viral infection and mitigating the cytopathic effects induced by DENV. Collectively, these findings underscore the potential of lithospermic acid as a promising candidate for the development of therapeutic strategies targeting DENV infection.

Anti-HIV activity in traditional Chinese medicine: clinical implications of monomeric herbal remedies and compound decoctions

With the global spread of human immunodeficiency virus (HIV) infection and acquired immune deficiency syndrome (AIDS), the pursuit of potent treatments has ascended as a paramount concern in global healthcare. Traditional Chinese medicine (TCM) has been used for thousands of years in China and other East Asian countries and it offers remedies for an extensive array of ailments, including HIV and AIDS. This review focuses on the clinical significance of single herbs and composite tonics in TCM with antiviral activity against HIV. Initially, the anti-HIV activity of single herbs was analyzed in detail. Many herbs have been shown to have significant anti-HIV activity. The active ingredients of these herbs exhibit their anti-HIV effects through various mechanisms, such as inhibiting viral replication, preventing viral binding to host cells, and interfering with the viral lifecycle. Furthermore, we delved into the clinical significance of HIV-associated formulations provided as a result of Chinese compound prescription. These combinations of herbal ingredients are designed to amplify therapeutic efficacy and minimize adverse effects. Clinical trials have demonstrated the therapeutic benefits of these prescriptions for individuals infected with HIV. The intricate composition of these prescriptions potentially augments their anti-HIV activity through synergistic effects. Additionally, this review underscores the clinical importance of TCM in the context of HIV treatment. While numerous herbs and prescriptions exhibit anti-HIV activity, their safety and efficacy in clinical applications warrant further investigation. When combined with contemporary antiretroviral drugs, TCM may serve as an adjunctive therapy, assisting in reducing side effects, and enhancing patients' quality of life. To optimally harness these natural resources, further exploration is imperative to ascertain their efficacy, safety, and optimal utilization, thereby offering a broader spectrum of therapeutic options for HIV-afflicted individuals.

Effects and safety of Chinese herbal medicine on inflammatory biomarkers in cardiovascular diseases: A systematic review and meta-analysis of randomized controlled trials

Inflammation drives cardiovascular disease (CVD) in individuals with underlying chronic inflammatory diseases, including People with HIV (PWH), independently of dyslipidemia. Adjunctive treatments that lower inflammation may be useful to lower CVD risk in such populations. There is very little data on the efficacy of Chinese herbal medicine (CHM) in reducing inflammation in PWH to address its potential in reducing this CVD risk factor, therefore we evaluated its impact on inflammatory biomarkers relevant to CVD risk in the general population. Six English and Chinese databases were searched for studies investigating CHM’s effects on inflammatory biomarkers relevant to CVD from respective inceptions to February 2022. A systematic review and meta-analysis of randomized controlled trials (RCTs) were conducted and the most-frequently prescribed herbs were identified. Thirty-eight RCTs involving 4,047 participants were included. Greater than or equal to 50% of included studies had a low risk of bias in five domains (random sequence generation, detection, attrition, reporting and other bias) and 97% had a high risk of performance bias. CHM provided significant additive effects on attenuating relevant inflammatory indices including hs-CRP (SMD −2.05, 95% CI −2.55 to −1.54), IL-6 (SMD −1.14, 95% CI −1.63 to −0.66) and TNF-α levels (SMD −0.88, 95% CI −1.35 to −0.41), but no significant effects on hs-CRP were found between CHM and placebo when co-treating with Western drugs (MD 0.04, 95% CI −1.66 to 1.74). No severe adverse events were reported in CHM groups. The two most prevalent herbs present in formulae demonstrating reduction of at least one inflammatory biomarker were Dan shen (Salviae Miltiorrhizae Radix et Rhizoma) and Huang qi (Astragali Radix). CHM, in combination with standard anti-inflammatory medications, may depress inflammation and reduce the risk of inflammatory conditions such as CVD. Rigorously-conducted trials and adequate reporting are needed to provide more robust evidence supporting the use of CHM to reduce CVD risk in people with underlying chronic inflammation such as PWH.

Active Components from Cassia abbreviata Prevent HIV-1 Entry by Distinct Mechanisms of Action

Cassia abbreviata is widely used in Sub-Saharan Africa for treating many diseases, including HIV-1 infection. We have recently described the chemical structures of 28 compounds isolated from an alcoholic crude extract of barks and roots of C. abbreviata, and showed that six bioactive compounds inhibit HIV-1 infection. In the present study, we demonstrate that the six compounds block HIV-1 entry into cells: oleanolic acid, palmitic acid, taxifolin, piceatannol, guibourtinidol-(4α→8)-epiafzelechin, and a novel compound named as cassiabrevone. We report, for the first time, that guibourtinidol-(4α→8)-epiafzelechin and cassiabrevone inhibit HIV-1 entry (IC₅₀ of 42.47 µM and 30.96 µM, respectively), as well as that piceatannol interacts with cellular membranes. Piceatannol inhibits HIV-1 infection in a dual-chamber assay mimicking the female genital tract, as well as HSV infection, emphasizing its potential as a microbicide. Structure-activity relationships (SAR) showed that pharmacophoric groups of piceatannol are strictly required to inhibit HIV-1 entry. By a ligand-based in silico study, we speculated that piceatannol and norartocarpetin may have a very similar mechanism of action and efficacy because of the highly comparable pharmacophoric and 3D space, while guibourtinidol-(4α→8)-epiafzelechin and cassiabrevone may display a different mechanism. We finally show that cassiabrevone plays a major role of the crude extract of CA by blocking the binding activity of HIV-1 gp120 and CD4.