Antiviral activities of hemp cannabinoids

Hemp is an understudied source of pharmacologically active compounds and many unique plant secondary metabolites including more than 100 cannabinoids. After years of legal restriction, research on hemp has recently demonstrated antiviral activities in silico, in vitro, and in vivo for cannabidiol (CBD), Δ9-tetrahydrocannabinol (Δ9-THC), cannabidiolic acid (CBDA), cannabigerolic acid (CBGA), and several other cannabinoids against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), human immunodeficiency virus (HIV), and γ-herpes viruses. Mechanisms of action include inhibition of viral cell entry, inhibition of viral proteases, and stimulation of cellular innate immune responses. The anti-inflammatory properties of cannabinoids are also under investigation for mitigating the cytokine storm of COVID-19 and controlling chronic inflammation in people living with HIV. Retrospective clinical studies support antiviral activities of CBD, Δ9-THC, and cannabinoid mixtures as do some prospective clinical trials, but appropriately designed clinical trials of safety and efficacy of antiviral cannabinoids are urgently needed.

Towards improved HIV-microbicide activity through the co-encapsulation of NRTI drugs in biocompatible metal organic framework nanocarriers

The efficacy of the routinely used anti-HIV (Human Immunodeficiency Virus) therapy based on nucleoside reverse transcriptase inhibitors (NRTIs) is limited by the poor cellular uptake of the active triphosphorylated metabolites and the low efficiency of intracellular phosphorylation of their prodrugs. Nanoparticles of iron(iii) polycarboxylate Metal-Organic Frameworks (nanoMOFs) are promising drug nanocarriers. In this study, two active triphosphorylated NRTIs, azidothymidine triphosphate (AZT-Tp) and lamivudine triphosphate (3TC-Tp), were successfully co-encapsulated into the biocompatible mesoporous iron(iii) trimesate MIL-100(Fe) nanoMOF in order to improve anti-HIV therapies. The drug loaded nanoMOFs could be stored for up to 2-months and reconstituted after freeze drying, retaining similar physicochemical properties. Their antiretroviral activity was evidenced in vitro on monocyte-derived macrophages experimentally infected with HIV, making these co-encapsulated nanosystems excellent HIV-microbicide candidates.

B, Golla K, Kondapi AK. Improved Safety, Bioavailability and Pharmacokinetics of Zidovudine through Lactoferrin Nanoparticles during Oral Administration in Rats

Zidovudine (AZT) is one of the most referred antiretroviral drug. In spite of its higher bioavailability (50–75%) the most important reason of its cessation are bone marrow suppression, anemia, neutropenia and various organs related toxicities. This study aims at the improvement of oral delivery of AZT through its encapsulation in lactoferrin nanoparticles (AZT-lactonano). The nanoparticles (NPs) are of 50–60 nm in size and exhibit 67% encapsulation of the AZT. They are stable in simulated gastric and intestinal fluids. Anti-HIV-1 activity of AZT remains unaltered in nanoformulation in acute infection. The bioavailability and tissue distribution of AZT is higher in blood followed by liver and kidney. AZT-lactonano causes the improvement of pharmacokinetic profile as compared to soluble AZT; a more than 4 fold increase in AUC and AUMC in male and female rats. The serum C_max for AZT-lactonano was increased by 30%. Similarly there was nearly 2-fold increase in T_max and t_1/2. Our in vitro study confirms that, the endosomal pH is ideal for drug release from NPs and shows constant release from up to 96h. Bone marrow micronucleus assay show that nanoformulation exhibits approximately 2fold lower toxicity than soluble form. Histopathological and biochemical analysis further confirms that less or no significant organ toxicities when nanoparticles were used. AZT-lactonano has shown its higher efficacy, low organs related toxicities, improved pharmacokinetics parameter while keeping the antiviral activity intact. Thus, the nanoformulation are safe for the target specific drug delivery.