Development of new and effective therapeutics for sexually transmitted herpes simplex virus-2 (HSV-2) infection is important from public health perspective. With an aim to identify natural products from medicinal plants, in the present study, the potential of Terminalia chebula Retz was investigated for its activity against HSV-2. Fruits of Terminalia chebula Retz were used to prepare 50% ethanolic extract. In addition, chebulagic acid and chebulinic acid both purified from T. chebula were also used. The extract as well as purified compounds were first used to determine their in vitro cytotoxicity on Vero cells by MTT assay. T. chebula extract, chebulagic acid, chebulinic acid along with acyclovir were subsequently assessed for direct anti-viral activity, and their ability to inhibit attachment and penetration of HSV-2 to the Vero cells. In addition, their anti-HSV-2 activity was also determined by in vitro post-infection plaque reduction assay. Cytotoxicity assay using Vero cells revealed CC50 = 409.71 ± 47.70 μg/ml for the extract whereas chebulagic acid and chebulinic acid showed more than 95% cell viability up to 200 μg/ml. The extract from T. chebula (IC50 = 0.01 ± 0.0002 μg/ml), chebulagic (IC50 = 1.41 ± 0.51 μg/ml) and chebulinic acids (IC50 = 0.06 ± 0.002 μg/ml) showed dose dependent potent in vitro direct anti-viral activity against HSV-2. These also effectively prevented the attachment as well as penetration of the HSV-2 to Vero cells. In comparison, acyclovir showed poor direct anti-viral activity and failed to significantly (p > 0.05) prevent the attachment as well as penetration of HSV-2 to Vero cells when tested upto 50 μg/ml. However, in post-infection plaque reduction assay, T. chebula extract, chebulagic and chebulinic acids showed IC50 values of 50.06 ± 6.12, 31.84 ± 2.64, and 8.69 ± 2.09 μg/ml, respectively, which were much lower than acyclovir (71.80 ± 19.95 ng/ml). The results presented herein suggest that T. chebula extract, chebulagic and chebulinic acids have higher direct antiviral activity against HSV-2 and efficacy to inhibit virus attachment and penetration to the host cells as compared to acyclovir. However, acyclovir is more potent to inhibit post-infection virus replication. Hence, T. chebula may be a useful candidate for developing alternative therapy for prevention of sexually transmitted HSV-2 infection. ᅟ

Herpes simplex virus-2 (HSV-2) infection is the most common cause of genital ulcers. The impact of ulcers also demonstrates a strong link to the human immunodeficiency virus (HIV) infection. Complications, drug resistance, and side-effects of anti-viral drugs make the treatment of HSV-2 infection challenging. Herbal medicines have shown potential against HSV-2 and HIV infections. In this context, polyherbal gel formulation comprising 50% ethanolic extracts from Acacia catechu, Lagerstroemia speciosa, Terminalia chebula and Phyllanthus emblica has been developed. The gel formulation significantly exhibited virucidal activity against both HIV-1 and HSV-2 infections with IC₅₀, 55.93 ± 5.30 µg/mL and 27.26 ± 4.87 µg/mL, respectively. It also inhibited HSV-2 attachment and penetration to the Vero cells with an IC₅₀ = 46.55 ± 1.25 µg/mL and 54.94 ± 2.52 µg/mL respectively, which were significantly lower than acyclovir. However, acyclovir is more potent in post-infection assay with an IC₅₀ = 0.065 ± 0.01 µg/mL whereas gel formulation showed an IC₅₀ = 469.05 ± 16.65 µg/mL under similar conditions. Gel formulation showed no inhibitory effect on the viability of lactobacilli, human vaginal keratinocyte cells (Vk2/E6E7), and the integrity of the Caco-2 cells monolayer. Gel formulation did not lead to any significant increase in the secretion of pro-inflammatory cytokines and mutagenic index. The proposed gel formulation may be a promising candidate microbicide for the prevention of sexually transmitted HIV-1 and HSV-2.

Multiple sclerosis (MS) is an inflammatory disease of the central nervous system that finally leads to demyelination. Demyelinating optic neuritis is a frequent symptom in MS. Recent studies also revealed synapse dysfunctions in MS patients and MS mouse models. We previously reported alterations of photoreceptor ribbon synapses in the experimental auto-immune encephalomyelitis (EAE) mouse model of MS. In the present study, we found that the previously observed decreased imunosignals of photoreceptor ribbons in early EAE resulted from a decrease in synaptic ribbon size, whereas the number/density of ribbons in photoreceptor synapses remained unchanged. Smaller photoreceptor ribbons are associated with fewer docked and ribbon-associated vesicles. At a functional level, depolarization-evoked exocytosis as monitored by optical recording was diminished even as early as on day 7 after EAE induction. Moreover compensatory, post-depolarization endocytosis was decreased. Decreased post-depolarization endocytosis in early EAE correlated with diminished synaptic enrichment of dynamin3. In contrast, basal endocytosis in photoreceptor synapses of resting non-depolarized retinal slices was increased in early EAE. Increased basal endocytosis correlated with increased de-phosphorylation of dynamin1. Thus, multiple endocytic pathways in photoreceptor synapse are differentially affected in early EAE and likely contribute to the observed synapse pathology in early EAE.

Complement component C3 mediates pathology in CNS neurodegenerative diseases. Here we use scRNAseq of sorted C3-reporter positive cells from mouse brain and optic nerve to characterize C3 producing glia in experimental autoimmune encephalomyelitis (EAE), a model in which peripheral immune cells infiltrate the CNS, causing reactive gliosis and neuro-axonal pathology. We find that C3 expression in the early inflammatory stage of EAE defines disease-associated glial subtypes characterized by increased expression of genes associated with mTOR activation and cell metabolism. This pro-inflammatory subtype is abrogated with genetic C3 depletion, a finding confirmed with proteomic analyses. In addition, early optic nerve axonal injury and retinal ganglion cell oxidative stress, but not loss of post-synaptic density protein 95, are ameliorated by selective deletion of C3 in myeloid cells. These data suggest that in addition to C3b opsonization of post synaptic proteins leading to neuronal demise, C3 activation is a contributor to reactive glia in the optic nerve.

Multiple sclerosis (MS) has traditionally been viewed as a chronic inflammatory disease affecting the white matter of the central nervous system. However, over the past two decades, increasing evidence has highlighted the role of gray matter pathology in MS-related disability. Numerous studies have linked the presence of leptomeningeal inflammation to a more severe disease course, underscoring its potential importance as a driver of gray matter pathology in MS. The major components of leptomeningeal inflammation include T cells, B cells, macrophages, follicular dendritic cells, and plasma cells. Since BAFF [B cell-activating factor of the tumor necrosis factor (TNF) family] promotes B cell survival and maturation and is a co-stimulator of T cells, we used anti-BAFF antibody 10F4 as a BAFF antagonist to study its effect on meningeal inflammation and adjacent brain regions in a relapsing–remitting PLP-EAE (rr-EAE) model of multiple sclerosis in SJL/J mice. rr-EAE mice were treated either with anti-BAFF antibody 10F4 or with IgG control antibody. We performed ultra-high field (11.7 T) MRI to identify areas of meningeal inflammation and track them over time in both treatment groups. We also performed histopathological analysis in brain sections of these mice to study the effects of the BAFF antagonist on leptomeningeal inflammation, and hippocampal and cortical neurons and synapses. We observed that BAFF antagonist treatment reduced B cells, T cells, and myeloid cells in regions of meningeal inflammation. Additionally, we noted that BAFF treatment protected against EAE-induced synaptic and neuronal loss in the adjacent cortex and in the CA1, CA3, and dentate gyrus regions of the hippocampus likely due to its effects on meningeal inflammation.

Single-cell chemical and metabolic imaging technologies provide unprecedented insights into individual cell dynamics, advancing our understanding of cellular processes, molecular interactions, and metabolic activities. Advances in fluorescence, Raman, optoacoustic (photoacoustic), or mass spectrometry methods have paved the way to characterize metabolites, signaling molecules, and other moieties within individual cells. These modalities can also lead to single-cell imaging capabilities by targeting endogenous cell contrast or by employing exogenous contrast generation techniques, including contrast agents that target specific cell structure or function. In this review, we present key developments, summarize recent applications in single-cell interrogation and imaging, and illustrate their advantages, limitations, and outlook.