Anti-AIDS agents, 18. Sodium and potassium salts of caffeic acid tetramers from Arnebia euchroma as anti-HIV agents

Caffeic acid alleviates cerebral ischemic injury in rats by resisting ferroptosis via Nrf2 signaling pathway

There are few effective and safe neuroprotective agents for the treatment of ischemic stroke currently. Caffeic acid is a phenolic acid that widely exists in a number of plant species. Previous studies show that caffeic acid ameliorates brain injury in rats after cerebral ischemia/reperfusion. In this study we explored the protective mechanisms of caffeic acid against oxidative stress and ferroptosis in permanent cerebral ischemia. Ischemia stroke was induced on rats by permanent middle cerebral artery occlusion (pMCAO). Caffeic acid (0.4, 2, 10 mg·kg-1·d-1, i.g.) was administered to the rats for 3 consecutive days before or after the surgery. We showed that either pre-pMCAO or post-pMCAO administration of caffeic acid (2 mg·kg-1·d-1) effectively reduced the infarct volume and improved neurological outcome. The therapeutic time window could last to 2 h after pMCAO. We found that caffeic acid administration significantly reduced oxidative damage as well as neuroinflammation, and enhanced antioxidant capacity in pMCAO rat brain. We further demonstrated that caffeic acid down-regulated TFR1 and ACSL4, and up-regulated glutathione production through Nrf2 signaling pathway to resist ferroptosis in pMCAO rat brain and in oxygen glucose deprivation/reoxygenation (OGD/R)-treated SK-N-SH cells in vitro. Application of ML385, an Nrf2 inhibitor, blocked the neuroprotective effects of caffeic acid in both in vivo and in vitro models, evidenced by excessive accumulation of iron ions and inactivation of the ferroptosis defense system. In conclusion, caffeic acid inhibits oxidative stress-mediated neuronal death in pMCAO rat brain by regulating ferroptosis via Nrf2 signaling pathway. Caffeic acid might serve as a potential treatment to relieve brain injury after cerebral ischemia. Caffeic acid significantly attenuated cerebral ischemic injury and resisted ferroptosis both in vivo and in vitro. The regulation of Nrf2 by caffeic acid initiated the transcription of downstream target genes, which were shown to be anti-inflammatory, antioxidative and antiferroptotic. The effects of caffeic acid on neuroinflammation and ferroptosis in cerebral ischemia were explored in a primary microglia-neuron coculture system. Caffeic acid played a role in reducing neuroinflammation and resisting ferroptosis through the Nrf2 signaling pathway, which further suggested that caffeic acid might be a potential therapeutic method for alleviating brain injury after cerebral ischemia.

Three new compounds with their anti-glioma effects from the roots of Arnebia guttata Bunge

Three new compounds, arneatas A-C (1-3), together with three known compounds (4-6) were isolated from the roots of Arnebia guttata Bunge. The structures were established on the basis of extensive spectroscopic data including NMR and HRESIMS. All the new compounds (1-3) were tested for their cytotoxic activity against two glioma cell lines (U118-MG and U373-MG) in vitro after treatment for 48 h. Compound 1 exhibited moderate cytotoxic activity against U118-MG and U373-MG glioma cell lines, with IC50 values of 10.4 and 17.5 µM, respectively.

Exploring pharmaphylogeny from multiple perspectives: a case study on Lithospermeae

Lithospermeae Dumort., a tribe under the subfamily Boraginoidae, is a perennial herb containing approximately 470 species under 26 genera, primarily distributed in temperate and tropical regions. To gain a deeper understanding of the medicinal plants of Lithospermeae and better protect and develop plant medicinal resources, the phytochemistry, pharmacology, and traditional use of Lithospermeae with medicinal value were analyzed. Phylogenetic analysis was carried out based on the internal transcribed spacer sequence. Through spatial analysis and the species distribution model, the spatial distribution pattern of Lithospermeae medicinal plants was analyzed. Meanwhile, the relevant targets and pathways involved in the pharmacological effects of commonly used medicinal plants were predicted using network pharmacology to further explore the genetic origin of Lithospermeae and enrich the pharmaphylogeny of medicinal plants. In this study, the chemical composition, traditional efficacy, and modern pharmacological activity of Lithospermeae were collected for the first time and analyzed in combination with the geographical distribution model, molecular phylogeny, and network pharmacology. Based on our findings, the pharmaphylogeny of Lithospermeae was preliminarily discussed, providing the scientific basis for basic research regarding Lithospermeae. Concurrently, this study explored the relationship between the development of the regional medicinal plant industry and the protection of biodiversity. Furthermore, our findings provide direction and theoretical guidance for the study of the phylogenetic relationships in medicinal plants and the development of Lithospermeae medicinal plant resources.

A comprehensive overview on the role of phytocompounds in human immunodeficiency virus treatment

Acquired immune deficiency syndrome (AIDS) is a worldwide epidemic caused by human immunodeficiency virus (HIV) infection. Newer medicines for eliminating the viral reservoir and eradicating the virus are urgently needed. Attempts to locate relatively safe and non-toxic medications from natural resources are ongoing now. Natural-product-based antiviral candidates have been exploited to a limited extent. However, antiviral research is inadequate to counteract for the resistant patterns. Plant-derived bioactive compounds hold promise as powerful pharmacophore scaffolds, which have shown anti-HIV potential. This review focuses on a consideration of the virus, various possible HIV-controlling methods and the recent progress in alternative natural compounds with anti-HIV activity, with a particular emphasis on recent results from natural sources of anti-HIV agents. Please cite this article as: Mandhata CP, Sahoo CR, Padhy RN. A comprehensive overview on the role of phytocompounds in human immunodeficiency virus treatment. J Integr Med. 2023; Epub ahead of print.

Rosmarinic acid and its derivatives: Current insights on anticancer potential and other biomedical applications

Cancer is still the leading cause of death worldwide, burdening the global medical system. Rosmarinic acid (RA) is among the first secondary metabolites discovered and it is a bioactive compound identified in plants such as Boraginaceae and Nepetoideae subfamilies of the Lamiaceae family, including Thymus masticmasti chinaythia koreana, Ocimum sanctum, and Hyptis pectinate. This updated review is to highlight the chemopreventive and chemotherapeutic effects of RA and its derivatives, thus providing valuable clues for the potential development of some complementary drugs in the treatment of cancers. Relevant information about RA's chemopreventive and chemotherapeutic effects and its derivatives were collected from electronic scientific databases, such as PubMed/Medline, Scopus, TRIP database, Web of Science, and Science Direct. The results of the studies showed numerous significant biological effects such as antiviral, antibacterial, anti-inflammatory, anti-tumour, antioxidant and antiangiogenic effects. Most of the studies on the anticancer potential with the corresponding mechanisms are still in the experimental preclinical stage and are missing evidence from clinical trials to support the research. To open new anticancer therapeutic perspectives of RA and its derivatives, future clinical studies must elucidate the molecular mechanisms and targets of action in more detail, the human toxic potential and adverse effects.

Liver protection and hemostatic effects of medicinal plant Arnebia euchroma (Royle) I.M.Johnst extract in a rat model

ETHNOPHARMACOLOGICAL RELEVANCE

Arnebia euchroma (Royle) I.M.Johnst. (AE) is a Chinese medicinal herb that is traditionally used to treat various circulatory diseases. It exhibits certain effects, such as the promotion of blood circulation and cooling, rash clearance, and detoxification.

AIM OF THE STUDY

This study was designed to explore the hepatoprotective and hemostatic effects of the ethyl acetate extract of AE in rats with carbon tetrachloride (CCl4)-induced liver injury.

MATERIALS AND METHODS

Wistar rats were treated via oral gavage with different doses of the ethyl acetate extract of AE (3.5, 7, or 14 g kg^-1·day^-1) for 14 consecutive days, following which hemostatic and liver function tests were conducted. For the hemostatic tests, the platelet count, blood platelet aggregation, blood platelet adhesion to fibrinogen, platelet factor 4 (PF-4) secretion from blood platelets, prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time (TT), and fibrinogen levels were measured at the end of the treatment period. For the liver function tests, 0.25 mL/200 g (1.25 mL kg^-1·day^-1) of olive oil was injected into the abdominal cavity of the control rats, whereas 15% CCl₄ plus olive oil (prescription: 7.5 mL CCl₄ + 42.5 olive oil) was injected into that of the treated rats at 1 h after extract administration on day 6, 13, and 20. Additionally, food and water were withheld from all the animals. On the following day, the rats were anesthetized and their albumin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), gamma-glutamyl transpeptidase (GGT), lactate dehydrogenase (LDH), reactive oxygen species (ROS), methane dicarboxylic aldehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) levels were measured. Glutathione S-transferase (GST), glutathione reductase (GR), and glutathione peroxidase (GPx) levels among the groups were determined using a one-way analysis of variance.

RESULTS

The platelet count and blood platelet aggregation, blood platelet adhesion to fibrinogen and PF-4 secretion levels were significantly increased in the (3.5 g kg^-1 day^-1) AE group as compared to those in the control group (all p < 0.001; for the 7 and 14 g kg^-1 day^-1 AE groups, all p > 0.05, respectively). Although the PT and aPTT were not affected by the AE extract (all p > 0.05), the TT was reduced and the FIB levels were significantly increased in all AE groups (p < 0.05). Liver function tests showed that CCl₄ caused significant liver damage, thereby decreasing the albumin, SOD, CAT, GSH, GST, GR, and GPx levels, while increasing the AST, ALT, ALP, SGOT, SGPT, GGT, LDH, ROS, and MDA levels (all p < 0.001). By contrast, treatment with the different doses of AE extract reversed the CCl₄ effects on all these parameters. Compared with the levels in the CCl₄ group, the GSH and GR levels in the three AE groups (3.5, 7, and 14 g kg^-1·day^-1) were significantly higher (p < 0.05, p < 0.01, and p < 0.001, respectively), whereas the differences in the other parameters for these three groups were all at the significance levels of p < 0.05, p < 0.05, and p < 0.01, respectively.

CONCLUSIONS

AE extracts administered orally exhibited hepatoprotective activity by affecting platelet production and blood coagulation and ameliorating liver function-damaging modifications. Specifically, a dosage of 3.5 g kg^-1·day^-1 resulted in the most optimal effects.

A Review of Medicinal Plants of the Himalayas with Anti-Proliferative Activity for the Treatment of Various Cancers

Simple Summary

Drugs are used to treat cancer. Most drugs available in the market are chemosynthetic drugs and have side effects on the patient during and after the treatment, in addition to cancer itself. For instance, hair loss, loss of skin color and texture, loss of energy, nausea, infertility, etc. To overcome these side effects, naturally obtained drugs from medicinal plants are preferred. Our review paper aims to encourage the study of anticancer medicinal plants by giving detailed information on thirty-three medicinal plants and parts that constitute the phytochemicals responsible for the treatment of cancer. The development of plant-based drugs could be a game changer in treating cancer as well as boosting the immune system.

Abstract

Cancer is a serious and significantly progressive disease. Next to cardiovascular disease, cancer has become the most common cause of mortality in the entire world. Several factors, such as environmental factors, habitual activities, genetic factors, etc., are responsible for cancer. Many cancer patients seek alternative and/or complementary treatments because of the high death rate linked with cancer and the adverse side effects of chemotherapy and radiation therapy. Traditional medicine has a long history that begins with the hunt for botanicals to heal various diseases, including cancer. In the traditional medicinal system, several plants used to treat diseases have many bioactive compounds with curative capability, thereby also helping in disease prevention. Plants also significantly contributed to the modern pharmaceutical industry throughout the world. In the present review, we have listed 33 medicinal plants with active and significant anticancer activity, as well as their anticancer compounds. This article will provide a basic set of information for researchers interested in developing a safe and nontoxic active medicinal plant-based treatment for cancer. The research will give a scientific foundation for the traditional usage of these medicinal herbs to treat cancer.

Three-Dimensional Large-Scale Fused Silica Microfluidic Chips Enabled by Hybrid Laser Microfabrication for Continuous-Flow UV Photochemical Synthesis

We demonstrate a hybrid laser microfabrication approach, which combines the technical merits of ultrafast laser-assisted chemical etching and carbon dioxide laser-induced in situ melting for centimeter-scale and bonding-free fabrication of 3D complex hollow microstructures in fused silica glass. With the developed approach, large-scale fused silica microfluidic chips with integrated 3D cascaded micromixing units can be reliably manufactured. High-performance on-chip mixing and continuous-flow photochemical synthesis under UV irradiation at ~280 nm were demonstrated using the manufactured chip, indicating a powerful capability for versatile fabrication of highly transparent all-glass microfluidic reactors for on-chip photochemical synthesis.

Investigating the hemostatic effect of medicinal plant Arnebia euchroma (Royle) I.M.Johnst extract in a mouse model

ETHNOPHARMACOLOGICAL RELEVANCE

Arnebia euchroma (Royle) I.M.Johnst (AE) has been reported to be a potentially useful medicinal herb for the treatment of several circulatory diseases in traditional Chinese medicine. It shows effects such as "cooling of the blood," promotion of blood circulation, detoxification, and rash clearance.

AIM OF THE STUDY

To explore the hemostatic effect of the ethyl acetate extract of AE in mice.

MATERIALS AND METHODS

In this study, we explored the effects of AE on bleeding time, blood coagulation time, platelet count, and blood coagulation parameters in normal Kunming mice. Different doses of the AE extract (5, 10, and 20 g kg^-1·day^-1) were administered to mice for 14 days. Sodium carboxymethyl cellulose (CMC-Na at 0.5%) and Yunnan Baiyao (0.8 g kg^-1·day^-1) were administered as negative and positive control treatments, respectively. Bleeding time, blood coagulation time, platelet count, blood platelet aggregation, blood platelet adhesion to fibrinogen, platelet factor 4 (PF-4) secretions from blood platelets, and blood coagulation parameters including prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time (TT), and fibrinogen (FIB) levels were measured on day 15 of administration.

RESULTS

Bleeding and blood coagulation time were significantly lower and TT was shorter in the AE extract-treated groups than in the control groups. Furthermore, FIB levels and platelet count were higher, whereas blood platelet aggregation, blood platelet adhesion to fibrinogen, and PF-4 secretion from blood platelets were more obvious in the AE extract-treated groups than in the control group. However, no significant differences were detected for PT and aPTT between the extract-treated and control groups.

CONCLUSIONS

The ethyl acetate extract of AE showed potential hemostasis effects in mice by shortening the bleeding and coagulation time. In addition, the extract increased platelet count and induced blood platelet aggregation, blood platelet adhesion to fibrinogen, PF-4 secretion from blood platelets, and FIB level, while it shortened TT.

Globoidnan A, rabdosiin and globoidnan B as new phenolic markers in European-sourced comfrey (Symphytum officinale L.) root samples

INTRODUCTION

Symphytum officinale L. (comfrey, Boraginaceae) is a cultivated or spontaneously growing medicinal plant that is traditionally used for the treatment of bone fractures, hematomas, muscle pains and joint pains. A wide range of topical preparations and dried roots for ex tempore applications are marketed in European drug stores or pharmacies.

OBJECTIVE

The aim of this study was to perform the qualitative and quantitative analysis of pyrrolizidine alkaloids (PAs) and phenolic compounds in the hydroethanolic extracts of 16 commercial comfrey root batches purchased from 12 different European countries.

METHODS

Liquid chromatography hyphenated with high-resolution tandem mass spectrometry (LC-HRMS/MS) was used for the profiling of PAs and phenolic compounds, whereas LC-MS/MS and liquid chromatography with diode array detection (LC-DAD) were used for their quantification.

RESULTS

20 PAs (i.e. intermedine, lycopsamine, acetylintermedine, acetyllycopsamine, symphytine, symphytine-N-oxide), 17 phenolic compounds (i.e. caffeic and rosmarinic acids, rabdosiin, globoidnan A, globoidnan B) and 9 nonphenolic compounds (sugars, organic and fatty acids) were fully or partly annotated in the analysed samples. In addition, the quantitative analyses revealed that globoidnan B, rabdosiin and globoidnan A are new phenolic markers that can be used together with rosmarinic acid and PAs for the quality control of commercial comfrey root batches.

CONCLUSIONS

This study brings new insights into the phytochemical complexity of S. officinale, revealing not only numerous toxic PAs, but also a significant number of valuable phenolic compounds that could contribute to the bioactivities of comfrey-based preparations.

Phytochemical constituents, distributions and traditional usages of Arnebia euchroma: A review

ETHNOPHARMACOLOGICAL RELEVANCE

The present study has indicated phytochemical composition, distribution and ethno-medicinal uses of Arnebia euchroma (Royle) I.M. Johnst, which is commonly known as "Ratanjot" in the Indian subcontinent. It has widely been used in the traditional systems of the Unani, Ayurvedic and Chinese medicines recipes due to its anti-fungal and anti-microbial properties. Instead, the gap of earlier studies is well defined that will be helpful for researchers to carry out more analysis and increase medicinal importance of this plant.

AIM OF STUDY

The main aim of this review study is to demonstrate the phytochemical composition and traditional ethno-medicinal uses of A. euchroma all over the world. Earlier studies related to this plant have been discussed in the present study and on that basis, future perspective of A. euchroma is also proposed.

MATERIALS AND METHODS

The information of A. euchroma has been gathered from various electronic database, reference books and available literature.

RESULTS

The study has indicated that Arnebia euchroma owing to anti-microbial and anti-inflammatory properties is used in the traditional medicines and pharmaceutical industries for the treatment of hair problems, remitting, chronic diseases, burnt limbs, cough and cold, etc., and besides as a vegetable colorant and dyeing of cloths. The important phytochemical constituents viz., shikonin, acetyl-shikonin, iso-butyryl-shikonin, β,β-di-methylacryl-shikonin, isovaleryl-shikonin, β-hydroxy-isovaleryl-shikonin, deoxy-shikonin, isobutyl-shikonin, arnebinone, arnebin-7, stigmasterol, etc., isolated from the roots of Arnebia euchroma are used for curing various harmful diseases.

CONCLUSIONS

The earlier studies have confirmed that Arnebia euchroma is having wound healing, anti-microbial and anti-bacterial properties and thus used for the treatment of several diseases. Although, a little works is done on the experimental study regarding anti-HIV, anti-cancer diseases, etc., so there is a requirement of more exploration via analytical studies on phytochemical compounds to treat such diseases. Moreover, the information of its clinical and pharmacokinetics uses is also limited. Therefore, further research is needed to understand bioavailability and pharmacokinetics of this species. In-situ and ex-situ conservations for the management of this endangered species are also lacking in the Himalayan perspective. Such studies will emphasize to explore the possibilities for its conservation and development of agro-technological protocol.

Anti-HIV activity of some natural phenolics

Acquired immunodeficiency syndrome (AIDS) is an immunosuppressive disease caused by human immunodeficiency virus (HIV). The urgent need for searching novel anti-HIV/AIDS medicines is a global concern. So far, a lot of medicinal and aromatic plants (MAPs) have been analyzed to select those that could assist in the prevention and/or amelioration of the disease. Among biologically active compounds present in these plants, one of the most promising group are phenolics. The purpose of this article was to report anti-HIV activity of selected phenolic compounds of plant origin.

Symphytum officinale L.: Liquid-liquid chromatography isolation of caffeic acid oligomers and evaluation of their influence on pro-inflammatory cytokine release in LPS-stimulated neutrophils

ETHNOPHARMACOLOGICAL RELEVANCE

Symphytum officinale L. (comfrey, Boraginaceae) has been traditionally used for millennia in joint distortions, myalgia, bone fractures and hematomas. However, key activity-determining constituents and molecular mechanisms underlying its use have not been completely elucidated.

AIM OF THE STUDY

The objective of this study was to isolate and identify the major compounds from a hydroethanolic root extract of S. officinale and evaluate their antioxidant potential, alongside their effect on the cytokine production of ex vivo stimulated neutrophils, thus providing scientific support for the traditional use of comfrey root.

MATERIAL AND METHODS

Four caffeic acid oligomers were isolated from comfrey roots by liquid-liquid chromatography, their structures being established by MS and NMR analyses. In vitro antioxidant evaluation was performed by DPPH and ABTS assays. The cytotoxicity of isolated compounds was established by flow cytometry. The effect on cytokine release, such as interleukin (IL)-1β, IL-8 and tumor necrosis factor alpha (TNF-α), in lipopolysaccharide (LPS)-stimulated neutrophils was determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The main constituents found in comfrey root were represented by four caffeic acid oligomers, namely globoidnan B (1), rabdosiin (2), rosmarinic acid (3) and globoidnan A (4). Rabdosiin, globoidnans A and B were isolated for the first time from S. officinale. In the in vitro antioxidant tests, compound 2 was the most active, with EC₅₀ values in DPPH and ABTS assays of 29.14 ± 0.43 and 11.13 ± 0.39, respectively. Neutrophils' viability over the tested concentration domain of 12.5-50 μM was not altered. At 50 μM, all compounds significantly inhibited IL-1β release, with compound 3 (45.60% release vs. LPS stimulated neutrophils) being the most active, followed by compounds 1 (53.85%), 2 (69.89%) and 4 (60.68%).

CONCLUSIONS

The four caffeic acid oligomers reported in S. officinale root may contribute to the overall anti-inflammatory activity for which comfrey preparations are used in traditional medicine.

Archromones A-F, unusual polycyclic dearomatic geranylquinol derivatives from the roots of Arnebia euchroma

Eight new geranylquinol derivatives (1-8) were purified from the roots of Arnebia euchroma. Compounds 1-6 possess an unprecedented dearomatic benzocogeijerene skeleton with a rare trans-fused hydronaphthalene moiety. Their structures and absolute configurations were elucidated by HRESIMS, NMR, ECD, and X-ray diffraction. A convenient strategy for rapid determination of the relative configuration of H-1/H-7/Me-16 and the absolute configuration at C-1 for 1-6 was summarized. Compound 2 exhibited cytotoxicity against all the tested cell lines, namely PC9, BGC823, HCT116, HepG2, HeLa, and U87-MG, with IC50 values ranging from 13.7 to 29.3 μM.

Electrochemical determination of caffeic acid in antioxidant beverages samples via a facile synthesis of carbon/iron-based active electrocatalyst

An electrochemical method has described for the voltammetric determination and oxidation of caffeic acid (CA) at a glassy carbon electrode (GCE) modified carbon/iron-based active catalyst as a sensing platform. In this study, we have developed a highly sensitive electrochemical CA sensor with f-MWCNTs/α-NaFeO₂ composite, which was developed by a simple ultrasonication method. The microstructural features of the f-MWCNTs/α-NaFeO₂ composite characterized by different physicochemical and analytical techniques. Under the optimized condition, the developed sensor archive the ultra-sensitivity (44.6859 μA μM^-1cm^-2) at a lower concentration with excellent linearity (R² = 0.9943) and which shows low detection limit (LOD = 0.002 μM) and Limit of quantification (LOQ = 0.0068 μM) by using differential pulse voltammetry (DPV) technique. The suggested sensor may improve the effective and efficient platform to the determination of CA in the healthcare system.

Caffeic acid improves microscopic sperm parameters and antioxidant status of buffalo (Bubalus bubalis) bull semen following freeze-thawing process

This study investigates the effects of cryopreservation and supplementation of buffalo's semen with Caffeic acid. It studies the effects of different Caffeic acid concentrations on cryopreservation capacity of the buffalo and evaluates their influence on various sperm parameters like motility, viability, progressive motility, sperm plasma membrane integrity, and antioxidant status. Twenty-four semen samples were collected with an artificial vaginal from three adult water buffalos. The semen samples were evaluated and the qualified ejaculates were separated and were diluted in a Tris-based extender. The resulting samples were classified into 5 groups: No antioxidant (control), Control sham (NaOH), Caffeic acid 50 μM, Caffeic acid 100 μM, and Caffeic acid 200 μM. The semen samples encountered cryodamage and the quality was deteriorating during the cryopreservation (P < 0.05). The semen evaluation after thawing showed that the groups of samples receiving 100 μM Caffeic acid had higher viability, total motility, and lower abnormal sperm and better linearity (LIN), curvilinear velocity (VCL), straight-line velocity (VSL) and path velocity and higher intact plasma membrane (P < 0.05) compared to other groups. It is notable that adding 100 μM Caffeic acid to freezing extenders enhances the CAT, GPx, SOD, and GSH and also ameliorates total antioxidant capacity of spermatozoa after thawing. It is notable that the addition of 100 μM Caffeic acid decreases the amount of Malondialdehyde. These reactions lead us to conclude that 100 μM Caffeic acid enhances the semen quality of water buffalo after thawing.

Structure-Activity-Relationship and Mechanistic Insights for Anti-HIV Natural Products

Acquired Immunodeficiency Syndrome (AIDS), which chiefly originatesfroma retrovirus named Human Immunodeficiency Virus (HIV), has impacted about 70 million people worldwide. Even though several advances have been made in the field of antiretroviral combination therapy, HIV is still responsible for a considerable number of deaths in Africa. The current antiretroviral therapies have achieved success in providing instant HIV suppression but with countless undesirable adverse effects. Presently, the biodiversity of the plant kingdom is being explored by several researchers for the discovery of potent anti-HIV drugs with different mechanisms of action. The primary challenge is to afford a treatment that is free from any sort of risk of drug resistance and serious side effects. Hence, there is a strong demand to evaluate drugs derived from plants as well as their derivatives. Several plants, such as Andrographis paniculata, Dioscorea bulbifera, Aegle marmelos, Wistaria floribunda, Lindera chunii, Xanthoceras sorbifolia and others have displayed significant anti-HIV activity. Here, weattempt to summarize the main results, which focus on the structures of most potent plant-based natural products having anti-HIV activity along with their mechanisms of action and IC50 values, structure-activity-relationships and important key findings.

Design, synthesis and biological evaluation of benzoylacrylic acid shikonin ester derivatives as irreversible dual inhibitors of tubulin and EGFR

In this study, a series of shikonin derivatives combined with benzoylacrylic had been designed and synthesized, which showed an inhibitory effect on both tubulin and the epidermal growth factor receptor (EGFR). In vitro EGFR and cell growth inhibition assay demonstrated that compound PMMB-317 exhibited the most potent anti-EGFR (IC₅₀ = 22.7 nM) and anti-proliferation activity (IC₅₀ = 4.37 μM) against A549 cell line, which was comparable to that of Afatinib (EGFR, IC₅₀ = 15.4 nM; A549, IC₅₀ = 6.32 μM). Our results on mechanism research suggested that, PMMB-317 could induce the apoptosis of A549 cells in a dose- and time-dependent manner, along with decrease in mitochondrial membrane potential (MMP), production of ROS and alterations in apoptosis-related protein levels. Also, PMMB-317 could arrest cell cycle at G2/M phase to induce cell apoptosis, and inhibit the EGFR activity through blocking the signal transduction downstream of the mitogen-activated protein MAPK pathway and the anti-apoptotic kinase AKT pathway; typically, such results were comparable to those of afatinib. In addition, PMMB-317 could suppress A549 cell migration through the Wnt/β-catenin signaling pathway in a dose-dependent manner. Additionally, molecular docking simulation revealed that, PMMB-317 could simultaneously combine with EGFR protein (5HG8) and tubulin (1SA0) through various forces. Moreover, 3D-QSAR study was also carried out, which could optimize our compound through the structure-activity relationship analysis. Furthermore, the in vitro and in vivo results had collectively confirmed that PMMB-317 might serve as a promising lead compound to further develop the potential therapeutic anticancer agents.

The potential of plant systems to break the HIV-TB link

Tuberculosis (TB) and human immunodeficiency virus (HIV) can place a major burden on healthcare systems and constitute the main challenges of diagnostic and therapeutic programmes. Infection with HIV is the most common cause of Mycobacterium tuberculosis (Mtb), which can accelerate the risk of latent TB reactivation by 20-fold. Similarly, TB is considered the most relevant factor predisposing individuals to HIV infection. Thus, both pathogens can augment one another in a synergetic manner, accelerating the failure of immunological functions and resulting in subsequent death in the absence of treatment. Synergistic approaches involving the treatment of HIV as a tool to combat TB and vice versa are thus required in regions with a high burden of HIV and TB infection. In this context, plant systems are considered a promising approach for combatting HIV and TB in a resource-limited setting because plant-made drugs can be produced efficiently and inexpensively in developing countries and could be shared by the available agricultural infrastructure without the expensive requirement needed for cold chain storage and transportation. Moreover, the use of natural products from medicinal plants can eliminate the concerns associated with antiretroviral therapy (ART) and anti-TB therapy (ATT), including drug interactions, drug-related toxicity and multidrug resistance. In this review, we highlight the potential of plant system as a promising approach for the production of relevant pharmaceuticals for HIV and TB treatment. However, in the cases of HIV and TB, none of the plant-made pharmaceuticals have been approved for clinical use. Limitations in reaching these goals are discussed.

Antiproliferative Activity of (-)-Rabdosiin Isolated from Ocimum sanctum L

Background:Ocimum sanctum L. (holy basil; Tulsi in Hindi) is an important medicinal plant, traditionally used in India. Methods: The phytochemical study of the nonpolar (dichloromethane 100%) and polar (methanol:water; 7:3) extracts yielded fourteen compounds. Compounds 6, 7, 9, 11, 12, and 13, along with the methanol:water extract were evaluated for their cytotoxicity against the human cancer cell lines MCF-7, SKBR3, and HCT-116, and normal peripheral blood mononuclear cells (PBMCs). Results: Five terpenoids, namely, ursolic acid (1), oleanolic acid (2), betulinic acid (3), stigmasterol (4), and β-caryophyllene oxide (5); two lignans, i.e., (-)-rabdosiin (6) and shimobashiric acid C (7); three flavonoids, luteolin (8), its 7-O-β-D-glucuronide (9), apigenin 7-O-β-D-glucuronide (10); and four phenolics, (E)-p-coumaroyl 4-O-β-D-glucoside (11), 3-(3,4-dihydroxyphenyl) lactic acid (12), protocatechuic acid (13), and vanillic acid (14) were isolated. Compound 6 was the most cytotoxic against the human cancer lines assessed and showed very low cytotoxicity against PBMCs. Conclusions: Based on these results, the structure of compound 6 shows some promise as a selective anticancer drug scaffold.

Meroterpenoids isolated from Arnebia euchroma (Royle) Johnst. and their cytotoxic activity in human hepatocellular carcinoma cells

Six previously undescribed naturally occurring meroterpenoids (2, 5-9) together with seven known meroterpenoids (1, 3, 4, 10-13) were isolated from the root plant of Arnebia euchroma. Their structures and absolute configurations were determined by extensive 1D (¹H NMR, ¹³C NMR) and 2D NMR (¹H¹H COSY, DEPT, HMQC, HMBC, NOESY) spectroscopic methods, spectroscopy high resolution mass spectrometry, as well as DFT and MM2 force-field calculations. Meroterpenoids 1-13 were evaluated for their cytotoxicities against human liver cancer cell lines SMMC-7721, HepG2, QGY-7703 and HepG2/ADM. Meroterpenoid 5 exhibited the most potent activity with IC₅₀ values of 6.40 ± 0.51, 3.86 ± 0.28, 3.43 ± 0.27 and 11.31 ± 0.67 μM, respectively. Meroterpenoid 4 exhibited significant growth inhibitory effects against HepG2/ADM with IC₅₀ at 18.77 ± 1.23 μM, and meroterpenoid 8 with IC₅₀ at 5.41 ± 0.51 and 6.18 ± 0.47 μM against HepG2 and QGY-7703, respectively. These were more potent than the positive drug, Cisplatin.

Manipulation of Plant Growth Regulators on Phytochemical Constituents and DNA Protection Potential of the Medicinal Plant Arnebia benthamii

Arnebia benthamii of the family Boraginaceae is a critically endangered nonendemic plant of the Kashmir Himalayas and is used to treat a number of human diseases. The current study was based on developing an in vitro micropropagation protocol vis-à-vis induction of various secondary metabolites under in vitro conditions for the possible biological activity. A tissue culture protocol was developed for A. benthamii for the first time in the Himalayan region using varied combinations and proper media formulations, including various adjuvants: Murashige and Skoog (MS) media, growth hormones, sugars, agar, and so forth. The influence of different media combinations was estimated, and the MS + thidiazuron (TDZ) + indole 3-acetic acid (IAA) combination favors a higher regeneration potential. The higher amounts of chemical constituents were also recorded on the same treatment. The in vitro plant samples also showed a noteworthy effect of scavenging of hydroxyl radicals vis-à-vis protection from oxidative DNA damage. The in vitro raised plants are good candidates for the development of antioxidant molecules.

Inhibitory mechanism against oxidative stress of caffeic acid

The purpose of this article is to summarize the reported antioxidant activities of a naturally abundant bioactive phenolic acid, caffeic acid (CA, 3,4-dihydroxycinnamic acid), so that new avenues for future research involving CA can be explored. CA is abundantly found in coffee, fruits, vegetables, oils, and tea. CA is among the most potential and abundantly found in nature, hydroxycinnamic acids with the potential of antioxidant behavior. Reactive oxygen species produced as a result of endogenous processes can lead to pathophysiological disturbances in the human body. Foods containing phenolic substances are a potential source for free radical scavenging; these chemicals are known as antioxidants. This review is focused on CA’s structure, availability, and potential as an antioxidant along with its mode of action. A brief overview of the literature published about the prooxidant potential of caffeic acid as well as the future perspectives of caffeic acid research is described. CA can be effectively employed as a natural antioxidant in various food products such as oils.

Synthesis and Anti-HSV-1 Activity of New 3-Amino-3-Arylpropionic Acid Esters

A number of 3-methylbut-2-enyl esters of various 3-amino-3-arylpropionic acids have been synthesized and tested for antiviral activity against HSV-1. Many of these compounds, analogues of the 3-methylbut-2-enyl caffeate, isolated from poplar buds, show marked anti-HSV-1 activity and are less toxic than the natural ester.

Natural Products as Anti-HIV Agents and Role in HIV-Associated Neurocognitive Disorders (HAND): A Brief Overview

As the threat of Human Immunodeficiency Virus (HIV)/Acquired Immunodeficiency Syndrome (AIDS) persists to rise, effective drug treatments are required to treat the infected people. Even though combination antiretroviral therapy (cART) provides stable viral suppression, it is not devoid of undesirable side effects, especially in persons undergoing long-term treatment. The present therapy finds its limitations in the emergence of multidrug resistance and accordingly finding new drugs and novel targets is the need of the hour to treat the infected persons and further to attack HIV reservoirs in the body like brain, lymph nodes to achieve the ultimate goal of complete eradication of HIV and AIDS. Natural products such as plant-originated compounds and plant extracts have enormous potential to become drug leads with anti-HIV and neuroprotective activity. Accordingly, many research groups are exploring the biodiversity of the plant kingdom to find new and better anti-HIV drugs with novel mechanisms of action and for HIV-associated neurocognitive disorders (HAND). The basic challenge that still persists is to develop viral replication-targeted therapy using novel anti-HIV compounds with new mode of action, accepted toxicity and less resistance profile. Against this backdrop, the World Health Organization (WHO) suggested the need to evaluate ethno-medicines for the management of HIV/AIDS. Consequently, there is need to evaluate traditional medicine, particularly medicinal plants and other natural products that may yield effective and affordable therapeutic agents. Although there are a good number of reports on traditional uses of plants to treat various diseases, knowledge of herbal remedies used to manage HIV/AIDS and HAND are scanty, vague and not well documented. In this review, plant substances showing a promising action that is anti-HIV and HAND will be explored along with what they interact. Since some plant substances are also known to modulate several cellular factors which are also involved in the replication of HIV and hence their role as potential candidates will be discussed. HIV/AIDS being an exceptional epidemic, demands an exceptional approach and that forms very much focus for the current review.

Total Synthesis of Cannabisin B

Cannabisin B, a naturally occurring lignanamide, has been synthesised for the first time in 15% overall yield. The convergent synthesis is based on the Stobbe reaction and Friedel–Crafts alkylation reaction as the C–C bond-forming steps to afford the skeleton of the lignanamide which was then condensed with 4-methoxyphenethylamine to obtain Cannabisin B.

Bioinspired syntheses of dimeric hydroxycinnamic acids (lignans) and hybrids, using phenol oxidative coupling as key reaction, and medicinal significance thereof

Lignans are mainly dimers of 4-hydroxycinnamic acids (HCAs) and reduced analogs thereof which are produced in Nature through phenol oxidative coupling (POC) as the primary C-C or C-O bond-forming reaction under the action of the enzymes peroxidases and laccases. They present a large structural variety and particularly interesting biological activities, therefore, significant efforts has been devoted to the development of efficient methodologies for the synthesis of lignans isolated from natural sources, analogs and hybrids with other biologically interesting small molecules. We summarize in the present review those methods which mimic Nature for the assembly of the most common lignan skeleta by using either enzymes or one-electron inorganic oxidants to effect POC of HCAs and derivatives, such as esters and amides, or cross-POC of pairs of HCAs or HCAs with 4-hydrocycinnamyl alcohols. We, furthermore, provide outlines of mechanistic schemes accounting for the formation of the coupled products and, where applicable, indicate their potential application in medicine.

Synthesis of caffeic acid amides bearing 2,3,4,5-tetra-hydrobenzo[b][1,4]dioxocine moieties and their biological evaluation as antitumor agents

A series of caffeic acid amides D₁-D₁₇ bearing 2,3,4,5-tetrahydrobenzo-[b][1,4]dioxocine units has been synthesized and their biological activities evaluated for potential antiproliferative and EGFR inhibitory activity. Of all the compounds studied, compound D₉ showed the most potent inhibitory activity (IC₅₀ = 0.79 μM for HepG2 and IC₅₀ = 0.36 μM for EGFR). The structures of compounds were confirmed by ¹H-NMR, ESI-MS and elemental analysis. Among all, the structure of compound D₉ ((E)-N-(4-ethoxyphenyl)-3-(2,3,4,5-tetrahydrobenzo[b][1,4]dioxocin-8-yl)acrylamide) was also determined by single-crystal X-ray diffraction analysis. Compound D₉ was found to be a potential antitumor agent according to biological activity, molecular docking, apoptosis assay and inhibition of HepG2.

Rosmarinic acid and its derivatives: biotechnology and applications

Rosmarinic acid (RA) is one of the first secondary metabolites produced in plant cell cultures in extremely high yields, up to 19% of the cell dry weight. More complex derivatives of RA, such as rabdosiin and lithospermic acid B, later were also obtained in cell cultures at high yields. RA and its derivatives possess promising biological activities, such as improvement of cognitive performance, prevention of the development of Alzheimer's disease, cardioprotective effects, reduction of the severity of kidney diseases and cancer chemoprevention. The TNF-α-induced NF-κB signaling pathway has emerged as a central target for RA. Despite these impressive activities and high yields, the biotechnological production of these metabolites on an industrial scale has not progressed. We summarized data suggesting that external stimuli, the Ca(2+)-dependent NADPH oxidase pathway and processes of protein phosphorylation/dephosphorylation are involved in the regulation of biosynthesis of these substances in cultured plant cells. In spite of growing information about pathways regulating biosynthesis of RA and its derivatives in cultured plant cells, the exact mechanism of regulation remains unknown. We suggest that further progress in the biotechnology of RA and its derivatives can be achieved by using new high-throughput techniques.

Glutathione-S-transferase enhances proliferation-migration and protects against shikonin-induced cell death in breast cancer cells

Glutathione-S-transferase (GST) is a cytoplasmic protein responsible for detoxification, but the effect of the enzyme on cell biological events, including proliferation and migration, has never been reported. Thus, we evaluated the detoxification effect of in vitro-applied GST on cancer cell proliferation and migration. Assays for proliferation and migration of human breast cancer cells in the presence of GST were carried out. Binding of GST on the surface of the cancer cells was studied by flow cytometry. Detoxification through GST pathway was studied in the presence of shikonin. The effective dosage of GST in enhancement of cell proliferation was 10-50 nM, and the cell migration could be significantly enhanced after 6 hours in the presence of 2-50 nM GST. Therefore, overall cell proliferation and migration could be enhanced in the presence of 10nM or greater concentration of GST, and 15 μM shikonin-induced toxification of the cancer cells could be neutralized by 1.0 μM GST. Flow cytometry showed that GST directly bound to the surface of the cancer cells, and this was confirmed by fluorescence confocal microscopic observation. It is concluded that human class π-GST enhances proliferation and migration of human breast cancer cells by means of direct binding to the cell surface and maintaining cell viability by detoxification.

Advances of research on anti-HIV agents from traditional Chinese herbs

The current approach for dealing with the global pandemic of AIDS focuses on pharmaceuticals. The classic treatment of AIDS is highly active antiretroviral therapy, but most people living with HIV/AIDS-especially those in developing countries-have little or no access to the treatment because of the high cost of the therapy. Such treatment is associated with toxic side effects and drug resistance. As such, the search for better anti-HIV agents continues, with much attention focused on natural sources-particularly, plant species. Thousands of herbs have been screened for anti-HIV activity, and new compounds have been discovered from the extracts, many of which demonstrate inhibitory activity against HIV. Their mechanisms of action include inhibiting the activities of reverse transcriptase, protease, and integrase; weakening infection at the level of viral entry; and downregulating related gene expression. This provides researchers with new clues to synthesize drugs for the anti-HIV battle. Some synthetic derivatives of the anti-HIV natural products have stronger inhibitory effects in vitro than do their natural counterparts. Various mixed preparations of these anti-HIV herbs are in clinical trials or are applied in the treatment of people living with HIV/AIDS-some of which yield lower plasma viral load, enhance immune function, relieve related symptoms and signs, improve the quality of life, or, in combination with highly active antiretroviral therapy, alleviate the side effects of biomedical drugs. This article reviews current laboratory findings and clinical trials of anti-HIV agents from traditional herbs-particularly, herbs in traditional Chinese medicine. Drug interactions with highly active antiretroviral therapy and criteria for clinical evaluation of traditional Chinese medicine treatment are also discussed.

Discovery and development of natural product-derived chemotherapeutic agents based on a medicinal chemistry approach

Medicinal plants have long been an excellent source of pharmaceutical agents. Accordingly, the long-term objectives of the author's research program are to discover and design new chemotherapeutic agents based on plant-derived compound leads by using a medicinal chemistry approach, which is a combination of chemistry and biology. Different examples of promising bioactive natural products and their synthetic analogues, including sesquiterpene lactones, quassinoids, naphthoquinones, phenylquinolones, dithiophenediones, neo-tanshinlactone, tylophorine, suksdorfin, DCK, and DCP, will be presented with respect to their discovery and preclinical development as potential clinical trial candidates. Research approaches include bioactivity- or mechanism of action-directed isolation and characterization of active compounds, rational drug design-based modification and analogue synthesis, and structure-activity relationship and mechanism of action studies. Current clinical trial agents discovered by the Natural Products Research Laboratories, University of North Carolina, include bevirimat (dimethyl succinyl betulinic acid), which is now in phase IIb trials for treating AIDS. Bevirimat is also the first in a new class of HIV drug candidates called "maturation inhibitors". In addition, an etoposide analogue, GL-331, progressed to anticancer phase II clinical trials, and the curcumin analogue JC-9 is in phase II clinical trials for treating acne and in development for trials against prostate cancer. The discovery and development of these clinical trial candidates will also be discussed.

High rabdosiin and rosmarinic acid production in Eritrichium sericeum callus cultures and the effect of the calli on masugi-nephritis in rats

During an investigation of plant cell cultures that might be useful in the treatment of renal disorders, we established a vigorously-growing E-4 callus culture of Eritrichium sericeum that produced large amounts of caffeic acid metabolites, (-)-rabdosiin (1.8% dry wt) and rosmarinic acid (4.6% dry wt). Elicitation of the calli by methyl jasmonate induced a 38% increase in total polyphenol production. The most efficient method of eliciting (-)-rabdosiin biosynthesis was through the treatment of E-4 calli with cuprum glycerate, which induced an increase in (-)-rabdosiin production of as much as 4.1% dry wt. Oral administration of E-4 callus biomass (100 mg/kg/d for 30 d) to rats with induced Masugi-nephritis caused an increase in diuresis and lowered creatinine excretion and proteinuria levels as compared with Masugi-nephritis untreated rats. While all of the Masugi-nephritis untreated rats began to suffer, near a quarter of the E-4 treated rats remained in good health. This result indicates that the E-4 culture has the potential to alleviate the symptoms associated with nephritis.

Prooxidant DNA breakage induced by caffeic acid in human peripheral lymphocytes: Involvement of endogenous copper and a putative mechanism for anticancer properties

Plant-derived dietary material contains several classes of polyphenols such as flavonoids, curcuminoids, stilbenes and hydroxycinnamic acids. They are recognized as naturally occurring antioxidants but also act as prooxidants catalyzing cellular DNA degradation in the presence of transition metal ions such as copper. Earlier we have shown that the stilbene resveratrol is able to mobilize endogenous copper ions leading to oxidative breakage of cellular DNA. In this paper, we show that caffeic acid (a hydroxycinnamic acid), which is a major constituent of coffee, is also capable of DNA breakage in human peripheral lymphocytes. Incubation of lymphocytes with neocuproine inhibited the DNA degradation confirming that Cu(I) is an intermediate in the DNA cleavage reaction. Further, we have also shown that caffeic acid generates oxidative stress in lymphocytes, which is inhibited by scavengers of reactive oxygen species and neocuproine. These results are in further support of our hypothesis that anticancer mechanism of plant polyphenols involves mobilization of endogenous copper, possibly chromatin bound copper, and the consequent prooxidant action.

Caffeic acid protects hydrogen peroxide induced cell damage in WI-38 human lung fibroblast cells

Cytoprotective effect of caffeic acid (3,4-dihydroxy cinnamic acid) on human lung fibroblast (WI-38) cells against hydrogen peroxide induced damage was investigated. Caffeic acid was found to scavenge intracellular reactive oxygen species, and 1,1-diphenyl-2-picrylhydrazyl radical, and thus prevented lipid peroxidation. The caffeic acid protected cell damage of WI-38 cells exposed to hydrogen peroxide (H(2)O(2)), via the activation of extracellular signal regulated kinase protein. Caffeic acid increased the activity of catalase and its protein expression. Hence, from the present study, it is suggestive that caffeic acid protects WI-38 cells against H2O2 damage by enhancing the cellular antioxidant activity.

Triterpenes from Tripterygium wilfordii Hook

Two new friedelane-type triterpenes, tripterfrielanons A (1) and B (2), along with six known triterpenoids, friedelin (3), canophyllal (4), canophyllalic acid (5), 3-oxo-29-hydroxyfriedelane (6), wilforlide A (7), wilforlide B (8), have been isolated from the EtOH extract of the roots of Tripterygiumwilfordii Hook.f. Compounds 4, 5, 6 were isolated for the first time from this plant. The new triterpenes 1 and 2 exhibited mild cytotoxic activity against human Hela cell lines in vitro. The assay showed the IC50 of 1 and 2 were 8.5 and 25 microg/mL, respectively.

Inhibitory effects of caffeic acid phenethyl ester on cancer cell metastasis mediated by the down-regulation of matrix metalloproteinase expression in human HT1080 fibrosarcoma cells

Caffeic acid phenethyl ester (CAPE) derived from honeybee propolis has been used as a folk medicine. Recent study also revealed that CAPE has several biological activities including antioxidation, anti-inflammation and inhibition of tumor growth. The present study investigated the effect of CAPE on tumor invasion and metastasis by determining the regulation of matrix metalloproteinases (MMPs). Matrix metalloproteinases, which are zinc-dependent proteolytic enzymes, play a pivotal role in tumor metastasis by cleavage of extracellular matrix (ECM) as well as nonmatrix substrates. On this line, we examined the influence of CAPE on the gene expression of MMPs (MMP-2, MMP-9, MT1-MMP), tissue inhibitor of metalloproteinase-2 (TIMP-2) and in vitro invasiveness of human fibrosarcoma cells. Dose-dependent decreases in MMP and TIMP-2 mRNA levels were observed in CAPE-treated HT1080 human fibrosarcoma cells as detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Gelatin zymography analysis also exhibited a significant down-regulation of MMP-2 and MMP-9 expression in HT1080 cells treated with CAPE compared to controls. In addition, CAPE inhibited the activated MMP-2 activity as well as invasion, motility, cell migration and colony formation of tumor cells. These data therefore provide direct evidence for the role of CAPE as a potent antimetastatic agent, which can markedly inhibit the metastatic and invasive capacity of malignant cells.

New developments in natural products-based anti-AIDS research

This review discusses anti-HIV natural products from several compound classes, including terpenoids, coumarins, alkaloids, polyphenols, tannins, and flavonoids. Natural products can provide novel anti-AIDS chemotherapeutic leads that are structurally unique or have new mechanisms of action. The drug discovery and development process proceeds from bioactivity-directed isolation and identification of a promising lead natural product, followed by rational design-based structural modification and structure-activity relationship analyses to optimize the lead compound as a drug candidate. This process is notably exemplified by the discovery of the modified betulinic acid derivative, DSB [PA-457], which is currently in Phase II clinical trial and is the first-in-class HIV maturation inhibitor (MI).