Downregulation of topoisomerase 1 and 2 with acriflavine sensitizes bladder cancer cells to cisplatin-based chemotherapy.

BACKGROUND: Resistance to cisplatin is a major obstacle to effective treatment of bladder cancer (BC). The present study aimed to determine whether a combination of acriflavine (ACF) with cisplatin could potentiate the antitumor property of cisplatin against the BC cells. Furthermore, the molecular mechanism behind the anticancer action of ACF was considered. METHODS AND RESULTS: Two human BC cells (5637 and EJ138) contain mutated form of p53 was culture in standard condition. Cotreatment protocol (simultaneous combination of IC30 value of ACF + various dose of cisplatin for 72 h) and pretreatment protocol (pretreatment with IC15 value of ACF for 24 h + various dose of cisplatin for 48 h) was used to determine the effect of ACF on the cells' sensitivity to main drug cisplatin. To assess the mechanism of action of ACF, real-time PCR was used to evaluate mRNA levels of hypoxia-inducible factor-1α (HIF-1α), Bax, Bcl-2, topoisomerase1 (TOP1) and topoisomerase 2 (TOP2A). Combination of ACF with cisplatin either as cotreatment or opretreatment protocol could significantly reduce the IC50 values of cisplatin as compared to the IC50 of cisplatin when use as a single drug. In addition, ACF could markedly decrease mRNA expression of TOP1 and TOP2A without changing the expression of HIF-1ɑ, Bax and Bcl-2. CONCLUSIONS: Our findings indicate that combination of cisplatin with ACF was able to significantly enhance the sensitivity of BC cells to cisplatin. The antitumor activity of ACF is exerted through the downregulation of TOP1 and TOP2A genes expression. ACF may serve as an adjuvant to boost cisplatin-based chemotherapy.

Development of Inflammatory Hypoxia and Prevalence of Glycolytic Metabolism in Progressing Herpes Stromal Keratitis Lesions.

Chronic inflammation in tissues often causes the development of hypoxia. Herpes stromal keratitis (HSK) is a corneal chronic inflammatory condition that develops in response to recurrent HSV-1 infection. In this study, we investigated the development of hypoxia, the expression of hypoxia-associated glycolytic genes in HSV-1 infected corneas, and the outcome of blocking hypoxia-inducible factor (HIF) dimerization on the severity of HSK. Our results showed the development of hypoxia, an elevated expression of hypoxia-associated glycolytic genes, and an increased level of lactate in corneas with progressing HSK lesions. The magnitude of hypoxia correlated with the extent of neutrophils infiltrating the infected corneas, and the depletion of neutrophils reduced the development of hypoxia in infected corneas. Additionally, in progressing HSK lesions, nuclear localization of HIF-2α protein was detected in corneal epithelial cells, whereas HIF-1α protein stabilization was observed in infiltrating immune cells. Administration of acriflavine drug to HSV-1-infected mice inhibited nuclear accumulation of HIF-1α and HIF-2α protein in immune cell types and epithelial cells, respectively, in infected corneas. As a result, a decreased influx of CD4 T cells and nongranulocytic myeloid cells, but an increased influx of neutrophils, was noted in developing HSK lesions. Interestingly, acriflavine treatment given during the clinical disease period decreased neovascularization but increased the opacity in HSV-1-infected corneas. Taken together, the results of our study lay the foundation to dissect the role of inflammatory hypoxia and hypoxia-associated genes in the pathogenesis of HSK.

Ultrastable Iodinated Oil-Based Pickering Emulsion Enables Locoregional Sustained Codelivery of Hypoxia Inducible Factor-1 Inhibitor and Anticancer Drugs for Tumor Combination Chemotherapy.

Tumor hypoxia-associated drug resistance presents a major challenge for cancer chemotherapy. However, sustained delivery systems with a high loading capability of hypoxia-inducible factor-1 (HIF-1) inhibitors are still limited. Here, we developed an ultrastable iodinated oil-based Pickering emulsion (PE) to achieve locally sustained codelivery of a HIF-1 inhibitor of acriflavine and an anticancer drug of doxorubicin for tumor synergistic chemotherapy. The PE exhibited facile injectability for intratumoral administration, great radiopacity for in vivo examination, excellent physical stability (>1 mo), and long-term sustained release capability of both hydrophilic drugs (i.e., acriflavine and doxorubicin). We found that the codelivery of acriflavine and doxorubicin from the PE promoted the local accumulation and retention of both drugs using an acellular liver organ model and demonstrated significant inhibition of tumor growth in a 4T1 tumor-bearing mouse model, improving the chemotherapeutic efficacy through the synergistic effects of direct cytotoxicity with the functional suppression of HIF-1 pathways of tumor cells. Such an iodinated oil-based PE provides a great injectable sustained delivery platform of hydrophilic drugs for locoregional chemotherapy.

Acriflavine-Functionalized Silica@Manganese Ferrite Nanostructures for Synergistic Radiation and Hypoxia Therapies.

Mesoporous and nonmesoporous SiO2@MnFe2O4 nanostructures were loaded with the hypoxia-inducible factor-1 inhibitor acriflavine for combined radiation and hypoxia therapies. The X-ray irradiation of the drug-loaded nanostructures not only triggered the release of the acriflavine inside the cells but also initiated an energy transfer from the nanostructures to surface-adsorbed oxygen to generate singlet oxygen. While the drug-loaded mesoporous nanostructures showed an initial drug release before the irradiation, the drug was primarily released upon X-ray radiation in the case of the nonmesoporous nanostructures. However, the drug loading capacity was less efficient for the nonmesoporous nanostructures. Both drug-loaded nanostructures proved to be very efficient in irradiated MCF-7 multicellular tumor spheroids. The damage of these nanostructures toward the nontumorigenic MCF-10A multicellular spheroids was very limited because of the small number of nanostructures that entered the MCF-10A spheroids, while similar concentrations of acriflavine without nanostructures were toxic for the MCF-10A spheroids.

Targeting hypoxia-inducible factors with 32-134D safely and effectively treats diabetic eye disease in mice.

Many patients with diabetic eye disease respond inadequately to anti-VEGF therapies, implicating additional vasoactive mediators in its pathogenesis. We demonstrate that levels of angiogenic proteins regulated by HIF-1 and -2 remain elevated in the eyes of people with diabetes despite treatment with anti-VEGF therapy. Conversely, by inhibiting HIFs, we normalized the expression of multiple vasoactive mediators in mouse models of diabetic eye disease. Accumulation of HIFs and HIF-regulated vasoactive mediators in hyperglycemic animals was observed in the absence of tissue hypoxia, suggesting that targeting HIFs may be an effective early treatment for diabetic retinopathy. However, while the HIF inhibitor acriflavine prevented retinal vascular hyperpermeability in diabetic mice for several months following a single intraocular injection, accumulation of acriflavine in the retina resulted in retinal toxicity over time, raising concerns for its use in patients. Conversely, 32-134D, a recently developed HIF inhibitor structurally unrelated to acriflavine, was not toxic to the retina, yet effectively inhibited HIF accumulation and normalized HIF-regulated gene expression in mice and in human retinal organoids. Intraocular administration of 32-134D prevented retinal neovascularization and vascular hyperpermeability in mice. These results provide the foundation for clinical studies assessing 32-134D for the treatment of patients with diabetic eye disease.

Acriflavine, a HIF-1 inhibitor, preserves vision in an experimental autoimmune encephalomyelitis model of optic neuritis.

Introduction: Optic neuritis (ON) is often an early sign of multiple sclerosis (MS), and recent studies show a link between HIF-1 pathway activation and inflammation. This study aimed to determine if inhibition of the HIF-1 pathway using the HIF-1a antagonist acriflavine (ACF) can reduce clinical progression and rescue the ocular phenotype in an experimental autoimmune encephalomyelitis (EAE) ON model. Methods: EAE-related ON was induced in 60 female C57BL/6J mice by immunization with MOG33-55, and 20 EAE mice received daily systemic injections of ACF at 5 mg/kg. Changes in the visual function and structure of ACF-treated EAE mice were compared to those of placebo-injected EAE mice and naïve control mice. Results: ACF treatment improved motor-sensory impairment along with preserving visual acuity and optic nerve function. Analysis of retinal ganglion cell complex alsoshowed preserved thickness correlating with increased survival of retinal ganglion cells and their axons. Optic nerve cell infiltration and magnitude of demyelination were decreased in ACF-treated EAE mice. Subsequent in vitro studies revealed improvements not only attributed to the inhibition of HIF-1 butalso to previously unappreciated interaction with the eIF2a/ATF4 axis in the unfolded protein response pathway. Discussion: This study suggests that ACF treatment is effective in an animal model of MS via its pleiotropic effects on the inhibition of HIF-1 and UPR signaling, and it may be a viable approach to promote rehabilitation in MS.

Inhibition of hypoxia-inducible factor 1 by acriflavine renders glioblastoma sensitive for photodynamic therapy.

BACKGROUND: photodynamics therapy (PDT) induces tumor cell death through oxidative stress and is closely associated with the expression of hypoxia inducible factor-1a (HIF1a), which activates multiple downstream survival signaling pathways. Therefore, the purpose of this study was to investigate the expression levels of HIF1a proteins in PDT-treated GBM cells and to determine whether inhibition of HIF1a reduces survival signals to enhance the efficacy of PDT. RESULTS: PDT combined with Acriflavine (ACF, PA) decreased the expression of HIF1a and regulated the downstream expression of GLUT-1, GLUT-3, HK2 and other gluconeogenic pathway proteins. PA group significantly suppressed tumor growth to improve the efficacy of PDT. METHODS: We first performed the correlation of HIF1a, GLUT-1, GLUT-3, and HK2, and quantified the expression of HIF1a on tumor grades and IDH mutation classification by TCGA and CGGA databases. Then, we used immunohistochemistry method to detect four gene expression levels in human GBM tissues. Besides, we examined the effects of different treatments on the proliferation, migration and invasion ability of GBM cell lines by CCK8, wound healing and transwell assays. ACF, a HIF1a/HIF1ß dimerization inhibitor, was used to evaluate its adjuvant effect on the efficacy of PDT. CONCLUSION: HIF1a is activated in GBM cell lines and contributes to the survival of tumor cells after PDT in vitro and in vivo. PA group inhibited HIF1a expression and improved PDT efficacy in the treatment of recalcitrant GBM.

Acriflavine, an Acridine Derivative for Biomedical Application: Current State of the Art.

Acriflavine (ACF) has been known for years as an antibacterial drug. The identification of key oncogenic mechanisms has brought, in recent years, a significant increase in studies on ACF as a multipurpose drug that would improve the prognosis for cancer patients. ACF interferes with the expression of the hypoxia inducible factor, thus acting on metastatic niches of tumors and significantly enhancing the effects of other anticancer therapies. It has been recognized as the most potent HIF-1 inhibitor out of the 336 drugs approved by the FDA. This work presents up-to-date knowledge about the mechanisms of action of ACF and its related prodrug systems in the context of anticancer and SARS-CoV-2 inhibitory properties. It explains the multitask nature of this drug and suggests mechanisms of ACF's action on the coronavirus. Other recent reports on ACF-based systems as potential antibacterial and antiviral drugs are also described.

Synergism of a novel MCL­1 downregulator, acriflavine, with navitoclax (ABT­263) in triple­negative breast cancer, lung adenocarcinoma and glioblastoma multiforme.

Myeloid cell leukemia sequence 1 (MCL­1), an anti­apoptotic B­cell lymphoma 2 (BCL­2) family molecule frequently amplified in various human cancer cells, is known to be critical for cancer cell survival. MCL­1 has been recognized as a target molecule for cancer treatment. While various agents have emerged as potential MCL­1 blockers, the present study presented acriflavine (ACF) as a novel MCL­1 inhibitor in triple­negative breast cancer (TNBC). Further evaluation of its treatment potential on lung adenocarcinoma and glioblastoma multiforme (GBM) was also investigated. The anticancer effect of ACF on TNBC cells was demonstrated when MDA­MB­231 and HS578T cells were treated with ACF. ACF significantly induced typical intrinsic apoptosis in TNBCs in a dose­ and time­dependent manner via MCL­1 downregulation. MCL­1 downregulation by ACF treatment was revealed at each phase of protein expression. Initially, transcriptional regulation via reverse transcription­quantitative PCR was validated. Then, post­translational regulation was explained by utilizing an inhibitor against protein biosynthesis and proteasome. Lastly, immunoprecipitation of ubiquitinated MCL­1 confirmed the post­translational downregulation of MCL­1. In addition, the synergistic treatment efficacy of ACF with the well­known MCL­1 inhibitor ABT­263 against the TNBC cells was explored [combination index (CI)<1]. Conjointly, the anticancer effect of ACF was assessed in GBM (U87, U251 and U343), and lung cancer (A549 and NCI­H69) cell lines as well, using immunoblotting, cytotoxicity assay and FACS. The effect of the combination treatment using ACF and ABT­263 was estimated in GBM (U87, U343 and U251), and non­small cell lung cancer (A549) cells likewise. The present study suggested a novel MCL­1 inhibitory function of ACF and the synergistic antitumor effect with ABT­263.

The Activation of the Tumor Suppressor Protein p53 by Acriflavine Leads to Mitochondrial Dysfunction and Improves the Radiosensitivity of Colon Cancer Cells.

Colon cancer ranks third worldwide, and it has a growing incidence with urbanization and industrialization. Drug resistance in colon cancer is gradually affecting the treatment. This study focused on the mechanisms by which acriflavine (ACF) enhances the radiosensitivity of colon cancer cells. First, the expression and activation levels of tumor suppressor protein p53 were shown high in normal cells and tissues in its detection, which suggests that p53 is likely to be a key factor in colon cancer. Then, the expression of p53 ended up increasing in ACF group after SW620 cells were cultured with ACF. In addition, ACF group had some other changes. The expression of mitochondrial related antiapoptotic protein Bcl-2 increased, while the expression of proapoptotic protein Bax, Bad, cytopigment C, and apoptotic inducer AIF decreased. At the same time, the ability of apoptosis was enhanced, and the ability of proliferation and invasion was decreased. This suggests that ACF can promote p53 expression and affect mitochondrial function and the radiosensitivity of SW620. The luciferase reporting experiment showed that there was a binding site between ACF and p53. Besides, when IR treatment was applied to SW620 with high p53 expression, there was an increase in the expression of Bcl-2 in SW620 and decrease in Bax, Bad, and cytopigment C in AIF. Meanwhile, the cell apoptosis became stronger, and the proliferation and invasion became weaker. The experimental results were similar to those of SW620 cells cultured with ACF, suggesting that p53 is an intermediate factor in the regulation of SW620 by ACF. Finally, in this study, cells were cultured with ACF, and p53 was knocked down at the same time. The experimental results showed that after p53 was knocked down. ACF's ability to regulate SW620 is partially removed. This confirms the view that ACF regulates SW620 cells by regulating p53. In summary, this study found the mechanism by which ACF causes mitochondrial dysfunction and improves the radiosensitivity of colon cancer cells by activating the tumor suppressor protein p53, which may contribute to solving the drug resistance in colon cancer.

Antibacterial action of acriflavine hydrochloride for eradication of the gastric pathogen Helicobacter pylori.

Helicobacter pylori, a type 1 carcinogen, accounts for numerous gastric cancer-related deaths worldwide. Repurposing existing drugs or developing new ones for a combinatorial approach against increasing antimicrobial resistance is the need of the hour. This study highlights the efficacy of acriflavine hydrochloride (ACF-HCl) in inhibiting the growth of H. pylori reference strain and antibiotic-resistant clinical isolates at low concentrations. ACF-HCl inhibits H. pylori growth at MIC value 10 times less than that in Escherichia coli, another Gram-negative bacteria. Furthermore, ACF-HCl demonstrates synergistic effect with clarithromycin, a commonly used antibiotic against H. pylori. ACF-HCl treatment also eradicates H. pylori infection in the mice model efficiently. Our in vitro data indicate that bacterial membrane is the prime target. The novel action of ACF-HCl against antibiotic-resistant clinical isolates, synergistic effect with the conventional antibiotic clarithromycin and eradication of H. pylori from infected mice highlight the potential of ACF-HCl as a promising therapeutic agent against H. pylori by itself as well as for combinatorial therapy.

Clinical observations on the use of honcrivine in the chemical debridement of wounds.

BACKGROUND: Chronic and non healing wounds, necrotic wounds and contused and devitalized wounds require debridement to rid the wounds of all these impediments that encourage bacterial growth and multiplications with consequent impairment of wound healing. Whereas there are several methods of wound debridement with their peculiar indications, merits and demerits, the ideal method of debridement is yet to be discovered. AIM: The aim of this study is to investigate clinically the ability of honcrivine (honey plus acriflavine 0.1%) to chemically debride various wounds in routine clinical practice. PATIENTS AND METHOD: One hundred and eighty nine consecutive patients managed by the author between June 1995 and June 2005 were included in this study. They were 125 males and 64 females and their ages ranged between 6 and 78 years. Initially swab was taken for bacterial culture from each wound before being cleaned with normal saline, then dressed daily with gauze soaked in honcrivine. Bacterial culture was repeated fortnightly. Antibiotics were administered as dictated by culture and sensitivity report. RESULTS: Wound debridement progressed rapidly and impressively with necrotic and devitalized tissues as well as tenacious pus and fibrin deposits being replaced with healthy granulation tissue. Patients age, sex and bacterial burden did not influence the rate of debridement, rather wound age and necrotic burden were inversely proportional to the debridement rate. Honcrivine did not provoke any inflammatory response nor was any allergic reaction observed. CONCLUSION: It is one of the oldest remedies known to mankind and is still useful and versatile today as it was 2000 years ago. It is a very effective chemical wound debridant.

Macrophage metabolic reprogramming aggravates aortic dissection through the HIF1α-ADAM17 pathway✰.

BACKGROUND: Aortic dissection is a severe inflammatory vascular disease with high mortality and limited therapeutic options. The hallmarks of aortic dissection comprise aortic inflammatory cell infiltration and elastic fiber disruption, highlighting the involvement of macrophage. Here a role for macrophage hypoxia-inducible factor 1-alpha (HIF-1α) in aortic dissection was uncovered. METHODS: Immunochemistry, immunofluorescence, western blot and qPCR were performed to test the change of macrophage HIF-1α in two kinds of aortic dissection models and human tissues. Metabolomics and Seahorse extracellular flux analysis were used to detect the metabolic state of macrophages involved in the development of aortic dissection. Chromatin Immunoprecipitation (ChIP), enzyme-linked immunosorbent assay (ELISA) and cytometric bead array (CBA) were employed for mechanistic studies. FINDINGS: Macrophages involved underwent distinct metabolic reprogramming, especially fumarate accumulation, thus inducing HIF-1α activation in the development of aortic dissection in human and mouse models. Mechanistic studies revealed that macrophage HIF-1α activation triggered vascular inflammation, extracellular matrix degradation and elastic plate breakage through increased a disintegrin and metallopeptidase domain 17 (ADAM17), identified as a novel target gene of HIF-1α. A HIF-1α specific inhibitor acriflavine elicited protective effects on aortic dissection dependent on macrophage HIF-1α. INTERPRETATION: This study reveals that macrophage metabolic reprogramming activates HIF-1α and subsequently promotes aortic dissection progression, suggesting that macrophage HIF-1α inhibition might be a potential therapeutic target for treating aortic dissection.

HIF1α inhibition facilitates Leflunomide-AHR-CRP signaling to attenuate bone erosion in CRP-aberrant rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic inflammatory disorder characterized by progressive bone erosion. Leflunomide is originally developed to suppress inflammation via its metabolite A77 1726 to attenuate bone erosion. However, distinctive responsiveness to Leflunomide is observed among RA individuals. Here we show that Leflunomide exerts immunosuppression but limited efficacy in RA individuals distinguished by higher serum C-reactive protein (CRPHigher, CRPH), whereas the others with satisfactory responsiveness to Leflunomide show lower CRP (CRPLower, CRPL). CRP inhibition decreases bone erosion in arthritic rats. Besides the immunomodulation via A77 1726, Leflunomide itself induces AHR-ARNT interaction to inhibit hepatic CRP production and attenuate bone erosion in CRPL arthritic rats. Nevertheless, high CRP in CRPH rats upregulates HIF1α, which competes with AHR for ARNT association and interferes Leflunomide-AHR-CRP signaling. Hepatocyte-specific HIF1α deletion or a HIF1α inhibitor Acriflavine re-activates Leflunomide-AHR-CRP signaling to inhibit bone erosion. This study presents a precision medicine-based therapeutic strategy for RA.

The HIF-1 antagonist acriflavine: visualization in retina and suppression of ocular neovascularization.

Acriflavine, a fluorescent drug previously used for bacterial and trypanosomal infections, reduces hypoxia-inducible factor-1 (HIF-1) and HIF-2 transcriptional activity. In mice with oxygen-induced ischemic retinopathy, intraocular or intraperitoneal injections of acriflavine caused dose-dependent suppression of retinal neovascularization (NV) and significantly reduced expression of HIF-1-responsive genes. Intraocular injection of 100 ng caused inner retina fluorescence within 1 h that was seen throughout the entire retina between 1 and 5 days, and at 7 days after injection, strongly suppressed choroidal NV at Bruch's membrane rupture sites. After suprachoroidal injection of 300 ng in rats, there was retinal fluorescence in the quadrant of the injection at 1 h that spread throughout the entire retina and choroid by 1 day, was detectable for 5 days, and dramatically reduced choroidal NV 14 days after rupture of Bruch's membrane. After topical administration of acriflavine in mice, fluorescence was seen in the retina and retinal pigmented epithelium within 5 min and was detectable for 6-12 h. Administration of 0.5% drops to the cornea twice a day significantly reduced choroidal NV in mice. Electroretinographic b-wave amplitudes were normal 7 days after intravitreous injection of 100 ng of acriflavine in mice, showed mild threshold reductions at highest stimulus intensities after injection of 250 ng, and more extensive changes after injection of 500 ng. These data provide additional evidence for an important role for HIF-1 in retinal and choroidal NV and suggest that acriflavine can target HIF-1 through a variety of modes of administration and has good potential to provide a novel therapy for retinal and choroidal vascular diseases. KEY MESSAGE: Acriflavine, an inhibitor of HIF-1, suppresses retinal and choroidal neovascularization. HIF-1 plays a critical role in ocular neovascularization. Acriflavine's fluorescence provides a mean to track its entry and exit from the retina. Acriflavine has therapeutic potential for the treatment of ocular neovascularization.

HIF-1α- Targeting Acriflavine Provides Long Term Survival and Radiological Tumor Response in Brain Cancer Therapy.

Tumor progression, limited efficacy of current standard treatments, and the rise in patient mortality are associated with gene expression caused by the synergistic action of intratumoral hypoxia and HIF-1α activation. For this reason, recent investigations have focused on HIF-targeting therapeutic agents, with encouraging preclinical and clinical results in solid tumors. Here we describe the efficacy of a HIF-1α inhibitor, Acriflavine, and demonstrate its potency against brain cancer. This safe antibacterial dye induces cell death and apoptosis in several glioma cell lines, targets HIF-1α-mediated pathways, and decreases the level of PGK1, VEGF and HIF-1α in vitro and in vivo. Administered locally via biodegradable polymers, Acriflavine provides significant benefits in survival resulting in nearly 100% long term survival, confirmed by MRI and histological analyses. This study reports preclinical evidence that this safe, small molecule can contribute to brain tumor therapy and highlights the significance of HIF-1α-targeting molecules.

Data of pre-clinical and early clinical trials of acriflavine and hydroxy-methyl-ellipticine reviewed, enriched by the experience of their use for 18 months to 6 years in combinations with other HIV1 virostatics.

Two virostatics which we discovered in 1990, acriflavine (ACF) and hydroxy-methyl-ellipticine (HEL) and shown active on HIV1 resistant to AZT have been introduced into combinations of four virostatics selected among ten available: themselves, plus zidovudine, zalcitabine, didanosine, lamivudine, stavudine, saquinavir, ritonavir, indinavir, the combinations were applied in 3-week sequences, differing from each other by drug rotation. Those which contained ACF may have more often a CD34 decrease than those containing neither ACF nor HEL, and they present more often a CD4 increase. No significant difference as far as side effects or beneficial effects could be detected after 18 months to 6 years, between sequences containing ACF or HEL or both, and sequences not containing any one of them.

Why have ten or so nontoxic, retrovirus integrase inhibitors not been made available for AIDS treatment? A ten-year experience [correction of experiment] must liberate them.

We detected in 1989, with the inhibitor test of proviral insertion into c-erb B erythroblastosis, two retrovirus integrase inhibitors: hydroxy-methyl-ellipticine and acriflavine. They have been used for ten years in AIDS patients with high efficacy and no toxicity. Since vitamin B12 and cobalt, which it contains, have been detected as HIV1-integrase inhibitors by an in-vitro test, we have also used vitamin B12 (combined with folic acid), whose clinical action has been remarkable. Ten or so other compounds have been detected by such in-vitro tests, among which there are many compounds (such as flavones) which are used in many conditions and are not toxic.

AIDS therapy with two, three or four agent combinations, applied in short sequences, differing from each other by drug rotation. I. First of two parts: a phase I trial equivalent, concerning five virostatics: AZT, ddI, ddC, acriflavine and an ellipticine analogue.

We have individually treated ten AIDS patients whose CD4 numbers were inferior to 200/mm3, with the five following HIV1 virostatics: a) azido-deoxythymidine (AZT), dideoxyinosine (ddI) and dideoxycytidine (ddC), which affect the same viral target, retrotranscriptase, b) acriflavine (ACF) and methyl-hydroxy-ellipticine (MHE) which we have discovered to be strong virostatics in vivo, in mice, against Friend's virus, and in man, against AZT resistant HIV1. We have shown that their combinations with AZT, hitting three viral targets, reduces in mice, the blood Friend's virus load below detectable level. Due to the short doubling time of HIV1, AIDS therapy must be continuous, and to allow the best tolerance, the five virostatic combinations were applied in short, three-week sequences, each differing as much as possible from the former and from the following one, due to drug rotation [1]. Among the ten patients, a) three received the two-drug combinations for 15 to 30 months, followed by the three-drug combinations, b) three received the three-drug combinations from the beginning, c) four received the four-drug combinations also from the beginning, two having less than 10 CD4/mm3 at initiation of treatment, and two having more than 100. The tolerance was remarkable: the only side-effect being macrocytosis. The application of the two-drug combination sequences maintained stable CD4 levels in two subjects whose viral load (the evaluation of which had became available) was, at the end of this period, of 4,486 and 39,238 RNA copies. The third subject who had received, an intensive UV irradiation for a psoriasis, presented an irreversible decrease in his CD4 count and a high viral load (1,352,495 RNA copies/mL) at the end of the two-drug period. Fifteen to 25 months after the shift to the three-drug combinations, the viral load decreased, from 39,328 to 13,291 in one of the non-UV irradiated subjects, and from 1,352,495 to 314,387 in the irradiated one. No subject had an increase in CD4 number. In the three patients having initially received the three-drug combinations, a very strong decrease of viral load was registered after periods of observation varying from 77 to 40 months, while the CD4 counts increased moderately in two subjects, and noticeably in the third (from 126 to 266). Out of the four subjects initially treated with four-drug combinations, the two with less than 10 CD4/mm3 had a moderate decrease in viral load in about three months, and the CD4 increased from 9 to 34/mm3 in one. But the two subjects, because of opportunistic infections and psychological reasons, abandoned their treatments. In the two subjects who had more than 100 CD4/mm2 at initiation of the four-drug combination treatment, the viral load decreased to undetectable levels after four months: but their CD4 counts, after some oscillations, had very moderately increased at the end of the observation period (respectively, from 200 to 222, and from 129 to 134). In practice, these results suggest the interest of conducting phase II or III studies of AIDS treatment protocols, starting with the four-drug combination model, and attempting to maintain the effect with the three-drug combination one. As for theoretical considerations, one must underline the contrast between the remarkable reduction of the viral load and the usually moderate increase of the CD4 counts. The study but not the trial has been interrupted, due to the unavailability of three antiproteases, saquinavir, ritonavir and indinavir, which are now introduced in the same type of combinations, one by one, in replacement of one of the studied agents as shown in figure 1. The effect of increasing the total number of virostatics from five to eight will be published in the second part of this article series.

In vivo eradication of Friend virus as an experimental HIV-model, by combination of zidovudine, acriflavine and an ellipticine analogue. Possible application to the treatment of human pre-AIDS?

Simultaneous administration of zidovudine, acriflavine and celliptium to Friend virus-injected mice eradicates the virus, as evidenced by the impossibility of the treated-mouse serum, when injected to virgin recipients, to induce spleen foci formation. An adapted preliminary protocol given to patients in whose p 24 antigen was present in the blood, lead to a considerable reduction of that marker. The cures lasted 3 weeks, and were repeated after 3-week intervals. Since p 24 antigen returns to pre-treatment levels at the end of the interval, research should concentrate on the maintenance of the effect during the interval.