Celastrol: A lead compound that inhibits SARS-CoV-2 replication, the activity of viral and human cysteine proteases, and virus-induced IL-6 secretion.

The global emergence of coronavirus disease 2019 (COVID-19) has caused substantial human casualties. Clinical manifestations of this disease vary from asymptomatic to lethal, and the symptomatic form can be associated with cytokine storm and hyperinflammation. In face of the urgent demand for effective drugs to treat COVID-19, we have searched for candidate compounds using in silico approach followed by experimental validation. Here we identified celastrol, a pentacyclic triterpene isolated from Tripterygium wilfordii Hook F, as one of the best compounds out of 39 drug candidates. Celastrol reverted the gene expression signature from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected cells and irreversibly inhibited the recombinant forms of the viral and human cysteine proteases involved in virus invasion, such as Mpro (main protease), PLpro (papain-like protease), and recombinant human cathepsin L. Celastrol suppressed SARS-CoV-2 replication in human and monkey cell lines and decreased interleukin-6 (IL-6) secretion in the SARS-CoV-2-infected human cell line. Celastrol acted in a concentration-dependent manner, with undetectable signs of cytotoxicity, and inhibited in vitro replication of the parental and SARS-CoV-2 variant. Therefore, celastrol is a promising lead compound to develop new drug candidates to face COVID-19 due to its ability to suppress SARS-CoV-2 replication and IL-6 production in infected cells.

Development, Characterization and Cell Viability Inhibition of PVA Spheres Loaded with Doxorubicin and 4'-Amino-1-Naphthyl-Chalcone (D14) for Osteosarcoma.

Chalcones (1,3-diaryl-2-propen-1-ones) are naturally occurring polyphenols with known anticancer activity against a variety of tumor cell lines, including osteosarcoma (OS). In this paper, we present the preparation and characterization of spheres (~2 mm) from polyvinyl alcohol (PVA) containing a combination of 4'-Amino-1-Naphthyl-Chalcone (D14) and doxorubicin, to act as a new polymeric dual-drug anticancer delivery. D14 is a potent inhibitor of osteosarcoma progression and, when combined with doxorubicin, presents a synergetic effect; hence, physically crosslinked PVA spheres loaded with D14 and doxorubicin were prepared using liquid nitrogen and six freeze-thawing cycles. Physical-chemical characterization using a scanning electron microscope (SEM), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) presented that the drugs were incorporated into the spheres via weak interactions between the drugs and the polymeric chains, resulting in overall good drug stability. The cytotoxicity activity of the PVA spheres co-encapsulating both drugs was tested against the U2OS human osteosarcoma cell line by 3- (4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide (MTT) assay, and compared to the spheres carrying either D14 or doxorubicin alone. The co-delivery showed a cytotoxic effect 2.6-fold greater than doxorubicin alone, revealing a significant synergistic effect with a coefficient of drug interaction (CDI) of 0.49. The obtained results suggest this developed PVA sphere as a potential dual-drug delivery system that could be used for the prominent synergistic anticancer activity of co-delivering D14 and doxorubicin, providing a new potential strategy for improved osteosarcoma treatment.

Effect of Costus spiralis (Jacq.) Roscoe Leaves, Methanolic Extract and Guaijaverin on Blood Glucose and Lipid Levels in a Type II Diabetic Rat Model.

This study aimed to isolate and identify flavonoids with hypoglycemic activity in Costus spiralis leaves. The methanolic extract (ME) was rich in flavonoids, while the powdered leaves (PL) contained considerable amounts of macro- and microelements. Oral acute treatment of streptozotocin (STZ)-induced diabetic rats for 18 h with the C. spiralis PL, ME and isolated guaijaverin (GUA) lowered glycemia, improved oral glucose tolerance and inhibited liver lipid peroxidation. GUA and ME lowered plasma levels of low-density and non-high density lipoproteins; GUA also lowered total cholesterol levels. PL, ME and GUA did not significantly alter the plasma levels of triglycerides, high-density lipoproteins, very low-density lipoproteins, creatinine and aspartate transaminase, and the total protein levels in the kidney and liver tissues. Therefore, C. spiralis leaves are promising raw materials and rich sources of bioactive flavonoids for the development of novel antidiabetic drugs due to their hypoglycemic, antidyslipidemic and antioxidant actions.

Genetic structure and chemical diversity in natural populations of Uncaria guianensis (Aubl.) J.F.Gmel. (Rubiaceae).

Uncaria guianensis is native to the Amazon and is used traditionally as an anti-inflammatory. Natural populations of the species have declined markedly in recent times because of strong anthropic pressure brought about by deforestation and indiscriminate collection. The aim of the present study was to assess the genetic and chemical diversity among eight natural populations of U. guianensis located in the Brazilian states of Acre, Amapá and Amazonas. A set of four primer combinations was employed in sequence-related amplified polymorphism (SRAP) amplifications of leaf DNA, and the fragments were analyzed in an LI-COR model 4300 DNA Analyzer. Genetic variability within the populations (81%) was substantially greater than that detected between them (19%). The highest percentage of polymorphic loci (90.21%) and the largest genetic variability were observed in the population located in Mazagão, Amapá. Genetic differentiation between populations was high (Fst = 0.188) and the studied populations formed three distinct genetic groups (K = 3). The population located in Assis Brasil, Acre, presented the highest average content of the mitraphylline (0.60 mg/g dry weight,). However, mitraphylline and isomitraphylline not detected in most individuals in the studied populations, and it is questionable whether they should be considered as chemical markers of the species. The genetic data confirm the urgent need for conservation programs for U. guianensis, and for further studies aimed at ascertaining the genetic basis and heritability of alkaloid accumulation.

Genetic diversity and chemical variability of Lippia spp. (Verbenaceae).

BACKGROUND: The genus Lippia comprises 150 species, most of which have interesting medicinal properties. Lippia sidoides (syn. L. origanoides) exhibits strong antimicrobial activity and is included in the phytotherapy program implemented by the Brazilian Ministry of Health. Since species of Lippia are morphologically very similar, conventional taxonomic methods are sometimes insufficient for the unambiguous identification of plant material that is required for the production of certified phytomedicines. Therefore, genetic and chemical analysis with chemotype identification will contribute to a better characterization of Lippia species. METHODS: Amplified Length Polymorphism and Internal Transcribed Spacer molecular markers were applied to determine the plants' genetic variability, and the chemical variability of Lippia spp. was determined by essential oil composition. RESULTS: Amplified Length Polymorphism markers were efficient in demonstrating the intra and inter-specific genetic variability of the genus and in separating the species L. alba, L. lupulina and L. origanoides into distinct groups. Phylogenetic analysis using Amplified Length Polymorphism and markers produced similar results and confirmed that L. alba and L. lupulina shared a common ancestor that differ from L. origanoides. Carvacrol, endo-fenchol and thymol were the most relevant chemical descriptors. CONCLUSION: Based on the phylogenetic analysis it is proposed that L. grata should be grouped within L. origanoides due to its significant genetic similarity. Although Amplified Length Polymorphism and Internal Transcribed Spacer markers enabled the differentiation of individuals, the genotype selection for the production of certified phytomedicines must also consider the chemotype classification that reflects their real medicinal properties.

Costus spiralis (Jacq.) Roscoe: A Novel Source of Flavones with α-Glycosidase Inhibitory Activity.

Costus spiralis, a plant used in traditional Brazilian medicine for the treatment of complications in diabetes, was investigated. Assay of hexane, ethyl acetate, methanol, and aqueous fractions obtained by partition of a crude methanol extract of dried leaves of C. spiralis revealed that AGI activity was confined to the ethyl acetate fraction. Purification of this fraction yielded schaftoside and isoschaftoside. The AGI activities of the two flavones were lower than, but comparable with, that of the anti-diabetic drug acarbose. In contrast, the IC50 value of the ethyl acetate fraction was 1.95-, 2.34-, and 2.22-fold higher than those of acarbose, schaftoside, and isoschaftoside, respectively. The results demonstrate for the first time that schaftoside and isoschaftoside are responsible, in part, for the AGI activity of C. spiralis. Our study suggests that further investigations into C. spiralis may lead to the discovery of additional compounds with antihyperglycemic activity.

Antiproliferative and pro-apoptotic activities of 2'- and 4'-aminochalcones against tumor canine cells.

In the present study, a series of 2'- and 4'-aminochalcones were synthesized and their antiproliferative activity against a canine malignant histiocytic cell line (DH82) was evaluated. Particularly aminochalcones with a hydrophobic substituent on ring B proved to be potent antiproliferative agents. Among these compounds, aminochalcones 3, 4 and 11 inhibited the growth of DH82 cells, with IC50 values of 34.4, 31.4 and 38.2 µM, respectively, and were three times more potent than etoposide (IC50 = 95.5 µM). The selected chalcones induced death through apoptosis rather than necrosis in DH82 and non-tumorigenic Madin-Darby canine kidney cells (MDCK). Further experiments suggested that the aminochalcones interfere with the regulation of oncogenes/tumor suppressor genes. Aminochalcone 11 inhibited transcription of the TOPOIIα and TP53 genes and aminochalcone 4 down-regulated Sp1 protein expression in a concentration-dependent manner.

Thymus vulgaris L. essential oil and its main component thymol: Anthelmintic effects against Haemonchus contortus from sheep.

Haemonchus contortus is an important gastrointestinal parasite on sheep farms in tropical regions. The resistance of the parasite against most anthelmintic drugs represents a great economic problem to sheep farming and is a major challenge that needs to be overcome. The searches for new anthelmintic agents that act on different stages of the parasite's life cycle are necessary for the development of new therapeutic options. The aim of this study was to evaluate the in vitro and in vivo anthelmintic activity of Thymus vulgaris essential oil against H. contortus and of its main component, the monoterpene thymol. Despite the relative ineffectiveness of the oil in the in vivo test, which may be corrected in the future after technical improvements to increase the oil's bioavailability, the in vitro results validated the popular use of T. vulgaris oil as an anthelmintic agent, at least against H. contortus. In fact, both the essential oil and thymol, which accounts for 50.22% of the oil composition, were effective against the three main stages of H. contortus. The oil and thymol were able to inhibit egg hatching by 96.4-100%, larval development by 90.8-100%, and larval motility by 97-100%. Similar to the positive control (levamisole 20mg/mL), the oil and thymol completely inhibited the motility of H. contortus adults within the first 8h of the experiment. Since thymol reproduces the anthelmintic effects of the oil and because it is the main component of the oil, it is reasonable to assume that thymol is the most important compound responsible for the anthelmintic effect of T. vulgaris. These results are of ethnopharmacological importance and may contribute to the development of new drugs and even herbal medicines, increasing treatment options for the farm breeding.

Mevalonate-derived quinonemethide triterpenoid from in vitro roots of Peritassa laevigata and their localization in root tissue by MALDI imaging.

Biosynthetic investigation of quinonemethide triterpenoid 22ß-hydroxy-maytenin (2) from in vitro root cultures of Peritassa laevigata (Celastraceae) was conducted using (13)C-precursor. The mevalonate pathway in P. laevigata is responsible for the synthesis of the quinonemethide triterpenoid scaffold. Moreover, anatomical analysis of P. laevigata roots cultured in vitro and in situ showed the presence of 22ß-hydroxy-maytenin (2) and maytenin (1) in the tissues from transverse or longitudinal sections with an intense orange color. MALDI-MS imaging confirmed the distribution of (2) and (1) in the more distal portions of the root cap, the outer cell layers, and near the vascular cylinder of P. laevigata in vitro roots suggesting a role in plant defense against infection by microorganisms as well as in the root exudation processes.

Evaluation of anticandidal and antioxidant activities of phenolic compounds from Pyrostegia venusta (Ker Gawl.) Miers.

We have investigated the in vitro anticandidal and antioxidant activities of phenolic compounds from Pyrostegia venusta flower extracts. We used the HPLC technique to purify the flavonoid (quercetin-3-O-α-l-rhamnopyranosyl-(1→6)-ß-d-galactopyranoside) and two phenylpropanoid glycosides (verbascoside and isoverbascoside); we evaluated the antimicrobial activity of the extracts against Candida strains (Candidaalbicans; Candidakrusei ATCC 6258; and the clinical isolate strains of Candida sp. C. albicans, C. krusei, Candidatropicalis, Candidaparapsilosis, and Candidaguilhermondii). The P. venusta flower extracts displayed antimicrobial and antioxidant activities. The semi-purified fraction of the P. venusta flower extract and the phenylpropanoid glycoside verbascoside exhibited activity similar to that of amphotericin B, which denoted that they are potentially applicable as natural antioxidant and anticandidal agents in the pharmaceutical industries.

In vitro assessment of antimicrobial activity of Pothomorphe umbellata extracts against Enterococcus faecalis.

BACKGROUND: Due to the complex anatomy of the root canal system, biomechanical preparation is not able to completely eliminate all microorganisms present in the endodontic infections, making it necessary the use of an intracanal medication. AIM: The aim of this study was to assess the antimicrobial activity of an intracanal medication containing the ethyl-acetate fraction of Pothomorphe umbellata against Enterococcus faecalis. MATERIALS AND METHODS: Fifty seven human maxillary canine teeth were used, of which 54 were infected with E. faecalis every 72 h, for 28 days, and cultured for 24 h. Contaminated teeth were randomly separated into three groups (n = 18) and treated as follows: Group I - calcium hydroxide-based medication; Group II - P. umbellata-based medication; Group III - contaminated teeth without medication. Three teeth were used as negative control. After 7, 14 and 28 days of treatment, six teeth from each group were assessed for the level of microbial growth after each period of treatment. RESULTS: The intracanal medication containing P. umbellata was effective against E. faecalis after 7, 14, and 28 days of treatment without statistically significant difference in comparison to calcium hydroxide treatment (Kruskal-Wallis test, P > 0.05). CONCLUSION: Ethyl-acetate fraction of P. umbellate was efficient against E. faecalis, making this phytotherapy a viable option for endodontic treatment.

Chemical composition and antifungal activity of the essential oils of Schinus weinmannifolius collected in the spring and winter.

Reports on the chemical and pharmacological profile of the essential oil of Schinus weinmannifolius do not exist, although other Schinus species have been widely investigated for their biological activities. This work aimed to evaluate the chemical composition and antimicrobial activity of the essential oil of S. weinmannifolius collected in the spring and winter. The essential oils were extracted by hydrodistillation, analyzed by GC/MS and submitted to microdilution tests, to determine the minimum inhibitory concentration. The oils displayed different chemical composition and antimicrobial action. Bicyclogermacrene and limonene predominated in the oils extracted in the winter and spring, respectively, whereas only the latter oil exhibited antifungal activity.

In vitro action of flavonoids in the canine malignant histiocytic cell line DH82.

Cancer is commonly diagnosed in dogs over the age of 10 and is a leading cause of death due to the lack of effective drugs. Flavonoids possess antioxidant, anti-inflammatory and anticarcinogenic properties and have been studied as chemopreventive agents in human cancer therapy. However, the literature on dogs is sparse. In this study, we analyzed the effect of nine flavonoids on cell viability, DNA damage and topoisomerase IIa/IIb gene expression in a canine tumor cell line (DH82). Apigenin, luteolin, trans-chalcone and 4-methoxychalcone showed the highest degree of cytotoxicity in the absence of considerable DNA damage, whereas genistein exhibited low cytotoxicity but induced a high level of DNA damage. These five flavonoids inhibited topoisomerase IIa and IIb gene expression to variable extents and with variable specificity. Genistein exerted a lower inhibitory effect on the two topoisomerases than luteolin and apigenin. trans-Chalcone and 4-methoxychalcone exerted greater inhibition of topoisomerase IIa expression than topoisomerase IIb. The differences in the effects between genistein and luteolin and apigenin might be explained by the position of ring B, whereas the more specific effect of chalcones on topoisomerase IIa might be due to their open chain structure.

Evaluation of the Hypoglycemic Properties of Anacardium humile Aqueous Extract.

The antihyperglycemic effects of several plant extracts and herbal formulations which are used as antidiabetic formulations have been described and confirmed to date. The main objective of this work was to evaluate the hypoglycemic activity of the aqueous extract of Anacardium humile. Although the treatment of diabetic animals with A. humile did not alter body weight significantly, a reduction of the other evaluated parameters was observed. Animals treated with A. humile did not show variation of insulin levels, possibly triggered by a mechanism of blood glucose reduction. Levels of ALT (alanine aminotransferase) decreased in treated animals, suggesting a protective effect on liver. Levels of cholesterol were also reduced, indicating the efficacy of the extract in reestablishing the balance of nutrients. Moreover, a kidney protection may have been achieved due to the partial reestablishment of blood glucose homeostasis, while no nephrotoxicity could be detected for A. humile. The obtained results demonstrate the effectiveness of A. humile extracts in the treatment of alloxan-induced diabetic rats. Therefore, A. humile aqueous extract, popularly known and used by diabetic patients, induced an improvement in the biochemical parameters evaluated during and following treatment of diabetic rats. Thus, a better characterization of the medicinal potential of this plant will be able to provide a better understanding of its mechanisms of action in these pathological processes.

Anti-snake venom activities of extracts and fractions from callus cultures of Sapindus saponaria.

CONTEXT: Sapindus saponaria L. (Sapindaceae) bark, root, and fruits are used as sedatives and to treat gastric ulcer and also demonstrate diuretic and expectorant effects. OBJECTIVE: The anti-snake venom properties of callus of S. saponaria are investigated here for the first time. MATERIALS AND METHODS: In vitro cultivated callus of Sapindus saponaria were lyophilized, and the extracts were prepared with different solvents, before submitting to phytochemical studies and evaluation of the anti-ophidian activity. Crude extracts were fractionated by liquid-liquid partition and the fractions were monitored by thin layer chromatography (TLC). Subsequently, anti-ophidian activities were analyzed toward Bothrops jararacussu Lacerda (Viperidae), B. moojeni Hoge (Viperidae), B. alternates Duméril (Viperidea) and Crotalus durissus terrificus Lineu (Viperidae) venoms and isolated myotoxins and phospholipase A(2) (PLA(2)). RESULTS: Fractions A1, A2 and the extract in MeOH:H(2)O (9:1) significantly inhibited the toxic and pharmacological activities induced by snake venoms and toxins, when compared to other extracts and fractions. The lethal, clotting, phospholipase, edema-inducing, hemorrhagic and myotoxic activities were partially inhibited by the different extracts and fractions. TLC profiles of the crude extracts (B and C) and fractions (A1 and A2) showed ß-sitosterol and stigmasterol as their main compounds. Stigmasterol exhibited inhibitory effects on enzymatic and myotoxic activities of PLA(2). DISCUSSION AND CONCLUSION: Sapindus saponaria extracts and fractions presented anti-ophidian activity and could be used as an adjuvant to serum therapy or for its supplementation, and in addition, as a rich source of potential inhibitors of enzymes involved in several pathophysiological human and animal diseases.

Morphological analysis of tissue reaction caused by a new endodontic paste in subcutaneous tissue of rats.

AIM: To assess the biocompatibility of an experimental endodontic paste based on the ethyl acetate fraction of Pothomorphe umbellata + calcium hydroxide, using propylene glycol as vehicle, in connective tissue of rats. MATERIALS AND METHODS: Fifteen rats had four polyethylene tubes implanted in their backs, with each one containing the experimental paste. The tube side was considered the control group. After 7, 21, and 42 days, animals were euthanized. RESULTS: Intense inflammatory reaction was noticed after 7 days for experimental paste and it was moderate for control group. At 21 days, the inflammatory reaction was moderate for experimental paste and discrete for control group; and at 42 days, it was discrete for experimental paste and control group. Statistical analysis (Dunn's test, P < 0.01) demonstrated significant difference between the fibrous capsule area at 7 and 42 days (P > 0.01) for experimental paste. CONCLUSIONS: Experimental endodontic paste presented satisfactory tissue reaction in the connective tissue of rats.

Protective effect of schizolobium parahyba flavonoids against snake venoms and isolated toxins.

Four compounds (isoquercitrin, myricetin-3-O-glucoside, catechin and gallocatechin) were isolated from lyophilized aqueous extract of Schizolobium parahyba leaves by chromatography on Sephadex LH-20, followed by semipreparative HPLC using a C-18 column, and identified by 1H and 13C NMR. The compounds were then, tested against hemorrhagic and fibrinogenolytic activities of Bothrops crude venoms and isolated metalloproteinases. The inhibitors neutralized the biological and enzymatic activities of Bothrops venoms and toxins isolated from B. jararacussu and B. neuwiedi venoms. The results showed that gallocatechin and myricetin-3-O-glucoside are good inhibitors of hemorrhagic and fibrinogenolytic activities of metalloproteinases, respectively. Gallocatechin also inhibited the myotoxic activity of both B. alternatus venom and BnSP-6 (Lys49 PhospholipaseA2 from B. neuwiedi). Circular dichroism and docking simulation studies were performed in order to investigate the possible interaction between BnSP-6 and gallocatechin. This is the first time these compounds and their anti-ophidian properties are reported for S. parahyba species. Forthcoming studies involving X-ray co-crystallization, will be of great importance for the development of new therapeutic agents for the treatment of ophidian accidents and for the better understanding of the structure/function relationship of venom toxins.

Behavioral and enzymatic bioassays with Serjania erecta Radlk., Sapindaceae, correlated with cognitive dysfunctions / Comportamento e ensaios bioenzimáticos com Serjania erecta Radlk., sapindaceae, correlacionados com disfunções cognitivas

The purpose of this study was to investigate the crude extract of Serjania erecta Radlk., Sapindaceae, and its bioactive agents as preventive or inhibitor of memory loss in rodents, as well as other factors correlated with Alzheimer's syndrome: antioxidant and anticholinesterase activity, mainly as plant adaptogen - low toxicity and regulation action. The blocking cholinergic reversion activity (scopolamine) in the test of the passive avoidance was detected by measuring latency in young and adult animals. It presented low toxicity, with protective effect as shown by biochemical analysis (hypoglycemic/hypotriglyceridemic). Elevated levels (above 83 percent) of antioxidant activity were detected. AchE and BuChE inhibition were also detected in the chromatographic fractions, which were active both orally and directly on CNS (ICV).

O objetivo deste estudo foi pesquisar o extrato bruto de Serjania erecta Radlk., Sapindaceae, e seus bioativos como preventivos ou inibidores de perda de memória em roedores, e outros fatores correlacionados com a síndrome de Alzheimer: atividade antioxidante e anticolinesterásicas, principalmente como planta adaptógena, baixa toxicidade e ação regulatória. A reversão do bloqueador colinérgico (escopolamina) no teste da esquiva passiva foi detectada pela latência mensurada em animais jovens e adultos. Apresentou baixa toxicidade, com efeito protetor na análise bioquímica (hipoglicemia/hipotrigliceridemia). Índices elevados (acima 83 por cento) na atividade antioxidante foram observados. A inibição da AChE e BuChE foi perceptível nas frações cromatográficas, confirmando as ações via oral e diretamente no SNC.

Bioactive chemical constituents and comparative antimicrobial activity of callus culture and adult plant extracts from Alternanthera tenella.

Crude extracts of a callus culture (two culture media) and adult plants (two collections) from Alternanthera tenella Colla (Amaranthaceae) were evaluated for their antibacterial and antifungal activity, in order to investigate the maintenance of antimicrobial activity of the extracts obtained from plants in vivo and in vitro. The antibacterial and antifungal activity was determined against thirty strains of microorganisms including Gram-positive and Gram-negative bacteria, yeasts and dermatophytes. Ethanolic and hexanic extracts of adult plants collected during the same period of the years 1997 and 2002 [Ribeirão Preto (SP), collections 1 and 2] and obtained from plant cell callus culture in two different hormonal media (AtT43 and AtT11) inhibited the growth of bacteria, yeasts and dermatophytes with inhibition halos between 6 and 20 mm. For the crude extracts of adult plants bioassay-guided fractionation, purification, and isolation were performed by chromatographic methods, and the structures of the isolated compounds were established by analysis of chemical and spectral evidences (UV, IR, NMR and ES-MS). Steroids, saponins and flavonoids (aglycones and C-glycosides) were isolated. The minimum inhibitory concentration (MIC) of the isolated compounds varied from 50 to 500 microg/mL.

Phototherapy promotes healing of chronic diabetic leg ulcers that failed to respond to other therapies.

OBJECTIVE: We tested the hypothesis that combined 660 and 890 nm LED phototherapy will promote healing of diabetic ulcers that failed to respond to other forms of treatment. RESEARCH DESIGN AND METHODS: A double-blind randomized placebo controlled design was used to study 23 diabetic leg ulcers in two groups of 14 patients. Group one ulcers were cleaned, dressed with 1% silver sulfadiazine cream and treated with "placebo" phototherapy (<1.0 J cm(-2)) twice per week, using a Dynatron Solaris 705(R) device. Group two ulcers were treated similarly but received 3 J cm(-2) dose. RESULTS: At each of 15, 30, 45, 60, 75, and 90 days of healing, mean ulcer granulation and healing rates were significantly higher for group two than the "placebo" group (P < 0.02). While "placebo" treated ulcers worsened during the initial 30 days, group two ulcers healed rapidly; achieving 56% more granulation and 79.2% faster healing by day 30, and maintaining similarly higher rates of granulation and healing over the "placebo" group all through. By day 90, 58.3% of group two ulcers had healed fully and 75% had achieved 90-100% healing. In contrast, only one "placebo" treated ulcer healed fully by day 90; no other ulcer attained > or =90% healing. CONCLUSION: Combined 660 and 890 nm light promotes rapid granulation and healing of diabetic ulcers that failed to respond to other forms of treatment.