A proline derivative-enriched methanol fraction from Sideroxylon obtusifolium leaves (MFSOL) stimulates human keratinocyte cells and exerts a healing effect in a burn wound model

It was previously demonstrated that the methanol fraction of Sideroxylon obtusifolium (MFSOL) promoted anti-inflammatory and healing activity in excisional wounds. Thus, the present work investigated the healing effects of MFSOL on human keratinocyte cells (HaCaT) and experimental burn model injuries. HaCaT cells were used to study MFSOL's effect on cell migration and proliferation rates. Female Swiss mice were subjected to a second-degree superficial burn protocol and divided into four treatment groups: Vehicle, 1.0% silver sulfadiazine, and 0.5 or 1.0% MFSOL Cream (CrMFSOL). Samples were collected to quantify the inflammatory mediators, and histological analyses were performed after 3, 7, and 14 days. The results showed that MFSOL (50 μg/mL) stimulated HaCaT cells by increasing proliferation and migration rates. Moreover, 0.5% CrMFSOL attenuated myeloperoxidase (MPO) activity and also stimulated the release of interleukin (IL)-1β and IL-10 after 3 days of treatment. CrMFSOL (0.5%) also enhanced wound contraction, promoted improvement of tissue remodeling, and increased collagen production after 7 days and VEGF release after 14 days. Therefore, MFSOL stimulated human keratinocyte (HaCaT) cells and improved wound healing via modulation of inflammatory mediators of burn injuries.

Amifostine reduces inflammation and protects against 5-fluorouracil-induced oral mucositis and hyposalivation

Oral mucositis (OM) is a common and dose-limiting side effect of cancer treatment, including 5-fluorouracil (5-FU) and radiotherapy. The efficacy of the therapeutic measures to prevent OM is limited and disease prevention is not fully observable. Amifostine is a cytoprotective agent with a described anti-inflammatory potential. It is clinically used to reduce radiotherapy and chemotherapy-associated xerostomia. This study investigated the protective effect of amifostine on an experimental model of OM. Hamsters were divided into six groups: saline control group (5 mL/kg), mechanical trauma (scratches) of the right cheek pouch; 5-FU (60 and 40 mg/kg, ip, respectively, administered on days 1 and 2); amifostine (12.5, 25, or 50 mg/kg) + 5-FU + scratches. Salivation rate was assessed and the animals were euthanized on day 10 for the analysis of macroscopic and microscopic injury by scores. Tissue samples were harvested for the measurement of neutrophil infiltration and detection of inflammatory markers by ELISA and immunohistochemistry. 5-FU induced pronounced hyposalivation, which was prevented by amifostine (P<0.05). In addition, 5-FU injection caused pronounced tissue injury accompanied by increased neutrophil accumulation, tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β) tissue levels, and positive immunostaining for TNF-α, IL-1β, and inducible nitric oxide synthase (iNOS). Interestingly, amifostine prevented the inflammatory reaction and consequently improved macroscopic and microscopic damage (P<0.05 vs 5-FU group). Amifostine reduced inflammation and protected against 5-FU-associated oral mucositis and hyposalivation.

Pro- and anti-inflammatory activities of the latex from Calotropis procera (Ait.) R.Br. are triggered by compounds fractionated by dialysis

OBJECTIVES AND DESIGN

Previous studies have described pro- and anti-inflammatory activities displayed by the latex from Calotropis procera. This report aims to clarify these observations and shows that such activities can be segregated from the whole latex.

METHODS

The latex was divided into water-soluble fractions devoid of poly-isoprene by centrifugation and dialysis and both the activities were assayed by the peritonitis model in rats. The drugs dexamethasone, thalidomide, meclizine, indomethacin and celecoxib were used to modulate the inflammatory stimuli.

RESULTS

Inflammation in rats was observed 2 h after intraperitoneal administration of the stimulus (DL fraction) in a dose dependent manner. This activity was inhibited by previous intravenous injection of dexamethasone, thalidomide and meclizine. Indomethacin and celecoxib did not reverse inflammation. These results suggest the involvement of histamine release and TNF-alpha mediated inflammation while prostaglandins seem not to be required. The anti-inflammatory fraction (NDL) inhibited inflammation triggered by proinflammatory fraction (DL) suggesting that NDL ought to follow a similar pathway of action to that of the anti-inflammatory drugs that were able to inhibit inflammation triggered by DL.

CONCLUSIONS

Pro- and anti-inflammatory activities of the latex are displayed by compounds suitable to be fractionated on the basis of their molecular size.

Effect of atorvastatin on 5-fluorouracil-induced experimental oral mucositis

PURPOSE

Oral mucositis (OM) is a frequent side effect in patients with cancer. We investigate the effect of atorvastatin (ATV), a cholesterol-lowering drug, on OM induced by 5-fluorouracil (5-FU) in hamsters.

METHODS

OM was induced by the i.p. administration of 5-FU, with excoriations of the cheek pouch mucosa. The animals were pretreated with i.p. ATV 1, 5 or 10 mg/kg or vehicle (saline and 5% (vol/vol) ethanol) 30 min before 5-FU injection and daily for 5 or 10 days. Samples of cheek pouches and main organs were removed for histopathological analysis, determination of TNF-α, IL-1β, nitrite, non-protein sulfhydryl group (NP-SH) levels, myeloperoxidase (MPO) assay and immunohistochemistry for induced nitric oxide synthase (iNOS). Blood was collected for a leukogram analysis of biochemical parameters and analysis of bacteremia.

RESULTS

ATV at doses of 1 and 5 mg/kg reduced mucosal damage and inflammation, as well as the levels of cytokines, nitrite and myeloperoxidase activity on the 5th and 10th day of OM and immunostaining for iNOS on the 5th day of OM.ATV at 1 mg/kg increased cheek pouch NP-SH when compared to 5-FU groups on the 10th day of OM. The association between ATV 5 mg/kg and 5-FU decreased the survival rate, amplified the leukopenia of animals, increased transaminase serum levels and caused liver lesions. We also detected the presence of Gram-negative bacillus in the blood of 100% of the animals treated with ATV 5 mg/kg + 5-FU.

CONCLUSIONS

Atorvastatin prevented mucosal damage and inflammation associated with 5-FU-induced OM, but the association of a higher dose of ATV with 5-FU induced hepatotoxicity and amplified leukopenia.

Lectin of Pisum arvense seeds induces in-vivo and in-vitro neutrophil migration

PAL is a glucose/mannose-specific lectin isolated from Pisum arvense seeds. Previously, we demonstrated the capacity of other leguminous lectins to induce oedema formation and neutrophil stimulation. To investigate the potential pro-inflammatory activity of PAL, we have studied its ability to induce neutrophil migration into peritoneal cavities of rats and neutrophil chemotaxis in-vitro. The role of resident cells and sugar residues on PAL activity was analysed. PAL or saline (control) were administered intraperitoneally to rats, and total and differential leucocyte (macrophages, neutrophils and mast cells) counts were performed. The role of resident cells on the PAL effect was evaluated using three strategies: reducing the total resident cell population by lavage of rat cavities with saline; increasing macrophage population by treating animals with thioglycolate; and depleting mast cell population by subchronic treatment of rats with compound 48/80. PAL induced in-vitro and in-vivo neutrophil migration. In-vivo, PAL (50, 100, 200 and 300 μg) significantly (P &lt; 0.05) and dose-dependently increased neutrophil migration by 600, 740, 900 and 940%, respectively, showing maximal effect 4 h after injection. PAL induced mononuclear cell migration. The neutrophil stimulatory effect of PAL was potentiated in animals treated with both thioglycolate and compound 48/80. The indirect lectin chemotactic effect was shown in rats injected with supernatant from cultured macrophages stimulated by PAL. In conclusion, PAL was shown to exhibit in-vivo and in-vitro proinflammatory activity. The in-vivo effect seemed to occur by a dual mechanism that was independent, but also dependent, on resident cells.

Immunological and allergenic responses induced by latex fractions of Calotropis procera (Ait.) R.Br

Immunological and allergenic responses against the latex of Calotropis procera were investigated in mice by oral and subcutaneous routes. The latex was fractionated according to water solubility and molecular size of its components. The fractions were named as non-dialyzable latex (NDL) corresponding to the major latex proteins, dialyzable latex (DL) corresponding to low molecular size substances and rubber latex (RL) which was highly insoluble in water. Anti-sera against these fractions were assayed for total IgG and IgA titration by ELISA and IgE and IgG(1) were quantified by passive cutaneous anaphylaxis (PCA) in rats and mice, respectively. None of the fractions induced antibodies level increases when mice received latex fractions by oral route and thus, did not develop allergy. Nonetheless, anti-sera of mice sensitized with NDL and RL by subcutaneous route displayed considerable immunological response while DL did not. IgG level augmented consistently against NDL and RL while IgA response was detected only to NDL. NDL and RL induced very strong PCA reactions suggesting that both fractions would contain latex substances involved in allergy. Furthermore, protein analysis of NDL and RL suggests that RL still retain residual proteins abundantly found in NDL that could explain its similar allergenic effect. No IgG(1) reaction was detected in any of the anti-sera tested. According to the results, the proteins of latex of Calotropis procera can provoke allergy by subcutaneous route. The NDL has previously shown to display anti-inflammatory and analgesic activities by intraperitoneal injection. It should be relevant to determine whether NDL could induce such activities when assayed by oral route since it was ineffective to induce allergy by this way.

Anti-inflammatory and antimicrobial effect of lectin from Lonchocarpus sericeus seeds in an experimental rat model of infectious peritonitis

We have investigated the anti-inflammatory and antimicrobial effect of the lectin from Lonchocarpus sericeus seeds (LSL) in a model of infectious peritonitis in adult Wistar rats. Animals were treated with saline or LSL (10 mg kg(-1), i.v) immediately and 6 h after the induction of peritonitis via cecal ligation and single puncture. Twelve hours after surgery, animals were killed and the infectious process was monitored by total and differential count of cells from blood and peritoneal washing liquid, adenosine deaminase activity, antibiogram and the number of viable bacteria of the peritoneal cavity. LSL treatment decreased the inflammatory response evoked by the induction of peritonitis, as seen by the inhibition of neutrophil migration into peritoneal cavities, leucocytosis and reduction of adenosine deaminase activity in the peritoneal fluid. All these effects were reversed by the lectin association to N-acetyl-glucosamine. LSL in-vitro did not show any antimicrobial action, but promoted a marked decrease of the viable bacterial population in peritoneal cavities. In conclusion, LSL inhibited the inflammatory response and the bacterial colonization of infectious peritonitis in rats.

Anti-inflammatory effect of the latex from Calotropis procera in three different experimental models: peritonitis, paw edema and hemorrhagic cystitis

Latex from Calotropis procera is widely used in folk medicine as a rich source of biologically active compounds capable of promoting diverse benefits such as control of dermal fungal infections, antimicrobial activities and pain relief among other useful properties. The aim of this work was to characterize the anti-inflammatory effect of a non-dialysable protein fraction recovered from the rubber-free latex using three different experimental models when administrated intravenously. In vivo neutrophil migration induced by carrageenin (500 microg) was severely inhibited by doses of latex proteins reaching maximum inhibition (80%) at 100 mg/kg. Paw edema exacerbated by the effect of carrageenin was almost completely suppressed after 4 hours and was controlled within the first hour following latex protein administration. However, the same latex fraction was completely unable to control the paw edema invoked with dextran stimulation (400 microg), suggesting that the inhibitory effect of the latex is likely to be cell-mediated. Iphosphamide-induced vesical edema in mice was also largely prevented by the latex protein fraction. These results indicate that an effect similar to that of mesna, the classical drug used for this purpose, is operative. Our findings suggest that the sample tested seems to act over a wide spectrum as a novel anti-inflammatory agent. The results also suggest that the active molecules are of a proteinaceous nature despite the presence of numerous secondary metabolites naturally occurring in the C. procera latex.