Analgesic and anti-inflammatory articular effects of essential oil and camphor isolated from Ocimum kilimandscharicum Gürke leaves.

ETHNOPHARMACOLOGICAL RELEVANCE: Leaves from Ocimum kilimandscharicum Gürke (Lamiaceae) are popularly used against articular pain. AIM OF STUDY: The aim of this study was to test the anti-inflammatory and anti-hyperalgesic (analgesic) properties of the essential oil and camphor isolated from O. Kilimandscharicum leaves (EOOK) in 4 models including zymosan induced-articular inflammation model in mice. MATERIAL AND METHODS: For in vivo models, EOOK was tested in carrageenan-induced paw edema model with oral doses of 30, 100, and 300 mg/kg (oral administration = p.o.) and in zymosan-induced articular inflammation (including knee edema, leukocyte infiltration, mechanical hyperalgesia and nitric oxide), EOOK (100 mg/kg, p. o.) and camphor (30 mg/kg, p. o.) were tested. EOOK (100 mg/kg, p. o.) was tested in the rolling and also in the adhesion of leukocytes to the mesenteric microcirculation in situ model of carrageenan induced inflammation and EOOK (1, 3, 10, 30, and 60 µg/mL) was tested in vitro against neutrophils chemotaxis induced by N-formyl methionyl leucyl phenylalanine (fMLP). RESULTS: The treatment with EOOK significantly inhibited the carrageenan-induced edema, mechanical and cold hyperalgesia. Both, EOOK and camphor inhibited all articular parameters induced by zymosan. In situ intravitral microscopy analysis, EOOK significantly inhibited carrageenan-induced leukocyte rolling and adhesion. In vitro neutrophils chemotaxis, EOOK inhibited the leukocyte chemotaxis induced by fMLP. CONCLUSIONS: The present study showed that EOOK inhibited pain and inflammatory parameters contributing, at least in part, to explain the popular use of this plant as analgesic natural agent. This study also demonstrates that camphor and some known anti-inflammatory compounds present in EOOK could contribute for analgesic and anti-inflammatory articular properties.

Hepatoprotective Effect of Citral on Acetaminophen-Induced Liver Toxicity in Mice.

High doses of acetaminophen (APAP) lead to acute liver damage. In this study, we evaluated the effects of citral in a murine model of hepatotoxicity induced by APAP. The liver function markers alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and gamma-glutamyl transferase (γGT) were determined to evaluate the hepatoprotective effects of citral. The livers were used to determine myeloperoxidase (MPO) activity and nitric oxide (NO) production and in histological analysis. The effect of citral on leukocyte migration and antioxidant activity was evaluated in vitro. Citral pretreatment decreased significantly the levels of ALT, AST, ALP, and γGT, MPO activity, and NO production. The histopathological analysis showed an improvement of hepatic lesions in mice after citral pretreatment. Citral inhibited neutrophil migration and exhibited antioxidant activity. Our results suggest that citral protects the liver against liver toxicity induced by APAP.

Protective Effect of Cymbopogon citratus Essential Oil in Experimental Model of Acetaminophen-Induced Liver Injury.

To investigate the hepatoprotective effect of Cymbopogon citratus or lemongrass essential oil (LGO), it was used in an animal model of acute liver injury induced by acetaminophen (APAP). Swiss mice were pretreated with LGO (125, 250 and 500[Formula: see text]mg/kg) and SLM (standard drug, 200[Formula: see text]mg/kg) for a duration of seven days, followed by the induction of hepatotoxicity of APAP (single dose, 250[Formula: see text]mg/kg). The liver function markers alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and gamma-glutamyl transferase were determined to evaluate the hepatoprotective effects of the LGO. The livers were used to determine myeloperoxidase (MPO) activity, nitric oxide (NO) production and histological analysis. The effect of LGO on leukocyte migration was evaluated in vitro. Anti-oxidant activity was performed by assessing the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) in vitro. LGO pretreatment decreased significantly the levels of ALT, AST and ALP compared with APAP group. MPO activity and NO production were decreased. The histopathological analysis showed an improved of hepatic lesions in mice after LGO pretreatment. LGO inhibited neutrophil migration and exhibited anti-oxidant activity. Our results suggest that LGO has protective activity against liver toxicity induced by paracetamol.

Fish Oil and Adjuvant-Induced Arthritis: Inhibitory Effect on Leukocyte Recruitment.

Fish oil, a rich source of n-3 fatty acids, has been studied for its beneficial effects in many diseases. Recent studies have shown the robust anti-inflammatory activity of fish oil (FO), when administered orally to rats, in models of acute inflammation. Herein, we investigated if treatment with fish oil preparation (FOP) could interfere with the recruitment of leukocytes into the joint cavity of arthritic rats. We also evaluated the effect of treatment on rolling behavior and leukocyte adhesion in vivo and on leukocyte chemotaxis in vitro. Treatment with FOP (75, 150, and 300 mg/kg) initiated on the day of induction of arthritis (day 0) and maintained for 21 days reduced the total number of leukocytes recruited into the joint cavity, the number of rolling and adhered leukocytes in arthritic rats, and leukocyte migration in response to stimulation with N-formyl-methionyl-leucyl-phenylalanine (fMLP) and leukotriene B4 (LTB4). Together, our data provide evidence that FOP plays an important inhibitory role in the recruitment of leukocytes into the joint cavity of arthritic rats.

Hepatoprotective Effect of Silymarin (Silybum marianum) on Hepatotoxicity Induced by Acetaminophen in Spontaneously Hypertensive Rats.

This study was aimed to investigate the effect of Silymarin (SLM) on the hypertension state and the liver function changes induced by acetaminophen (APAP) in spontaneously hypertensive rat (SHR). Animals normotensive (N) or hypertensive (SHR) were treated or not with APAP (3 g/kg, oral) or previously treated with SLM. Twelve hours after APAP administration, plasmatic levels of liver function markers: alanine aminotransferase (ALT), aspartate aminotransferase (AST), glucose (GLU), gamma glutamyl transferase (γ-GT), and alkaline phosphatase (ALP) of all groups, were determined. Liver injury was assessed using histological studies. Samples of their livers were then used to determine the myeloperoxidase (MPO) activity and nitric oxide (NO) production and were also sectioned for histological analysis. No differences were observed for ALT, γ-GT, and GLU levels between SHR and normotensive rats groups. However, AST and ALP levels were increased in hypertensive animals. APAP treatment promoted an increase in ALT and AST in both SHR and N. However, only for SHR, γ-GT levels were increased. The inflammatory response evaluated by MPO activity and NO production showed that SHR was more susceptible to APAP effect, by increasing leucocyte infiltration. Silymarin treatment (Legalon) restored the hepatocyte functional and histopathological alterations induced by APAP in normotensive and hypertensive animals.

Effect of estragole on leukocyte behavior and phagocytic activity of macrophages.

Estragole, a chemical constituent of the essential oils of many aromatic plants, is used as flavoring in beverage and food industries. In vivo and in vitro experimental assays have shown that EST has sedative, anticonvulsant, antioxidant, antimicrobial, and anesthetic activity. In this work, we evaluate the effect of EST on leukocyte behavior and phagocytic activity of macrophages. In the peritonitis model, EST (500 and 750 mg/kg) decreased the infiltration of peritoneal exudate leukocytes. In vitro chemotaxis assay showed that EST (3, 10, 30, and 60 µg/mL) inhibited neutrophil migration toward fMLP. In the in vivo microcirculation assay, EST at doses of 250, 500, and 750 mg/kg significantly reduced the number of rolling and adherent leukocytes and at doses of 250 and 500 mg/kg decreased number of leukocyte migrated to perivascular tissue. The results showed that EST (3, 10, and 30 µg/mL) was able to stimulate the macrophages phagocytosis but only at concentration of 10 µg/mL promoted an increase in nitric oxide (NO) production. In conclusion, this study showed that EST had potential anti-inflammatory effects, likely by inhibiting leukocyte migration and by stimulating macrophages phagocytosis.