Suppression of cyclooxygenase-2 expression of skin fibroblasts by wogonin, a plant flavone from Scutellaria radix

Previously, wogonin (5,7-dihydroxy-8-methoxyflavone) was found to suppress proinflammatory enzyme expression including cyclooxygenase-2 (COX-2), contributing to in vivo anti-inflammatory activity against skin inflammation. However, the detailed effect on each skin cell type has not been understood. Therefore, present investigation was carried out to find the effect of wogonin on inflammation associated gene expression from skin fibroblasts in culture using reverse transcriptase-polymerase chain reaction. As a result, it was found that wogonin (10-100 microM) clearly down-regulated COX-2 expression from NIH/3T3 cells treated with 12-O-tetradecanoylphorbol 13-acetate, interleukin-1beta or tumor necrosis factor-alpha. But, the expression levels of COX-1, interleukin-1beta and fibronectin were not significantly affected. This finding was well correlated with significant reduction of prostaglandin E2 (PGE2) production by wogonin. As a comparison, NS-398 (selective cyclooxygenase 2 inhibitor) did not suppress COX-2 expression and other gene levels, while PGE2 production was potently reduced at 0.1-10 microM. All these results suggest that COX-2 down-regulation of skin fibroblasts may be, at least in part, one of anti-inflammatory mechanisms of wogonin against skin inflammation.

Effects of naturally occurring prenylated flavonoids on enzymes metabolizing arachidonic acid: cyclooxygenases and lipoxygenases

Prenylated flavonoids are chemical entities having an isoprenyl, a geranyl, a 1,1-dimethylallyl, and/or a lavandulyl moiety as part of their flavonoid backbone structure. In this study, the effects of 19 naturally occurring prenylated flavonoids, isolated from medicinal plants, on cyclooxygenase (COX)-1 and COX-2 and on 5-lipoxygenase (5-LOX) and 12-LOX were investigated using [14C]arachidonic acid as a substrate. The homogenates of bovine platelets and polymorphonuclear leukocytes were used as COX-1, 12-LOX, and 5-LOX enzyme sources; the homogenate of aspirin-pretreated lipopolysaccharide-induced RAW 264.7 cells was used for the COX-2 enzyme source. Among the 19 prenylated flavonoids, morusin, kuwanon C, sanggenon B, sanggenon D and kazinol B inhibited COX-2 activity (ic(50) = 73-100 microM), but the potencies were far less than that of NS-398 (ic(50) = 2.9 microM). In contrast, many prenylated flavonoids, such as kuraridin, kuwanon C and sophoraisoflavanone A, inhibited COX-1 activity. Of the COX-1 inhibiting prenylated flavonoids, kuraridin, kurarinone, and sophoraflavanone G, all having a C-8 lavandulyl moiety, showed potent activity (ic(50) = 0.1 to 1 microM) comparable to that of indomethacin (ic(50) = 0.7 microM). Most of the prenylated flavonoids tested inhibited 5-LOX activity with ic(50) values ranging from 0.09 to 100 microM. Of these, only kuwanon C, papyriflavonol A and sophoraflavanone G showed inhibitory activity against 12-LOX at low concentration ranges (ic(50) = 19-69 microM) comparable to that of NDGA (ic(50) = 2.6 microM). Our results suggest that the position and the nature of the prenyl substitution greatly influence in vitro biological activities of these molecules.

Effect of wogonin, a plant flavone from Scutellaria radix, on the suppression of cyclooxygenase-2 and the induction of inducible nitric oxide synthase in lipopolysaccharide-treated RAW 264.7 cells

Plant flavonoids show anti-inflammatory activity both in vitro and in vivo. Some flavonoids, such as flavone derivatives, have been reported previously to inhibit nitric oxide (NO) production by suppressing inducible nitric oxide synthase (iNOS) expression. In this investigation, the effects of wogonin, a potent inhibitor of NO production among the flavonoids tested, on cyclooxygenase-2 (COX-2) induction and activity were elucidated further in connection with iNOS, using a mouse macrophage cell line, RAW 264.7. Wogonin inhibited NO and prostaglandin E(2) (PGE(2)) production from lipopolysaccharide-induced RAW cells with IC(50) values of 31 and 0.3 microM, respectively. When added after the induction of iNOS and COX-2, wogonin inhibited the formation of PGE(2) (IC(50) = 0.8 microM), but not the production of NO. Wogonin inhibited COX-2 activity directly (IC(50) = 46 microM) from the homogenate of aspirin-pretreated RAW cells, as determined by measuring [(14)C]PGE(2) formation from [(14)C]arachidonic acid. However, it did not inhibit iNOS or phospholipase A(2) activity. Western blotting showed that wogonin suppressed the induction of both iNOS and COX-2. Prednisolone also suppressed the induction of iNOS and COX-2. Whereas RU-486 (a steroid receptor antagonist) reversed the suppressive activity of prednisolone, it did not affect the suppressive activity of wogonin, suggesting that the suppressive activity of wogonin is not mediated by binding to a steroid receptor. Results from the present study demonstrated that wogonin is a direct COX-2 inhibitor, as well as an inhibitor of iNOS and COX-2 induction. Wogonin may be a potential agent for use in the treatment of inflammatory diseases.

Minilaparoscopy to reduce complications from cannula insertion in patients with previous pelvic or abdominal surgery

STUDY OBJECTIVE

To evaluate the safety and efficacy of minilaparoscopy for visualization and adhesiolysis of intraabdominal adhesions for safe insertion of a primary umbilical cannula in patients who had previous pelvic or abdominal surgery.

DESIGN

Prospective, observational study (Canadian Task Force classification II-1).

SETTING

University-affiliated hospital.

PATIENTS

Twenty women who had previous pelvic or abdominal surgery, excluding tubal ligation and simple appendectomy.

INTERVENTION

Minilaparoscopy was carried for visualization and adhesiolysis at the entry site before insertion of an umbilical cannula.

MEASUREMENTS AND RESULTS

Eleven patients had Pfannenstiel scars and nine had vertical midline scars from previous surgeries (4 total abdominal hysterectomies, 13 adnexal surgery, 7 cesarean sections, 3 ectopic pregnancies, 1 ruptured appendix, 1 unknown bowel surgery). Thirteen women (65%) had had one previous surgery, five (25%) had had two, and two (10%) had had three. Nine patients (45%) had significant adhesions of omentum or intestine that required adhesiolysis. Mean operating time for minilaparoscopy was 5 minutes for 11 women who had no or minimal adhesions that did not interfere with safe insertion of the umbilical cannula and effective use of a 10-mm telescope, and 25 minutes in 9 patients who required adhesiolysis before insertion of the umbilical cannula because of dense adhesions of omentum or intestine at the entry site. No complications with minilaparoscopy occurred.

CONCLUSION

Minilaparoscopy can be performed safely and effectively to reduce serious vascular or visceral injury from insertion of primary cannula in patients who had previous pelvic and/or abdominal surgery. However, conclusions cannot be derived from this study due to the small number of subjects. Further study is necessary in a larger patient population to evaluate efficacy, safety, and advantages of minilaparoscopy over other techniques. (J Am Assoc Gynecol Laparosc 6(1):91-95, 1999)

Should neonates with specific "risk factors" be admitted to the special care nursery?

Existing criteria for admission of newborns to the special care nursery, Sarawak General Hospital, resulted in the admission of many neonates with certain risk factors ("at risk" neonates). To test whether such babies could be safely and better cared for in postnatal wards, 392 of these babies were randomly allocated into two groups. One group of 196 was admitted to the special care nursery and the other group of 196 was cared for with their mothers in the postnatal wards. The two groups were compared for mortality, morbidity and breastfeeding. There was no significant difference in mortality and morbidity between the two groups. While in hospital a larger proportion of babies cared for in postnatal wards were breastfed, compared to babies admitted to the special care nursery. In addition, they initiated their breastfeeding earlier. Babies with these risk factors should therefore be cared for with their mothers in the postnatal wards.