title: Antihistaminic and antiviral activities of steroids of Turbinaria conoides.
abstract: The steroids 3,6,17-trihydroxy-stigmasta-4,7,24(28)-triene (A) and 14,15,18,20-diepoxyturbinarin (B) were isolated from the cyclohexane extract of brown alga, Turbinaria conoides (J. Agardh) Kutzing, and have been reported for their antimicrobial activity by us. In this study, the isolated compounds were evaluated for comprehensive antihistaminic, antiviral and cytotoxicity screening. The antihistaminic study was performed using in vitro standard animal models. Evaluation of the potency (EC(50)), affinity (pA(2)) and the maximal response (E(max)) of the histamine alone and in the presence of the compounds were determined. Antiviral activity and cytotoxicity were performed in Crandell-Rees feline kidney (CRFK) cells by a colorimetric formazan-based MTS assay. No significant antiviral activity or cytotoxicity were observed for the compounds in the CRFK cells. Compound A inhibited the histamine-induced concentration at 20 µg mL(-1)(p < 0.05). The most significant inhibition (97%) was observed for compound B (p < 0.01) at the same concentration, which was comparable to that of the positive control chlorpheniramine maleate (10 µg mL(-1)). This potentiality suggests that 14,15,18,20-diepoxyturbinarin (B) can be developed as a new lead antihistaminic agent.
authors.affiliation: Department of Pharmaceutical Chemistry, ITS Paramedical College (Pharmacy), Ghaziabad, Uttar Pradesh, India. jesisjes@yahoo.co.in
authors.forename: S Sadish
authors.initials: SS
authors.lastname: Kumar
authors.forename: Y
authors.initials: Y
authors.lastname: Kumar
authors.forename: M S Y
authors.initials: MS
authors.lastname: Khan
authors.forename: J
authors.initials: J
authors.lastname: Anbu
authors.forename: E
authors.initials: E
authors.lastname: De Clercq
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D000998:Antiviral Agents / Q000302:isolation & purification / Q000494:pharmacology; D002415:Cats; D002460:Cell Line; D006633:Histamine Antagonists / Q000302:isolation & purification / Q000494:pharmacology*; D000459:Phaeophyceae / Q000737:chemistry*; D013141:Spiro Compounds / Q000302:isolation & purification / Q000494:pharmacology; D013256:Steroids / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D013265:Stigmasterol / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: C568200:14,15,18,20-diepoxyturbinarin; C568199:3,6,17-trihydroxy-stigmasta-4,7,24(28)-triene; D000972:Antineoplastic Agents, Phytogenic; D000998:Antiviral Agents; D006633:Histamine Antagonists; D013141:Spiro Compounds; D013256:Steroids; D013265:Stigmasterol