Antiallergic activity of alkyl substituted pyrazolo[3, 4-d]pyrimidine (compound 88-765).

Compound 88-765 (4-amino-6-methylthio-1-(2', 2'-diethoxyethyl)-1 H-pyrazolo[3, 4-d]pyrimidine) has shown potent antiallergic activity in experimental models. The compound inhibited the passive cutaneous anaphylaxis (PCA) reaction in rats in dose-dependent manner (5-100 mg/kg, po) by 47 to 87%. In mice it inhibited PCA by 78% at 50 mg/kg, po. It also inhibited mast cell degranulation of normal and passively sensitised rats induced by compound 48/80 and egg albumin, respectively. These effects of Compound 88-765 were comparable with that of disodium cromoglycate (DSCG). The results suggest that compound 88-765 possesses potent antiallergic activity.

Bioactivity of marine organisms: Part VII--Effect of seaweed extract on central nervous system.

Alcohol extracts of marine algae (Rhodophyceae, Phaeophyceae and Chlorophyceae) were screened for their effect on central nervous system. Of 69 species investigated 8 appeared biologically active, 6 being CNS stimulant and two depressant, sites and dates of collection are given.

Post-coital antifertility activity of the marine plant, Achrostichum aureum L. in rat.

The ethanolic extract of A. aureum and its fractions were evaluated for postovulatory antifertility activity in female rats. The water soluble fraction of ethanolic (95%) extract prevented (100%) pregnancy when administered to female rats on days 1-7 postcoitum. This fraction was found devoid of both estrogenic and antiestrogenic activities.

Bioactivity of marine organisms: Part VI--Screening of some marine flora from Indian coasts.

Alcoholic extracts of 50 botanically identified species of marine flora have been screened for a wide range of biological activities. Of these, 2 extracts exhibited anti-amoebic and antiviral activity each, 3 of them had anti-implantation activity; 9 had hypoglycaemic activity while hypotensive activity was associated with 11 extracts; 14 extracts were found to be diuretic and 1 of them had anti-inflammatory activity. Further, 10 of these extracts exhibited 2 types of activities while a combination of 3 and 4 types of activities was observed in one extract each. Follow-up studies have been carried out in some plants with confirmed activity. The active principles and results of these studies are reported.

Efficacy of methyl 5(6)-(alpha-hydroxyphenylmethyl) benzimidazole-2-carbamate, a metabolite of mebendazole, against developing forms of experimental helminth parasites.

Methyl 5(6)-(alpha-hydroxyphenylmethyl) benzimidazole-2- carbamate, a metabolite of mebendazole, was evaluated against metamorphic forms of Ancylostoma ceylanicum in hamsters, Nippostrongylus brasiliensis in rats and cysticercoids of Hymenolepis nana in grain beetles. The test compound offered better action than mebendazole except against H. nana cysticercoids where the activity of the compound and mebendazole was comparable, but was inferior to the standard cestodicidal drug, praziquantel. The results suggest that the action was better by ip route compared to per os route of drug administration.

Screening of Indian plants for biological activity: Part XIV.

Alcoholic extracts of 300 botanically identified plant materials from 275 plant species have been tested for various biological activities including chemotherapeutic and pharmacological screenings. Biological activities have been observed in 111 extracts. Follow-up studies have been carried out in some plants with confirmed activity. The active principles and results of these studies are reported.

Methyl 5(6)-(alpha-hydroxyphenyl methyl) benzimidazole-2-carbamate and cysticercosis: chemotherapeutic and electron microscopic studies.

Methyl 5(6)-(alpha-hydroxyphenyl methyl) benzimidazole-2-carbamate, a major metabolite of mebendazole was evaluated against Cysticercus fasciolaria (larval form of Taenia taeniaeformis) in rats. The metabolite was assessed in various doses. A regimen of 50 mg/kg x 10 (ip), given one day apart, was found to be most effective and killed all the mature cysticerci. On developing cysts, the treatment was initiated in two schedules; 5 days prior to (d-5 to d-1) and 5 days after (d + 6 to d + 10) administration of T. taeniaeformis eggs to rats. The later protocol with 100 mg/kg x 5 dose (ip) resulted in 95% inhibition in the establishment of cysticerci. Activity of mebendazole against mature cysts was parallel to metabolite whereas against developing cysts, it was inferior. The time related topographical changes that occurred in mature C. fasciolaris after treatment with metabolite (50 mg/kg x 10, ip, one day apart) were observed by scanning electron microscopy. There was loss of contractivity, gradual disappearance of microtriches and progressive degeneration of tegument. Similar changes were noticed with mebendazole. The possession of better efficacy and higher safety range [Indian J Exp. Biol, 25 (1987) 871], suggests that the metabolite can be a potential anthelmintic for man and animals.