title: Search for a potent microbicidal spermicide from the isolates of Shorea robusta resin.
abstract: BACKGROUND
  An alarming increase in global population is the root cause of poverty, malnutrition, sexually transmitted infections (STIs) and many other social problems. Microbicidal spermicides possessing dual function of contraception and STI protection can effectively combat this problem, and their development is of utmost importance at present.
  
  
  METHODS
  A major metabolite isolated from Shorea robusta resin was spectroscopically characterized as asiatic acid. Spermicidal efficacy of the isolate was evaluated in vitro by a modified Sander-Cramer test. The mode of spermicidal action was assessed by (a) double fluoroprobe staining, (b) hypoosmotic swelling test and (c) scanning electron microscopy. Antimicrobial efficacy was assessed by disc diffusion and broth dilution methods using human isolates of bacteria (Escherichia coli ATCC 25938 and Pseudomonas aeruginosa 71) and fungus (Candida tropicalis).
  
  
  RESULTS
  The minimum effective concentration of asiatic acid that induced instantaneous immobilization of rat spermatozoa in vitro was 125 mcg/mL. The mechanism of action involved disruption of sperm plasma membrane. The microbicidal efficacy was found to be moderate for vaginal pathogens, with no effect on normal vaginal flora.
  
  
  CONCLUSIONS
  Asiatic acid possesses appreciable spermicidal and microbicidal potential and may be explored as an effective microbicidal spermicide.
authors.affiliation: Department of Chemistry, Indian Institute of Chemical Biology, Council of Scientific and Industrial Research, Jadavpur, Kolkata 700 032, India.
authors.forename: Yogesh P
authors.initials: YP
authors.lastname: Bharitkar
authors.forename: Maitreyee
authors.initials: M
authors.lastname: Banerjee
authors.forename: Shrabanti
authors.initials: S
authors.lastname: Kumar
authors.forename: Rupankar
authors.initials: R
authors.lastname: Paira
authors.forename: Ravindra
authors.initials: R
authors.lastname: Meda
authors.forename: Ketousetu
authors.initials: K
authors.lastname: Kuotsu
authors.forename: Nirup B
authors.initials: NB
authors.lastname: Mondal
mesh_terms: D000818:Animals; D000891:Anti-Infective Agents, Local / Q000302:isolation & purification / Q000494:pharmacology*; D041022:Candida tropicalis / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification; D002462:Cell Membrane / Q000187:drug effects / Q000648:ultrastructure; D053958:Dipterocarpaceae / Q000737:chemistry*; D055808:Drug Discovery; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification; D006801:Humans; D007194:India; D008297:Male; D008826:Microbial Sensitivity Tests; D053978:Pentacyclic Triterpenes / Q000302:isolation & purification / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification; D051381:Rats; D017207:Rats, Sprague-Dawley; D012116:Resins, Plant / Q000737:chemistry*; D012749:Sexually Transmitted Diseases / Q000382:microbiology / Q000517:prevention & control* / Q000635:transmission; D013081:Sperm Motility / Q000187:drug effects; D013089:Spermatocidal Agents / Q000302:isolation & purification; D013094:Spermatozoa / Q000187:drug effects* / Q000648:ultrastructure
chemical_list: D000891:Anti-Infective Agents, Local; D053978:Pentacyclic Triterpenes; D012116:Resins, Plant; D013089:Spermatocidal Agents; C017032:asiatic acid