title: Assessment of long-term storage on antimicrobial and cyclooxygenase-inhibitory properties of South African medicinal plants.
abstract: In traditional medicine, plant materials are often stored by traditional healers, plant gatherers and traders before they are eventually consumed or sold. The critical point is whether stored medicinal plants are as active as freshly harvested dried material. We evaluated the effects of long-term storage (12 or 16 years) on the antimicrobial (microplate dilution method) and anti-inflammatory (COX-1 and COX-2 inhibition) potencies of 21 extensively used traditional medicinal plants in treating pain and infection-related ailments. The minimum inhibitory concentration (MIC) values obtained against Staphylococcus aureus and Pseudomonas aeruginosa in the stored plant materials were generally either lower or roughly the same as in the fresh material. Most of the stored plant material had comparable minimum microbicidal concentration (MMC) values as the fresh material against S. aureus and P. aeruignosa. Similarly, the majority (71%) of the stored plant material had similar MIC and/or MMC values as fresh material against the fungus Candida albicans. The percentage inhibition of COX-1 by the majority (88%) of the stored material was not significantly different when compared to those freshly collected. Stored material of Clausena anisata, Ekebergia capensis and Trichilia dregeana showed a significantly higher COX-1 inhibition than the fresh material. The therapeutic and conservation implications of the results are discussed.
authors.affiliation: Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa.
authors.forename: Stephen O
authors.initials: SO
authors.lastname: Amoo
authors.forename: Adeyemi O
authors.initials: AO
authors.lastname: Aremu
authors.forename: Mack
authors.initials: M
authors.lastname: Moyo
authors.forename: Johannes
authors.initials: J
authors.lastname: Van Staden
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology*; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects; D052246:Cyclooxygenase 2 Inhibitors / Q000737:chemistry / Q000494:pharmacology; D016861:Cyclooxygenase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D004356:Drug Storage; D005658:Fungi / Q000187:drug effects; D016488:Medicine, African Traditional; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry*; D011451:Prostaglandin-Endoperoxide Synthases / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects; D013997:Time Factors
chemical_list: D000890:Anti-Infective Agents; D000893:Anti-Inflammatory Agents; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D010936:Plant Extracts; D011451:Prostaglandin-Endoperoxide Synthases