OBJECTIVES: This review exhaustively gathers available information on ethnopharmacological uses, phytochemistry, and bioactivity studies on more than 20 species of Premna and critically analyzes the reports to provide the perspectives and directions for future research for the plants as potential source of drug leads and pharmaceutical agents.
METHODS: A literature search was performed on Premna species based on books of herbal medicine, major scientific databases including Chemical Abstract, Pubmed, SciFinder, Springerlink, Science Direct, Scopus, the Web of Science, Google Scholar, and ethnobotanical databases.
RESULTS: More than 250 compounds have been isolated and identified from Premna species, comprising of diterpenoids, iridoid glycosides, and flavonoids as the most common secondary metabolites, followed by sesquiterpenes, lignans, phenylethanoids, megastigmanes, glyceroglycolipids, and ceramides. Many in vitro and in vivo studies have been conducted to evaluate the biological and pharmacological properties of the extracts, and isolated compounds of Premna species with antimicrobial, antioxidant, anti-inflammatory, immunomodulatory, antihyperglycaemia, and cytotoxic activities.
CONCLUSION: The bioactive compounds responsible for the bioactivities of most plants have not been well identified as the reported in vivo pharmacological studies were mostly carried out on the crude extracts. The isolated bioactive components should also be further subjected to more preclinical studies and elaborate toxicity study before clinical trials can be pursued.
OBJECTIVES: The anti-inflammatory and anti-catabolic actions of Diclofenac were compared with apigenin-C-glycosides rich Clinacanthus nutans (CN) leaf extract in osteoporotic-osteoarthritis rats.
METHODS: Female Sprague Dawley rats were randomized into five groups (n = 6). Four groups were bilateral ovariectomised for osteoporosis development, and osteoarthritis were induced by intra-articular injection of monosodium iodoacetate (MIA) into the right knee joints. The Sham group was sham-operated, received saline injection and deionized drinking water. The treatment groups were orally given 200 or 400 mg extract/kg body weight or 5 mg diclofenac /kg body weight daily for 28 days. Articular cartilage and bone changes were monitored by gross and histological structures, micro-CT analysis, serum protein biomarkers, and mRNA expressions for inflammation and catabolic protease genes.
RESULTS: HPLC analysis confirmed that apigenin-C-glycosides (shaftoside, vitexin, and isovitexin) were the major compounds in the extract. The extract significantly and dose-dependently reduced cartilage erosion, bone loss, cartilage catabolic changes, serum osteoporotic-osteoarthritis biomarkers (procollagen-type-II-N-terminal-propeptide PIINP; procollagen-type-I-N-terminal-propeptide PINP; osteocalcin), inflammation (IL-1β) and mRNA expressions for nuclear-factor-kappa-beta NF-κβ, interleukin-1-beta IL-1β, cyclooxygenase-2; and matrix-metalloproteinase-13 MMP13 activities, in osteoporotic-osteoarthritis rats comparable to Diclofenac.
CONCLUSION: This study demonstrates that apigenin-C-glycosides at 400 mg CN extract/kg (about 0.2 mg apigenin-equivalent/kg) is comparable to diclofenac in suppressing inflammation and catabolic proteases for osteoporotic-osteoarthritis prevention. Graphical abstract.