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Objective: To investigate the antimalarial potential of kolaviron (KV), a biflavonoid fraction from Garcinia kola seeds, against Plasmodium berghei (P. berghei) infection in Swiss albino mice., Methods: The study consists of seven groups of ten mice each. Groups I, II and III were normal mice that received corn oil, KV1 and chloroquine (CQ), respectively. Groups IV, V, VI and VII were infected mice that received corn oil, CQ, KV1 and KV2, respectively. CQ, KV1 and KV2 were given at 10-, 100- and 200-mg/kg daily, respectively for three consecutive days., Results: Administration of KV1 and KV2 significantly (P<0.05) suppressed P. berghei-infection in the mice by 85% and 90%, respectively, while CQ produced 87% suppression relative to untreated infected group after the fifth day of treatment. Also, KV2 significantly (P<0.05) increased the mean survival time of the infected mice by 175%. The biflavonoid prevented a drastic reduction in PCV from day 4 of treatment, indicating its efficacy in ameliorating anaemia. Significant (P<0.05) oxidative stress assessed by the elevation of serum and hepatic malondialdehydewere observed in untreated P. berghei-infected mice. Specifically, serum and hepatic malondialdehyde levels increased by 93% and 78%, respectively in the untreated infected mice. Furthermore, antioxidant indices, viz; superoxide dismutase, catalase, glutathione-s-transferase, gluathione peroxidase and reduced gluathione decreased significantly (P<0.05) in the tissues of untreated P. berghei-infected mice. KV significantly (P<0.05) ameliorated the P. berghei-induced decrease in antioxidant status of the infected mice., Conclusions: This study shows that kolaviron, especially at 200 mg/kg, has high antimalarial activities in P. berghei-infected mice, in addition to its known antioxidant properties., (Copyright © 2014 Hainan Medical College. Published by Elsevier B.V. All rights reserved.)

Objective: To investigate the abilities of two flavonoids - Garcinia biflavanol-1 (GB-1) and Garcinia biflavanol-2 (GB-2) from Garcinia kola (G. kola) in reducing cadmium-induced effects on raw U937 cells and U937-derived macrophages., Methods: Macrophage U937 cells were incubated with cadmium followed by treatment with the flavonoids and cell viability assessed via trypan blue staining. In the other experiment, the U937 cells were transformed to the macrophage form and treated with cadmium in order to activate them. The cells were later incubated with the flavonoids and finally the supernatant of each cell culture was analysed for the secretion of nitric oxide, catalyse activity, and the release of tumour necrosis factor-alpha, interleukin-1 and interleukin-2 as indices of macrophage activation. Quercetin (a flavonol) was used as the reference flavonoid in all experiments., Results: It revealed that the flavonoids significantly increased the viability of the cells and also reduced the cadmium-induced activation of the macrophage cells in a concentration-dependent manner. The flavanols GB-1 and GB-2 possessed higher activities than quercetin in all cases (P<0.05). Garcinia biflavanol-2 possessed a higher bioactivity than GB-1 significantly (P<0.05)., Conclusions: In addition to corroborating the several reported importance of G. kola as a potential neutraceutical and pharmacological condiment, the study also clearly indicates the role hydroxylation especially at the 3'- position of polyphenols could play in enhancing bioactivities of flavonoids., (Copyright © 2013 Hainan Medical College. Published by Elsevier B.V. All rights reserved.)

Objective: To investigate three tropical plant materials - clove seeds [Syzygium aromaticum (S. aromaticum)], bitter kola fruits [Garcinia kola (G. kola)] and tobacco leaves (Nicotiana species) as potential targeted killers of Streptococcus mutans (S. mutans), a cavity-causing bacterium (gram-positive, facultative anaerobe) that resides in a multispecies microbial community (dental plaque) for the treatment of dental caries (tooth decay)., Methods: Thirty one (31) teeth samples were collected from patients with obvious signs of tooth decay (swollen gum, weak or fallen tooth, etc.) using sterile swab sticks. These samples were collected from two major dental clinics in Nsukka, Enugu State, Nigeria and investigated by spread inoculation onto sterile blood agar and Mueller Hinton agar (MHA) respectively and incubated at 37 °C for 24 h. The discrete colonies obtained were further re-inoculated onto sterile Mitis salivarius agar (MSA) plates and incubated as above. The isolates were characterized by gram staining and catalase test. Tobacco leaves, clove seeds and bitter kola fruits were ground into powder, extracted with three different solvents (n-hexane, hot water and ethanol), filtered, dried and stored in clean containers, corked and kept until used. The plant extracts were investigated for phytochemistry, minimum inhibitory concentration (MIC), minimum cidal concentration (MCC) and compared with some conventional antibiotics commonly used against tooth decay. Antibiotic sensitivity test was also carried out. The results were statistically analyzed., Results: The extracts showed varied phytochemical composition but most abundantly the flavonoids. Our result also shows that females (16) have more tooth decay than males (15) and that 16 samples were very bloody while 15 were slightly bloody. The microbial characterization showed that 18 samples were catalase-positive indicating the presence of S. mutans while 13 were catalase-negative suspected to be Staphylococcus spp. The Gram reaction confirmed 13 Gram-negative and 18 Gram-positive organisms. The n-hexane extract had the best antimicrobial activity followed by the ethanol and lastly hot water. MIC showed that n-hexane clove extract had the largest inhibition zone diameter, followed by bitter kola extract and lastly tobacco extract. The antibiotic sensitivity test credited ciprofloxacin the best because it exhibited broad spectrum of action., Conclusions: Since the n-hexane extract of clove seeds demonstrated preferential growth-inhibitory activity against the causal cariogenic pathogens (S. mutans) in dental caries, we therefore, report here that clove extract be henceforth considered as a potential ingredient in toothpaste preparation., (Copyright © 2011 Hainan Medical College. Published by Elsevier B.V. All rights reserved.)