1.Antibacterial activity and toxicity of Duckweed, Lemna minor L. (Arales: Lemnaceae) from Malaysia
Li Peng Tan ; Ruhil Hayati Hamdan ; Maizan Mohamed ; Siew Shean Choong ; Yean Yean Chan ; Seng Hua Lee
Malaysian Journal of Microbiology 2018;14(5):387-392
Aims:
New therapeutics are needed to ease the prevailing waterborne disease, and one of the alternatives is by exploring the natural compounds with antimicrobial properties. Duckweed, Lemna sp. is recorded as a medicinal herb that known to have antifungal and antibacterial activities towards several fungi and bacteria. Suitability of duckweed (Lemna minor) as an antibacterial resource against selected waterborne bacteria were evaluated in terms of its antibacterial activity and toxicity.
Methodology and results:
Antibacterial activity of the duckweed methanolic extract was tested against 11 selected waterborne bacteria using disc diffusion, minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) assay. Brine shrimp lethality assay was used to determine the toxicity of this extract. The lethal concentrations of plant extract resulting in 50% mortality of the brine shrimp (LC50) were then determined.
Conclusion, significance and impact of study
Results showed that duckweed extract exhibited bacteriostatic and bactericidal against the selected bacteria activity at the concentration of MIC = 1.8-2.0 mg/mL and MBC ≥ 2.0 mg/mL. This study shows that methanolic extract of L. minor may contain bioactive compounds against bacteria and potential therapeutic effect. The crude extract is slightly toxic and may not safe to be used in high concentration but is valuable in further study as a potential antitumor agent.
2.Mechanisms underlying the vascular relaxation activities of Zingiber officinale var. rubrum in thoracic aorta of spontaneously hypertensive rats.
Nadiah RAZALI ; Aidiahmad DEWA ; Mohd Zaini ASMAWI ; Nornisah MOHAMED ; Nurul Maizan MANSHOR
Journal of Integrative Medicine 2020;18(1):46-58
OBJECTIVE:
To evaluate vasorelaxant and vasoconstriction effects of Zingiber officinale var. rubrum (ZOVR) on live rats and isolated aortic rings of spontaneously hypertensive rats (SHRs).
METHODS:
Extracts of ZOVR were subjected to in-vivo antihypertensive screening using noninvasive blood pressures in SHRs. The most potent extract, ZOVR petroleum ether extract (ZOP) was then fractionated using n-hexane, chloroform and water. Isolated thoracic aortic rings were harvested and subjected to vascular relaxation studies of n-hexane fraction of ZOP (HFZOP) with incubation of different antagonists such as N-nitro-l-arginine methyl ester (L-NAME, 10 µmol/L), indomethacin (10 µmol/L), methylene blue (10 µmol/L), atropine (1 µmol/L), glibenclamide (10 µmol/L), prazosin (0.01 µmol/L), and propranolol (1 µmol/L).
RESULTS:
During the screening of various ZOVR extracts, ZOP produced the most reduction in blood pressures of SHRs and so did HFZOP. HFZOP significantly decreased phenylephrine-induced contraction and enhanced acetylcholine-induced relaxation. L-NAME, indomethacin, methylene blue, atropine, and glibenclamide significantly potentiated the vasorelaxant effects of HFZOP. Propranolol and prazosin did not alter the vasorelaxant effects of HFZOP. HFZOP significantly suppressed the Ca-dependent contraction and influenced the ratio of the responses to phenylephrine in Ca-free medium.
CONCLUSION
This study demonstrates that ZOP may exert an antihypertensive effect in the SHR model. Its possible vascular relaxation mechanisms involve nitric oxide and prostacyclin release, activation of cGMP-K channels, stimulation of muscarinic receptors, and transmembrane calcium channel or Ca release from intracellular stores. Possible active compounds that contribute to the vasorelaxant effects are 6-gingerol, 8-gingerol and 6-shogaol.
3.Molecular detection of selected zoonotic respiratory pathogens and the presence of virulence and antibiotic resistance genes via PCR among Kelantan Hajj pilgrims
Ilia Eleena Mohd Baharin ; Habsah Hasan ; Nik Zuraina Nik Mohd Noor ; Maizan Mohamed
Malaysian Journal of Microbiology 2021;17(3):254-265
Aims:
Respiratory tract infections (RTIs) among Malaysian pilgrims are caused by exposure to zoonotic-potential
respiratory pathogens, symptomatically and asymptomatically affected by rigorous pilgrimage rituals, overcrowding and
other stressors. This study aimed to determine the prevalence, virulence and antibiotic resistance genes of selected
zoonotic respiratory pathogens using polymerase chain reaction (PCR) assays among Hajj pilgrims from Kelantan state,
Malaysia.
Methodology and results:
Throat swab specimens were obtained from 189 Kelantan Hajj pilgrims in 2016 and
examined by PCR for the identification of respiratory pathogens. Thirteen samples (6.88%) were positive for
Streptococcus pneumoniae and four (2.11%) were positive for Klebsiella pneumoniae. All the samples were negative for
Influenza A virus, MERS-CoV and Mycobacterium bovis. One sample was positive for S. pneumoniae virulence lytA
gene. One sample was positive for K. pneumoniae virulence magA and K2A genes respectively, and three samples
were positive for K. pneumoniae rmpA genes. Ten and seven samples were positive for S. pneumoniae mefA and pbpA
antibiotic resistance genes respectively. Two samples were positive for K. pneumoniae blaKPC and blaOXA-48 antibiotic
resistance genes.
Conclusion, significance and impact of study
This work provided insight into the existence of zoonotic respiratory
pathogens inducing Hajj RTIs in Kelantan pilgrims. It showed promising findings for zoonotic studies in Hajj settings. The
findings could be relevant in potential control measures for the management of zoonotic infections among Hajj pilgrims.
Respiratory Tract Infections
;
Polymerase Chain Reaction
;
Bacterial Zoonoses
4.Tualang Honey Potentially Delay Deterioration in Haematological and Immunological Parameters in Asymptomatic, Treatment-naïve HIV-infected Patients
Tang Suk Peng ; Che Badariah Abdul Aziz ; Mahiran Mustafa ; Maizan Mohamed ; Wan Nazirah Wan Yusuf
Malaysian Journal of Medicine and Health Sciences 2021;17(No.4):166-173
Introduction: This report aimed to assess the effects of administration of Tualang honey for six months duration on
the haematological and immunological parameters in treatment-naïve HIV-infected patients who were asymptomatic. Methods: This was a randomised, controlled, open-labelled study. A total of 95 asymptomatic HIV-positive
subjects with low CD4 counts of 250-600 cells/mm3
and not on antiretroviral therapy were recruited. Tualang honey
was administered at 20 g each, once daily (HLD; total of 20 g honey), twice daily (HID; total of 40 g honey) or thrice
daily (HHD; total of 60 g honey) for six months period. Control (CT) group did not receive any honey supplementation. Haematological and immunological parameters were measured at baseline, three-month and six-month follow-up. The differences within the group (time effect) and between the groups (regardless of time) for all four groups
were analysed using Repeated Measures ANOVA followed by a post-hoc test. Results: A significant reduction in total
white blood cell, neutrophil and lymphocyte counts were observed at six-month follow-up in CT and HLD groups
when compared to baseline. The immunological parameters showed similar trend of reduction in the CT and HLD
groups. Meanwhile, the measured parameters were relatively maintained in HID and HHD groups at six-month period when compared to baseline. Conclusion: Tualang honey supplementation at intermediate and high doses for six
months delay the deterioration of haematological and immunological parameters in asymptomatic, treatment-naïve
HIV subjects.