Sivananthan Manoharan | University of Malaya, Malaysia (original) (raw)

Papers by Sivananthan Manoharan

The tripeptide GVR was previously shown to inhibit ACE and was able to reduce systolic blood pres... more The tripeptide GVR was previously shown to inhibit ACE and was able to reduce systolic blood pressure in SHRs within 6 h after administration. To further analyse the potential of tripeptide GVR in lowering blood pressure, a long term study was carried out where the tripeptide was orally administered to SHRs for 21 days. Elevated systolic blood pressure was significantly reduced when the peptide was administered at 50 mg/kg body weight and 100 mg/kg body weight. Body weight of the SHRs did not change significantly between the studied groups and the histopathological findings indicated that there were no abnormalities in liver and kidney tissues. From the acute toxicity analysis of this tripeptide, using the Up and Down method revealed that the peptide was non-toxic to SHRs. Tripeptide GVR demonstrated endothelium-dependent vasorelaxation activity using thoracic aortas from SD rats in which vasorelaxation was not observed in denuded aortas. The metabolomic analysis carried out from the sera of SHRs demonstrated changes on metabolites associated with pathways related to renin angiotensin system. As for proteomic analysis, differentially expressed proteins detected were mainly proteins related with inflammation. Based on the results, tripeptide GVR has a potential to ameliorate the elevated blood pressure in SHRs.

It has been shown that fraction D 6 from Pleurotus pulmonarius has the potential to inhibit ACE. ... more It has been shown that fraction D 6 from Pleurotus pulmonarius has the potential to inhibit ACE. After this discovery , additional studies were conducted to obtain peptides from that fraction, as ACE inhibitors. By size exclusion chromatography, single peak was resolved and termed as Psec. The IC 50 of Psec was assessed to be 4.50 μg/mL, which was 2.5 times lower than that of D 6. When Psec was resolved by SDS-PAGE, three bands with estimated molecular weight of 63 kDa, 55 kDa and 11 kDa were observed. The protein bands were subjected to MALDI-Tof MS/MS for protein identification. By using the BIOPEP database for predicting in silico digestion of gastrointestinal (GI) enzymes, four stable tripeptides with ACE inhibitor potential resulting from GI enzyme digestion were identified, namely GVR, VVR, NPR, and VVL. The IC 50 was estimated to be 55 μg/mL, 93 μg/mL, 110 μg/mL and > 250 μg/mL individually. Based on a Lineweaver-Burk plot, tripeptide GVR was determined to be a competitive inhibitor and this was confirmed by molecular docking analysis. At 100 mg/kg of body weight (bw), the tripeptide GVR reduced SBP 33.5 mm Hg in SHRs. The results suggested that this tripeptide is potentially beneficial as an antihypertensive agent.

Background: The commercially available synthetic angiotensin-I-converting enzyme (ACE) inhibitors... more Background: The commercially available synthetic angiotensin-I-converting enzyme (ACE) inhibitors are known to exert negative side effects which have driven many research groups globally to discover the novel ACE inhibitors. Method: Literature search was performed within the PubMed, ScienceDirect.com and Google Scholar. Results: The presence of proline at the C-terminal tripeptide of ACE inhibitor can competitively inhibit the ACE activity. The effects of other amino acids are less studied leading to difficulties in predicting potent peptide sequences. The broad specificity of the enzyme may be due to the dual active sites observed on the somatic ACE. The inhibitors may not necessarily competitively inhibit the enzyme which explains why some reported inhibitors do not have the common ACE inhibitor characteristics. Finally, the in vivo assay has to be carried out before the peptides as the antihypertensive agents can be claimed. The peptides must be absorbed into circulation without being degraded, which will affect their bioavailability and potency. Thus, peptides with strong in vitro IC50 values do not necessarily have the same effect in vivo and vice versa. Conclusion: The relationship between peptide amino acid sequence and inhibitory activity, in vivo studies of the active peptides and bioavailability must be studied before the peptides as antihypertensive agents can be claimed.

Very few ABO blood group and rhesus based research has been done in Malaysia. From the literature... more Very few ABO blood group and rhesus based research has been done in Malaysia. From the literature survey, literature about sarawakian and sabahan ethnics blood group pattern was not present and may be this research was the first conducted in Malaysia focusing individually on sarawakian and sabahan ethnics living in East Malaysia. In this research 600 participants were included with 300 were sarawakian students ( 150 males and 150 females) and another 300 were sabahan students ( 150 males and 150 females). A 1.0-2.0 ml sample of blood was drawn from the antecubital vein of each subject in a disposable syringe, and transferred immediately to a tube containing ethylene diamine tetra acetic acid (EDTA). Blood grouping (ABO) and Rhesus factors (Rh), was done by the antigen antibody agglutination test. The anti sera used were obtained from Plasmatec Laboratory, Great Britain. From this research can be concluded that among both sarawakians and sabahans blood group systems, both were revealing the same scenarios where blood group O> B> A> AB and in rhesus system rhesus positive > rhesus negative.

Most of the researchers from different parts of the world conducted research mostly focusing on l... more Most of the researchers from different parts of the world conducted research mostly focusing on leaves of Andrographis paniculata (AP) and few researchers conducted research focusing on stems and roots of the AP. One of the part of AP known as flowers were not concentrated by the researchers with very limited information regarding the AP flower available online. In present research, flower of AP were used to evaluate the antimicrobial properties of the AP's flowers. From the results can be best described that the flowers of AP were having antibacterial and antifungal activities but the strength of zone of inhibition produced can be classified as mild may be due to few reasons. Further evaluation of this flower needed since the phytochemistry was not found online and may be can be concluded that the phytochemistry study has not been conducted yet. The compound/s which lead to antimicrobial activity need to be evaluated.

Since immemorial time, utilization of medicinal plants has been in practice by the practitioner t... more Since immemorial time, utilization of medicinal plants has been in practice by the practitioner to treat variety of ailments without knowing the active bio-compound which lead to the reduction or elimination of symptoms of the disease. Recent advancement in technologies became a turning point in health care setting where many medicinal plants which are gifted from the nature were being employed in research to synthesized variety of phytochemical compounds which were responsible for the various pharmacological properties of the plants. Few compounds which are plant derivative have been patented for the commercial use to treat illness. In this review, medicinal plants related to few pharmacological properties like anticancer, antiviral, antidiabetics, antifungal were reviewed and documented. Also the phytochemical constituents were reviewed and documented. This review proved few related pharmacological properties of the plants where these plants are employed in the folk medicine. Advancement in technologies and also research fundings provide the suitable platform for the researchers to conduct extensive research on the medicinal plants.

This study was conducted to determine the antimicrobial activity of steamed lime and honey agains... more This study was conducted to determine the antimicrobial activity of steamed lime and honey against Streptococcus pneumonia. The inhibition zone of pure steamed honey concoction against Streptococcus pneumoniae ATCC 49619 was 17.75 mm and the pure steamed lime was 26.5 mm. The combination of both pure steamed honey and lime was 25.25 mm. The concoction have shown that the antimicrobial activity of pure steamed lime and honey remedy highly significant and compare favorably with the effect of steamed pure lime alone and pure steamed honey against the Streptococcus pneumoniae. The dilution exhibit mild outcome against Streptococcus pneumoniae ATCC 49619.

Aim: This study was conducted to determine the synergistic activity of chloroform extract of Duri... more Aim: This study was conducted to determine the synergistic activity of chloroform extract of Durio zibethinus wood bark with Penicillin G against Staphylococcus aureus. Method:Extract of the plant obtained after maceration of plant powder into cloroform, than was filtered using filter paper and finally evaporated. The powder form was freshly reconstitute in dimethyl sulfoxide (DMSO) and tested against Staphylococcus aureus ATCC 33862 using Kirby Baur technique and the plates were incubated at 37 ºC. The zone of inhibition was measured after 24 hours and recorded in millimeters. The synergistic study was conducted using the Durio zibethinus wood bark extract in combination with penicillin G with the propotion of 1:1 in homogenous condition and incubated at 37 ºC for 24 hours. The zone of inhibition was measured and recorded. Result: The inhibition zone of Durio zibethinus wood bark extract against Staphylococcus aureus ATCC 33862 was 10 mm and the Penicillin G was 12 mm. The combination of both Durio zibethinus wood bark extract and Penicillin G was 14 mm. Conclusion: Staphylococcus aureus have created resistance to various antibiotics. Chloroform extract of Durio zibethinus bark exhibit mild synergistic activity against Staphylococcus aureus ATCC 33862. Although the effect was mild but it is possible that Durio zibethinus could reverse such resistance and thus potentiate the effect of common penicillins against resistant Staphylococcus aureus.

From the literature survey, no published data was found regarding the topic of repeatedly heated ... more From the literature survey, no published data was found regarding the topic of repeatedly heated cooking oil from Raub, Pahang. Thus this study was designed to evaluate the level of knowledge, attitude and practice of food outlet operators in Raub, Pahang morning market regarding the usage of repeatedly heated cooking oil. Food prepared from repeatedly heated cooking oil becoming a common issue in Malaysian setting. Few related articles to this topic (not focusing Raub) has been published previously also mentioning the seriousness of this practice to the health of human being. The main purpose of the food operators using repeatedly cooking oil because to saves cost. Level of knowledge, attitude and practice of food outlet operators in Raub, Pahang morning market regarding the usage of repeatedly heated cooking oil need to be improved. Many of the consumers not aware of the danger of using the repeatedly heated cooking oil. Only small portion of consumers aware of this situation. This small portion need to be changed to a bigger portion of consumers who well aware of this situation. This only can be achieved by doing campaign by health related agencies to create awareness that repeatedly heated cooking oil can cause harm to the health. Apart from these agencies, public must play a role in spreading the information to relatives, friends and family members.

Increasing bacterial resistances are continually recorded in most of the regions in the world.

Emergence of bacterial resistance is critically an alarming situation in the health care industry... more Emergence of bacterial resistance is critically an alarming situation in the health care industry. The bacterial resistance getting more serious and effort of developing new drugs initiated. Researchers from different part of the world extensively involved in the research. One of the method they employed is using the medicinal plants. These medicinal plants were used in the folk medicine to treat the illness. In previous time, the medicinal plants were just employed as a treatment without knowing the active compound/s which responsible to cure the disease. Most of the research done were based on the belief in traditional medicine and after the research done many researchers had concluded that the practice in the earlier time using the medicinal plants were right and having activities to overcome certain illness example involving bacterial illness. Some researchers proved that usage of medicinal plants in earliest time revealing negative results. In this review, all 50 medicinal plants were used in folk medicine and the modern research proved that the plants were having antibacterial property as claimed by in earliest time. Further research using the medicinal plants are needed to overcome the emergence of the bacterial resistance. To date synergistic study are very limited and it should be conducted so that any synergistic activities may reverse the bacterial resistance.

Aim: This study was conducted to study the distribution of ABO blood group and Rhesus factor amon... more Aim: This study was conducted to study the distribution of ABO blood group and Rhesus factor among Malay, Chinese, Indian and other races' students in Asia Metropolitan University, Malaysia. Method : 428 students were involved in this study. They were divided into 4 different groups named as Malay, Chinese, Indian, Others. 107 students (male and female) were chosen randomly and being placed in each respective group. A 1.0-2.0 ml sample of blood was drawn from the antecubital vein of each subject in a disposable syringe, and transferred immediately to a tube containing ethylene diamine tetra acetic acid (EDTA). Blood grouping (ABO) and Rhesus factors (Rh), was done by the antigen antibody agglutination test. The anti sera used were obtained from Plasmatec Laboratory, Great Britain. Result : Blood group O was prevalent among Malay, Chinese, Other etnics but among Indians blood group B was prevalent. Blood group AB was least prevalent. Among rhesus positive races, blood group O was prevalent and blood group AB was least prevalent. Among rhesus negative races, blood group B was prevalent and blood group A and AB were sharing the same percentage respectively that was 0.23%. Conclusion: Blood group O was most prevalent and blood group AB was least prevalent. When narrowly focused interestingly Indians were having blood group B as most prevalent but for Malay, Chinese, Others etnics, blood group O were most prevalent. Another interesting finding was almost 67% rhesus negative were among the Indians and only 33% rhesus negative were distributed among Malay and Others etnics with no rhesus negative were recorded for Chinese etnic. From the present finding, Indians were having unique blood group distribution when compared to other etnics live in Malaysia.

Background: Up till now about 200 antigen have been identified. The ABO blood group system was fi... more Background: Up till now about 200 antigen have been identified. The ABO blood group system was first to be known and rhesus factors (Rh) blood group, both are most essential for blood transfusion purposes. Gene for ABO antigens is on the 9th chromosome and Rh antigen gene is on the first chromosome. Objective: This study was conducted to determine the distribution of ABO blood group and Rhesus factor among students in ASIA Metropolitan University, Malaysia. Materials and Methods: Blood grouping (ABO) and rhesus factors (Rh) was done by the antigen antibody agglutination test. 1414 randomly chosen health sciences students from ASIA Metropolitan University were screened for their blood group systems. Out of these subjects, 259 were males and 1155 were females. Results: Out of 1414 subjects that were randomly selected, 259 (18.32%) were males and 1155 (81.68%) were females. From the total number of males subjects, 257 (99.23%) and from the total number of females subjects, 1134 (98.18%) were found to be Rh positive. Overall 1391 (98.37%) subjects were found of having the Rhpositive and 23 (1.63%) subjects were having Rh-negative.Conclusion: In the present study, the frequency of Rh-negative blood group in male and female subjects were O, B, A, AB and B, O, A and AB. Whereas the most common Rh-positive in male and female subjects are O, B, A, AB and O, B, A and AB respectively.

The study was designed to evaluate the antibacterial potential of three plants which are Androgra... more The study was designed to evaluate the antibacterial potential of three plants which are Andrographis paniculata,
Durio zibethinus and Psidium guajava. Andrographis paniculata leaves (30mg/ml) and roots (30 mg/ml), Durio
zibethinus wood bark (10mg/ml), and Psidium guajava leaves (15mg/ml) extract was obtained through the process
called maceration, filtration, evaporation and the paste form was freshly reconstitute in dimethyl sulfoxide (DMSO)
and tested against Staphylococcus aureus for Andrographis paniculata, Psidium guajava. Streptococcus agalactiae
for Durio zibethinus and Psidium guajava and Escherichia coli for Durio zibethinus using Kirby Baur technique and
the plates were incubated at 37 ºC. The zone of inhibition was measured after 24 hours and recorded in millimeters.
The combination study was conducted using extract in combination with Penicillin G (6.25 µg/ ml) and erythromycin
(15 µg/ ml; Andrographis paniculata) with the propotion of 1:1 in homogenous condition and incubated at 37 ºC for
24 hours. The zone of inhibition was measured and recorded. Mean and standard deviation was calculated.
Andrographis paniculata do possesses some antibacterial activity against Staphylococcus aureus. Leaves (17.33
mm), roots (10.67 mm), erythromycin (24.00 mm), leaves and erythromycin (20.67 mm), roots and erythromycin
(21.67 mm), leaves and roots (17.33 mm). Wood bark against Streptococcus agalactiae (14.67 mm), Penicillin G
(14.00 mm), and combination (16.67 mm). Durio zibethinus showed antibacterial activity against Escherichia coli
(11.00mm) and Penicillin G (13.33 mm). Psidium guajava leaves extract were having slightly higher activity than
Penicillin G and in combination activity, leaves were having a slightly higher activity than Penicillin G.

Increasing bacterial resistances are continually recorded in most of the regions in the world.