Asian Pacific Journal of Tropical Biomedicine

371-375

Authors: Jerapan Krungkrai, Sudaratana Rochanakij Krungkrai

Malaria is a major cause of human morbidity and mortality in the tropical endemic countries worldwide. This is largely due to the emergence and spread of resistance to most antimalarial drugs currently available. Based on the World Health Organization recommendation, artemisinin-based combination therapies are now used as first-line treatment for Plasmodium falciparum malaria. Artemisinin or qinghaosu (Chinese name) and its derivatives are highly potent, rapidly acting antimalarial drugs. Artemisinin was discovered in 1971 by a Chinese medical scientist Youyou Tu, who was awarded the Nobel Prize in 2015 on her discovering the antimalarial properties of qinghaosu from the traditional Chinese qinghao plant. Nevertheless, artemisinin resistance in falciparum malaria patients has first emerged on the Thai-Cambodian border in 2009, which is now prevalent across mainland Southeast Asia from Vietnam to Myanmar. Here, we reviewed malaria disease severity, history of artemisinin discovery, chemical structure, mechanism of drug action, artemisinin-based combination therapies, emergence and spread of drug resistance, including the recent findings on mechanism of resistance in the falciparum malaria parasite. This poses a serious threat to global malaria control and prompts renewed efforts for the urgent development of new antimalarial drugs.

382-383

Authors: Somsri Wiwanitkit, Viroj Wiwanitkit

Anisakiasis is an important worm infestation. It is seen in some non-tropical countries and becomes an important issue in coastal medicine. However, in the few recent years, there are some reports on occurrence of anisakiasis in tropical countries. In this specific short article, the authors review and present the situation of anisakiasis in Southeast Asia. It can be said that anisakiasis becomes a new focused interest in tropical coastal medicine at present.

390-395

Authors: Al Thabiani Aziz, Jazem Abdullah Mahyoub, Hasibur Rehman, Shalini Saggu, Kadarkarai Murugan, Chellasamy Panneerselvam, Majed Salum S. Alrefaei, Marcello Nicoletti, Hui Wei, Angelo Canale, Giovanni Benelli

Objective: To investigate the susceptibility to some conventional and non-conventional insecticides in laboratory and field larval populations of the West Nile vector Culex pipiens L. (Cx. pipiens), the dominant species in Jeddah Province, Saudi Arabia. Methods: The tested conventional insecticides were Actikil and Pesgard, while the nonconventional ones were Bacilod, Dudim and Baycidal. Probit analysis and photomicroscopical observations were carried out to shed light on acute toxicity in laboratory and field Cx. pipiens strains. Results: Cx. pipiens were more susceptible to Pesgard (LC50: 0.045 and 0.032 mg/L) than Actikil (0.052 and 0.038 mg/L) and Bacilod (0.129 and 0.104 mg/L), for the field and laboratory strains, respectively. Results showed that treatments with the chitin synthesis inhibitor Dudim and Baycidal evoked morphological effects similar to those induced by other insect growth regulators. According to IC50 values obtained (concentration which to inhibit the emergence of 50% of mosquito adults), the compound Dudim (0.0003 and 0.0001 mg/L) was more effective against Cx. pipiens L. mosquitoes than Baycidal (0.0004 and 0.0003 mg/L) for both the field and laboratory strains, respectively. Conclusions: Our results provide baseline data to enhance control programs and orient public health decisions on the selection of pesticides againstmosquito vectors inSaudiArabia.

400-403

Authors: Dyanne Medina-Flores, Gabriela Ulloa-Urizar, Rosella Camere-Colarossi, Stefany Caballero-García, Frank Mayta-Tovalino, Juana del Valle-Mendoza

Objective: To evaluate the cytotoxic and antibacterial effect of Bixa orellana L. (B. orellana) (achiote) methanol extract against Streptococcus mutans (ATCC 25175) (S. mutans) and Streptococcus sanguinis (ATCC 10556) (S. sanguinis). Methods: Two methanol extracts of B. orellana were prepared in vitro, from the seeds and leaves. The antibacterial activity of extracts against S. mutans and S. sanguinis was evaluated using the cup-plate agar diffusion method. The minimum inhibitory concentration (MIC) was determined using the microdilution method and the cytotoxic activity was determinated by using the cell line MDCK. Results: A stronger antibacterial effect was observed with the leaves methanolic extract with an inhibition zone of (19.97 ± 1.31) mm against S. mutans and (19.97 ± 1.26) mm against S. sanguinis. The methanolic extract of the seeds had an activity of (15.11 ± 1.03) mm and (16.15 ± 2.15) mm against S. mutans and S. sanguinis, respectively. The MIC of the leaf and the seed extracts against S. sanguinis was 62.5 and 125 mg/mL, respectively, and the MIC of the leaf extract against S. mutans was 62.5 mg/mL, and for the seed extract it was 31.25 mg/mL. The 50% cytotoxic concentration was 366.45 and 325.05 mg/mL for the leaves and seeds extracts, respectively. Conclusions: The experimental findings demonstrated the antibacterial effect of the methanolic extract of B. orellana (achiote) on S. mutans and S. sanguinis. The extract of this plant is cytotoxic at high concentrations.

410-417

Authors: Muhammad Ali Khan, Md. Mahbubur Rahman, Md. Nazmul Sardar, Md. Saiful Islam Arman, Md. Badrul Islam, Md. Jahangir Alam Khandakar, Mamunur Rashid, Golam Sadik, AHM Khurshid Alam

Objective: To investigate the comparative effects of Diospyros blancoi (Ebenaceae) leaves (DBL), root bark (DBRB) and stem bark (DBSB) on free radicals and cancer. Methods: The polyphenol contents, antioxidant and free radical scavenging propertieswere determined using standard spectrophotometric methods. Cytotoxicity and anticancer activities were performed on brine shrimp nauplii and Ehrlich ascite carcinoma cells, respectively. Results: Among the extracts, DBSB showed the highest total antioxidant capacity and reducing capacity on ferrous ion. Based on 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radical scavenging activities, DBSB showed (95.760 ± 0.343)% and (67.460 ± 2.641)% scavenging with IC50 of (3.10 ± 0.17) and (50.00 ± 3.11) mg/mL, respectively. The IC50 values of standard butylated hydroxytoluene and catechin (CA) for 1,1-diphenyl-2- picrylhydrazyl and hydroxyl radicals were (8.50 ± 0.25) and (75.00 ± 0.14) mg/mL, respectively suggesting that DBSB had a significant (P < 0.05) radical scavenging activity than standards. In lipid peroxidation inhibition assay, the inhibitory activity of the extracts and the standard was in the following order: DBSB > DBRB > CA > DBL. Also, the phenolic [(139.91 ± 3.924) mg gallic acid equivalent/g] and flavonoid contents [(412.00 ± 16.70) mg catechin equivalent/g)] of DBSB were higher than that of other extracts. In addition, the DBSB showed the moderate cytotoxic and anticancer properties. Conclusions: Our results indicate thatDiospyros blancoi stembark had the significant highest antioxidant and free radical scavenging properties as well as moderate anticancer activity. Hence, we assume that the anticancer activity of this plant can be, at least in part, attributed to its content in phenolic compounds as well as its significant free radical scavenging properties.

422-428

Authors: Prameela Kannan Kutty

The anticancer potential by breastfeeding is not fully tapped in the light of the present knowledge of the subject. Literature indicates that breastmilk has anticancer action but may underestimate its full capacity. The protective spectrum within breastmilk hints on the need for a more comprehensive understanding of it as an anticancer tool. Exclusive breastfeeding could confer protection from carcinogenesis with a greater impact than realised. A literature review was conducted using four electronic databases. Selected areas were extracted after thorough perusal of the articles. The uninitiated would take exclusive breastfeeding seriously if actively counselled as an anticancer tool. Advice on details of the breastfeeding process and holistic information on breastfeeding may endow a greater impact among the skeptics. Counselling the breastfeeding mother on information sometimes not imparted, such as on maternal nutrition, details of the process of breastfeeding, benefits of direct breastfeeding versus milk expression and her psychosocial well being may make a difference in optimising anticancer action that exists in breastmilk. Additionally, its anticancer potential provides a platform to universally improve physical and psychosocial well being of women who breastfeed. Statistics of protection by breastfeeding in some maternal and childhood cancers are evident. “Bio-geno-immunonutrition” of breastmilk may shield the mother and infant from carcinogenesis in more ways than appreciated. The molecular basis of mother-to-infant signals and their “energies” need to be researched. Breastfeeding as a modifiable behaviour provides cost effective nutrition with potential for both cancer immunoprophylaxis and immunotherapy.

441-442

Authors: Alcides Troncoso

It has been more than 30 years since AIDS was introduced in people's daily life, and it is a milestone that causes taboos, myths and prejudices. At that time, a patient told me his feelings, and he was very convincing: “I am horrified of living and afraid of dying.” Three decades later, AIDS infection is not a death sentence anymore. First, doctors could make that infected patients did not die from the disease; then, that the medication which kept them alive was not so toxic. And finally, that the treatments were more comfortable. And once at this point, the possibility that the virus may disappear from the body is a more realistic goal than ever. The story of AIDS has changed and, for the first time, we can foresee in the short term the beginning of the end of the pandemic. Now it is not about whether the cure is possible or not, but about when we will have it. This current momentum, so hard to get, should be maintained. We have never been so close to achieving this goal. Although the end of the pandemic is close, this is not enough. It is worrying that some world leaders have absolved themselves of responsibility for not stopping or at least having understood the explosion of the pandemic as if it was a natural disaster. “Zero tolerance for HIV” requires a profound understanding of the stigma and discrimination of the infected people to finally get rid of the epidemic of fear and the devastation that the pandemic caused.

446-450

Authors: Raweewan Srisawat, Thipruethai Phanitchat, Narumon Komalamisra, Naoki Tamori, Lucky Runtuwene, Kaori Noguchi, Kyoko Hayashida, Shinya Hidano, Naganori Kamiyama, Ikuo Takashima, Tomohiko Takasaki, Ichiro Kurae, Narihiro Narita, Takashi Kobayashi, Yuki Eshita

Objective: To evaluate the potential of local mosquitoes to act as vectors for dengue transmission in Japan. Methods: Serotype 2ThNH28/93was used to test the dengue susceptibility profiles of Aedes flavopictus miyarai (Ae. f. miyarai), Aedes galloisi (Ae. galloisi) and Aedes albopictus (Ae. albopictus),whichwere collected in Japan.WeusedAedes aegypti fromThailand as a positive control. The mosquitoes were infected with the virus intrathoracically or orally. At 10 or 14 days post infection, the mosquitoes were dissected and total RNA was extracted from their abdomens, thoraxes, heads and legs. Mosquito susceptibility to dengue virus was evaluated using RT-PCR with dengue virus-specific primers. Differences in the infection and mortality rates of the different mosquito species were tested using Fisher's exact probability test. Results: The infection rates for dengue virus administered intrathoracically to Ae. f. miyarai, Ae. galloisi and Aedes aegypti mosquitoes were identical byRT-PCRonDay 10 post infection. All of the body parts we tested were RT-PCR-positive for dengue virus. For the orally administered virus, the infection rates in the different body parts of theAe. f.miyaraimosquitoes were slightly higher than those of Ae. albopictus mosquitoes, but were similar to the control mosquitoes (P>0.05).Themortalityrates forAe. f.miyarai andAe.albopictus mosquitoeswere similar (P = 0.19).Our data indicated that dengue viruswas able to replicate and disseminate to secondary infection sites in all of the fourmosquito species (Japanese and Thai). Conclusions: Ae. albopictus is a well-known candidate for dengue transmission in Japan. However, our data suggest that Ae. f. miyarai from Ishigaki Island (near Okinawa Island) and Ae. galloisi from Hokkaido (Northern Japan) should also be regarded as potential vectors for dengue transmission in these regions. Further studies on these mosquitoes should be conducted.

455-460

Authors: Ravinder Kaur, Megh Singh Dhakad, Ritu Goyal, Rakesh Kumar

Objective: To evaluate the epidemiology of candidiasis and the antifungal susceptibility profile of Candida species isolated from the intensive care unit (ICU) patients. Methods: The study used a qualitative descriptive design. Relevant samples depending on organ system involvement from 100 ICU patients were collected and processed. Identification and speciation of the isolates was conducted by the biochemical tests. Antifungal susceptibility testing was carried out as per CLSI-M27-A3 document. Results: Ninety Candida isolates were isolated from the different clinical samples: urine (43.3%), tracheal aspirate (31.1%), urinary catheter (12.2%), endotracheal tube (7.8%), abdominal drains (3.3%), sputum (2.2%). The incidence of candidiasis caused by nonalbicans Candida (NAC) species (63.3%) was higher than Candida albicans (36.7%). The various NAC species were isolated as: Candida tropicalis (41.1%), Candida glabrata (10%), Candida parapsilosis (6.7%), Candida krusei (3.3%) and Candida kefyr (2.2%). The overall isolation rate of Candida species from samples was 53.3%. Antifungal susceptibility indicated that 37.8% and 7.8% of the Candida isolates were resistant to fluconazole and amphotericin B, respectively. Conclusions: Predominance of NAC species in ICU patients along with the increasing resistance being recorded to fluconazole which has a major bearing on the morbidity and management of these patients and needs to be further worked upon.