Filipino researchers exploring new antibiotics have identified a component derived from the leaves of a mangrove species found in coastal ecosystems.
A research team from the University of Santo Tomas (UST) has successfully extracted crude material from the leaves of Rhizophora apiculata, which harbors endophytes – fungi that reside within plant tissues and establish a mutually beneficial relationship with their host without causing harm.
The researchers aimed to determine whether these endophytes possess the ability to combat drug-resistant bacteria, thereby enhancing the prospects of discovering a novel source of antibiotics.
Following the isolation of the endophyte, researchers conducted tests to determine its ability to inhibit Enterobacter cloacae. This particular pathogen is frequently associated with urinary tract infections, which are among the primary reasons individuals seek medical attention and require antimicrobial treatment in both community and hospital environments, according to The Philippine Clinical Practice Guidelines on the Diagnosis and Management of Urinary Tract Infections in Adults.
The results of the testing revealed that the pathogen exhibited greater sensitivity to the endophyte compared to penicillin. This finding suggests that the endophyte could serve as “an excellent source of bioactive material products” and may be “attractive to medical chemistry,” as noted in a report published in The Varsitarian.
Vincent Gonzales, a UST alumnus who conducted the study, emphasized the importance of discovering new sources of antimicrobial compounds. “Finding new sources of antimicrobial compounds would be beneficial to the development (of antibiotics) and combat the current crisis we are facing today,” he told the UST publication.
The current crisis Gonzales was referring to is the antimicrobial resistance (AMR). The World Health Organization (WHO) defines antimicrobials – which include antibiotics, antivirals, antifungals, and antiparasitics – as “medicines used to prevent and treat infectious diseases in humans, animals and plants.”
AMR arises when microorganisms such as bacteria, viruses, fungi, and parasites develop the ability to withstand the effects of antimicrobial medications. As a result, the efficacy of antibiotics and other antimicrobial agents diminishes, making infections difficult or impossible to treat. This situation heightens the likelihood of disease transmission, severe health complications, disability, and death.
AMR has emerged as a significant global health threat in the 21st century, accounting for approximately 1.27 million fatalities each year. The WHO says that without immediate intervention, AMR may result in a higher mortality rate than cancer by the year 2050.
Dr. Marc Van Ranst, a virologist at the Rega Institute KU Leuven in Belgium, has indicated that there is a rising incidence of bacteria developing resistance to an increasing number of antibiotics.
He noted that while antibiotics were once considered miraculous treatments, their effectiveness has significantly diminished against certain bacterial strains. Despite the emergence of more effective treatments, the likelihood of bacterial infections worsening due to AMR is on the rise.
The WHO echoes the same concern. “Some of the world’s most common – and potentially most dangerous – infections are proving drug-resistant,” it admits.
Dr. Van Ranst provided a grave forecast. “If this trend continues, it is entirely reasonable to predict that in 25 years, some antibiotics will become useless, certain bacterial infections will be much harder to treat, and deaths will outnumber those caused by cancer,” he told MediQuality, part of the Medscape Professional Network.
Asst. Prof. Melfei Bungihan of the UST Department of Chemistry agreed, stating there is an urgent need to mitigate AMR.
“It has been speculated that by 2050, drug resistance can kill more people than war and famine combined,” said Prof. Bungihan who served as advisers of the study along with fellow faculty member Prof. Mario Tan. “So, we have to start now before we wait for 2050.”
This discovery is another reason why mangroves should be protected from further denudation.
Around the world, there are 54 species of true mangroves (34 major and 20 minor) and 60 mangrove associates. True mangrove species are those that strictly grow in the mangrove environment while associated species may thrive on other habitat types such as beach forest and lowland areas.
The Philippines has around 47 “true mangroves” and associated species belonging to 26 families. Most of the remaining mangroves can be found in Mindanao (29% of the total) and the remaining can be found in Luzon and Mindoro. Old-growth mangrove forests are mainly located in Mindanao and Palawan.
Unfortunately, the future of the mangroves in the Philippines and other members of the Southeast Asian Nations (ASEAN) looms uncertain. The forecast was based on a comprehensive survey of over 300 mangrove studies across the Philippines and the rest of Southeast Asia.
The survey has “found large gaps in our understanding of the current and future state of these already dwindling natural resources,” deplored Maria Gerona-Daga and Professor Dr. Severino Salmo III.
Gerona-Daga is a biology student currently pursuing her Ph.D. at UP while Dr. Salmo is a biology associate professor at the same university.
The UP scientists singled out the Philippines as the second worst country in ASEAN in terms of mangrove losses. It suffered a 10.5% decline between 1990 and 2010, based on independent studies included in the survey. The country is surpassed only by Myanmar (Burma), which suffered a 27.6% loss between 2000 and 2014.
Mangroves are fast disappearing due to various reasons. Report showed only 150,000 hectares of mangroves remained out of the 450,000 hectares reported in 1918, the most rapid decrease occurring during the 1960s and 1970s when government policies encouraged the expansion of aquaculture.
Despite a 1980 government ban on further conversion of mangroves to fishponds, the reduction of mangrove area from that year through 1991 continued at the annual rate of about 3,700 hectares in the following decade. This decline parallels the increase of fishpond area, approximately 41,000 hectares per year over the same period.
The conversion of mangrove areas to fishponds is the final step in a process of destruction that started with over-harvesting of mangroves for fuelwood, frequently by persons other than those who ultimately built the fishponds.
According to studies, cutting mangroves for fuelwood, charcoal making and construction is probably the second most pervasive intrusion on the resource.
Small bakeries, for instance, prefer mangrove wood. The demand for these products leads to illegal cutting, over harvesting, and subsequent degradation of the habitat and ecosystem.
Mangroves are very important to marine life. “Mangroves are like the kindergarten, seagrasses are the secondary schools, and coral reefs are the high schools and colleges for fishes! And, once (the fishes) graduate from university, they return to kindergarten to spawn,” said Khun Psit, cofounder of Thailand’s Yad Fon mangrove preservation project.
“Mangroves are critical spawning, nursery, feeding and transient shelter areas to hundreds of fish species, crustaceans and invertebrates and support an abundant and productive marine life,” the website bohol-philippines.com states.
The leaves of mangroves are a source of food for fish, shrimps and crabs and other marine animals. When a leaf falls, it breaks up and decomposes into smaller pieces, until they become too small to be seen by the naked eye.
According to some studies, mangroves contribute about 3.65 tons of litter per hectare per year. One hectare of healthy mangroves ecosystem produces about 1.08 tons of fish per year.
Some of the country’s commercial species – bangus (milkfish), shrimps, crabs and prawns, for instance – spend their early life within the mangrove area where they find food and protection from predators. All in all, mangroves are home to 68 species of fish, 54 species of crustaceans, and 56 species of gastropods.
“Mangroves support the natural food chain by forming a link between the land and the sea,” Prof. Baldevarona wrote in his article, “The Role of Mangrove in the Philippine Coastal Environment.” “They serve as the sanctuary of both aquatic and terrestrial wildlife. Other forms of life are extremely dependent on mangroves.”
In a typhoon-prone country like the Philippines, mangroves are very important, too. “Between 2005 to 2015, 56% of property damage in the Philippines was due to typhoons and storms, and another 29% due to floods,” wrote World Bank’s Michael Beck and Glenn-Marie Lange.
Mangroves, unknowingly help protect people and even properties from destruction brought about by typhoons. Moises Neil V. Seriño, assistant professor of the Department of Economics at the Visayas State University, found this out after he and co-researchers conducted a study on the aftermath of Super Typhoon Yolanda in 2013.
“Our study shows that mangrove vegetation reduced the number of deaths and damaged houses during the Yolanda incident,” Seriño told Edge Davao. “This property and lifesaving effects of mangrove is robust. Mangroves can protect us (our lives, livelihood and properties) from damaging effects of typhoons.”
“Their crowns, trunks and stems serve as physical barriers that help break the winds and waves, reducing their speed and intensity and subsequently their destructive impact,” said bohol-philippines.com.
