Tests on bioactive compounds in Mainit Hot Springs underway

CEBUI, Philippines —  Mainit Hot Springs located in Barangay Montañeza, Malabuyoc, Cebu has become an area of interest for potential biologically active compounds.

According to the Department of Science and Technology (DOST), several thermophilic strains were isolated from Mainit Hot Springs with remarkable bioactivities against Gram-positive pathogens including Staphylococcus aureus and Bacillus subtilis compared with gentamicin or oxytetracycline antibiotic control.

Isolation and characterization of the bioactive compounds are currently underway in laboratories.

The microbial species and chemical diversity in hot springs and volcanic habitats are indicative of future exploration. These novel microorganisms will also likely produce novel druggable molecules.

Explorations in the Mainit Springs under Project ISAAC (Isolation, Screening, and Antimicrobial Activity of Compounds from Actinobacteria) aim to isolate, screen, and characterize thermophilic Actinobacteria for the production of bioactive compounds with the potential for drug development.

The research is funded by the DOST–National Research Council of the Philippines (DOST-NRCP).

Researchers have urged further microbial and natural product (NP) exploration on volcanoes and hot springs in the country as these underexplored habitats are expected to yield a huge repertoire of novel and biologically active compounds.

DOST said, in its latest release, those microbial natural products (NPs) have been prominent sources of drugs for a long history, especially for cancer and infectious diseases, and hot springs and volcanic environments represent valuable sources of novel natural products (NPs), yet largely untapped and understudied.

There are almost 400 volcanoes located all over the country according to the Philippine Institute of Volcanology and Seismology, with around 25 of which are considered active.

The Philippines is also endowed with many natural hot springs including the one in Malabuyoc.

Dr. Fleurdeliz Maglangit’s study team surveyed the bioactive NPs from hot springs and volcanic microbes from 2006–2022, highlighting their chemical structures and biological potential.

“Microbial pathogens or microorganisms that are capable of producing diseases, quickly evolve new ways to combat drug therapy, more rapidly than the introduction of new drugs and drug candidates to the clinical pipeline, that’s why new sources of biologically active compounds effective against drug-resistant cells are urgently needed,” said Dr. Maglangit, one of the researchers.

The threat of antimicrobial resistance (AMR) and superbugs, which are microbial strains that have become resistant to the drugs used to treat them, have continued to rise relentlessly, rendering the current antibiotics and drugs ineffective for common infections.

AMR, DOST reported, is considered the “next silent pandemic.”

DOST said, according to the World Health Organization, AMR is one of the top 10 biggest threats of the century, causing nearly five million deaths annually and over 1.2 million deaths directly attributed to AMR.

“Hot springs and volcanic environments have been shown to harbor high microbial biodiversity with unique metabolic profiles, yet they remained untapped and understudied for their production of novel druggable chemical entities,” Dr. Maglangit said.

The NPs isolated from hot springs and volcanic microbes represent structural diversity and novelty in comparison to the NPs isolated from terrestrial or marine habitats.

The hot spring water temperatures provide favorable conditions for thermophilic microbes to generate a wide array of bioactive metabolites.

Hot springs, also called thermal springs, are springs with water temperatures above their surroundings.

These kinds of springs are produced by geothermally heated groundwater which is warmed either by shallow intrusions of molten rock in volcanic areas or by circulation through faults to hot rock deep in the Earth’s crust.

Hot springs are inhabited by heat-loving microorganisms or thermophiles that can thrive at high temperatures.

The diversity of these organisms has been mainly attributed to temperature along with pH, dissolved hydrogen sulfide levels, biogeography, and geological history.

Thermophiles have attracted significant interest in recent years for their production of heat-stable enzymes for biotechnological applications including industrial, agriculture, and medical processes.

With this, Maglangit’s team recommended the conduct of more extensive experiments, whether in animal models or human subjects since some of the compounds that have been identified from hot springs and volcanic microbes have only been tested in vitro.