Phaeanthus ophthalmicus (Roxb. ex G.Don) J.Sinclair (previously known as P. ebracteolatus (Presl) Merr) is a Philippine medicinal plant occurring as evergreen shrub in the lowland forests of Luzon islands. It is used traditionally by Filipinos to treat bacterial conjunctivitis, ulcer and wound infections. Based on previous investigations where cyclooxygenase-2 (COX-2) functions as immune-linked factor in infectious sensitivities to bacterial pathogens by triggering pro-inflammatory immune-associated reactions, we investigated the antimicrobial and COX inhibitory activities of the extracts and tetrahydrobisbenzylisoquinoline alkaloids of P. ophthalmicus in vitro and in silico to validate its ethnomedicinal uses. Thus, the dichloromethane–methanol (DCM–MeOH) crude extract and alkaloid extracts exhibiting antibacterial activities against drug-resistant bacterial strains such as methicillin-resistance Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), Klebsiella pneumoniae + CRE and Pseudomonas aeruginosa + MBL afforded (+)-tetrandrine (1) and (+)-limacusine (2) as the major biologically active tetrahydrobisbenzylisoquinoline alkaloidal constituents after purification. Both tetrahydrobisbenzylisoquinoline alkaloids 1 and 2 showed broad spectrum antibacterial activity with strongest inhibition against the Gram-negative bacteria MβL-Pseudomonas aeruginosa Klebsiella pneumoniae + CRE. Interestingly, the alkaloid limacusine (2) showed selective inhibition against ovine COX-2 in vitro. These results were ascertained by molecular docking and molecular dynamics simulation experiments where alkaloid 2 showed strong affinity in the catalytic sites of Gram-negative bacterial enzymes P. aeruginosa elastase and K. pneumoniae KPC-2 carbapenemase (enzymes involved in infectivity mechanisms), and of ovine COX-2. Overall, our study provides credence on the ethnomedicinal use of the Philippine medicinal plant P. ophthalmicus as traditional plant-based adjuvant to treat bacterial conjunctivitis and other related infections. The antibacterial activities and selective COX-2 inhibition observed for limacusine (2) point to its role as the biologically active constituent of P. ophthalmicus. A limited number of drugs with COX-2 inhibitory properties like celecoxib also confer antibacterial activity. Thus, tetrahydrobisbenzyl alkaloids, especially 2, are promising pharmaceutical inspirations for developing treatments of bacterial/inflammation-related infections.

The study was ca rried out to determine proxima te content of the Bicol One Town One Product (OTOP) smoked round scad (Decapterus macrosoma) a nd pinangat a nd evalua te their nutrient content based on the Philippine Dieta ry Reference Intakes (PDRI) for selected age groups. Smoked fish sa mples were ga thered from the two la rgest producers in Mercedes, Ca ma rines Norte, while the pinangat sa mples were obta ined from three Depa rtment of Trade a nd Industry (DTI)-accredited OTOP producers in Ca malig, Albay. Sa mples were subjected to va rious a nalyses using sta nda rd a nalytical techniques. The proxima te a nalysis of smoked fish products revealed the moisture content of 54.84%; ash content, 9.71%’; crude protein, 31.29%; ca rbohydra tes, 0.47%; a nd total fa t, 3.70%. The mineral content of the fish indica ted tha t Na (2210mg) a nd Ca (157mg) were the most a bunda nt. The overall nutritional composition of smoked fish showed tha t it is highly nutritive with crude protein having the la rgest qua ntity of the dry ma tter in the fish sa mples. Pinangat products conta ined moisture (65.48%), ash content (2.3%), crude protein (4.2%), ca rbohydra tes (3.83%), a nd total fa t (24.3%). Presence of major a nd trace minerals (sodium, calcium, iron, a nd zinc) was reported, with sodium being the most a bunda nt mineral. In all age groups from children to adults, nutrient contents of smoked fish a nd pinangat products in general ra nged from low to high levels based on the recommended ra nge in requirement estima ted for groups with different activity levels. The study suggests tha t smoked fish a nd pinangat ca n serve as sources of different nutrients a nd minerals needed by the body, however, modera te consumption must be observed due to the high sodium content which exceeds the recommended dieta ry a mount.