ANTIOXIDANT, ANTI-INFLAMMATORY AND ANTICANCER POTENTIALS OF PHILIPPINE FERNS AND LYCOPODS

Reggie Y. Dela Cruz, Aileen Mae G. Ang, Glenda Z. Doblas, Heidi C. Porquis, Cinderilla C.Cabresos, Diana Rose Y. Jacalan and Victor B. Amoroso

Dept of Biology, Central Mindanao University, Bukidnon, Philippines

Abstract

Ferns and lycopods, collectively called as pteridophytes, are among those neglected plant resources whose medicinal potentials are very high. This study explored the antioxidant, anti-inflammatory and anticancer potentials of selected pteridophyte species. Ethnopharmacological surveys were initially carried out in three ethnic tribes, Talaandig Tribe in Mt. Kitanglad, Bukidnon; Higaonon tribe in Mt. Caburakanan, Bukidnon as well as the Mandaya Tribe in San Isidro, Davao Oriental. Ten species of pteridophytes were found to be used by these tribes for a total of 13 illnesses which include arthritis and inflammation. A total of fifty-seven (57) methanolic extracts were produced from the fronds and rhizomes of 25 species of ferns and three species of lycopods collected from eight locations in Mindanao. These were studied in terms of their DPPH radical scavenging activity, cytotoxicity against human epidermal keratinocytes, cyclooxygenase inhibition and anticancer activity against lung cancer A549 cell line. The selected species were also identified using morphology and barcoded using the chloroplast rbcL gene with an average length of 561 bp. The sequences were compared with the GenBank and BOLD databases to confirm initial identification and phylogenetic analysis was carried out using neighbor joining method. Qualitative phytochemical screening revealed 19 extracts positive to alkaloids, 41 extracts positive to anthraquinones, 46 extracts positive to phenolics, 54 extracts positive to saponins, 22 extracts positive to tannins and 45 extracts positive to terpenoids. Highest total phenolic content was 302.19 ± 28.83 mg gallic acid equivalent/g sample and flavonoid content of 36.74 ± 2.17 μg quercetin equivalent/g sample. The results further showed that crude rhizome extracts from all collected fern samples generally had higher values of total phenolic and total flavonoid contents compared to crude frond extracts. Antioxidant values of more than 50% radical scavenging activity relative to ascorbic acid were observed in 5 rhizome and 1 frond extracts. All 57 extracts were found to be nontoxic based on MTT cell viability assay using neonatal human epidermal keratinocytes at two doses of 20 and 200 ppm. Assays were conducted to measure inhibition of the two forms of the enzyme cyclooxygenase, COX-1 and COX-2. Twenty-four (24) crude extracts exhibited more than 50% COX-2 inhibition. Moreover, ten extracts gave COX-2: COX-1 selectivity indices of =1.2. The highest value was that of extract 20F with 2.64 followed by 21R with 2.34. Moreover, two extracts, 5R and 20F were active against lung A549 cancer cell line. It is interesting that 20F has both anti-inflammatory and anticancer activities. Isolation of the bioactive compounds as well as mechanistic and cell-based assays will be done to provide more conclusive data for the reported bioactivities.

Keywords: Ferns, lycopods, cyclooxygenase, anticancer and antioxidant.