@article {1739, title = {Angiotensin Converting Enzyme (ACE) Inhibition Activity by Syzygium polyanthum Wight (Walp.) Leaves: Mechanism and Specificity}, journal = {Pharmacognosy Journal}, volume = {14}, year = {2022}, month = {February 2022}, pages = {76-84}, type = {Original Article}, chapter = {76}, abstract = {

Introduction: One of the potential antihypertensive mechanisms include angiotensin converting enzyme (ACE) inhibition. So far, there is no in-depth study on the ACE inhibition activity of S. polyanthum, an ethnomedicinal plant used in treating hypertension. Thus, we aimed to study the ACE inhibition activity of S. polyanthum leaves by evaluating its potency, mechanism, and specificity. Methods: S. polyanthum leaves were macerated in a bath-sonicator with either water, methanol, ethyl acetate, and hexane producing aqueous (ASP), methanolic (MSP), ethyl acetate (EASP) and hexane (HSP) extracts. Each extract (100 μg/mL) were initially screened for ACE inhibition activity and then compared with standard drug, captopril (2.06 ng/mL), then the most active extract was further tested at 1 to 1000μg/ml. Inhibition mechanism was studied using zinc chloride and bovine serum albumin (BSA), while inhibition specificity was determined upon screening for α-chymotrypsin and trypsin inhibition activity. Results: ASP at 100 μg/ mL exhibited the highest inhibition activity (69.43 {\textpm} 0.60 \%) compared to MSP (41.63 {\textpm} 0.15 \%), EASP (9.62 {\textpm} 1.60 \%), and HSP (45.40 {\textpm} 0.15 \%). ASP showed dose-dependent ACE inhibition activity with IC50 of 41 μg/mL. ASP{\textquoteright}s ACE inhibition activity was significantly reduced in the presence of BSA, but not upon the presence of zinc chloride. ASP did not significantly inhibit α-chymotrypsin and trypsin. Conclusion: This study showed that the enzyme inhibition activity by S. polyanthum leaves was specific towards ACE. The ACE inhibition possibly occurs via protein precipitation and was non-dependent to the chelation with zinc at ACE active site.

Key words: Antihypertensive, ACE, Angiotensin converting enzyme, Hypertension, Syzygium polyanthum

}, doi = {10.5530/pj.2022.14.11}, author = {A Ismail and TAFT Anuar and IFM Suffian and AA Abdul Hamid and MN Omar and BE Mustafa and WAN Wan Ahmad} } @article {1754, title = {Anti-inflammatory Effects of Astaxanthin Extracted from Microalgae Hematococcus pluvialis and Combinations with Palm Tocotrienol Rich-Fraction in RAW 264.7 Macrophages}, journal = {Pharmacognosy Journal}, volume = {14}, year = {2022}, month = {February 2022}, pages = {205-215}, type = {Research Article}, chapter = {205}, abstract = {

Astaxanthin and tocotrienols, known as antioxidants derived from natural compounds and shown to have anti-inflammatory properties. This study aims to investigate the effects of a combination of astaxanthin extracted from Hematococcus pluvialis microalga and palm tocotrienols rich-fraction (TRF) on inflammatory reaction in lipopolysaccharide (LPS)-stimulated mouse RAW 264.7 macrophages cells. MTT assay was used to test cell viability and nitrite oxide (NO) was determined using Griess assay. Isobologram confirmed that the combined treatment produced synergistic effect and measurement of inflammatory cytokines such as interleukin 6 (IL-6) and interleukin 12 (IL-12) through ELISA assay. Our results showed that the combination of astaxanthin and TRF exhibited inflammatory markers such as NO production. The concentration of astaxanthin ranging from 10 to 100 μg/mL and TRF at 4-25 μg/mL had no toxicity and achieved higher cell viability. The combination treatments led to more potent inhibition of NO production compared to single treatments. Combination Index (CI) was achieved from the combination treatments at IC80, resulting in synergism at a CI value of 0.81. Furthermore, ELISA showed that the combined treatment significantly further reduced the expression levels of pro-inflammatory cytokines IL-6 and IL-12. Our findings suggest that the combination of astaxanthin and TRF enhanced anti-inflammatory and antioxidant activities in stimulated macrophages and may act synergistically to produce health effects reducing inflammation.

Key Words: Inflammation, Tocotrienol-Rich Fraction, Astaxanthin, Antioxidant, Combination, Macrophages

}, doi = {10.5530/pj.2022.14.26}, author = {KA Radzun and MHH Rusmidi and Aini and I Norisam and N Iran and F Pardi and A Ismail and WRWA Razak and SRA Hafid} }