Study assessing the efficacy of herbal teas on bone health and quality of life in a population with osteopenia: rooibos actions on melatonin and tulsi actions on quality of life.

Abstract

The purpose of the OsTea translational study was to assess the efficacy of teas (tulsi, rooibos, oolong) compared to placebo (coriander) on markers of bone health and quality of life (QOL) in those with osteopenia and on human mesenchymal stem cell (hMSC) differentiation into osteoblasts to identify potential mechanisms of action. Following consumption of tea (3 times/day; 90 days), participants collected a urine sample during the night (10pm-6am) and filled in questionnaires before and after the study. Rooibos consumption demonstrated a significant decrease in urinary CTX levels vs placebo; trended towards increases in nocturnal melatonin levels (p=0.06); significantly decreased serotonin-producing microbes in the gut; and demonstrated trends towards improvements (p=0.09) in QUALIOST emotional parameters. Tulsi consumption primarily affected subjective measures, such as significantly improved scores for PSS, STAI-trait anxiety, and osteoporosis/osteopenia-related parameters in the QUALIOST. To further identify potential mechanisms underlying these actions of rooibos on CTX and melatonin (urinary and gut), rooibos and melatonin effects on human osteoblastogenesis were carried out for 21 days under oxidative stress conditions to mimic osteopenia. Although both rooibos and melatonin protected against oxidative stress-induced loss of osteoblasts in vitro, their underlying mechanisms were different. Melatonin, like tulsi and oolong, demonstrated the greatest protection against oxidative stress at days 10-11 of exposure, which was due to effects on hMSC viability and through melatonin receptors. Rooibos, on the other hand, demonstrated protection at days 10-11 and 20-21, which was through signaling mechanisms involved in differentiation processes and not on cell viability. These findings suggest that the clinical actions of rooibos on decreasing CTX levels in a population with osteopenia may be through a cooperative effort between melatonin and rooibos by protecting hMSC viability against oxidative stress-induced loss and by promoting osteoblast differentiation, respectively. This study also supports the use of tulsi for improving quality of life in a population susceptible to osteoporosis.

The role of MEK1/2 and MEK5 in melatonin‐mediated actions on osteoblastogenesis, osteoclastogenesis, bone microarchitecture, biomechanics, and bone formation

“…Although there is evidence that both mouse and human bone marrow cells are capable of de novo synthesis of melatonin, 83 exogenous melatonin produces an osteoblast‐promoting effect in mMSCs (present study) in mouse pre‐and mature osteoblastic cell lines and in bone through melatonin receptors 39,41 and, more specifically, MT2s 31,40,42,49 (present study). Furthermore, this study also demonstrates a unique and critical role for melatonin receptors in mMSC (MT1) and osteoblast viability (MT2) under oxidative stress conditions similar to that reported in mouse MSCs, 31 hMSCs, 74 and rat MSCs 76 These are important findings considering that oxidative stress in vitro mimic those conditions leading to progressive bone loss, osteopenia, osteoporosis and fracture as reviewed 17 …”

“…To assess if melatonin protects MSCs or osteoblasts against conditions known to induce bone loss similar to what has been reported, 74 mMSCs were exposed to melatonin for 21 days under normal and oxidative stress conditions. Mouse MSC monocultures (described previously) were cultured in DMEM:F12 medium containing 10% FBS, 1% l ‐glutamine, and 1% antibiotic–antimycotic until 80% confluence and then split into 96‐well plates.…”

The health benefits of rooibos tea in humans (aspalathus linearis)‑a scoping review

“…Regarding other clinical parameters, chronic supplementation with rooibos tea three times per day for 3 months among older women diagnosed with osteopenia ( 28 ) did not have any significant (P≤0.05) effect on the bone markers procollagen type 1 intact amino-terminal propeptide (total-P1NP) or on P1NP (ng/ml) levels. For type I collagen C-telopeptide (CTX-I, ng/ml), CTX levels were reduced (-38.23±22.63; -29.64%) in the individuals who were supplemented with rooibos.…”

“…Most of the articles matched one or two of the three criteria for quality assessment and was classified as good quality. Six papers were deemed low quality ( 11 , 14 , 25 , 26 , 31 , 35 ), while two publications ( 23 , 28 ) were judged as high quality.…”

“…Studies were conducted in South Africa (n=8), Italy (n=2), Germany (n=1), the United Kingdom (n=1), Argentina (n=1), New Zealand (n=1), Sweden (n=1), the United States (n=2), and Japan (n=1). Almost all studies featured participants who appeared to be in good health, except for Hesseling and Joubert ( 35 ), Marnewick et al ( 13 , 14 ), Rodgers et al ( 31 ), and Munmum et al ( 28 ), which included individuals with at-risk factors and those diagnosed with clinical conditions. While the at-risk individuals were defined as those with one or more risk factors for a chronic condition, the seemingly healthy populations comprised individuals who were said to have no diagnosis of any risk factor or chronic condition.…”