“Inflammaging” is a form of low level inflammation which is associated with aging (Franceschi C. and Campisi J. 2014). It is a significant risk factor for both morbidity and mortality in the elderly people, since most age-related diseases such as osteoarthritis, lupus, rheumatoid arthritis, inflammatory bowel disease and Crohn’s disease, share an inflammatory pathological process (Franceschi C. and Campisi J. 2014). According to the report, An Aging World (Goodkind D. and Kowal P, 2015), the percentage of people aged 65 and over is projected to increase to nearly 17% of the world’s population by 2050 which is approximately 1.6 billion people. Between 1990 and 2015 the population of people aged 60 and over, in sub-Saharan Africa increased from 23 million to 46 million. In 2050, a projected 161 million older persons will reside in the region (Population Facts. 2016). The increasing population of elderly people will result in an increase in the number of inflammation-related diseases.
Inflammation is a response to potential danger signals and damage in organs in our body. In diseases such as rheumatoid arthritis, lupus, ulcerative colitis, Crohn’s disease and others, the immune system turns against the bodies’ organs as a result of chronic inflammation (Pfizer, 2017).
In Europe the direct healthcare cost incurred by patients affected by chronic inflammatory bowel disease, have been estimated to be €4.6–5.6 billion per year (Burisch, J, Lakatos P, Martinato M and Tine J. 2013). Rheumatoid arthritis affects approximately 17.6 million people worldwide (cdc.gov. 2017). According to the WHO Global Burden of Disease report (2004), the prevalence of osteoarthritis in Africa was approximately 10.1 million. There is limited detailed information on the numbers for each specific country.
Immune reconstitution inflammatory syndrome (IRIS) is common in Sub-Saharan Africa in antiretroviral therapy–treated central nervous system infections. In a South African study, IRIS occurred in 47% of patients treated for TB meningitis (Asselman V, Thienemann F, Pepper DJ, Boulle A, Wilkinson RJ, Meintjes G, Marais S. 2010). IRIS affecting the central nervous system has mortality rates of approximately 20%–30% (Boulware DR, Meya DB, Bergemann TL, Wiesner DL, Rhein J, Musubire A, Lee SJ, Kambugu A, Janoff EN and Bohjanen PR. 2010). These painful and progressively debilitating conditions take a toll on people’s quality of life and create both societal and economic burdens.
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) such as aspirin, ibuprofen, indomethacin, etc. are used to treat inflammation. In recent years it has been discovered that long term use of NSAIDs increases the risk of peptic ulcer disease, acute renal failure, and stroke/myocardial infarction, heart failure and hypertension (Marcum Z. A and Hanlon J. T. 2010). This has created the need for an alternative medications which give the same results but with fewer risks.
There has been an increase in the number of studies on plant extracts and their anti-inflammatory properties. Harpagophytum procumbens (Devil’s claw) is a Sub-Saharan plant with known anti-inflammatory properties. It is native to areas in the Transvaal of South Africa, Botswana and Namibia (Mahomoodally M. F. 2013). Devil’s claw is mainly used to treat inflammatory issues and analgesic in joint diseases, back pain, and headache (Mahomoodally M. F. 2013).
Research on the Ximenia caffra leaf extract showed the expression of IL-6, which is an indication of potentially significant anti-inflammatory activity (Zhen J, Guo Y, Villani T, Carr S, Brendler T, Mumbengegwi D. R, Kong A.T, Simon J. E and Wu Q. 2015). Ximenia caffra is a member of the genus of flowering plants in the Olacaceae family and it is mainly found in the southern African region.
A study carried out by Kamau J. K, Nthiga P. M, Mwonjoria J. K, Ngeranwa J. J. N and Ngugi MP (2016) on the anti-inflammatory activity of Kigelia Africana on carrageenan-induced inflammation in Swiss albino mice, showed that the anti-inflammatory activity of extract at the dose level of 150 mg/kg body weight, was comparable to that of aspirin which was used as the reference drug.
A study on Filipendula vulgaris showed that the extract contained phenolics like flavonoids, tannins, procyanidins and gaultherin. Filipendula vulgaris (dropwort) is used in traditional medicine for relieving various inflammation-related diseases. At 50??g/mL, the Filipendula vulgaris aerial extract significantly inhibited cyclooxygenase-1 and -2 activities in vitro and showed ;50% inhibition, and the root extract considerably inhibited COX-2 activity and showed approximately 52.5% inhibition (Katania J , Pferschy-Wenzig EM, Mihailovi? V, Boroja T , San-PoPan, Nikles S, Kretschmer N, Rosi? G, Selakovi? D. ,Joksimovi? J and Bauer R. 2018). The extracts also showed in vivo anti-inflammatory potential upon oral administration in rats. Studies were carried out on Curcuma longa which produces the secondary metabolite curcumin, which is responsible for anti-inflammatory effect of this plant (Leiherer A, Mündlein A and Drexel H. 2013). In one study, curcumin at concentrations of 0.5?M and 20?M inhibited pro-inflammatory cytokine TNF-?, IL-1? and IL-8 production induced by lipopolysaccharide (LPS) in lung inflammatory cells ex vivo. Treatment with curcumin also inhibited the upregulation of COX-2 in ultraviolet B-irradiated HaCaT cells (Literat A, Su F, Norwicki M, Durand M, Ramanathan R, et al. (2001).
The anti-inflammatory and anti-oxidant properties of these medicinal plants has been attributed to phytochemicals have. Phytochemicals are non-nutritive chemicals which are found in plants. A study on phytochemical analysis, antioxidant and anti-inflammatory potential of Feretia apodanthera root bark extracts showed that the significant anti-inflammatory effect of the extracts was due to the presence of flavonoids, triterpenes and tannins while the reduced anti-inflammatory effect of n-hexane was probably due to the absence of tannin, saponin and flavonoids. Ethanol extracts showed the highest anti-inflammation potential, which may have been due to a higher intensity of triterpenes and flavonoids, along with the presence of saponin, tannin, cardiac glycosides, steroids and alkaloids (Owolabi O. O, James D. B, Sani I, Andongma B. T, Fasanya O. O and Barnabas Kure B. 2018). This shows a correlation between anti-inflammatory activity and the number of phytochemicals present. Flavonoids have also been reported to inhibit pro-inflammatory mediators such as TNF-? and phospholipase A2 (Bhaskar VH, Balakrishnan N. 2009).
Information on the exact point of action of the phytochemicals is somewhat limited and there is little scientific information on the anti-inflammatory activity of most Namibian herbs. Most medicinal claims are based on the indigenous ethnobotanical knowledge from knowledgeable community members such as traditional healers. Therefore more research is required on other potentially beneficial plants such as Albizia anthelmintica, Cassine transvaalensis and Celosia trigyna which are indigenous to Southern Africa.